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Sample records for bacterial overgrowth endotoxaemia

  1. Probiotic yogurt in the elderly with intestinal bacterial overgrowth: endotoxaemia and innate immune functions

    DEFF Research Database (Denmark)

    Schiffrin, E.J.; Parlesak, Alexandr; Bode, C.

    2009-01-01

    A study was conducted in healthy elderly living independently in senior housing to assess the impact of a probiotic yoghurt supplement on small intestinal bacterial overgrowth. Twenty-three participants with positive and thirteen participants with negative hydrogen breath test were studied before...... and was unaffected by probiotic treatment. Both plasma endotoxin levels and the basal phagocytic activity of leucocytes decreased after yoghurt intake in the two groups. Exposure of monocytes and neutrophils ex vivo led to an increased cytokine response and free radical response, respectively. The normalisation...

  2. Probiotic yogurt in the elderly with intestinal bacterial overgrowth: endotoxaemia and innate immune functions.

    Science.gov (United States)

    Schiffrin, Eduardo J; Parlesak, Alexandr; Bode, Christiane; Bode, J Christian; van't Hof, Martin A; Grathwohl, Dominik; Guigoz, Yves

    2009-04-01

    A study was conducted in healthy elderly living independently in senior housing to assess the impact of a probiotic yoghurt supplement on small intestinal bacterial overgrowth. Twenty-three participants with positive and thirteen participants with negative hydrogen breath test were studied before and after a period of 4 weeks of probiotic yoghurt administration. Intestinal permeability, plasma endotoxin levels, phagocytic activity of leucocytes, cytokine production by monocytes and free radical response of neutrophils were determined. Intestinal permeability was similar for the two groups and was unaffected by probiotic treatment. Both plasma endotoxin levels and the basal phagocytic activity of leucocytes decreased after yoghurt intake in the two groups. Exposure of monocytes and neutrophils ex vivo led to an increased cytokine response and free radical response, respectively. The normalisation of the various cytokine responses was more apparent in the group with positive breath test. In addition, the plasma levels of lipoplysaccharide binding protein and soluble CD14, lipoplysaccharide pattern recognition receptors and surrogate markers of lipoplysaccharide permeability were diminished by the end of the study. In conclusion, probiotic administration in the elderly normalises the response to endotoxin, and modulates activation markers in blood phagocytes, and therefore may help reduce low-grade chronic inflammation.

  3. Small intestinal bacterial overgrowth syndrome

    Institute of Scientific and Technical Information of China (English)

    Jan; Bures; Jiri; Cyrany; Darina; Kohoutova; Miroslav; Frstl; Stanislav; Rejchrt; Jaroslav; Kvetina; Viktor; Vorisek; Marcela; Kopacova

    2010-01-01

    Human intestinal microbiota create a complex polymi-crobial ecology. This is characterised by its high population density, wide diversity and complexity of interaction. Any dysbalance of this complex intestinal microbiome, both qualitative and quantitative, might have serious health consequence for a macro-organism, including small intestinal bacterial overgrowth syndrome (SIBO).SIBO is defined as an increase in the number and/or alteration in the type of bacteria in the upper gastro-intestinal tract. There...

  4. Link between hypothyroidism and small intestinal bacterial overgrowth

    Directory of Open Access Journals (Sweden)

    Anant D Patil

    2014-01-01

    Full Text Available Altered gastrointestinal (GI motility is seen in many pathological conditions. Reduced motility is one of the risk factors for development of a small intestinal bacterial overgrowth (SIBO. Hypothyroidism is associated with altered GI motility. The aim of this article was to study the link between hypothyroidism, altered GI motility and development of SIBO. Published literature was reviewed to study the association of altered GI motility, SIBO and hypothyroidism. Altered GI motility leads to SIBO. SIBO is common in patients with hypothyroidism. Patients with chronic GI symptoms in hypothyroidism should be evaluated for the possibility of SIBO. Both antibiotics and probiotics have been studied and found to be effective in management of SIBO.

  5. Pediatric small intestine bacterial overgrowth in low-income countries.

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    Donowitz, Jeffrey R; Petri, William A

    2015-01-01

    Small intestine bacterial overgrowth (SIBO) occurs when colonic quantities of commensal bacteria are present in the small bowel. SIBO is associated with conditions of disrupted gastrointestinal (GI) motility leading to stasis of luminal contents. Recent data show that SIBO is also found in children living in unsanitary conditions who do not have access to clean water. SIBO leads to impaired micronutrient absorption and increased GI permeability, both of which may contribute to growth stunting in children. SIBO also disrupts mucosal immunity and has been implicated in oral vaccination underperformance and the development of celiac disease. SIBO in the setting of the impoverished human habitats may be an under-recognized cause of pediatric morbidity and mortality in the developing world.

  6. Small intestine bacterial overgrowth and fat digestion and absorption in cystic fibrosis patients

    OpenAIRE

    Aleksandra Lisowska; Andrzej Pogorzelski; Grzegorz Oracz; Wojciech Skorupa; Szczepan Cofta; Jerzy Socha; Jarosław Walkowiak

    2010-01-01

    Background. Available data suggests that small intestine bacterial overgrowth (SIBO) may frequently occur in cystic fibrosis (CF) subjects. SIBO may result in synthesis of enterotoxic and unabsorbable metabolites which may cause mucosal damage and – additionally – interfere with digestion and absorption. Such a relationship was documented in CF mouse model. Therefore, in the present study we aimed to assess the influence of bacterial overgrowth in small intestine in CF pat...

  7. Small Intestine Bacterial Overgrowth and Environmental Enteropathy in Bangladeshi Children

    Directory of Open Access Journals (Sweden)

    Jeffrey R. Donowitz

    2016-01-01

    Full Text Available Recent studies suggest small intestine bacterial overgrowth (SIBO is common among developing world children. SIBO’s pathogenesis and effect in the developing world are unclear. Our objective was to determine the prevalence of SIBO in Bangladeshi children and its association with malnutrition. Secondary objectives included determination of SIBO’s association with sanitation, diarrheal disease, and environmental enteropathy. We performed a cross-sectional analysis of 90 Bangladeshi 2-year-olds monitored since birth from an impoverished neighborhood. SIBO was diagnosed via glucose hydrogen breath testing, with a cutoff of a 12-ppm increase over baseline used for SIBO positivity. Multivariable logistic regression was performed to investigate SIBO predictors. Differences in concomitant inflammation and permeability between SIBO-positive and -negative children were compared with multiple comparison adjustment. A total of 16.7% (15/90 of the children had SIBO. The strongest predictors of SIBO were decreased length-for-age Z score since birth (odds ratio [OR], 0.13; 95% confidence interval [CI], 0.03 to 0.60 and an open sewer outside the home (OR, 4.78; 95% CI, 1.06 to 21.62. Recent or frequent diarrheal disease did not predict SIBO. The markers of intestinal inflammation fecal Reg 1β (116.8 versus 65.6 µg/ml; P = 0.02 and fecal calprotectin (1,834.6 versus 766.7 µg/g; P = 0.004 were elevated in SIBO-positive children. Measures of intestinal permeability and systemic inflammation did not differ between the groups. These findings suggest linear growth faltering and poor sanitation are associated with SIBO independently of recent or frequent diarrheal disease. SIBO is associated with intestinal inflammation but not increased permeability or systemic inflammation.

  8. Bacteria: a new player in gastrointestinal motility disorders--infections, bacterial overgrowth, and probiotics.

    LENUS (Irish Health Repository)

    Quigley, Eamonn M M

    2012-02-03

    Irritable bowel syndrome (IBS) may result from a dysfunctional interaction between the indigenous flora and the intestinal mucosa, which in turn leads to immune activation in the colonic mucosa. Some propose that bacterial overgrowth is a common causative factor in the pathogenesis of symptoms in IBS; others point to evidence suggesting that the cause stems from more subtle qualitative changes in the colonic flora. Bacterial overgrowth will probably prove not to be a major factor in what will eventually be defined as IBS. Nevertheless, short-term therapy with either antibiotics or probiotics seems to reduce symptoms among IBS patients. However, in the long term, safety issues will favor the probiotic approach; results of long-term studies with these agents are eagerly awaited.

  9. Gastrointestinal complaints in runners are not due to small intestinal bacterial overgrowth

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    Bärtsch Peter

    2011-07-01

    Full Text Available Abstract Background Gastrointestinal complaints are common among long distance runners. We hypothesised that small intestinal bacterial overgrowth (SIBO is present in long distance runners frequently afflicted with gastrointestinal complaints. Findings Seven long distance runners (5 female, mean age 29.1 years with gastrointestinal complaints during and immediately after exercise without known gastrointestinal diseases performed Glucose hydrogen breath tests for detection of SIBO one week after a lactose hydrogen breath test checking for lactose intolerance. The most frequent symptoms were diarrhea (5/7, 71% and flatulence (6/7, 86%. The study was conducted at a laboratory. In none of the subjects a pathological hydrogen production was observed after the intake of glucose. Only in one athlete a pathological hydrogen production was measured after the intake of lactose suggesting lactose intolerance. Conclusions Gastrointestinal disorders in the examined long distance runners were not associated with small intestinal bacterial overgrowth.

  10. THE ETHIOPATOGENESIS AND THE ANALYSIS OF AN ANTIBIOTIC TREATMENT OF A SMALL INTESTINE BACTERIAL OVERGROWTH SYNDROME

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    V. L. Martynov

    2015-01-01

    Full Text Available Article is attempt of the critical analysis of modern approaches to treatment of a small intestine bacterial overgrowth syndrome (SIBO. SIBO now is one of the major problems in gastroenterology. At the same time, the bacterial overgrowth is cause and consequence of many diseases of digestive system and extradigestive manifestations. Many researches testify to prevalence of SIBO in patients with digestive diseases. However, pathogenesis of a disease is studied insufficiently today. Nevertheless, the available data of scientific researches allow to belong to the offered ways of diagnostics and treatment critically.Data on physiology of microbiota of the digestive tract of the healthy person are provided in a review. Mechanisms of antimicrobic resistance of a microbiota of intestines are considered. Interrelations between an antibiotikassociated degeneration of normal flora and bacterial overgrowth are presented. The analysis of an antibiotiktherapi of SIBO indicates low efficiency and also possible ways became chronicle diseaseand frequent recurrence of an illness. The multiple-factors and complexity of pathogenesis of SIBO are leaded authors to a conclusion to use ethiopathogenesis approaches for solution of SIBO.

  11. Altered motility and duration of bacterial overgrowth in experimental blind loop syndrome.

    Science.gov (United States)

    Justus, P G; Mcherron, L E; Ward, T T

    1984-07-01

    To better understand the pathogenesis of the increased motility previously described in the blind loop rat, we studied the relationship between duration of bacterial overgrowth and both myoelectric activity and bacterial flora in this model. Myoelectric studies and quantitative bacterial cultures were performed on self-filling and self-emptying (control) blind loop rats one, two, and three weeks postoperatively. All self-filling blind loop rats had greater random action potential activity and higher frequencies of migrating action potential complexes than controls (P less than 0.05). One-week self-filling blind loop rats had a higher frequency of migrating action potential complexes (P less than 0.05) and a higher ratio of counts of Escherichia coli to Bacteroides species (P less than 0.05) than the two- or three-week self-filling blind loop groups. Thus, qualitative changes in myoelectric activity occur during the development of bacterial overgrowth in the blind loop rat which may reflect evolving alterations in the bacterial flora.

  12. Small intestine bacterial overgrowth and fat digestion and absorption in cystic fibrosis patients

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    Aleksandra Lisowska

    2010-12-01

    Full Text Available Background. Available data suggests that small intestine bacterial overgrowth (SIBO may frequently occur in cystic fibrosis (CF subjects. SIBO may result in synthesis of enterotoxic and unabsorbable metabolites which may cause mucosal damage and – additionally – interfere with digestion and absorption. Such a relationship was documented in CF mouse model. Therefore, in the present study we aimed to assess the influence of bacterial overgrowth in small intestine in CF patients on lipid digestion and absorption. Material and methods. The study comprised 60 pancreatic insufficient CF patients, 30 children and 30 adults. All enrolled CF subjects were tested for the presence of SIBO using hydrogen/methane breath test with glucose loading. According to the obtained results CF patients were divided into SIBO positive and negative subgroups. Subsequently, 13C-labelled mixed triglyceride breath test was performed to assess lipid digestion and absorption. Cumulative percentage dose recovery (cPDR was considered to reflect digestion and absorption of lipids. Results. SIBO was detected in 12 (40.0% children and 11 (36.7% adults with CF. The cPDR did not differ between SIBO positive and negative subgroups, neither when assessed separately for children (mean ±SEM: 5.5 ±0.8 vs. 7.4 ±1.0% and adults (4.9 ±0.8 vs. 7.1 ±0.7% nor for the entire studied population. Conclusions. Small intestine bacterial overgrowth does not seem to play a key role in lipid digestion and absorption in cystic fibrosis patients.

  13. Prevalence of small bowel bacterial overgrowth and its association with nutrition intake in nonhospitalized older adults

    DEFF Research Database (Denmark)

    Parlesak, Alexandr; Klein, B.; Schecher, K.

    2003-01-01

    OBJECTIVES: To determine the prevalence of small bowel bacterial overgrowth (SBBO) in older adults and to assess whether SBBO is associated with abdominal complaints and nutrient intake. DESIGN: Cross-sectional survey. SETTING: Eight senior residence sites in Stuttgart, Germany. PARTICIPANTS: Older...... and nutritional status was recorded with a computer-aided diet history. RESULTS: The prevalence of a positive hydrogen breath test (>10 ppm increase) was 15.6% in older adults, compared with 5.9% in subjects aged 24 to 59. The intake of inhibitors of gastric acid production contributed significantly to the high...

  14. Methane production and small intestinal bacterial overgrowth in children living in a slum

    Institute of Scientific and Technical Information of China (English)

    Carolina Santos Mello; Soraia Tahan; Lígia Cristina FL Melli; Mirian Silva do Carmo Rodrigues; Ricardo Martin Pereira de Mello; Isabel Cristina Affonso Scaletsky; Mauro Batista de Morais

    2012-01-01

    AIM:To analyze small intestinal bacterial overgrowth in school-aged children and the relationship between hydrogen and methane production in breath tests.METHODS:This transversal study included 85 children residing in a slum and 43 children from a private school,all aged between 6 and 10 years,in Osasco,Brazil.For characterization of the groups,data regarding the socioeconomic status and basic housing sanitary conditions were collected.Anthropometric data was obtained in children from both groups.All children completed the hydrogen (H2) and methane (CH4) breath test in order to assess small intestinal bacterial overgrowth (SIBO).SIBO was diagnosed when there was an increase in H2 ≥ 20 ppm or CH4 ≥ 10 ppm with regard to the fasting value until 60 min after lactulose ingestion.RESULTS:Children from the slum group had worse living conditions and lower nutritional indices than children from the private school.SIBO was found in 30.9% (26/84) of the children from the slum group and in 2.4% (1/41) from the private school group (P =0.0007).Greater hydrogen production in the small intestine was observed in children from the slum group when compared to children from the private school (P =0.007).A higher concentration of hydrogen in the small intestine (P < 0.001) and in the colon (P < 0.001) was observed among the children from the slum group with SIBO when compared to children from the slum group without SIBO.Methane production was observed in 63.1% (53/84) of the children from the slum group and in 19.5% (8/41) of the children from the private school group (P < 0.0001).Methane production was observed in 38/58 (65.5%) of the children without SIBO and in 15/26 (57.7%) of the children with SIBO from the slum.Colonic production of hydrogen was lower in methaneproducing children (P =0.017).CONCLUSION:Children who live in inadequate environmental conditions are at risk of bacterial overgrowth and methane production.Hydrogen is a substrate for methane

  15. Assessment of small intestinal bacterial overgrowth in uncomplicated acute diverticulitis of the colon

    Institute of Scientific and Technical Information of China (English)

    Antonio Tursi; Giovanni Brandimarte; Gian Marco Giorgetti; Walter Elisei

    2005-01-01

    AIM: Small intestinal bacterial overgrowth (SIBO) maycontribute to the appearance of several gastrointestinal nonspecific symptoms. Acute diverticulitis is affected by some similar symptoms and bacterial colonic overgrowth. We assessed the prevalence of SIBO in acute uncomplicated diverticulitis and evaluated its influence on the clinical course of the disease.METHODS: We studied 90 consecutive patients (39 males, 51 females, mean age 67.2 years, range 32-91 years). Sixty-one patients (67.78%) and 29 patients (32.22%) were affected by constipation-or diarrhea-prevalent diverticulitis respectively. All subjects were investigated by lactulose H2-breath test at the entry and at the end of treatment. We also studied a control group of 20 healthy subjects (13 males, 7 females, mean age 53 years, range 22-71 years).RESULTS: Oro-cecal transit time (OCTT) was delayed in67/90 patients (74.44%) (range 115-210 min, mean 120 min). Fifty-three of ninety patients (58.88%) showed SIBO, while OCTT was normal in 23/90 patients (25, 56%). In the control group, the mean OCTT was 88.2 min (range 75-135 min). The difference between diverticulitic patients and healthy subjects was statistically significant (P<0.01). OCTT was longer in constipation-prevalent disease than in diarrheaprevalent disease [180.7 min (range 150-210 min) vs 121 min (range 75-180 min) (P<0.001)], but no difference in bacterial overgrowth was found between the two forms of diverticulitis.After treatment with rifaximin plus mesalazine for 10 d, followed by mesalazine alone for 8 wk, 70 patients (81.49%) were completely asymptomatic, while 16 patients (18.60%) showed only slight symptoms. Two patients (2.22%) had recurrence of diverticulitis, and two other patients (2.22%) were withdrawn from the study due to side-effects. Seventy-nine of eighty-six patients (91.86%) showed normal OCTT (range 75-105 min, mean 83 min), while OCTT was longer, but it was shorter in the remaining seven (8.14%) patients (range 105

  16. Prevalence of Small Intestinal Bacterial Overgrowth among Chronic Pancreatitis Patients: A Case-Control Study

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    Bouchard, Simon; Sidani, Sacha

    2016-01-01

    Background. Patients with chronic pancreatitis (CP) exhibit numerous risk factors for the development of small intestinal bacterial overgrowth (SIBO). Objective. To determine the prevalence of SIBO in patients with CP. Methods. Prospective, single-centre case-control study conducted between January and September 2013. Inclusion criteria were age 18 to 75 years and clinical and radiological diagnosis of CP. Exclusion criteria included history of gastric, pancreatic, or intestinal surgery or significant clinical gastroparesis. SIBO was detected using a standard lactulose breath test (LBT). A healthy control group also underwent LBT. Results. Thirty-one patients and 40 controls were included. The patient group was significantly older (53.8 versus 38.7 years; P PERT), and severity of symptoms. Conclusion. The prevalence of SIBO detected using LBT was high among patients with CP. There was no association between clinical features and the risk for SIBO. PMID:27446865

  17. Small Intestine Bacterial Overgrowth: An Underdiagnosed Cause of Diarrhea in Patients with Pancreatic Cancer

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    Ivan Bustillo

    2009-09-01

    Full Text Available Dear Sir: Pancreatic cancer is currently the fourth leading cause of cancer related death in the United States, with an overall survival rate at five years of diagnosis of less than 5%. It affects more men than women, with slight preponderance for African Americans and 77% of patients are diagnosed after the age of 60 years [1]. The majority of patients with advanced pancreatic cancer report a poor quality of life, with special compromise in the areas of emotional and social functioning, presumably due to anxiety and depression [2]. Among the physical symptoms reported to affect quality of life, fatigue and pain were ranked the highest. However, we are yet to understand how other less commonly recognized symptoms such as diarrhea and weight loss affect the functioning and comfort level of these patients. Small intestine bacterial overgrowth is a frequent, yet unrecognized, cause of diarrhea in patients with advanced pancreatic cancer.

  18. Malabsorption, Orocecal Transit Time and Small Intestinal Bacterial Overgrowth in Type 2 Diabetic Patients: A Connection.

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    Rana, S V; Malik, Aastha; Bhadada, Sanjay K; Sachdeva, Naresh; Morya, Rajesh Kumar; Sharma, Gaurav

    2017-03-01

    Type 2 diabetes mellitus consists of dysfunctions characterized by hyperglycemia and resulting from combination of resistance to insulin action and inadequate insulin secretion. Most of diabetic patients report significant gastrointestinal symptoms. Entire GI tract can be affected by diabetes from oral cavity to large bowel and anorectal region. Proteins, carbohydrates, fats, and most fluids are absorbed in small intestine. Malabsorption may occurs when proper absorption of nutrients does not take place due to bacterial overgrowth or altered gut motility. The present study was planned to measure various malabsorption parameters in type 2 diabetic patients. 175 patients and 175 age and sex matched healthy controls attending Endocrinology Clinic in PGI, Chandigarh were enrolled. Lactose intolerance was measured by using non-invasive lactose hydrogen breath test. Urinary d-xylose and fecal fat were estimated using standard methods. Orocecal transit time and small intestinal bacterial overgrowth were measured using non-invasive lactulose and glucose breath test respectively. Out of 175 diabetic patients enrolled, 87 were males while among 175 healthy subjects 88 were males. SIBO was observed in 14.8 % type 2 diabetic patients and in 2.8 % of controls. There was statistically significant increase (p diabetic patients compared with controls. OCTT was observed to be more delayed (p diabetic patients and 39.4 % in controls. Urinary d-xylose levels were also lower in case of diabetic patients but no significant difference was found in 72 h fecal fat excretion among diabetic patients and controls. Urinary d-xylose and lactose intolerance in SIBO positive type 2 diabetic patients was more severe as compared to SIBO negative diabetic patients. From this study we can conclude that delayed OCTT may have led to SIBO which may have instigated the process of malabsorption among type 2 diabetic patients.

  19. Small intestinal bacterial overgrowth in nonalcoholic steatohepatitis: association with toll-like receptor 4 expression and plasma levels of interleukin 8.

    LENUS (Irish Health Repository)

    Shanab, Ahmed Abu

    2011-05-01

    Experimental and clinical studies suggest an association between small intestinal bacterial overgrowth (SIBO) and nonalcoholic steatohepatitis (NASH). Liver injury and fibrosis could be related to exposure to bacterial products of intestinal origin and, most notably, endotoxin, including lipopolysaccharide (LPS).

  20. The interaction between vitamin K nutriture and warfarin administration in patients with bacterial overgrowth due to atrophic gastritis.

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    Camilo, M E; Paiva, S A; O'Brien, M E; Booth, S L; Davidson, K W; Sokoll, L J; Sadowski, J A; Russell, R M

    1998-01-01

    Atrophic gastritis patients have intestinal bacterial overgrowth which could produce menaquinones. The aim of this study was to evaluate the interaction between a diet low in phylloquinone and minidoses of warfarin in subjects with and without bacterial overgrowth. Subjects with atrophic gastritis (indicated by serum pepsinogen ratio) and healthy volunteers were studied while fed a restrictive phylloquinone diet and while receiving a minidose of warfarin. Coagulation times, serum osteocalcin, serum undercarboxylated osteocalcin, plasma phylloquinone, plasma K-epoxide, plasma undercarboxylated prothrombin (PIVKA)-II and urinary gamma-carboxyglutamic acid (Gla) were measured. At baseline, there were no differences between groups for any variable measured. Comparisons between baseline and post intervention in both groups, showed significant increases in circulating levels of K-epoxide, PIVKA II and undercarboxylated osteocalcin. However, no differences were observed when comparisons were made between groups. Our data do not support the hypothesis that bacterial synthesis of menaquinones in patients with bacterial overgrowth due to atrophic gastritis confers considerable resistance to the effect of warfarin.

  1. Effect of melatonin on human nighttime endotoxaemia

    DEFF Research Database (Denmark)

    Alamili, Mahdi; Bendtzen, Klaus; Lykkesfeldt, Jens

    2014-01-01

    BACKGROUND: Endotoxaemia is widely used as an experimental model to study sepsis under controlled conditions. Nighttime endotoxaemia induces a more pronounced inflammatory stress response compared to daytime. Previously, we have shown that melatonin has antioxidative and anti-inflammatory effects...... in inflammatory response to daytime endotoxaemia. Herein, we examined the effect of melatonin in response to human nighttime endotoxaemia. PATIENTS AND METHODS: Twelve healthy male volunteers were enrolled in a randomized, placebo-controlled, double-blinded cross-over trial. Subjects were induced...... by lipopolysaccharide (LPS) endotoxin 0.3 ng/kg body weight intravenously at 24:00. One hour prior to induction of endotoxaemia, an 8-h infusion of melatonin 100 mg or placebo was initiated. Blood samples were drawn before and 2, 4, 6 and 8 h after induction of endotoxaemia and plasma was tested for pro...

  2. Small intestine bacterial overgrowth and irritable bowel syndrome-related symptoms: Experience with Rifaximin

    Institute of Scientific and Technical Information of China (English)

    Sergio Peralta; Claudia Cottone; Tiziana Doveri; Piero Luigi Almasio; Antonio Craxi

    2009-01-01

    AIM: To estimate the prevalence of small intestinal bacterial overgrowth (SIBO) in our geographical area (Western Sicily, Italy) by means of an observational study, and to gather information on the use of locally active, nonabsorbable antibiotics for treatment of SIBO. METHODS: Our survey included 115 patients fulfilling the Rome Ⅱ criteria for diagnosis of irritable bowel syndrome (IBS); a total of 97 patients accepted to perform a breath test with lactulose (BTLact), and those who had a positive test, received Rifaximin (Normix., Alfa Wassermann) 1200 mg/d for 7 d; 3 wk after the end of treatment, the BTLact was repeated. RESULTS: Based on the BTLact results, SIBO was present in about 56% of IBS patients, and it was responsible for some IBSrelated symptoms, such as abdominal bloating and discomfort, and diarrhoea. 1wktreatment with Rifaximin turned the BTLact to negative in about 50% of patients and significantly reduced the symptoms, especially in those patients with an alternated constipation/diarrhoeavariant IBS.CONCLUSION: SIBO should be always suspected in patients with IBS, and a differential diagnosis is done by means of a"breath test". Rifaximin may represent a valid approach to the treatment of SIBO.

  3. Systematic review and meta-analysis: Small intestinal bacterial overgrowth in chronic pancreatitis

    Science.gov (United States)

    Signoretti, Marianna; Archibugi, Livia; Stigliano, Serena; Delle Fave, Gianfranco

    2016-01-01

    Background Evidence on small intestinal bacterial overgrowth (SIBO) in patients with chronic pancreatitis (CP) is conflicting. Aim The purpose of this study was to perform a systematic review and meta-analysis on the prevalence of SIBO in CP and to examine the relationship of SIBO with symptoms and nutritional status. Methods Case-control and cross-sectional studies investigating SIBO in CP patients were analysed. The prevalence of positive tests was pooled across studies, and the rate of positivity between CP cases and controls was calculated. Results In nine studies containing 336 CP patients, the pooled prevalence of SIBO was 36% (95% confidence interval (CI) 17–60%) with considerable heterogeneity (I2 = 91%). A sensitivity analysis excluding studies employing lactulose breath test gave a pooled prevalence of 21.7% (95% CI 12.7–34.5%) with lower heterogeneity (I2 = 56%). The odds ratio for a positive test in CP vs controls was 4.1 (95% CI 1.6–10.4) (I2 = 59.7%). The relationship between symptoms and SIBO in CP patients varied across studies, and the treatment of SIBO was associated with clinical improvement. Conclusions One-third of CP patients have SIBO, with a significantly increased risk over controls, although results are heterogeneous, and studies carry several limitations. The impact of SIBO and its treatment in CP patients deserve further investigation.

  4. Partially responsive celiac disease resulting from small intestinal bacterial overgrowth and lactose intolerance

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    Misra Asha

    2004-05-01

    Full Text Available Abstract Background Celiac disease is a common cause of chronic diarrhea and malabsorption syndrome all over the world. Though it was considered uncommon in India in past, it is being described frequently recently. Some patients with celiac disease do not improve despite gluten free diet (GFD. A study described 15 cases of celiac disease unresponsive to GFD in whom small intestinal bacterial overgrowth (SIBO or lactose intolerance was the cause for unresponsiveness. Case presentation During a three-year period, 12 adult patients with celiac disease were seen in the Luminal Gastroenterology Clinic in a tertiary referral center in northern India. Two of these 12 patients (16.6%, who did not fully respond to GFD initially, are presented here. Unresponsiveness resulted from SIBO in one and lactose intolerance in the other. The former patient responded to antibiotics and the latter to lactose withdrawal in addition to standard GFD. Conclusion In patients with celiac disease partially responsive or unresponsive to GFD, SIBO and lactose intolerance should be suspected; appropriate investigations and treatment for these may result in complete recovery.

  5. Prevalence of Small Intestinal Bacterial Overgrowth among Chronic Pancreatitis Patients: A Case-Control Study

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    Amelie Therrien

    2016-01-01

    Full Text Available Background. Patients with chronic pancreatitis (CP exhibit numerous risk factors for the development of small intestinal bacterial overgrowth (SIBO. Objective. To determine the prevalence of SIBO in patients with CP. Methods. Prospective, single-centre case-control study conducted between January and September 2013. Inclusion criteria were age 18 to 75 years and clinical and radiological diagnosis of CP. Exclusion criteria included history of gastric, pancreatic, or intestinal surgery or significant clinical gastroparesis. SIBO was detected using a standard lactulose breath test (LBT. A healthy control group also underwent LBT. Results. Thirty-one patients and 40 controls were included. The patient group was significantly older (53.8 versus 38.7 years; P < 0.01. The proportion of positive LBTs was significantly higher in CP patients (38.7 versus 2.5%: P < 0.01. A trend toward a higher proportion of positive LBTs in women compared with men was observed (66.6 versus 27.3%; P = 0.056. The subgroups with positive and negative LBTs were comparable in demographic and clinical characteristics, use of opiates, pancreatic enzymes replacement therapy (PERT, and severity of symptoms. Conclusion. The prevalence of SIBO detected using LBT was high among patients with CP. There was no association between clinical features and the risk for SIBO.

  6. Small Intestinal Bacterial Overgrowth and Irritable Bowel Syndrome: A Bridge between Functional Organic Dichotomy

    Science.gov (United States)

    Ghoshal, Uday C.; Shukla, Ratnakar; Ghoshal, Ujjala

    2017-01-01

    The pathogenesis of irritable bowel syndrome (IBS), once thought to be largely psychogenic in origin, is now understood to be multifactorial. One of the reasons for this paradigm shift is the realization that gut dysbiosis, including small intestinal bacterial overgrowth (SIBO), causes IBS symptoms. Between 4% and 78% of patients with IBS and 1% and 40% of controls have SIBO; such wide variations in prevalence might result from population differences, IBS diagnostic criteria, and, most importantly, methods to diagnose SIBO. Although quantitative jejunal aspirate culture is considered the gold standard for the diagnosis of SIBO, noninvasive hydrogen breath tests have been popular. Although the glucose hydrogen breath test is highly specific, its sensitivity is low; in contrast, the early-peak criteria in the lactulose hydrogen breath test are highly nonspecific. Female gender, older age, diarrhea-predominant IBS, bloating and flatulence, proton pump inhibitor and narcotic intake, and low hemoglobin are associated with SIBO among IBS patients. Several therapeutic trials targeting gut microbes using antibiotics and probiotics have further demonstrated that not all symptoms in patients with IBS originate in the brain but rather in the gut, providing support for the micro-organic basis of IBS. A recent proof-of-concept study showing the high frequency of symptom improvement in patients with IBS with SIBO further supports this hypothesis. PMID:28274108

  7. Small Intestinal Bacterial Overgrowth in Patients with Refractory Functional Gastrointestinal Disorders

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    Shimura, Shino; Ishimura, Norihisa; Mikami, Hironobu; Okimoto, Eiko; Uno, Goichi; Tamagawa, Yuji; Aimi, Masahito; Oshima, Naoki; Sato, Shuichi; Ishihara, Shunji; Kinoshita, Yoshikazu

    2016-01-01

    Background/Aims Small intestinal bacterial overgrowth (SIBO) is considered to be involved in the pathogenesis of functional gastrointestinal disorders (FGID). However, the prevalence and clinical conditions of SIBO in patients with FGID remain to be fully elucidated. Here, we examined the frequency of SIBO in patients with refractory FGID. Methods We prospectively enrolled patients with refractory FGID based on Rome III criteria. A glucose hydrogen breath test (GHBT) was performed using a gas analyzer after an overnight fast, with breath hydrogen concentration measured at baseline and every 15 minutes after administration of glucose for a total of 3 hours. A peak hydrogen value ≥ 10 ppm above the basal value between 60 and 120 minutes after administration of glucose was diagnosed as SIBO. Results A total of 38 FGID patients, including 11 with functional dyspepsia (FD), 10 with irritable bowel syndrome (IBS), and 17 with overlapping with FD and IBS, were enrolled. Of those, 2 (5.3%) were diagnosed with SIBO (one patient diagnosed with FD; the other with overlapping FD and IBS). Their symptoms were clearly improved and breath hydrogen levels decreased to normal following levofloxacin administration for 7 days. Conclusions Two patients initially diagnosed with FD and IBS were also diagnosed with SIBO as assessed by GHBT. Although the frequency of SIBO is low among patients with FGID, it may be important to be aware of SIBO as differential diagnosis when examining patients with refractory gastrointestinal symptoms, especially bloating, as a part of routine clinical care. PMID:26554916

  8. Small intestinal bacterial overgrowth and thiamine deficiency after Roux-en-Y gastric bypass surgery in obese patients.

    Science.gov (United States)

    Lakhani, Shilen V; Shah, Hiral N; Alexander, Kenneth; Finelli, Frederick C; Kirkpatrick, John R; Koch, Timothy R

    2008-05-01

    It has been proposed that thiamine deficiency after gastric bypass surgery in obese patients results from prolonged nausea and emesis. We hypothesized that thiamine deficiency is induced by altered gut ecology. This report includes 2 retrospective studies of obese patients who underwent Roux-en-Y gastric bypass surgery at our institution from 1999 to 2005. In the first study, 80 patients (52 women and 28 men) had measurement of whole-blood thiamine diphosphate level and serum folate level. In these 80 patients, 39 (49%) had thiamine diphosphate levels less than the lower limit of the reference range, and 28 (72%) of the 39 had folate levels higher than the upper limit of the reference range, an indicator of small intestinal bacterial overgrowth. In 41 patients with normal thiamine levels, only 14 (34%) had folate levels higher than the upper limit of the reference range (chi(2) test, P thiamine diphosphate levels less than the lower limit of the reference range and abnormal glucose-hydrogen breath tests, consistent with small intestinal bacterial overgrowth. Fifteen patients received oral thiamine supplements, but repeated thiamine levels remained low in all 15. Nine of these patients then received oral antibiotic therapy; repeated thiamine levels were found to be normal in all 9 patients. These results support the hypothesis that small intestinal bacterial overgrowth results from altered gut ecology and induces thiamine deficiency after gastric bypass surgery in obese patients.

  9. Vitamin B12 uptake by intestinal microorganisms: mechanism and relevance to syndromes of intestinal bacterial overgrowth

    Science.gov (United States)

    Giannella, R. A.; Broitman, S. A.; Zamcheck, N.

    1971-01-01

    The mechanism of bacterial uptake of vitamin B12, the spectrum of microorganisms capable of such uptake, and the factors involved were the subject of this study. Bacterial uptake of vitamin B12 was found to be at least a two stage process. A primary uptake phase which was rapid (1 min or less), pH dependent, nontemperature dependent, did not require viable organisms and was insensitive to either the metabolic inhibitor dinitrophenol or to the sulfhydryl inhibitor N-ethyl-maleimide. Protein denaturation (formalin treatment or autoclaving) abolished all B12 uptake. This primary uptake phase is thought to represent adsorption to binding or “receptor” sites on the cell wall. Second stage uptake was slower, pH and temperature dependent, required living bacteria, and was abolished by either dinitrophenol or N-ethyl-maleimide. This phase is dependent upon metabolic processes and may reflect transfer of B12 from surface “receptor” sites into the bacterial cell. Although differences among organisms were observed in total 1 hr uptake, number of surface “receptor” sites, and relative avidities for B12, all organisms except Streptococcus fecalis shared the two stage mechanism. Two Gram-positive organisms. Bacillus subtilis and Group A streptococcus, demonstrated the highest 1 hr vitamin B12 uptake values; Gram-negative bacteria required 2,000-10,000 the number of organisms for comparable uptake. Binding constants (Km) varied from 5.05 ±1.67 × 10-10M for B. subtilis to 6.18 ±3.08 × 10-9M for Klebsiella pneumoniae which approximate the Km for human intrinsic factor (0.38 × 10-10M). Competition between bacteria and intrinsic factor for vitamin B12 may be inferred from the similarity of these constants. These observations suggest that a variety of enteric and nonenteric organisms, not requiring exogenous B12, may play a role in the pathogenesis of the vitamin B12 malabsorption found in the intestinal bacterial overgrowth syndromes. PMID:4994753

  10. Evaluation of small intestine bacterial overgrowth in patients with functional dyspepsia through H2 breath test

    Directory of Open Access Journals (Sweden)

    Michelle Bafutto Gomes Costa

    2012-12-01

    Full Text Available CONTEXT: Functional dyspepsia is a condition in which symptoms are not related to organic underlying disease; its pathogenesis is not well known. The small intestinal bacterial overgrowth (SIBO is characterized by the increase in the number and/or type of colonic bacteria in the upper gastrointestinal tract. The hypothesis of SIBO being associated to functional dyspepsia must be considered, since the impaired motility of the gastrointestinal tract is one of the main etiologic factors involved on both pathologies. OBJECTIVE: To determine if there is SIBO in patients with functional dyspepsia. METHODS: Case-control study, evaluating 34 patients: 23 functional dyspeptic and 11 non-dyspeptic (control group. Questionnaire applied based on Rome III criteria. The patients underwent H2-lactulose breath test, considered positive when: H2 peak exceeding 20 ppm, in relation to fasting, or two peaks exceeding 10 ppm sustained until 60 minutes. RESULTS: Of the 23 dyspeptic patients, 13 (56.5% obtained positive results for SIBO trough the H2-lactulose breath test. On control group, SIBO was not observed. The association between the dyspeptic group and the control group regarding SIBO was statistically significant, with P = 0.0052. In the group of dyspeptic patients, 12 (52.2% were using proton pump inhibitor; of these 9 (75% were positive for SIBO. In the control group, none of the 11 patients used proton pump inhibitors and SIBO was not observed. The association of the dyspeptic group using proton pump inhibitor that were positive for SIBO and the control group was statistically significant, with P = 0.0011. CONCLUSION: It was found that, patients with functional dyspepsia presented SIBO, when they underwent to H2-lactulose breath test, compared to the non-dyspeptic. In addition, it was observed a higher prevalence of SIBO in dyspeptic patients that were using proton pump inhibitors, compared to control group.

  11. Small intestinal bacterial overgrowth and lactose intolerance contribute to irritable bowel syndrome symptomatology in Pakistan

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    Javed Yakoob

    2011-01-01

    Full Text Available Background /Aim: The symptoms of irritable bowel syndrome resemble those of small intestinal bacterial overgrowth (SIBO. The aim of this study was to determine the frequency of SIBO and lactose intolerance (LI occurrence in patients with diarrhea-predominant irritable bowel syndrome (IBS-D according to Rome III criteria. Patients and Methods: In this retrospective case-control study, patients over 18 years of age with altered bowel habit, bloating, and patients who had lactose Hydrogen breath test (H 2 BT done were included. The "cases" were defined as patients who fulfill Rome III criteria for IBS-D, while "controls" were those having chronic nonspecific diarrhea (CNSD who did not fulfill Rome III criteria for IBS-D. Demographic data, predominant bowel habit pattern, concurrent use of medications, etc., were noted. Results: Patients with IBS-D were 119 (51% with a mean age of 35 ± 13 years, while those with CNSD were 115 (49% with mean age 36 ± 15 years. Patients in both IBS-D and CNSD were comparable in gender, with male 87 (74% and female 77 (64%. SIBO was documented by lactose H 2 BT in 32/234 (14% cases. It was positive in 22/119 (19% cases with IBS-D, while 10/115 (9% cases had CNSD (P = 0.03. LI was positive in 43/234 (18% cases. Of these, 25/119 (21% cases had IBS-D and 18/115 (16% cases had CNSD (P = 0.29. Conclusion: SIBO was seen in a significant number of our patients with IBS-D. There was no significant age or gender difference in patients with or without SIBO.

  12. Seventy-five gram glucose tolerance test to assess carbohydrate malabsorption and small bowel bacterial overgrowth

    Institute of Scientific and Technical Information of China (English)

    Yoshihisa Urita; Motonobu Sugimoto; Kazumasa Miki; Susumu Ishihara; Tatsuo Akimoto; Hiroto Kato; Noriko Hara; Yoshiko Honda; Yoko Nagai; Kazushige Nakanishi; Nagato Shimada

    2006-01-01

    AIM: To investigate non-invasively the incidence of absorption of carbohydrates in diabetic patients during an oral glucose tolerance test (OGTT) and to determine whether malabsorption may be associated with insulin secretion and insulin resistance.METHODS: A standard 75-g OGTT was performed in 82 diabetic patients. The patients received 75 g of anhydrous glucose in 225 mL of water after an overnight fasting and breath samples were collected at baseline and up to 120 min afler ingestion. Breath hydrogen and methane concentrations were measured. Blood glucose and serum insulin concentrations were measured before ingestion and at 30, 60, g0, 120 min post-ingestion.RESULTS: When carbohydrate malabsorption was defined as subjects with an increase of at least 10 ppm (parts per million) in hydrogen or methane excretion within a 2-h period, 28 (34%) had carbohydrate malabsorption. According to the result of increased breath test, 21 (75%) patients were classified as small bowel bacterial overgrowth and 7 (25%) as glucose malabsorption. Patients with carbohydrate malabsorption were older and had poor glycemic control as compared with those without carbohydrate malabsorption. The HOMA value, the sum of serum insulin during the test and the Ainsulin/Aglucose ratio were greater in patients with carbohydrate malabsorption.CONCLUSION: Insulin resistance may be overestimated by using these markers if the patient has carbohydrate malabsorption, or that carbohydrate malabsorption may be present prior to the development of insulin resistance.Hence carbohydrate malabsorption should be taken into account for estimating insulin resistance and β-cell function.

  13. Ileocecal valve dysfunction in small intestinal bacterial overgrowth: A pilot study

    Institute of Scientific and Technical Information of China (English)

    Larry S Miller; Anil K Vegesna; Aiswerya Madanam Sampath; Shital Prabhu; Sesha Krishna Kotapati; Kian Makipour

    2012-01-01

    AIM:To explore whether patients with a defective ileocecal valve (ICV)/cecal distension reflex have small intestinal bacterial overgrowth.METHODS:Using a colonoscope,under conscious sedation,the ICV was intubated and the colonoscope was placed within the terminal ileum (TI).A manometry catheter with 4 pressure channels,spaced 1 cm apart,was passed through the biopsy channel of the colonoscope into the TI.The colonoscope was slowly withdrawn from the TI while the manometry catheter was advanced.The catheter was placed across the ICV so that at least one pressure port was within the TI,ICV and the cecum respectively.Pressures were continuously measured during air insufflation into the cecum,under direct endoscopic visualization,in 19 volunteers.Air was insufflated to a maximum of 40 mmHg to prevent barotrauma.All subjects underwent lactulose breath testing one month after the colonoscopy.The results of the breath tests were compared with the results of the pressures within the ICV during air insufflation.RESULTS:Nineteen subjects underwent colonoscopy with measurements of the ICV pressures after intubation of the ICV with a colonoscope.Initial baseline readings showed no statistical difference in the pressures of the TI and ICV,between subjects with positive lactulose breath tests and normal lactulose breath tests.The average peak ICV pressure during air insufflation into the cecum in subjects with normal lactulose breath tests was significantly higher than cecal pressures during air insufflation (49.33 ± 7.99 mmHg vs 16.40 ± 2.14 mmHg,P =0.0011).The average percentage difference of the area under the pressure curve of the ICV from the cecum during air insufflations in subjects with normal lactulose breath tests was significantly higher (280.72% ± 43.29% vs 100% ± 0%,P =0.0006).The average peak ICV pressure during air insufflation into the cecum in subjects with positive lactulose breath tests was not significantly different than cecal pressures during

  14. SMALL INTESTINE BACTERIAL OVERGROWTH IN PATIENTS WITH FAILURE OF THE VALVE BAUHINIAS AND AFTER ITS SURGICAL TREATMENTS (THE FIRST RESULTS

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    V. L. Martvnov

    2015-01-01

    Full Text Available Оbjective: diagnosis of the a small intestine of bacterial overgrowth syndrome (SIBO in patients with the failure of the bauginias valve (FBV and after its surgical correction.Material and methods. Patients of the studied groups were examined by means of direct and indirect methods of diagnostics of SIBO. Bacteriological research of an aspirate of aillium gut and other operational material was conducted. To all patients the hydrogen respiratory test was carried out and highquality reaction of urine to an indican was carried out. 50 patients are examined, from them 30 are inclu ded in the main group by which surgical correction of FBV – a bauginoplastik is made; 20 patients are included in group of control at which the illeocecal valve is well-founded. Patients of the main group were examined before operation and for the 7th and 45th days after a bauginoplastik.Results. At all patients of the main group SIBO of varying severity is defined, at 80% of patients of SIBO was localized in distal part of the small intestine. Patients with normal function of the ileocecal valve a SIBO did not suffer. At 76% of patients revealed signs of a mezadenitisof a small intestine, the fact of a bacterial translocation at SIBO is confirmed. In 7 days after surgical correction of the bauginiasvalve normalization of a peak and background excretion of hydrogen was noted at 37% of patients. For the 45th days at all patients the hydrogen digram met standard.Conclusions. The failure of the bauginiasvalveis obligatory followed by a small intestine of bacterial overgrowth syndrome, surgical correction is an effective method of correction of a SIBO at patients with FBV.

  15. Endogenous ethanol production in a patient with chronic intestinal pseudo-obstruction and small intestinal bacterial overgrowth.

    Science.gov (United States)

    Spinucci, Giulio; Guidetti, Mariacristina; Lanzoni, Elisabetta; Pironi, Loris

    2006-07-01

    The case of the gastrointestinal production of ethanol from Candida albicans and Saccharomyces cerevisiae in a Caucasian man with chronic intestinal pseudo-obstruction is reported. The patient, who declared to have always abstained from alcohol, was hospitalized for abdominal pain, belching and mental confusion. The laboratory findings showed the presence of ethanol in the blood. Gastric juice and faecal microbiological cultures were positive for C. albicans and S. cerevisiae. At home, he was on oral antibiotic therapy with amoxicillin plus clavulanic acid for a small bowel bacterial overgrowth, associated with a simple sugar-rich diet. Twenty-four hours after stopping both the antibiotic therapy and the simple sugar-rich diet, the blood ethanol disappeared. A provocative test, performed by giving amoxicillin plus clavulanic acid associated with the simple sugar-rich diet was followed by the reappearance of ethanol in the blood. A review of the literature is reported.

  16. Pronounced inflammatory response to endotoxaemia during nighttime

    DEFF Research Database (Denmark)

    Alamili, Mahdi; Bendtzen, Klaus; Lykkesfeldt, Jens

    2014-01-01

    endotoxaemia model. DESIGN AND METHODS: A cross-over study, where 12 healthy young men received E. coli endotoxin (lipopolysaccharide, LPS) 0.3 ng/kg at 12 noon and, on another day, at 12 midnight. Blood samples were analysed for pro- and anti-inflammatory cytokines: tumour-necrosis factor (TNF)-alpha, soluble...

  17. Role of intestinal bacterial overgrowth and intestinal motility in bacterial translocation in experimental cirrhosis Papel del sobrecrecimiento bacteriano intestinal y de la motilidad intestinal en la traslocación bacteriana en un modelo experimental de cirrosis

    OpenAIRE

    Sánchez, E.; Casafont, F; Guerra, A; Benito, I.; Pons-Romero, F

    2005-01-01

    Background: intestinal bacterial overgrowth (IBO) is related to small bowel motility and has been involved in the pathogenesis of bacterial translocation (BT) in experimental models, and both overgrowing gut flora and translocating bacteria to mesenteric lymph nodes are common features in cirrhosis. Objectives: the aims of this study were to analyze cecal aerobic bacteria and intestinal transit in cirrhotic rats, and their relationship with BT, evaluating the role of intestinal bacterial over...

  18. Redefining the functional roles of the gastrointestinal migrating motor complex and motilin in small bacterial overgrowth and hunger signaling.

    Science.gov (United States)

    Deloose, Eveline; Tack, Jan

    2016-02-15

    During the fasting state the upper gastrointestinal tract exhibits a specific periodic migrating contraction pattern that is known as the migrating motor complex (MMC). Three different phases can be distinguished during the MMC. Phase III of the MMC is the most active of the three and can start either in the stomach or small intestine. Historically this pattern was designated to be the housekeeper of the gut since disturbances in the pattern were associated with small intestinal bacterial overgrowth; however, its role in the involvement of hunger sensations was already hinted in the beginning of the 20th century by both Cannon (Cannon W, Washburn A. Am J Physiol 29: 441-454, 1912) and Carlson (Carlson A. The Control of Hunger in Health and Disease. Chicago, IL: Univ. of Chicago Press, 1916). The discovery of motilin in 1973 shed more light on the control mechanisms of the MMC. Motilin plasma levels fluctuate together with the phases of the MMC and induce phase III contractions with a gastric onset. Recent research suggests that these motilin-induced phase III contractions signal hunger in healthy subjects and that this system is disturbed in morbidly obese patients. This minireview describes the functions of the MMC in the gut and its regulatory role in controlling hunger sensations.

  19. Small Intestinal Bacterial Overgrowth in Patients with Irritable Bowel Syndrome: Clinical Characteristics, Psychological Factors, and Peripheral Cytokines

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    Hua Chu

    2016-01-01

    Full Text Available Small intestinal bacterial overgrowth (SIBO has been implicated in the pathogenesis of irritable bowel syndrome (IBS. Psychosocial factors and low-grade colonic mucosal immune activation have been suggested to play important roles in the pathophysiology of IBS. In total, 94 patients with IBS and 13 healthy volunteers underwent a 10 g lactulose hydrogen breath test (HBT with concurrent Tc99m scintigraphy. All participants also completed a face-to-face questionnaire survey, including the Hospital Anxiety and Depression Scale, Life Event Stress (LES, and general information. Serum tumour necrosis factor-α, interleukin- (IL- 6, IL-8, and IL-10 levels were measured. The 89 enrolled patients with IBS and 13 healthy controls had no differences in baseline characteristics. The prevalence of SIBO in patients with IBS was higher than that in healthy controls (39% versus 8%, resp.; p=0.026. Patients with IBS had higher anxiety, depression, and LES scores, but anxiety, depression, and LES scores were similar between the SIBO-positive and SIBO-negative groups. Psychological disorders were not associated with SIBO in patients with IBS. The serum IL-10 level was significantly lower in SIBO-positive than SIBO-negative patients with IBS.

  20. Duodenal Aspirates for Small Intestine Bacterial Overgrowth: Yield, PPIs, and Outcomes after Treatment at a Tertiary Academic Medical Center

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    Diana L. Franco

    2015-01-01

    Full Text Available Duodenal aspirates are not commonly collected, but they can be easily used in detection of small intestinal bacterial overgrowth (SIBO. Proton pump inhibitor (PPI use has been proposed to contribute to the development of SIBO. We aimed to determine the yield of SIBO-positive cultures detected in duodenal aspirates, the relationship between SIBO and PPI use, and the clinical outcomes of patients identified by this method. In a retrospective study, we analyzed electronic medical records from 1263 consecutive patients undergoing upper endoscopy at a tertiary medical center. Aspirates were collected thought out the third and fourth portions of the duodenum, and cultures were considered to be positive for SIBO if they produced more than 100,000 cfu/mL. Culture analysis of duodenal aspirates identified SIBO in one-third of patients. A significantly higher percentage of patients with SIBO use PPIs than patients without SIBO, indicating a possible association. Similar proportions of patients with SIBO improved whether or not they received antibiotic treatment, calling into question the use of this expensive therapy for this disorder.

  1. Bile acid malabsorption or disturbed intestinal permeability in patients treated with enzyme substitution for exocrine pancreatic insufficiency is not caused by bacterial overgrowth

    DEFF Research Database (Denmark)

    Madsen, Jan Lysgård; Graff, Jesper; Philipsen, Else Kirstine;

    2003-01-01

    enzyme replacement therapy, were studied. The prevalence of bacterial overgrowth was evaluated by means of a hydrogen and methane breath test with glucose. Gamma camera scintigraphy after intake of 75Se-homocholic acid taurine (75Se-HCAT) was used to evaluate bile acid absorption capacity. Intestinal......INTRODUCTION: In some patients with severe exocrine pancreatic insufficiency, enzyme replacement therapy will not lead to clinical improvement or reduction of steatorrhea. Therefore, other mechanisms separately or in interplay with reduced enzyme secretion might be responsible for malabsorption...... in these patients. AIMS: To evaluate the prevalence of bacterial overgrowth, bile acid absorption capacity, and intestinal permeability in a group of patients with well-characterized exocrine pancreatic insufficiency. METHODOLOGY: Eleven men with severe exocrine pancreatic insufficiency, of whom 10 were receiving...

  2. Small intestinal bacterial overgrowth in irritable bowel syndrome: association with colon motility, bowel symptoms, and psychological distress.

    Science.gov (United States)

    Grover, M; Kanazawa, M; Palsson, O S; Chitkara, D K; Gangarosa, L M; Drossman, D A; Whitehead, W E

    2008-09-01

    Small intestinal bacterial overgrowth (SIBO) has been implicated in the pathogenesis of irritable bowel syndrome (IBS), although the issue is still under debate. The aim of this study was to determine the prevalence of SIBO in those with IBS and its association with colonic motility, bowel symptoms and psychological distress. Sucrose hydrogen and methane breath tests were performed in 158 IBS patients and 34 healthy controls (HC). Thresholds for pain and urgency were tested by barostat in the descending colon. The motility index (MI) was calculated as the average area under the curve for all phasic contractions. Questionnaires assessed psychological distress, IBS symptom severity (IBS-SS), IBS quality of life (IBS-QOL) and self-reported bowel symptoms. Fifty-two of 158 (32.9%) IBS patients had abnormal breath tests compared with six of 34 (17.9%) HC (chi(2) = 0.079). SIBO (SIBO+) and non-SIBO (SIBO-) patients did not differ in the prevalence of IBS subtypes, IBS-SS, IBS-QOL and psychological distress variables. IBS patients had a greater post-distension increase in MI than HC, but there was no difference between SIBO+ and SIBO- patients. Predominant methane producers had higher urge thresholds (28.4 vs 18.3, P < 0.05) and higher baseline MI (461 vs 301.45, P < 0.05) than SIBO- IBS patients, and they reported more 'hard or lumpy stools' when compared with predominant hydrogen producers (P < 0.05) and SIBO- IBS patients (P < 0.05). SIBO is unlikely to contribute significantly to the pathogenesis of IBS. Methane production is associated with constipation.

  3. Small bowel bacterial overgrowth

    Science.gov (United States)

    ... scleroderma . Immunodeficiency such as AIDS or immunoglobulin deficiency. Short bowel syndrome caused by surgical removal of the small intestine. ... obstruction Irritable bowel syndrome Liver disease Osteoporosis - overview Short bowel syndrome Toxic megacolon Vagina Review Date 5/11/2016 ...

  4. The Microbial Hypothesis: Contributions of Adenovirus Infection and Metabolic Endotoxaemia to the Pathogenesis of Obesity

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    Amos Tambo

    2016-01-01

    Full Text Available The global obesity epidemic, dubbed “globesity” by the World Health Organisation, is a pressing public health issue. The aetiology of obesity is multifactorial incorporating both genetic and environmental factors. Recently, epidemiological studies have observed an association between microbes and obesity. Obesity-promoting microbiome and resultant gut barrier disintegration have been implicated as key factors facilitating metabolic endotoxaemia. This is an influx of bacterial endotoxins into the systemic circulation, believed to underpin obesity pathogenesis. Adipocyte dysfunction and subsequent adipokine secretion characterised by low grade inflammation, were conventionally attributed to persistent hyperlipidaemia. They were thought of as pivotal in perpetuating obesity. It is now debated whether infection and endotoxaemia are also implicated in initiating and perpetuating low grade inflammation. The fact that obesity has a prevalence of over 600 million and serves as a risk factor for chronic diseases including cardiovascular disease and type 2 diabetes mellitus is testament to the importance of exploring the role of microbes in obesity pathobiology. It is on this basis that Massachusetts General Hospital is sponsoring the Faecal Microbiota Transplant for Obesity and Metabolism clinical trial, to study the impact of microbiome composition on weight. The association of microbes with obesity, namely, adenovirus infection and metabolic endotoxaemia, is reviewed.

  5. Breath test for differential diagnosis between small intestinal bacterial overgrowth and irritable bowel disease: An observation on non-absorbable antibiotics

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    AIM: To estimate the prevalence of small intestine bacterial overgrowth (SIBO) among patients with an earlier diagnosis of irritable bowel disease (IBS) in our geographical area, and to collect information on the use of locally acting non-absorbable antibiotics in the management of SIBO.METHODS: A non-interventional study was conducted in 73 consecutive patients with a symptom-based diagnosis..RESULTS: When the patients underwent a "breath test", 33 (45.2%) showed the presence of a SIBO. After treatment with rifaximin 1200 mg/d for seven days in 32 patients, 19 (59.4%) showed a negative "breath test" one week later as well as a significant reduction of symptoms, thus confirming the relationship between SIBO and many of the symptoms claimed by patients. In the other 13 patients, "breath test" remained positive,and a further cycle of treatment with ciprofloxacin 500mg/d was given for 7 additional days, resulting in a negative "breath test" in one atient only.CONCLUSION: (1) about half of the patients with a symptomatic diagnosis of IBS have actually SIBO, which is responsible for most of the symptoms attributed to IBS; (2) only a "breath test" with lactulose (or with glucose in subjects with an intolerance to lactose) can provide a differential diagnosis between IBS and SIBO,with almost identical symptoms; and (3) the use of non-absorbable antibiotics may be useful to reduce the degree of SIBO and related symptoms; it must be accompanied, however, by the correction of the wrong alimentary habits underlying SIBO.

  6. Day-night variation in heart rate variability changes induced by endotoxaemia in healthy volunteers

    DEFF Research Database (Denmark)

    Alamili, M.; Rosenberg, J; Gögenur, I

    2015-01-01

    /night variation in endotoxaemia-induced changes in HRV. METHODS: A randomized, crossover study with 12 healthy men (age 18-31) was conducted. Endotoxaemia were induced by lipopolysaccharide (LPS) endotoxin 0.3 ng/kg b.w. in two visits (day visit and night visit). At the day visit, endotoxaemia were induced at 12...... and parasympathetic activity can be estimated by measuring heart rate variability (HRV). Based on the intimate link between ANS and the inflammatory response, we hypothesized, that HRV changes seen during endotoxaemia would be different based on time of the day the endotoxaemia is initiated. We investigated day...... at both night and day resulted in a significant depression in HRV parameters high-frequency power (HF), low-frequency power (LF), standard deviation of normal-to-normal (NN) intervals, root mean square of successive differences and proportion of NN50 divided by total number of NNs (P

  7. Current treatment of sepsis and endotoxaemia.

    Science.gov (United States)

    Periti, P

    2000-09-01

    This article reviews the new criteria for selecting the proper antimicrobial agent and dosage regimen for standard treatment of severe sepsis, with the intention of preventing septic shock. After introducing new concepts on the pathogenesis of sepsis and septic shock, the authors analyse the parameters of beta-lactam antibacterial activity, the antibiotic-induced release of bacterial endotoxin and the interrelationships between pharmacokinetics and pharmacodynamics of antibiotics in the search for an optimum dosage regimen of antimicrobial mono- or polytherapy for severely ill septic patients admitted to the intensive care unit. The mortality rate resulting from severe bacterial sepsis, particularly that associated with shock, still approaches 50% in spite of appropriate antimicrobial therapy and optimum supportive care. Bacterial endotoxins that are part of the cell wall are one of the cofactors in the pathogenesis of sepsis and septic shock and are often induced by antimicrobial chemotherapy, even if administered rationally. Not all antimicrobial agents are equally capable of inducing septic shock; this is dependent on their mechanism of action rather than on the causative pathogen species. The quantity of endotoxin released depends on the drug dose and whether filaments or spheroplast formation predominate. Some antibiotics, such as carbapenems, ceftriaxone, cefepime, glycopeptides, aminoglycosides and quinolones, do not have the propensity to provoke septic shock because their rapid bacterial activity induces mainly spheroplast or fragile spheroplast-like bacterial forms.

  8. Role of intestinal bacterial overgrowth and intestinal motility in bacterial translocation in experimental cirrhosis Papel del sobrecrecimiento bacteriano intestinal y de la motilidad intestinal en la traslocación bacteriana en un modelo experimental de cirrosis

    Directory of Open Access Journals (Sweden)

    E. Sánchez

    2005-11-01

    Full Text Available Background: intestinal bacterial overgrowth (IBO is related to small bowel motility and has been involved in the pathogenesis of bacterial translocation (BT in experimental models, and both overgrowing gut flora and translocating bacteria to mesenteric lymph nodes are common features in cirrhosis. Objectives: the aims of this study were to analyze cecal aerobic bacteria and intestinal transit in cirrhotic rats, and their relationship with BT, evaluating the role of intestinal bacterial overgrowth and small bowel dismotility in the development of BT in experimental cirrhosis. Material and methods: we included twenty-seven male Sprague-Dawley rats with carbon tetrachloride-induced cirrhosis without ascites and ten controls. Cultures of mesenteric lymph nodes (MLN, peripheral and portal blood, liver, spleen and cecal samples were carried out. Small intestinal transit was determined in ten cirrhotic rats and in ten control rats. Results: the prevalence of bacterial translocation was 56%. Total cecal aerobic bacteria count was significantly higher in cirrhotic rats than in control rats (p Introducción: el sobrecrecimiento bacteriano intestinal (SBI está relacionado con la motilidad del intestino delgado y diferentes trabajos con modelos experimentales han sugerido su relación con el desarrollo de traslocación bacteriana (TB. Tanto el sobrecrecimiento bacteriano intestinal como la traslocación bacteriana son eventos frecuentes en la cirrosis hepática. Objetivos: los objetivos de este estudio han sido analizar la población cecal de bacterias aerobias y el tránsito intestinal en un modelo de ratas cirróticas y su relación con la TB. Material y métodos: el estudio se ha realizado en un modelo experimental de cirrosis inducida por tetracloruro de carbono por vía oral en ratas Sprague-Dawley. Se llevaron a cabo cultivos microbiológicos convencionales a partir de ganglios linfáticos mesentéricos (GLM, sangre portal y periférica, h

  9. Endotoxaemia in haemodialysis: a novel factor in erythropoetin resistance?

    Directory of Open Access Journals (Sweden)

    Laura E A Harrison

    Full Text Available BACKGROUND/OBJECTIVES: Translocated endotoxin derived from intestinal bacteria is a driver of systemic inflammation and oxidative stress. Severe endotoxaemia is an underappreciated, but characteristic finding in haemodialysis (HD patients, and appears to be driven by acute repetitive dialysis induced circulatory stress. Resistance to erythropoietin (EPO has been identified as a predictor of mortality risk, and associated with inflammation and malnutrition. This study aims to explore the potential link between previously unrecognised endotoxaemia and EPO Resistance Index (ERI in HD patients. METHODOLOGY/PRINCIPAL FINDINGS: 50 established HD patients were studied at a routine dialysis session. Data collection included weight, BMI, ultrafiltration volume, weekly EPO dose, and blood sampling pre and post HD. ERI was calculated as ratio of total weekly EPO dose to body weight (U/kg to haemoglobin level (g/dL. Mean haemoglobin (Hb was 11.3±1.3 g/dL with a median EPO dose of 10,000 [IQR 7,500-20,000] u/wk and ERI of 13.7 [IQR 6.9-23.3] ((U/Kg/(g/dL. Mean pre-HD serum ET levels were significantly elevated at 0.69±0.30 EU/ml. Natural logarithm (Ln of ERI correlated to predialysis ET levels (r = 0.324, p = 0.03 with a trend towards association with hsCRP (r = 0.280, p = 0.07. Ln ERI correlated with ultrafiltration volume, a driver of circulatory stress (r = 0.295, p = 0.046, previously identified to be associated with increased intradialytic endotoxin translocation. Both serum ET and ultrafiltration volume corrected for body weight were independently associated with Ln ERI in multivariable analysis. CONCLUSIONS: This study suggests that endotoxaemia is a significant factor in setting levels of EPO requirement. It raises the possibility that elevated EPO doses may in part merely be identifying patients subjected to significant circulatory stress and suffering the myriad of negative biological consequences arising from sustained

  10. Malassezia spp. overgrowth in allergic cats.

    Science.gov (United States)

    Ordeix, Laura; Galeotti, Franca; Scarampella, Fabia; Dedola, Carla; Bardagí, Mar; Romano, Erica; Fondati, Alessandra

    2007-10-01

    A series of 18 allergic cats with multifocal Malassezia spp. overgrowth is reported: atopic dermatitis was diagnosed in 16, an adverse food reaction in another and one was euthanized 2 months after diagnosis of Malassezia overgrowth. All the cats were otherwise healthy and those tested (16 out of 18) for feline leukaemia or feline immunodeficiency virus infections were all negative. At dermatological examination, multifocal alopecia, erythema, crusting and greasy adherent brownish scales were variably distributed on all cats. Cytological examination revealed Malassezia spp. overgrowth with/without bacterial infection in facial skin (n = 11), ventral neck (n = 6), abdomen (n = 6), ear canal (n = 4), chin (n = 2), ear pinnae (n = 2), interdigital (n = 1) and claw folds skin (n = 1). Moreover, in two cats Malassezia pachydermatis was isolated in fungal cultures from lesional skin. Azoles therapy alone was prescribed in seven, azoles and antibacterial therapy in eight and azoles with both antibacterial and anti-inflammatory therapy in three of the cats. After 3-4 weeks of treatment, substantial reduction of pruritus and skin lesions was observed in all 11 cats treated with a combined therapy and in five of seven treated solely with azoles. Malassezia spp. overgrowth may represent a secondary cutaneous problem in allergic cats particularly in those presented for dermatological examination displaying greasy adherent brownish scales. The favourable response to treatment with antifungal treatments alone suggests that, as in dogs, Malassezia spp. may be partly responsible for both pruritus and cutaneous lesions in allergic cats.

  11. Possible in vivo tolerance of human polymorphonuclear neutrophil to low-grade exercise-induced endotoxaemia

    Directory of Open Access Journals (Sweden)

    G. Camus

    1998-01-01

    Full Text Available To address the question of whether translocation of bacterial lipopolysaccharide (LPS into the blood could be involved in the process of exercise-induced polymorphonuclear neutrophil (PMN activation, 12 healthy male subjects who took part in a sprint triathlon (1.5 km river swim, 40 km bicycle race, 10 km road race were studied. While there was no detectable amount of endotoxin in the blood samples drawn at rest, exercise was followed by the appearance of circulating endotoxin molecules at the end of competition in four subjects, and after one and 24 h recovery in three and seven athletes, respectively. The concentrations of plasma granulocyte myeloperoxidase ([MPO], were significantly higher immediately after exercise and one hour later than baseline values (P<0.001. This variable returned to pre-race levels the day after exercise, despite the presence of detectable amounts of LPS, at that time, in seven athletes. The absence of significant correlation (r=0.26;P=0.383 and temporal association between [MPO]and plasma endotoxin levels led us to conclude that endotoxaemia was not involved in the process of exercise-induced PMN degranulation observed in our subjects.

  12. Diamond heteroepitaxial lateral overgrowth

    Science.gov (United States)

    Tang, Yung-Hsiu

    This dissertation describes improvements in the growth of single crystal diamond by microwave plasma-assisted chemical vapor deposition (CVD). Heteroepitaxial (001) diamond was grown on 1 cm. 2 a-plane sapphiresubstrates using an epitaxial (001) Ir thin-film as a buffer layer. Low-energy ion bombardment of the Ir layer, a process known as bias-enhanced nucleation, is a key step in achieving a high density of diamond nuclei. Bias conditions were optimized to form uniformly-high nucleation densities across the substrates, which led to well-coalesced diamond thin films after short growth times. Epitaxial lateral overgrowth (ELO) was used as a means of decreasing diamond internal stress by impeding the propagation of threading dislocations into the growing material. Its use in diamond growth requires adaptation to the aggressive chemical and thermal environment of the hydrogen plasma in a CVD reactor. Three ELO variants were developed. The most successful utilized a gold (Au) mask prepared by vacuum evaporation onto the surface of a thin heteroepitaxial diamond layer. The Au mask pattern, a series of parallel stripes on the micrometer scale, was produced by standard lift-off photolithography. When diamond overgrows the mask, dislocations are largely confined to the substrate. Differing degrees of confinement were studied by varying the stripe geometry and orientation. Significant improvement in diamond quality was found in the overgrown regions, as evidenced by reduction of the Raman scattering linewidth. The Au layer was found to remain intact during diamond overgrowth and did not chemically bond with the diamond surface. Besides impeding the propagation of threading dislocations, it was discovered that the thermally-induced stress in the CVD diamond was significantly reduced as a result of the ductile Au layer. Cracking and delamination of the diamond from the substrate was mostly eliminated. When diamond was grown to thicknesses above 0.1 mm it was found that

  13. Nifedipine-Induced gingival overgrowth

    OpenAIRE

    Florio, Ornella; School of Dentistry of São Jose dos Campos - State University of São Paulo; Tfouni, Maysa; School of Dentistry of São Jose dos Campos - State University of São Paulo; Balducci, Ivan; School of Dentistry of São Jose dos Campos - State University of São Paulo; Marco, Andrea Carvalho de; School of Dentistry of São Jose dos Campos - State University of São Paulo; Neves Jardini, Maria Aparecida; School of Dentistry of São Jose dos Campos - State University of São Paulo; Dias Almeida, Janete; School of Dentistry of São Jose dos Campos - State University of São Paulo

    2013-01-01

    Objective: The objective of the present study was to evaluate gingival overgrowth induced by nifedipine and to correlate it with plaque accumulation. Material and Methods: Sixty patients were divided into a treated group (n=30) consisting of hypertensive patients treated with nifedipine and a control group (n=30) consisting of patients without arterial hypertension. The following exams were performed on the first visit: anamnesis, measurement of blood pressure, weight and height, extra- and i...

  14. INITIAL METABOLIC STATE AND EXERCISE-INDUCED ENDOTOXAEMIA ARE UNRELATED TO GASTROINTESTINAL SYMPTOMS DURING EXERCISE

    Directory of Open Access Journals (Sweden)

    José Moncada-Jiménez

    2009-06-01

    Full Text Available The aim of the study was to investigate the association between the initial metabolic state and exercise-induced endotoxaemia on the appearance of gastrointestinal symptoms (GIS during exercise. Eleven males (36.6 ± 4.9 yrs, 1.7 ± 0.1 m, 74.5 ± 7.7 kg, DEXA body fat % 17.2 ± 6.6, VO2max 57.4 ± 7.4 ml·kg-1·min-1 underwent two isoenergetic diets designed to change their initial metabolic status by either depleting or maintaining their hepatic and muscular glycogen content. These diets and accompanying exercise sessions were performed by each participant in the days before completing a laboratory-based duathlon (5-km run, 30-km cycling, 10-km run. Blood samples were obtained before, immediately and 1- and 2-h following the duathlon for determination of insulin (IN, glucagon (GL, endotoxin, aspartic aminotransferase (AST, and alanine aminotransferase (ALT markers. GIS were assessed by survey before and after exercise. Diet content produced a different energy status as determined by macronutrient content and the IN/GL ratio (p < 0.05, and mild exercise-induced endotoxaemia was observed in both experimental duathlons. Regardless of the diet, the AST/ALT ratio following exercise and in the recovery phase indicated hepatocyte and liver parenchyma structural damage. In spite of GIS, no significant correlations between endotoxin levels and GIS were found. In conclusion, increased markers of endotoxaemia observed with the high-intensity exercise were unrelated to hepatic function and/or GIS before and after exercise

  15. Use of proton pump inhibitor and risk of small intestinal bacterial overgrowth:a meta-analysis of observational studies%质子泵抑制剂与小肠细菌过度增长关系的 Meta 分析

    Institute of Scientific and Technical Information of China (English)

    全晓静; 罗和生; 陈炜

    2015-01-01

    Objective To assess the associations between Proton Pump inhibitor(PPI)therapy and risk of bacterial overgrowth using Meta-analysis.Methods We searched MEDLINE(PubMed),the Cochrane Library,China Biological Medicine in December 2012.Two evaluators independently reviewed and selected articles,based on pre-determined selection criteria.Results Eight observational studies, which involved 576 participants,were included in the final analysis.The overall use of PPI was significant-ly associated with the risk of bacterial overgrowth in a fixed-effects model meta-analysis of all 8 observa-tional studies(OR =13.46,95%CI:7.00 ~25.88).Also,in Subgroup analysis of bacterial overgrowth positivity in PPI users based on PPI dose,there was a association between PPI use of 20 mg/d or 40 mg/d and the risk of bacterial overgrowth in a fixed-effects meta-analysis(P 0.05),while in treatment more than 1 month,there has a significant association(OR =16.47%, 95%CI:7.82 ~34.71 ).Based on diagnostic methods of bacterial overgrowth,there was a association between PPI use of bacterial culture or GHBT and the risk of bacterial overgrowth in a fixed-effects meta-analysis(P <0.01).Conclusion PPI therapy is associated with an increased risk of bacterial over-growth,But short-term management may not affect hydrochloric acid preventing bacteria from colonisation in gastrointestine.%目的评价质子泵抑制剂(PPI)与小肠细菌过度增长之间的关系。方法检索MEDLINE /PubMed、Cochrane Central Register of Controlled Trials、中国生物医学文献数据库等,按标准纳入 PPI 导致细菌过度增长的所有观察性研究。采用 Cochrane 协作网提供的 RevMan 5.1软件进行荟萃分析。结果8项观察性研究共576例患者纳入分析。结果显示,PPI 显著增加发生胃肠道细菌过度增长的风险(阳性率为46.61%),与对照组比较差异有统计学意义[风险比(OR)=13.46,95%可信区间(CI):7.00~25.88

  16. Síndrome de intestino corto: definición, causas, adaptación intestinal y sobrecrecimiento bacteriano Short bowel syndrome: definition, causes, intestinal adaptation and bacterial overgrowth

    Directory of Open Access Journals (Sweden)

    M. D. Ballesteros Pomar

    2007-05-01

    ón parenteral.The short bowel syndrome (SBS is a complex entity due to anatomical or functional loss of part of the small bowel originating a clinical picture with severe metabolic and nutritional impairments due to reduction of the effective absorptive surface area of the gut. SBS is one of the causes of a larger entity known as "intestinal failure". Currently, mesenteric vascular accidents are the main cause in adults, followed by inflammatory bowel disease, and radiation enteritis, whereas in children, the main causes are congenital and perinatal diseases. The clinical picture associated with SBS varies according to the length and location of affected small bowel, the presence of underlying disease, the presence or absence of the large bowel and ileocecal valve, and the nature of the underlying disease. Intestinal adaptation is the process by which, throughout 1-2 years, intestinal absorption is reestablished to the situation prior to intestinal resection, and is a key factor determining whether a patient with SBS will progress to intestinal failure and depend on DPN. Intestinal adaptation may take place if the patient does oral intake higher than the usual one (hyperphagia; besides, the bowel may also adapt to secure a more effective absorption per surface area unit, either by increasing the absorptive surface area (structural adaptation and/or slowing intestinal transit (functional adaptation. These changes are not still clearly established in humans, but there are so in animal models. The presence of nutrients within the intestinal lumen and certain gastrointestinal hormones, particularly GLP-2, have an influence on a successful adaptation process. Patients with SBS are prone to the occurrence of bacterial overgrowth that makes adaptation difficult and worsens the symptoms, besides being a factor for dependence on parenteral nutrition.

  17. Effects of endotoxaemia on markers of permeability, metabolism and inflammation in the large bowel of healthy subjects

    DEFF Research Database (Denmark)

    Jørgensen, V L; Ibsen, M; Andresen, L;

    2007-01-01

    Increased permeability and increased luminal concentrations of L-lactate have previously been shown in the large bowel in septic patients. To advance these observations, a human model of colorectal barrier failure in sepsis is desirable. Therefore, we assessed the effects of endotoxaemia on marke...

  18. Chronic Inflammatory Gingival Overgrowths: Laser Gingivectomy & Gingivoplasty

    OpenAIRE

    Shankar, B Shiva; T, Ramadevi; S, Neetha M; Reddy, P Sunil Kumar; Saritha, G; Reddy, J Muralinath

    2013-01-01

    It is quite common to note chronic inflammatory Gingival overgrowths during and/or post orthodontic treatment. Sometimes the overgrowths may even potentially complicate and/or interrupt orthodontic treatment. With the introduction of soft tissue lasers these problems can now be addressed more easily. Amongst many LASERS now available in Dentistry DIODE LASERS seem to be most ideal for orthodontic soft tissue applications. As newer treatments herald into minimally invasive techniques, DIODE LA...

  19. Chronic inflammatory gingival overgrowths: laser gingivectomy & gingivoplasty.

    Science.gov (United States)

    Shankar, B Shiva; T, Ramadevi; S, Neetha M; Reddy, P Sunil Kumar; Saritha, G; Reddy, J Muralinath

    2013-02-01

    It is quite common to note chronic inflammatory Gingival overgrowths during and/or post orthodontic treatment. Sometimes the overgrowths may even potentially complicate and/or interrupt orthodontic treatment. With the introduction of soft tissue lasers these problems can now be addressed more easily. Amongst many LASERS now available in Dentistry DIODE LASERS seem to be most ideal for orthodontic soft tissue applications. As newer treatments herald into minimally invasive techniques, DIODE LASERS are becoming more promising both in patient satisfaction and dentist satisfaction. How to cite this article: Shankar BS, Ramadevi T, Neetha M S, Reddy P S K, Saritha G, Reddy J M. Chronic Inflammatory Gingival Overgrowths: Laser Gingivectomy & Gingivoplasty. J Int Oral Health 2013; 5(1):83-87.

  20. Genetic syndromes associated with overgrowth in childhood.

    Science.gov (United States)

    Ko, Jung Min

    2013-09-01

    Overgrowth syndromes comprise a diverse group of conditions with unique clinical, behavioral and molecular genetic features. While considerable overlap in presentation sometimes exists, advances in identification of the precise etiology of specific overgrowth disorders continue to improve clinicians' ability to make an accurate diagnosis. Among them, this paper introduces two classic genetic overgrowth syndromes: Sotos syndrome and Beckwith-Wiedemann syndrome. Historically, the diagnosis was based entirely on clinical findings. However, it is now understood that Sotos syndrome is caused by a variety of molecular genetic alterations resulting in haploinsufficiency of the NSD1 gene at chromosome 5q35 and that Beckwith-Wiedemann syndrome is caused by heterogeneous abnormalities in the imprinting of a number of growth regulatory genes within chromosome 11p15 in the majority of cases. Interestingly, the 11p15 imprinting region is also associated with Russell-Silver syndrome which is a typical growth retardation syndrome. Opposite epigenetic alterations in 11p15 result in opposite clinical features shown in Beckwith-Wiedemann syndrome and Russell-Silver syndrome. Although the exact functions of the causing genes have not yet been completely understood, these overgrowth syndromes can be good models to clarify the complex basis of human growth and help to develop better-directed therapies in the future.

  1. Chronic endocannabinoid system stimulation induces muscle macrophage and lipid accumulation in type 2 diabetic mice independently of metabolic endotoxaemia.

    Directory of Open Access Journals (Sweden)

    Lucie Geurts

    Full Text Available AIMS: Obesity and type 2 diabetes are characterised by low-grade inflammation, metabolic endotoxaemia (i.e., increased plasma lipopolysaccharides [LPS] levels and altered endocannabinoid (eCB-system tone. The aim of this study was to decipher the specific role of eCB-system stimulation or metabolic endotoxaemia in the onset of glucose intolerance, metabolic inflammation and altered lipid metabolism. METHODS: Mice were treated with either a cannabinoid (CB receptor agonist (HU210 or low-dose LPS using subcutaneous mini-pumps for 6 weeks. After 3 weeks of the treatment under control (CT diet, one-half of each group of mice were challenged with a high fat (HF diet for the following 3-week period. RESULTS: Under basal conditions (control diet, chronic CB receptor agonist treatment (i.e., 6 weeks induced glucose intolerance, stimulated metabolic endotoxaemia, and increased macrophage infiltration (CD11c and F4/80 expression in the muscles; this phenomenon was associated with an altered lipid metabolism (increased PGC-1α expression and decreased CPT-1b expression in this tissue. Chronic LPS treatment tended to increase the body weight and fat mass, with minor effects on the other metabolic parameters. Challenging mice with an HF diet following pre-treatment with the CB agonist exacerbated the HF diet-induced glucose intolerance, the muscle macrophage infiltration and the muscle's lipid content without affecting the body weight or the fat mass. CONCLUSION: Chronic CB receptor stimulation under basal conditions induces glucose intolerance, stimulates metabolic inflammation and alters lipid metabolism in the muscles. These effects worsen following the concomitant ingestion of an HF diet. Here, we highlight the central roles played by the eCB system and LPS in the pathophysiology of several hallmarks of obesity and type 2 diabetes.

  2. Nonsurgical Management of Nifedipine Induced Gingival Overgrowth

    Directory of Open Access Journals (Sweden)

    George Sam

    2014-01-01

    Full Text Available Drug-induced gingival overgrowth is frequently associated with three particular drugs: phenytoin, cyclosporin, and nifedipine. As gingival enlargement develops, it affects the normal oral hygiene practice and may interfere with masticatory functions. The awareness in the medical community about this possible side effect of nifedipine is less when compared to the effects of phenytoin and cyclosporin. The frequency of gingival enlargement associated with chronic nifedipine therapy remains controversial. Within the group of patients that develop this unwanted effect, there appears to be variability in the extent and severity of the gingival changes. Although gingival inflammation is considered a primary requisite in their development, few cases with minimal or no plaque induced gingival inflammation have also been reported. A case report of gingival overgrowth induced by nifedipine in a patient with good oral hygiene and its nonsurgical management with drug substitution is discussed in this case report.

  3. Reduction of pulmonary inflammatory response by erythropoietin in a rat model of endotoxaemia

    Institute of Scientific and Technical Information of China (English)

    SHANG You; JIANG Yuan-xu; XU San-peng; WU Yan; WU Zhou-yang; YUAN Shi-ying; YAO Shang-long

    2009-01-01

    Background Erythropoietin elicits protective effects in lung tissue injury induced by ischaemic reperfusion and hyperoxia.We investigated the protective roles of erythropoietin in pulmonary inflammation and lung injury during acute endotoxaemia.Methods A total of 32 male Sprague-Dawley rats were randomly assigned to four groups:saline group,erythropoietin+saline group,saline+lipopolysaccharide group and erythropoietin+lipopolysaccharide group.Rats were treated with erythropoietin (3000 U/kg,i.p.) or saline,30 minutes prior to lipopolysaccharide administration (6 mg/kg,i.v.).Four hours after lipopolysaccharide injection,samples of pulmonary tissue were collected.Optical microscopy was performed to examine pathological changes in lungs.Wet/dry (W/D) ratios,myeloperoxidase activity,malondialdehyde concentrations and tumour necrosis factor-alpha (TNF-a) as well as interleukin 1 beta (IL-1β) levels in lungs were measured.The pulmonary expression of nuclear factor kappaB (NF-kB) p65 was evaluated by Western blotting.Differences between the different groups were analysed by one-way analysis of variance (ANOVA).Results The lung tissues from the saline+lipopolysaccharide group were significantly damaged,which were less pronounced in the erythropoietin+lipopolysaccharide group.The W/D ratio increased significantly in the saline+lipopolysaccharide group (5.75±0.22) as compared with the saline group (3.85±0.20) (P <0.01),which was significantly reduced in the erythropoietin+lipopolysaccharide group (4.50±0.35) (P <0.01).Myeloperoxidase activity and malondialdehyde levels increased significantly in the saline+lipopolysaccharide group compared with the saline group,which was reduced in the erythropoietin + lipopolysaccharide group.The TNF-a level of pulmonary tissue increased significantly in the saline+lipopolysaccharide group ((9.80±0.82) pg/mg protein) compared with the saline group ((4.20±0.42) pg/mg protein,P <0.01).However,the increase of TNF-a level of

  4. Efficacy of AZM therapy in patients with gingival overgrowth induced by Cyclosporine A: a systematic review

    Directory of Open Access Journals (Sweden)

    Deli Giorgio

    2008-12-01

    Full Text Available Abstract Background In daily clinical practice of a dental department it's common to find gingival overgrowth (GO in periodontal patients under treatment with Cyclosporine A (CsA. The pathogenesis of GO and the mechanism of action of Azithromycin (AZM are unclear. A systematic review was conducted in order to evaluate the efficacy of Azithromycin in patients with gingival overgrowth induced by assumption of Cyclosporine A. Methods A bibliographic search was performed using the online databases MEDLINE, EMBASE and Cochrane Central of Register Controlled Trials (CENTRAL in the time period between 1966 and September 2008. Results The literature search retrieved 24 articles; only 5 were Randomised Controlled Trials (RCTs, published in English, fulfilled the inclusion criteria. A great heterogeneity between proposed treatments and outcomes was found, and this did not allow to conduct a quantitative meta-analysis. The systematic review revealed that a 5-day course of Azithromycin with Scaling and Root Planing reduces the degree of gingival overgrowth, while a 7-day course of metronidazole is only effective on concomitant bacterial over-infection. Conclusion Few RCTs on the efficacy of systemic antibiotic therapy in case of GO were found in the literature review. A systemic antibiotic therapy without plaque and calculus removal is not able to reduce gingival overgrowth. The great heterogeneity of diagnostic data and outcomes is due to the lack of precise diagnostic methods and protocols about GO. Future studies need to improve both diagnostic methods and tools and adequate classification aimed to determine a correct prognosis and an appropriate therapy for gingival overgrowth.

  5. PROTEUS SYNDROME - SEGMENTAL OVERGROWTH WITH MULTIPLE NEVI

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    Ramasamy

    2015-01-01

    Full Text Available Proteus syndrome is a rare hamartomatous disorder characterized by various cutaneous and subcutaneous lesions , including vascular malformations , lipomas , hyperpigmentation , and several types of nevi. Partial gigantism with limb or digital overgrowth is pathognomonic of Proteus syndrome. We report a case of proteus syndrome in a 45 year old man , who presented with hypertrophy of index finger of both hands and middle , ring fing er of left hand , verrucous lesions over left axilla and two firm swellings over left palm for the past 15 years. Clinical findings , histopathology and imaging studies fulfilled the criteria of proteus syndrome which is rarely reported in literature.

  6. Genetic Considerations in the Prenatal Diagnosis of Overgrowth Syndromes

    Science.gov (United States)

    Vora, Neeta; Bianchi, Diana W.

    2015-01-01

    Large (>90%) for gestational age (LGA) fetuses are usually identified incidentally. Detection of the LGA fetus should first prompt the provider to rule out incorrect dates and maternal diabetes. Once this is done, consideration should be given to certain overgrowth syndromes, especially if anomalies are present. The overgrowth syndromes have significant clinical and molecular overlap, and are associated with developmental delay, tumors, and other anomalies. Although genetic causes of overgrowth are considered postnatally, they are infrequently diagnosed prenatally. Here, we review prenatal sonographic findings in fetal overgrowth syndromes, including Pallister-Killian, Beckwith-Wiedemann, Sotos, Perlman, and Simpson-Golabi-Behmel. We also discuss prenatal diagnosis options and recurrence risks. PMID:19609940

  7. Cleaved-edge-overgrowth nanogap electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Luber, Sebastian M; Bichler, Max; Abstreiter, Gerhard; Tornow, Marc, E-mail: m.tornow@tu-bs.de [Walter Schottky Institut, Technische Universitaet Muenchen, Am Coulombwall, 85748 Garching (Germany)

    2011-02-11

    We present a method to fabricate multiple metal nanogap electrodes of tailored width and distance in parallel, on the cleaved plane of a GaAs/AlGaAs heterostructure. The three-dimensional patterned structures are obtained by a combination of molecular-beam-epitaxial regrowth on a crystal facet, using the cleaved-edge-overgrowth (CEO) method, and subsequent wet selective etching and metallization steps. SEM and AFM studies reveal smooth and co-planar electrodes of width and distance of the order of 10 nm. Preliminary electrical characterization indicates electrical gap insulation in the 100 M{Omega} range with k{Omega} lead resistance. We propose our methodology to realize multiple electrode geometries that would allow investigation of the electrical conductivity of complex nanoscale objects such as branched organic molecules.

  8. EED-associated overgrowth in a second male patient.

    Science.gov (United States)

    Cohen, Ana Sa; Gibson, William T

    2016-09-01

    Following our discovery that constitutional mutations in EED can cause overgrowth, we screened our cohort of patients with Weaver-like features for mutations in this gene. Here we describe a second patient with a different, rare and de novo mutation in EED. Phenotypic overlap with our first case of EED-associated overgrowth is significant. Now that we have found two unrelated families of different ethnicities, with a similar rare phenotype, both associated with de novo mutations in this member of the PRC2 complex, we are confident that EED is indeed a novel overgrowth gene.

  9. Cortical overgrowth in fetuses with isolated ventriculomegaly.

    Science.gov (United States)

    Kyriakopoulou, Vanessa; Vatansever, Deniz; Elkommos, Samia; Dawson, Sarah; McGuinness, Amy; Allsop, Joanna; Molnár, Zoltán; Hajnal, Joseph; Rutherford, Mary

    2014-08-01

    Mild cerebral ventricular enlargement is associated with schizophrenia, autism, epilepsy, and attention-deficit/hyperactivity disorder. Fetal ventriculomegaly is the most common central nervous system (CNS) abnormality affecting 1% of fetuses and is associated with cognitive, language, and behavioral impairments in childhood. Neurodevelopmental outcome is partially predictable by the 2-dimensional size of the ventricles in the absence of other abnormalities. We hypothesized that isolated fetal ventriculomegaly is a marker of altered brain development characterized by relative overgrowth and aimed to quantify brain growth using volumetric magnetic resonance imaging (MRI) in fetuses with isolated ventriculomegaly. Fetal brain MRI (1.5 T) was performed in 60 normal fetuses and 65 with isolated ventriculomegaly, across a gestational age range of 22-38 weeks. Volumetric analysis of the ventricles and supratentorial brain structures was performed on 3-dimensional reconstructed datasets. Fetuses with isolated ventriculomegaly had increased brain parenchyma volumes when compared with the control cohort (9.6%, P ventriculomegaly may represent the neurobiological substrate for cognitive, language, and behavioral deficits in these children.

  10. Bacterial infections in cirrhosis: Role of proton pump inhibitors and intestinal permeability

    NARCIS (Netherlands)

    L.G. van Vlerken (Lotte); E.J. Huisman (Ellen); B. van Hoek (Bart); W. Renooij (W.); F.W.M. de Rooij (Felix); P.D. Siersema (Peter); K.J. van Erpecum (Karel)

    2012-01-01

    textabstractBackground Cirrhotic patients are at considerable risk for bacterial infections, possibly through increased intestinal permeability and bacterial overgrowth. Proton pump inhibitors (PPIs) may increase infection risk. We aimed to explore the potential association between PPI use and bacte

  11. Evaluation of small intestine bacterial overgrowth in patients with functional dyspepsia through H2 breath test Avaliação de supercrescimento bacteriano no intestino delgado em pacientes com dispepsia funcional, utilizando o teste de H2 no ar expirado

    Directory of Open Access Journals (Sweden)

    Michelle Bafutto Gomes Costa

    2012-12-01

    Full Text Available CONTEXT: Functional dyspepsia is a condition in which symptoms are not related to organic underlying disease; its pathogenesis is not well known. The small intestinal bacterial overgrowth (SIBO is characterized by the increase in the number and/or type of colonic bacteria in the upper gastrointestinal tract. The hypothesis of SIBO being associated to functional dyspepsia must be considered, since the impaired motility of the gastrointestinal tract is one of the main etiologic factors involved on both pathologies. OBJECTIVE: To determine if there is SIBO in patients with functional dyspepsia. METHODS: Case-control study, evaluating 34 patients: 23 functional dyspeptic and 11 non-dyspeptic (control group. Questionnaire applied based on Rome III criteria. The patients underwent H2-lactulose breath test, considered positive when: H2 peak exceeding 20 ppm, in relation to fasting, or two peaks exceeding 10 ppm sustained until 60 minutes. RESULTS: Of the 23 dyspeptic patients, 13 (56.5% obtained positive results for SIBO trough the H2-lactulose breath test. On control group, SIBO was not observed. The association between the dyspeptic group and the control group regarding SIBO was statistically significant, with P = 0.0052. In the group of dyspeptic patients, 12 (52.2% were using proton pump inhibitor; of these 9 (75% were positive for SIBO. In the control group, none of the 11 patients used proton pump inhibitors and SIBO was not observed. The association of the dyspeptic group using proton pump inhibitor that were positive for SIBO and the control group was statistically significant, with P = 0.0011. CONCLUSION: It was found that, patients with functional dyspepsia presented SIBO, when they underwent to H2-lactulose breath test, compared to the non-dyspeptic. In addition, it was observed a higher prevalence of SIBO in dyspeptic patients that were using proton pump inhibitors, compared to control group.CONTEXTO: A dispepsia funcional é uma afec

  12. Isolated gingival overgrowths: A review of case series

    Directory of Open Access Journals (Sweden)

    Shruti Raizada

    2016-01-01

    Full Text Available Clinicians are often intrigued by the varied manifestations of the gingival tissue. Gingival overgrowth is a common clinical finding and most of them represent a reactive hyperplasia as a direct result of plaque-related inflammatory gingival disease. These types of growth generally respond to good plaque control, removal of the causative irritants, and conservative tissue management. This case series highlights three different cases of localized gingival overgrowth and its management with emphasis on the importance of patient awareness and motivation.

  13. The Possible Potential Therapeutic Targets for Drug Induced Gingival Overgrowth

    Directory of Open Access Journals (Sweden)

    Tamilselvan Subramani

    2013-01-01

    Full Text Available Gingival overgrowth is a side effect of certain medications. The most fibrotic drug-induced lesions develop in response to therapy with phenytoin, the least fibrotic lesions are caused by cyclosporin A, and the intermediate fibrosis occurs in nifedipine-induced gingival overgrowth. Fibrosis is one of the largest groups of diseases for which there is no therapy but is believed to occur because of a persistent tissue repair program. During connective tissue repair, activated gingival fibroblasts synthesize and remodel newly created extracellular matrix. Proteins such as transforming growth factor (TGF, endothelin-1 (ET-1, angiotensin II (Ang II, connective tissue growth factor (CCN2/CTGF, insulin-like growth factor (IGF, and platelet-derived growth factor (PDGF appear to act in a network that contributes to the development of gingival fibrosis. Since inflammation is the prerequisite for gingival overgrowth, mast cells and its protease enzymes also play a vital role in the pathogenesis of gingival fibrosis. Drugs targeting these proteins are currently under consideration as antifibrotic treatments. This review summarizes recent observations concerning the contribution of TGF-β, CTGF, IGF, PDGF, ET-1, Ang II, and mast cell chymase and tryptase enzymes to fibroblast activation in gingival fibrosis and the potential utility of agents blocking these proteins in affecting the outcome of drug-induced gingival overgrowth.

  14. The Role of Intestinal Bacteria Overgrowth in Obesity-Related Nonalcoholic Fatty Liver Disease

    Directory of Open Access Journals (Sweden)

    Silvia M. Ferolla

    2014-12-01

    Full Text Available Nonalcoholic fatty liver disease (NAFLD is the most common chronic liver disease worldwide. It is a progressive disorder involving a spectrum of conditions that include pure steatosis without inflammation, nonalcoholic steatohepatitis (NASH, fibrosis and cirrhosis. The key factor in the pathophysiology of NAFLD is insulin resistance that determines lipid accumulation in the hepatocytes, which may be followed by lipid peroxidation, production of reactive oxygen species and consequent inflammation. Recent studies suggest that the characteristics of the gut microbiota are altered in NAFLD, and also, that small intestinal bacterial overgrowth (SIBO contributes to the pathogenesis of this condition. This review presents the chief findings from all the controlled studies that evaluated SIBO, gut permeability and endotoxemia in human NAFLD. We also discuss the possible mechanisms involving SIBO, lipid accumulation and development of NASH. The understanding of these mechanisms may allow the development of new targets for NASH treatment in the future.

  15. Microbial gut overgrowth guarantees increased spontaneous mutation leading to polyclonality and antibiotic resistance in the critically ill.

    Science.gov (United States)

    van Saene, H K F; Taylor, N; Damjanovic, V; Sarginson, R E

    2008-05-01

    Polyclonality is defined as the occurrence of different genotypes of a bacterial species. We are of the opinion that these different clones originate within the patient. When infections and outbreaks occur, the terms of polyclonal infections and polyclonal outbreaks have been used, respectively. The origin of polyclonality has never been reported, although some authors suggest the acquisition of different clones from different animate and inanimate sources. We think that the gut of the critically ill patient with microbial overgrowth is the ideal site for the de-novo development of new clones, following increased spontaneous mutation.

  16. Focal fibrous overgrowths: A case series and review of literature

    OpenAIRE

    Kolte, Abhay P.; Rajshri A Kolte; Shrirao, Tushar S.

    2010-01-01

    Intraoral fibrous overgrowths of the soft tissues are relatively common and may be benign reactive or neoplastic lesions. A series of 10 lesions is presented which included pyogenic granuloma, fibroma and peripheral ossifying fibroma. Almost all the lesions occurred in the second and third decades and were present in the anterior segment of the jaws, with a distinct female predilection. Majority of these lesions were asymptomatic and the patients reported for treatment only due to the discomf...

  17. SacB-SacR gene cassette as the negative selection marker to suppress Agrobacterium overgrowth in Agrobacterium-mediated plant transformation

    Directory of Open Access Journals (Sweden)

    Yiming Liu

    2016-10-01

    Full Text Available Agrobacterium overgrowth is a common problem in Agrobacterium-mediated plant transfor-mation. To suppress the Agrobacterium overgrowth, various antibiotics have been used during plant tissue culture steps. The antibiotics are expensive and may adversely affect plant cell differentiation and reduce plant transformation efficiency. The SacB-SacR proteins are toxic to most Agrobacterium tumefaciens strains when they are grown on culture medium sup¬plemented with sucrose. Therefore, SacB-SacR genes can be used as negative selection markers to suppress the overgrowth of Agrobacterium tumefaciens in the plant tissue culture process. We generated a mutant Agrobacterium tumefaciens strain GV2260 (recA-SacB/R that has the SacB-SacR cassette inserted into the bacterial genome at the recA gene locus. The mutant Agrobacterium strain is sensitive to sucrose but maintains its ability to transform plant cells in both transient and stable transformation assays. We demonstrated that the mutant strain GV2260 (recA-SacB/R can be inhibited by sucrose that reduces the overgrowth of Agrobacterium and therefore improves the plant transformation efficiency. We employed GV2260 (recA-SacB/R to generate stable transgenic N. benthamiana plants expressing a CRISPR-Cas9 for knocking out a WRKY transcrip¬tion factor.

  18. Concentrations of lipopolysaccharide-binding protein, bactericidal/permeability-increasing protein, soluble CD14 and plasma lipids in relation to endotoxaemia in patients with alcoholic liver disease

    DEFF Research Database (Denmark)

    Schäfer, C.; Parlesak, Alexandr; Schütt, C.;

    2002-01-01

    There is increasing evidence that gut leakage in persons with chronic alcohol misuse leads to endotoxaemia, which might contribute to the development of alcoholic hepatitis or cirrhosis. In addition, it was recently shown that the endotoxin-binding capacity of whole blood is reduced...... in these patients. To analyse this phenomenon, we measured the concentration of functionally important endotoxin-binding plasma components which modify the action of endotoxin. In patients with minimal (n = 10), intermediate (n = 9), and cirrhotic alcoholic liver disease (n = 11), and healthy controls (n = 11......), plasma endotoxin was determined in a limulus assay. The concentration of lipoproteins was assessed by measuring apolipoproteins, the other factors were directly measured in immunoassays. In the entire group of alcoholics, endotoxin and the concentration of binding factors that are involved in the action...

  19. Indomethacin injury to the rat small intestine is dependent upon biliary secretion and is associated with overgrowth of enterococci.

    Science.gov (United States)

    Mayo, Sara A; Song, Ye K; Cruz, Melissa R; Phan, Tri M; Singh, Kavindra V; Garsin, Danielle A; Murray, Barbara E; Dial, Elizabeth J; Lichtenberger, Lenard M

    2016-03-01

    NSAIDuse is limited due to the drugs' toxicity to the gastrointestinal mucosa, an action incompletely understood. Lower gut injury induced byNSAIDs is dependent on bile secretion and is reported to increase the growth of a number of bacterial species, including an enterococcal species,Enterococcus faecalis This study examined the relationships between indomethacin (INDO)-induced intestinal injury/bleeding, small bowel overgrowth (SBO) and dissemination of enterococci, and the contribution of bile secretion to these pathological responses. Rats received either a sham operation (SO) or bile duct ligation (BDL) prior to administration of two daily subcutaneous doses of saline orINDO, and 24 h later, biopsies of ileum and liver were collected for plating on selective bacterial media. Fecal hemoglobin (Hb) and blood hematocrit (Hct) were measured to assess intestinal bleeding. Of the four treatment groups, onlySO/INDOrats experienced a significant 10- to 30-fold increase in fecal Hb and reduction in Hct, indicating thatBDLattenuatedINDO-induced intestinal injury/bleeding. Ileal enterococcal colony-forming units were significantly increased (500- to 1000-fold) inSO/INDOrats. Of all groups, only theSO/INDOrats demonstrated gut injury, and this was associated with enterococcal overgrowth of the gut and dissemination to the liver. We also demonstrated thatINDO-induced intestinal injury andE. faecalisovergrowth was independent of the route of administration of the drug, as similar findings were observed in rats orally dosed with theNSAID Bile secretion plays an important role inINDO-induced gut injury and appears to support enterococcal overgrowth of the intestine.NSAID-induced enterococcalSBOmay be involved either as a compensatory response to gut injury or with the pathogenic process itself and the subsequent development of sepsis.

  20. Is periodontal health a predictor of drug-induced gingival overgrowth? A cross-sectional study

    OpenAIRE

    Ruchi Banthia; Santosh Gupta; Priyank Banthia; Pallavi Singh; Sapna Raje; Navkiran Kaur

    2014-01-01

    Background: Gingival overgrowth is a common side-effect of amlodipine regimen on the oral cavity. There is controversy regarding the cause and effect relationship of periodontal health and drug induced gingival overgrowth. Therefore, this study was conducted to investigate and to assess the relationship between the periodontal health and the onset and severity of gingival overgrowth in hypertensive patients receiving amlodipine. Materials and Methods: A total of 99 known hypertensive pati...

  1. An allelopathy based model for the Listeria overgrowth phenomenon.

    Science.gov (United States)

    Fgaier, Hedia; Kalmokoff, Martin; Ells, Timothy; Eberl, Hermann J

    2014-01-01

    In a standard procedure of food safety testing, the presence of the pathogenic bacterium Listeria monocytogenes can be masked by non-pathogenic Listeria. This phenomenon of Listeria overgrowth is not well understood. We present a mathematical model for the growth of a mixed population of L. innocua and L. monocytogenes that includes competition for a common resource and allelopathic control of L. monocytogenes by L. innocua when this resource becomes limited, which has been suggested as one potential explanation for the overgrowth phenomenon. The model is tested quantitatively and qualitatively against experimental data in batch experiments. Our results indicate that the phenomenon of masked pathogens can depend on initial numbers of each population present, and on the intensity of the allelopathic effect. Prompted by the results for the batch setup, we also analyze the model in a hypothetical chemostat setup. Our results suggest that it might be possible to operate a continuous growth environment such that the pathogens outcompete the non-pathogenic species, even in cases where they would be overgrown in a batch environment.

  2. Incidence of amlodipine-induced gingival overgrowth in the rural population of Loni

    Directory of Open Access Journals (Sweden)

    Avneesh Tejnani

    2014-01-01

    Full Text Available Aims: Since the incidence of gingival overgrowth induced by amlodipine remains poorly defined, this study was carried out with an aim to determine the incidence. Materials and Methods: Dental patients who received amlodipine (N = 115, for more than 3 months were studied to determine the drug-induced gingival overgrowth. Clinical diagnosis of drug-induced overgrowth was verified by disappearance or decreased severity of gingival overgrowth after withdrawal of the causative drug. Results: The prevalence rate of amlodipine-induced gingival hyperplasia among experimental patients was 3.4%, while it was not observed among the control subjects. Oral examination revealed gingival overgrowth as a lobular or nodular enlargement on interdental papilla located in the anterior interproximal regions. Conclusions: In this study, there was a significant relationship between gingival inflammation resulting from dental plaque and drug dosage, and hyperplasia.

  3. Focal fibrous overgrowths: a case series and review of literature.

    Science.gov (United States)

    Kolte, Abhay P; Kolte, Rajshri A; Shrirao, Tushar S

    2010-10-01

    Intraoral fibrous overgrowths of the soft tissues are relatively common and may be benign reactive or neoplastic lesions. A series of 10 lesions is presented which included pyogenic granuloma, fibroma and peripheral ossifying fibroma. Almost all the lesions occurred in the second and third decades and were present in the anterior segment of the jaws, with a distinct female predilection. Majority of these lesions were asymptomatic and the patients reported for treatment only due to the discomfort during function. Histopathologic examinations were done for diagnosis of these lesions. Surgical excision along with removal of causative irritants remains the treatment of choice. The extent of excision should depend on the severity of the lesion, as some of these lesions have a tendency for recurrence. All the patients in this series were closely followed up for a period of 2 years and showed no signs of recurrence.

  4. Focal fibrous overgrowths: A case series and review of literature

    Directory of Open Access Journals (Sweden)

    Abhay P Kolte

    2010-01-01

    Full Text Available Intraoral fibrous overgrowths of the soft tissues are relatively common and may be benign reactive or neoplastic lesions. A series of 10 lesions is presented which included pyogenic granuloma, fibroma and peripheral ossifying fibroma. Almost all the lesions occurred in the second and third decades and were present in the anterior segment of the jaws, with a distinct female predilection. Majority of these lesions were asymptomatic and the patients reported for treatment only due to the discomfort during function. Histopathologic examinations were done for diagnosis of these lesions. Surgical excision along with removal of causative irritants remains the treatment of choice. The extent of excision should depend on the severity of the lesion, as some of these lesions have a tendency for recurrence. All the patients in this series were closely followed up for a period of 2 years and showed no signs of recurrence.

  5. Relative trochanteric overgrowth after ischemic necrosis in congenital dislocation of the hip.

    Science.gov (United States)

    Iwersen, L J; Kalen, V; Eberle, C

    1989-01-01

    To determine the relative trochanteric overgrowth after ischemic necrosis of the femoral head during treatment of congenital dislocation of the hip (CDH), we reviewed radiographs of patients with ischemic necrosis and no femoral side surgery. The articulotrochanteric distance (ATD) was recorded after physeal closure. Ischemic necrosis was classified with the systems proposed by Salter et al. and Kalamchi and MacEwen. The resultant overgrowth was correlated with these systems. The articulotrochanteric distance in 29 patients with a Trendelenburg gait was also measured. The Kalamchi classification is more useful for predicting relative trochanteric overgrowth. Children with an ATD of less than or equal to 0 mm are likely to have a Trendelenburg gait.

  6. Assisted reproductive technology and congenital overgrowth: some speculations on a case of Pallister-Killian syndrome.

    Science.gov (United States)

    Chiurazzi, P; Bajer, J; Tabolacci, E; Pomponi, M G; Lecce, R; Zollino, M; Neri, G

    2004-10-15

    We report on a boy with Pallister-Killian syndrome (PKS) who was conceived by assisted reproductive technology (ART), specifically in vitro fertilization (IVF) with parents' gametes. A prenatal diagnosis performed elsewhere by CVS failed to detect the presence of the isochromosome 12p that was demonstrated postnatally in approximately 50% of cultured skin fibroblasts. Given that the patient did not show the congenital overgrowth typical of PKS, we speculate that ART might have restricted overgrowth in this particular case. More broadly, we hypothesize that overgrowth might protect from early demise fetuses conceived by ART, a technology known to cause low and very low birth weight.

  7. The dynamics of biofilm overgrowth of Enterococcus faecalis

    Directory of Open Access Journals (Sweden)

    E. A. Synetar

    2015-08-01

    Full Text Available The nature of microorganisms can exist in two physiological forms that allow microbes to preserve livelihoods and continue their life cycle. The first is the population of planktonic forms of microorganisms which live freely in the environment with the developed systems of active and passive mobility, contributing to the rapid spread of a liquid medium. The second forms are those expressing specific mechanisms of adhesion, and able to aggregate on biogenic and abiogenic surfaces. Even in the deep sea vast number of species of bacteria live in their inherent horizons. Thus, the study of biofilms tube life support systems, diagnostic, laparoscopic devices during prolonged catheterization of the urinary system is of great practical, theoretical and biological significance in medicine and biology. For almost 20% of catheter-associated infections antibiotic therapy is uneffective, particularly through the formation of microbial biofilms on the surface of urinary catheters. We characterized the dynamics of biofilm growth of Enterococcus faecalis on fragments ofsilicone catheter. The study was conducted using bacteriological and electron microscopic techniques. Study of the dynamics of biofilm formation was performed using E. faecalis strain 49, which is isolated from the urine of persons who are not the patients of the urological department of resuscitation and intensive therapy. Using scanning electron microscopy we have established dynamics and phase attachment ofE. faecalis bacteria and subsequent overgrowth of silicone catheter surface. Aftercalculations, index of adhesion on the turbulent wall amounted to 0,49 microbial cells. That is, every other cell of the monolayer adhered on the catheter. Area of biofilm growth of E. faecalis after 24 hour incubation was equal to 51.5 μm2, in 48 hours it increased to 231.5 μm2. After 72 hours of incubation we recorded the increase in biofilm growth of E. faecalisto 1922,8 μm2. The results were obtained

  8. Counteracting wetland overgrowth increases breeding and staging bird abundances

    Science.gov (United States)

    Lehikoinen, Petteri; Lehikoinen, Aleksi; Mikkola-Roos, Markku; Jaatinen, Kim

    2017-01-01

    Human actions have led to loss and degradation of wetlands, impairing their suitability as habitat especially for waterbirds. Such negative effects may be mitigated through habitat management. To date scientific evidence regarding the impacts of these actions remains scarce. We studied guild specific abundances of breeding and staging birds in response to habitat management on 15 Finnish wetlands. In this study management actions comprised several means of vegetation removal to thwart overgrowth. Management cost efficiency was assessed by examining the association between site-specific costs and bird abundances. Several bird guilds exhibited positive connections with both habitat management as well as with invested funds. Most importantly, however, red-listed species and species with special conservation concern as outlined by the EU showed positive correlations with management actions, underlining the conservation value of wetland management. The results suggest that grazing was especially efficient in restoring overgrown wetlands. As a whole this study makes it clear that wetland habitat management constitutes a feasible conservation tool. The marked association between invested funds and bird abundance may prove to be a valuable tool for decision makers when balancing costs and impact of conservation measures against one another.

  9. Counteracting wetland overgrowth increases breeding and staging bird abundances

    Science.gov (United States)

    Lehikoinen, Petteri; Lehikoinen, Aleksi; Mikkola-Roos, Markku; Jaatinen, Kim

    2017-01-01

    Human actions have led to loss and degradation of wetlands, impairing their suitability as habitat especially for waterbirds. Such negative effects may be mitigated through habitat management. To date scientific evidence regarding the impacts of these actions remains scarce. We studied guild specific abundances of breeding and staging birds in response to habitat management on 15 Finnish wetlands. In this study management actions comprised several means of vegetation removal to thwart overgrowth. Management cost efficiency was assessed by examining the association between site-specific costs and bird abundances. Several bird guilds exhibited positive connections with both habitat management as well as with invested funds. Most importantly, however, red-listed species and species with special conservation concern as outlined by the EU showed positive correlations with management actions, underlining the conservation value of wetland management. The results suggest that grazing was especially efficient in restoring overgrown wetlands. As a whole this study makes it clear that wetland habitat management constitutes a feasible conservation tool. The marked association between invested funds and bird abundance may prove to be a valuable tool for decision makers when balancing costs and impact of conservation measures against one another. PMID:28128327

  10. [Diagnosis of bacterial vaginosis].

    Science.gov (United States)

    Djukić, Slobodanka; Ćirković, Ivana; Arsić, Biljana; Garalejić, Eliana

    2013-01-01

    Bacterial vaginosis is a common, complex clinical syndrome characterized by alterations in the normal vaginal flora. When symptomatic, it is associated with a malodorous vaginal discharge and on occasion vaginal burning or itching. Under normal conditions, lactobacilli constitute 95% of the bacteria in the vagina. Bacterial vaginosis is associated with severe reduction or absence of the normal H2O2-producing lactobacilli and overgrowth of anaerobic bacteria and Gardnerella vaginalis, Atopobium vaginae, Mycoplasma hominis and Mobiluncus species. Most types of infectious disease are diagnosed by culture, by isolating an antigen or RNA/DNA from the microbe, or by serodiagnosis to determine the presence of antibodies to the microbe. Therefore, demonstration of the presence of an infectious agent is often a necessary criterion for the diagnosis of the disease. This is not the case for bacterial vaginosis, since the ultimate cause of the disease is not yet known. There are a variety of methods for the diagnosis of bacterial vaginosis but no method can at present be regarded as the best. Diagnosing bacterial vaginosis has long been based on the clinical criteria of Amsel, whereby three of four defined criteria must be satisfied. Nugent's scoring system has been further developed and includes validation of the categories of observable bacteria structures. Up-to-date molecular tests are introduced, and better understanding of vaginal microbiome, a clear definition for bacterial vaginosis, and short-term and long-term fluctuations in vaginal microflora will help to better define molecular tests within the broader clinical context.

  11. Drug-Induced Gingival Overgrowth: The Genetic Dimension

    Science.gov (United States)

    Charles, Noronha Shyam Curtis; Chavan, Rahul; Moon, Ninad Joshirao; Nalla, Srinivas; Mali, Jaydeepchandra; Prajapati, Anchal

    2014-01-01

    Background: Currently, the etiology of drug-induced gingival overgrowth is not entirely understood but is clearly multifactorial. Phenytoin, one of the common drugs implicated in gingival enlargement, is metabolized mainly by cytochrome P450 (CYP)2C9 and partly by CYP2C19. The CYP2C9 and CYP2C19 genes are polymorphically expressed and most of the variants result in decreased metabolism of the respective substrates. Aims: The present study was undertaken to investigate the influence of the CYP2C9*2 and *3 variant genotypes on phenytoin hydroxylation in subjects diagnosed with epilepsy from South India, thus establishing the genetic polymorphisms leading to its defective hydroxylation process. Materials and Methods: Fifteen epileptic subjects, age 9 to 60 years were included in the study. Among the study subjects, 8 were males and 7 were females. Genomic DNA was extracted from patients’ blood using Phenol-chloroform method and genotyping was done for CYP2C9 using customized TaqMan genotyping assays on a real time thermocycler, by allelic discrimination method. The genetic polymorphisms *1, *2 and *3 on CYP2C9 were selected based on their function and respective allele frequencies in Asian subcontinent among the Asian populations. Results: CYP2C9*1*2 and CYP2C9*3/*3 were identified with equal frequency in the study population. There were seven subjects with CYP2C9*1/*2 genotype (heterozygous mutant), one subject with CYP2C9*1/*1 (wild type) and seven study subjects with CYP2C9*3/*3 (homozygous mutant). Conclusion: The results obtained in the present study will be helpful in the medical prescription purposes of phenytoin, and a more personalized patient approach with its administration can be advocated. PMID:25317394

  12. ICC density predicts bacterial overgrowth in a rat model of post-infectious IBS

    Institute of Scientific and Technical Information of China (English)

    Sam-Ryong; Jee; Walter; Morales; Kimberly; Low; Christopher; Chang; Amy; Zhu; Venkata; Pokkunuri; Soumya; Chatterjee; Edy; Soffer; Jeffrey; L; Conklin; Mark; Pimentel

    2010-01-01

    AIM:To investigate the interstitial cells of Cajal(ICC) number using a new rat model.METHODS:Sprague-Dawley rats were assigned to two groups.The first group received gavage with Campylobacter jejuni(C.jejuni) 81-176.The second group was gavaged with placebo.Three months after clearance of Campylobacter from the stool,precise segments of duodenum,jejunum,and ileum were ligated in self-contained loops of bowel that were preserved in anaerobic bags.Deep muscular plexus ICC(DMP-ICC) were quantified by two blind...

  13. Testing Brain Overgrowth and Synaptic Models of Autism Using NPCs and Neurons From Patient Derived iPS Cells

    Science.gov (United States)

    2015-12-01

    AWARD NUMBER: W81XWH-13-1-0414 TITLE: Testing Brain Overgrowth and Synaptic Models of Autism Using NPCs and Neurons From Patient-Derived iPS...3. DATES COVERED 15 Sep 2013 - 14 Sep 2015 4. TITLE AND SUBTITLE Testing Brain Overgrowth and Synaptic Models of Autism Using NPCs and Neurons From...progenitors (NPCs) and neurons to study cellular phenotypes that directly test whether brain overgrowth and/or synaptogenesis mechanisms are found in

  14. Testing Brain Overgrowth and Synaptic Models of Autism Using NPCs and Neurons from Patient-Derived IPS Cells

    Science.gov (United States)

    2015-12-01

    Award Number: W81XWH-13-1-0415 TITLE: Testing Brain Overgrowth and Synaptic Models of Autism Using NPC’s and Neurons from Patient-Derived IPS... neurons to study cellular phenotypes that directly test whether brain overgrowth and/or synaptogenesis mechanisms are found in ASD NPCs and neurons ... Brain Overgrowth and Synaptic Models of Autism Using NPC’s and Neurons from Patient-Derived IPS Cells Table of Contents Page Introduction

  15. Segmental overgrowth syndrome due to an activating PIK3CA mutation identified in affected muscle tissue by exome sequencing

    DEFF Research Database (Denmark)

    Rasmussen, Maria; Sunde, Lone; Weigert, Karen Petra;

    2014-01-01

    Mosaic PIK3CA-mutations have been described in an increasing number of overgrowth syndromes. We describe a patient with a previously unreported segmental overgrowth syndrome with the mutation, PIKCA3 c.3140A>G (p.His1047Arg) in affected tissue diagnosed by exome sequencing. This PIK3CA-associated......-associated segmental overgrowth syndrome overlaps with CLOVES syndrome and fibroadipose hyperplasia but is distinct from each of these entities....

  16. Mutation analysis of the NSD1 gene in a group of 59 patients with congenital overgrowth.

    Science.gov (United States)

    Cecconi, M; Forzano, F; Milani, D; Cavani, S; Baldo, C; Selicorni, A; Pantaleoni, C; Silengo, M; Ferrero, G B; Scarano, G; Della Monica, M; Fischetto, R; Grammatico, P; Majore, S; Zampino, G; Memo, L; Cordisco, E Lucci; Neri, G; Pierluigi, M; Bricarelli, F Dagna; Grasso, M; Faravelli, Francesca

    2005-04-30

    Sotos syndrome is characterized by pre- and post-natal overgrowth, typical craniofacial features, advanced bone age, and developmental delay. Some degree of phenotypic overlap exists with other overgrowth syndromes, in particular with Weaver syndrome. Sotos syndrome is caused by haploinsufficiency of the NSD1 (nuclear receptor SET domain containing gene 1) gene. Microdeletions involving the gene are the major cause of the syndrome in Japanese patients, whereas intragenic mutations are more frequent in non-Japanese patients. NSD1 aberrations have also been described in some patients diagnosed as Weaver syndrome. Some authors have suggested a certain degree of genotype-phenotype correlation, with a milder degree of overgrowth, a more severe mental retardation, and a higher frequency of congenital anomalies in microdeleted patients. Data on larger series are needed to confirm this suggestion. We report here on microdeletion and mutation analysis of NSD1 in 59 patients with congenital overgrowth. Fourteen novel mutations, two previously described and one microdeletion were identified. All patients with a NSD1 mutation had been clinically classified as "classical Sotos," although their phenotype analysis demonstrated that some major criteria, such as overgrowth and macrocephaly, could be absent. All patients with confirmed mutations shared the typical Sotos facial gestalt. A high frequency of congenital heart defects was present in patients with intragenic mutations, supporting the relevance of the NSD1 gene in the pathogenesis of this particular defect.

  17. Combined treatment approach of gingivectomy and CO2 laser for cyclosporine-induced gingival overgrowth.

    Science.gov (United States)

    Haytac, Cenk M; Ustun, Yakup; Essen, Emin; Ozcelik, Onur

    2007-01-01

    The aim of this report is to present a combined treatment approach with gingivectomy and CO2 laser for the management of cyclosporine-induced gingival overgrowth in 4 cases. Four renal transplant patients were surgically treated for marked gingival overgrowth by means of gingivectomy and CO2 laser. Postoperatively, all patients were followed for bleeding, pain, infection during the early healing period, and recurrence of gingival overgrowth for 12 months. The healing was uneventful, and no signs of bleeding, postoperative pain, or infection were observed in any patient during the early healing period. In the 12th postoperative month, there was evidence of mild recurrence in 1 patient, while no sign of recurrence was observed in the other patients during the follow-up period. The advantages of this combined technique include satisfactory bleeding control and clear visibility during the procedure, as well as reduced postoperative pain and swelling.

  18. [Overgrowth and DNA synthesis of neuroepithelium in embryonic stages of induced Long-Evans rat myeloschisis].

    Science.gov (United States)

    Chono, Y

    1993-01-01

    Overgrowth of the myeloschisis, namely the excessive amount of the neural plate tissue, has been reported in the human myeloschisis. However, it is still debatable how the overgrowth develops and whether the overgrowth is the cause, or the secondary effect of spinal dysraphism. The author induced myeloschisis in the fetuses of Long-Evans rats by the administration of ethylenethiourea (ETU) to pregnant rats on day 10 of gestation. The fetuses were removed 1 hour after the treatment with bromodeoxyuridine (BrdU) to the dams on day 14 and 21. The fetuses were fixed in alcohol and embedded in paraffin. H-E staining and the immunohistologic examination were performed on the staining patterns to anti-neurofilament (NFP), anti-glial fibrillary acidic protein (GFAP) and anti-BrdU antibody by ABC method. On day 14, the lateral portion of everted neural plate showed a loose arrangement of cells and there was rosette formation in the mesoderm. On day 21, cell necrosis was observed at the dorsolateral portion of myeloschisis, although the ventral portion showed almost normal cytoarchitecture and was positive to NFP and GFAP. The cause of myeloschisis in this model is supposed to be the local and direct cytotoxic effect of ETU to neuro-ectodermal junction. On day 14, control animals contained few BrdU-incorporated cells at the basal plate of neural tube. In contrast, everted neural plate showed an active uptake of BrdU diffusely in the subependymal matrix layer cells. Overgrowth was not yet identified. On day 21, overgrowth of myeloschisis was found in spite of a few positive cells to BrdU which was identical to the control animals. These findings seem to suggest that cells in the myeloschisis retain their ability of DNA synthesis for longer periods of development and overgrowth found on day 21 is possibly a secondary effect of spinal dysraphism in this model.

  19. Using saliva nitrite and nitrate levels as a biomarker for drug induced gingival overgrowth

    Directory of Open Access Journals (Sweden)

    Erkan eSukuroglu

    2015-12-01

    Full Text Available Aim: Drug-induced gingival overgrowth has a multifactorial nature and the pathogenesis is still uncertain. It has been suggested that Nitric Oxide (NO might play a role in the pathogenesis of drug-induced gingival overgrowth due to the contribution of NO to immune response and matrix degradation. NO levels in biological fluids have been used as a diagnostic biomarker in many diseases. The aim of this study is to determine whether NO levels in plasma, saliva and gingival crevicular fluid (GCF can serve as a potential biomarker for the evaluation of drug-induced gingival overgrowth risk. Material and Methods: A total of 104 patients, receiving cyclosporine A (n=35, phenytoin (n=25, nifedipine (n=26 or diltiazem (n=18 participated in the study. The amount of gingival overgrowth was evaluated with two indices and was given as percentage. Periodontal clinical parameters including plaque index (PI, gingival index (GI, gingival bleeding time index (GBTI and probing depth (PD were also assessed. Saliva, GCF and plasma samples were obtained from each participants. Nitrite and nitrate levels in saliva, GCF and plasma were analyzed by Griess reagent. Results: Salivary nitrite and nitrate levels in responders were significantly higher than those in non-responders in only phenytoin group (p˂0.05. Nitrite and nitrate levels of gingival crevicular fluid and plasma did not significantly differ between responders and non-responders in all study groups (p˃0.05. Salivary nitrite levels exhibited a significant correlation with PD, GBTI, severity of gingival overgrowth (%GO and GCF volume (p˂0.05. Additionally, a strong positive correlation was detected between saliva and plasma nitrate levels (p˂0.005. However, both nitrite and nitrate levels in GCF and plasma demonstrated no significant correlation with clinical parameters, GO severity and GCF volume (p˃0.05.Conclusion: Salivary nitrite and nitrate levels could be used as periodontal disease biomarkers in

  20. Mutations in the DNA methyltransferase gene DNMT3A cause an overgrowth syndrome with intellectual disability

    DEFF Research Database (Denmark)

    Tatton-Brown, Katrina; Seal, Sheila; Ruark, Elise

    2014-01-01

    Overgrowth disorders are a heterogeneous group of conditions characterized by increased growth parameters and other variable clinical features such as intellectual disability and facial dysmorphism. To identify new causes of human overgrowth, we performed exome sequencing in ten proband...... and histone binding. Similar mutations were not present in 1,000 UK population controls (13/152 cases versus 0/1,000 controls; P ... methylation during embryogenesis and is commonly somatically mutated in acute myeloid leukemia. Thus, DNMT3A joins an emerging group of epigenetic DNA- and histone-modifying genes associated with both developmental growth disorders and hematological malignancies....

  1. GENERAL OVERGROWTH IN THE FRAGILE-X SYNDROME - VARIABILITY IN THE PHENOTYPIC-EXPRESSION OF THE FMR1 GENE MUTATION

    NARCIS (Netherlands)

    DEVRIES, BBA; ROBINSON, H; STOLTEDIJKSTRA, [No Value; GI, CVTP; DIJKSTRA, PF; VANDOOM, J; HALLEY, DJJ; OOSTRA, BA; TURNER, G; NIERMEIJER, MF

    1995-01-01

    The fragile X syndrome, which often presents in childhood with overgrowth, may in some cases show some diagnostic overlap with classical Sotos syndrome. We describe four fragile X patients with general overgrowth, all of whom are from families with other affected relatives who show the classic Marti

  2. Surgical treatment of gingival overgrowth with 10 years of follow-up

    Directory of Open Access Journals (Sweden)

    Ballini Andrea

    2010-08-01

    Full Text Available Abstract Background In some pathological conditions, gingivitis caused by plaque accumulation can be more severe, with the result of an overgrowth. Nevertheless, the overgrowth involves the gingival margin with extension to the inter-dental papilla. The lesion may involve the inter-proximal spaces, and become so extensive that the teeth are displaced and their crowns covered. Severe overgrowth may lead to impairment in aesthetic and masticatory functions, requiring surgical excision of the excessive tissue. Aim of this study is to describe an operative protocol for the surgical treatment of localized gingival overgrowth analyzing the surgical technique, times and follow-up. Methods A total of 20 patients were enrolled and underwent initial, non surgical, periodontal treatment and training sessions on home oral hygiene training. The treatment plan involved radical exeresis of the mass followed by positioning of an autograft of connective tissue and keratinized gingiva. Results During 10 years of follow-up, all the grafts appeared well vascularized, aesthetically satisfactory, and without relapse. Conclusions Periodontal examinations, surgical procedures, and dental hygiene with follow-up are an essential part of the treatment protocol. However, additional effort is needed from the patient. Hopefully, the final treatment result makes it all worthwhile.

  3. Use of an electrosurgical scalpel in gingival overgrowth associated with Rendu-Osler-Weber syndrome.

    Science.gov (United States)

    Lozano, Francisco Javier Rodríguez; Pérez, A Sanchez; Villaescusa, M J Moya

    2008-11-01

    We present a case of gingival overgrowth, with aesthetic repercussions, associated with Rendu-Osler-Weber syndrome. Treatment consisted of electric gingivectomy. We noted that it is necessary to carefully monitor hemorrhaging during surgery as well as to provide a correct differential diagnosis to distinguish this syndrome from other illnesses that involve gingival growth.

  4. Surgical management of gingival overgrowth associated with Cowden sydrome: a case report and current understanding.

    Science.gov (United States)

    Feitosa, Daniela da Silva; Santamaria, Mauro Pedrine; Casati, Márcio Zaffalon; Sallum, Enilson Antonio; Nociti Júnior, Francisco Humberto; de Toledo, Sérgio

    2011-05-01

    Cowden syndrome, also known as multiple hamartoma syndrome, is a rare autosomal dominant disorder characterized by multiple hamartomas and a high risk of development of malignancy. Oral findings, such as papillomatous lesions and fibromas, are common features; however, a periodontal phenotype has not been reported previously. Therefore, this report presents a case of gingival overgrowth associated with Cowden syndrome, its successful surgical management, and the 12-month follow-up results. Additionally, we discuss the implications for clinicians. A 23-year-old woman was referred to the Department of Periodontics, Piracicaba Dental School, presenting with generalized gingival overgrowth. A detailed dental and medical history and clinical examination confirmed the systemic diagnosis of Cowden syndrome. Histology, radiographs, and clinical data document the entire clinical approach and follow-up. Clinically, there were minor signs of recurrence of gingival overgrowth in a 12-month period after gingivectomy; however, papular lesions reappeared in keratinized gingiva immediately after healing. No signs of bone loss related to the systemic condition were observed radiographically. Histologically, a dense connective tissue with a moderate chronic inflammatory infiltrate and epithelial acanthosis, which is characteristic of gingival hyperplasia, were demonstrated. Gingival overgrowth may occur as an oral phenotype related to Cowden syndrome and can be successfully treated by means of external bevel gingivectomy, followed by regular maintenance therapy, contributing to the patient's well-being, both functionally and esthetically.

  5. An unusual case report of gingival overgrowth associated with the use of leflunomide.

    Science.gov (United States)

    Yavuz, F; Guzelkucuk, U

    2016-01-01

    Leflunomide is an immunomodulatory agent with antiproliferative activity that is used for the treatment of rheumatoid arthritis. Leflunomide induced side effects are hepatotoxicity, immunosuppression, skin reactions, peripheral neuropathy, hypertension, diarrhea, interstitial lung disease, and rarely oral mucosal lesions. Here, we presented an unusual case of gingival overgrowth associated with the use of leflunomide, which improved after ceasing the drug.

  6. An unusual case report of gingival overgrowth associated with the use of leflunomide

    Directory of Open Access Journals (Sweden)

    Ferdi Yavuz

    2016-04-01

    Full Text Available Leflunomide is an immunomodulatory agent with antiproliferative activity that is used for the treatment of rheumatoid arthritis. Leflunomide induced side effects are hepatotoxicity, immunosuppression, skin reactions, peripheral neuropathy, hypertension, diarrhea, interstitial lung disease, and rarely oral mucosal lesions. Here, we presented an unusual case of gingival overgrowth associated with the use of leflunomide, which improved after ceasing the drug.

  7. An unusual case report of gingival overgrowth associated with the use of leflunomide

    OpenAIRE

    Ferdi Yavuz; Umit Guzelkucuk

    2016-01-01

    Leflunomide is an immunomodulatory agent with antiproliferative activity that is used for the treatment of rheumatoid arthritis. Leflunomide induced side effects are hepatotoxicity, immunosuppression, skin reactions, peripheral neuropathy, hypertension, diarrhea, interstitial lung disease, and rarely oral mucosal lesions. Here, we presented an unusual case of gingival overgrowth associated with the use of leflunomide, which improved after ceasing the drug.

  8. Mactosylceramide Prevents Glial Cell Overgrowth by Inhibiting Insulin and Fibroblast Growth Factor Receptor Signaling

    DEFF Research Database (Denmark)

    Gerdøe-Kristensen, Stine; Lund, Viktor K; Wandall, Hans H

    2017-01-01

    , in which the mannosyltransferase Egghead controls conversion of glucosylceramide (GlcCer) to mactosylceramide (MacCer). Lack of elongated GSL in egghead (egh) mutants causes overgrowth of subperineurial glia (SPG), largely due to aberrant activation of phosphatidylinositol 3-kinase (PI3K). However, to what...... extent this effect involves changes in upstream signaling events is unresolved. We show here that glial overgrowth in egh is strongly linked to increased activation of Insulin and Fibroblast Growth Factor receptors (FGFR). Glial hypertrophy is phenocopied when overexpressing gain-of-function mutants...... hyperactivation is caused by absence of MacCer and not by GlcCer accumulation. We conclude that an early product in GSL biosynthesis, MacCer, prevents inappropriate activation of Insulin and Fibroblast Growth Factor Receptors in Drosophila glia. This article is protected by copyright. All rights reserved....

  9. Metal dendrimers: synthesis of hierarchically stellated nanocrystals by sequential seed-directed overgrowth.

    Science.gov (United States)

    Weiner, Rebecca G; Skrabalak, Sara E

    2015-01-19

    Hierarchically organized structures are prevalent in nature, where such features account for the adhesion properties of gecko feet and the brilliant color variation of butterfly wings. Achieving artificial structures with multiscale features is of interest for metamaterials and biomimetic applications. However, the fabrication of such structures relies heavily on lithographic approaches, although self-assembly routes to superstructures are promising. Sequential seed-directed overgrowth is now demonstrated as a route to metal dendrimers, which are hierarchically branched nanocrystals (NCs) with a three-dimensional order analogous to that of molecular dendrimers. This method was applied to a model Au/Pd NC system; in general, the principle of sequential seed-directed overgrowth should enable the synthesis of new hierarchical inorganic structures with high symmetry.

  10. A novel aromatic oil compound inhibits microbial overgrowth on feet: a case study

    OpenAIRE

    Misner Bill D

    2007-01-01

    Abstract Background Athlete's Foot (Tinea pedis) is a form of ringworm associated with highly contagious yeast-fungi colonies, although they look like bacteria. Foot bacteria overgrowth produces a harmless pungent odor, however, uncontrolled proliferation of yeast-fungi produces small vesicles, fissures, scaling, and maceration with eroded areas between the toes and the plantar surface of the foot, resulting in intense itching, blisters, and cracking. Painful microbial foot infection may prev...

  11. Is periodontal health a predictor of drug-induced gingival overgrowth? A cross-sectional study

    Directory of Open Access Journals (Sweden)

    Ruchi Banthia

    2014-01-01

    Full Text Available Background: Gingival overgrowth is a common side-effect of amlodipine regimen on the oral cavity. There is controversy regarding the cause and effect relationship of periodontal health and drug induced gingival overgrowth. Therefore, this study was conducted to investigate and to assess the relationship between the periodontal health and the onset and severity of gingival overgrowth in hypertensive patients receiving amlodipine. Materials and Methods: A total of 99 known hypertensive patients on amlodipine regimen were included in this study. Probing pocket depth (PPD and clinical attachment loss (CAL were noted on four sites of maxillary and mandibular anterior teeth. Gingival enlargement scores were assessed for each patient by employing the hyperplastic index. Oral hygiene status was evaluated using the calculus index (CI. Patients were divided into H, E and L groups based on their periodontal status and responders and non-responders based on their hyperplastic index scores. Differences in means of different periodontal variables in different groups were tested for significance by using ANOVA and unpaired Student t-test. Pearson′s correlation coefficient was calculated to assess the correlation between different variables. For all analyses, P < 0.05 was considered to be significant. Results: All the periodontal parameters were statistically highly significant (P = 0.00 amongst H, E and L groups and between responders and non-responders. Statistically highly significant Pearson correlation coefficients were found between mean PPD and mean hyperplastic score, mean CAL and mean hyperplastic score and mean calculus and mean hyperplastic score. Conclusion: The results of this study indicated a definite association between periodontal health and development and severity of amlodipine-induced gingival overgrowth

  12. Is periodontal health a predictor of drug-induced gingival overgrowth? A cross-sectional study

    Science.gov (United States)

    Banthia, Ruchi; Gupta, Santosh; Banthia, Priyank; Singh, Pallavi; Raje, Sapna; Kaur, Navkiran

    2014-01-01

    Background: Gingival overgrowth is a common side-effect of amlodipine regimen on the oral cavity. There is controversy regarding the cause and effect relationship of periodontal health and drug induced gingival overgrowth. Therefore, this study was conducted to investigate and to assess the relationship between the periodontal health and the onset and severity of gingival overgrowth in hypertensive patients receiving amlodipine. Materials and Methods: A total of 99 known hypertensive patients on amlodipine regimen were included in this study. Probing pocket depth (PPD) and clinical attachment loss (CAL) were noted on four sites of maxillary and mandibular anterior teeth. Gingival enlargement scores were assessed for each patient by employing the hyperplastic index. Oral hygiene status was evaluated using the calculus index (CI). Patients were divided into H, E and L groups based on their periodontal status and responders and non-responders based on their hyperplastic index scores. Differences in means of different periodontal variables in different groups were tested for significance by using ANOVA and unpaired Student t-test. Pearson's correlation coefficient was calculated to assess the correlation between different variables. For all analyses, P < 0.05 was considered to be significant. Results: All the periodontal parameters were statistically highly significant (P = 0.00) amongst H, E and L groups and between responders and non-responders. Statistically highly significant Pearson correlation coefficients were found between mean PPD and mean hyperplastic score, mean CAL and mean hyperplastic score and mean calculus and mean hyperplastic score. Conclusion: The results of this study indicated a definite association between periodontal health and development and severity of amlodipine-induced gingival overgrowth PMID:25426150

  13. Generalized dermatitis associated with Malassezia overgrowth in cats: A report of six cases in France.

    Science.gov (United States)

    Crosaz, Odile; Legras, Audrey; Vilaplana-Grosso, Federico; Debeaupuits, Julien; Chermette, René; Hubert, Blaise; Guillot, Jacques

    2013-02-13

    We recently observed six cases of generalized dermatitis associated with Malassezia overgrowth in cats presented to the Veterinary College of Alfort, France. Elevated numbers of yeasts were observed in lesional skin by cytology and culture. Skin lesions occurred on the face, ventral neck, abdomen and ear canals and were characterized by some degree of alopecia, erythema and crusting. In most cases, pruritus was intense. The species M. pachydermatis was systematically isolated.

  14. Immunoexpression of interleukin-6 in drug-induced gingival overgrowth patients

    Directory of Open Access Journals (Sweden)

    P R Ganesh

    2016-01-01

    Full Text Available Background: To analyze the role of proinflammatory cytokines in drug-induced gingival enlargement in Indian population. Aim: To evaluate for the presence of interleukin-6 (IL-6 in drug-induced gingival enlargement and to compare it with healthy control in the absence of enlargement. Materials and Methods: Thirty-five patients selected for the study and divided into control group (10 and study group (25 consisting of phenytoin (10; cyclosporin (10 and nifedipine (5 induced gingival enlargement. Gingival overgrowth index of Seymour was used to assess overgrowth and allot groups. Under LA, incisional biopsy done, tissue sample fixed in 10% formalin and immunohistochemically evaluated for the presence of IL-6 using LAB-SA method, Labeled- Streptavidin-Biotin Method (LAB-SA kit from Zymed- 2nd generation LAB-SA detection system, Zymed Laboratories, CA. The results of immunohistochemistry were statistically analyzed using Kruskaal–Wallis and Mann–Whitney test. Results: The data obtained from immunohistochemistry assessment shows that drug-induced gingival overgrowth (DIGO samples express more IL-6 than control group and cyclosporin expresses more IL-6 followed by phenytoin and nifedipine. Conclusion: Increased IL-6 expression was noticed in all three DIGO groups in comparison with control group. Among the study group, cyclosporin expressed maximum IL-6 expression followed by phenytoin and nifedipine.

  15. Stratigraphy of a diamond epitaxial three-dimensional overgrowth using doping superlattices

    Science.gov (United States)

    Lloret, F.; Fiori, A.; Araujo, D.; Eon, D.; Villar, M. P.; Bustarret, E.

    2016-05-01

    The selective doped overgrowth of 3D mesa patterns and trenches has become an essential fabrication step of advanced monolithic diamond-based power devices. The methodology here proposed combines the overgrowth of plasma-etched cylindrical mesa structures with the sequential growth of doping superlattices. The latter involve thin heavily boron doped epilayers separating thicker undoped epilayers in a periodic fashion. Besides the classical shape analysis under the scanning electron microscope relying on the appearance of facets corresponding to the main crystallographic directions and their evolution toward slow growing facets, the doping superlattices were used as markers in oriented cross-sectional lamellas prepared by focused ion beam and observed by transmission electron microscopy. This stratigraphic approach is shown here to be applicable to overgrown structures where faceting was not detectable. Intermediate growth directions were detected at different times of the growth process and the periodicity of the superlattice allowed to calculate the growth rates and parameters, providing an original insight into the planarization mechanism. Different configurations of the growth front were obtained for different sample orientations, illustrating the anisotropy of the 3D growth. Dislocations were also observed along the lateral growth fronts with two types of Burger vector: b 01 1 ¯ = /1 2 [ 01 1 ¯ ] and b 112 = /1 6 [ 112 ] . Moreover, the clustering of these extended defects in specific regions of the overgrowth prompted a proposal of two different dislocation generation mechanisms.

  16. Liver Cirrhosis and Intestinal Bacterial Translocation

    Institute of Scientific and Technical Information of China (English)

    2014-01-01

    Intestinal barrier dysfunction, facilitating translocation of bacteria and bacterial products, plays an important role in the pathophysiology of liver cirrhosis and its complications. Intestinal defense system including microbial barrier, immunologic barrier, mechanical barrier, chemical barrier, plays an important role in the maintenance of intestinal function. Under normal circumstances, the intestinal barrier can prevent intestinal bacteria through the intestinal wall from spreading to the body. Severe infection, trauma, shock, cirrhosis, malnutrition, immune suppression conditions, intestinal bacteria and endotoxin translocation, can lead to multiple organ dysfunction. The intestinal microlfora is not only involved in the digestion of nutrients, but also in local immunity, forming a barrier against pathogenic microorganisms. The derangement of the gut microlfora may lead to microbial translocation, deifned as the passage of viable microorganisms or bacterial products from the intestinal lumen to the mesenteric lymph nodes and other extraintestinal sites. In patients with cirrhosis, primary and intestinal lfora imbalance, intestinal bacterial overgrowth, intestinal mucosal barrier dysfunction, endotoxemia is associated with weakened immunity.

  17. Management of Gingival Overgrowth in a Cardiac Transplant Patient Using Laser-Assisted Gingivectomy/Gingivoplasty.

    Science.gov (United States)

    Maddi, Abhiram; Alluri, Leela Subhashini; Ciancio, Sebastian G

    2015-07-01

    Drug-induced gingival overgrowth (DIGO) is an oral clinical manifestation associated with certain medications such as immunosuppressants that are administered to organ transplant patients to prevent graft rejection. In patients with cardiac transplants, management of DIGO is critical. In such patients, plaque biofilm accumulation at the gingival interface might be detrimental as it may lead to transient bacteremia as well as systemic inflammation resulting in thromboembolic events. This case report describes the management of DIGO in a cardiac transplant recipient by change of immunosuppressant medication, non-surgical periodontal therapy and laser-assisted gingivectomy.

  18. Mechanism of drug-induced gingival overgrowth revisited: a unifying hypothesis

    Science.gov (United States)

    Brown, RS; Arany, PR

    2015-01-01

    Drug-induced gingival overgrowth (DIGO) is a disfiguring side effect of anti-convulsants, calcineurin inhibitors, and calcium channel blocking agents. A unifying hypothesis has been constructed which begins with cation flux inhibition induced by all three of these drug categories. Decreased cation influx of folic acid active transport within gingival fibroblasts leads to decreased cellular folate uptake, which in turn leads to changes in matrix metalloproteinases metabolism and the failure to activate collagenase. Decreased availability of activated collagenase results in decreased degradation of accumulated connective tissue which presents as DIGO. Studies supporting this hypothesis are discussed. PMID:24893951

  19. TGF-beta isoforms and TGF-beta receptors in drug-induced and hereditary gingival overgrowth.

    Science.gov (United States)

    Wright, H J; Chapple, I L; Matthews, J B

    2001-05-01

    Drug therapy and hereditary factors are two of the main causes of gingival overgrowth (GO). Both of these forms of GO are associated with increased extracellular matrix production by fibroblasts. Transforming growth factor beta (TGF-beta) is an important mediator of wound healing and tissue regeneration, which stimulates fibroblasts to produce extracellular matrix materials. The aim of this immunohistochemical study was to determine whether there is any altered expression of TGF-beta isoforms or its receptors in tissue from patients with drug-induced GO (DIGO; n=10) and hereditary gingival fibromatosis (n=10) when compared to non-overgrowth tissue (n=10). Compared to control tissues, significantly more fibroblasts expressed TGF-beta1 in both DIGO and hereditary gingival fibromatosis tissues (Pfibroblast densities between groups, there was a proportional increase in TGF-beta3 as well as TGF-beta1 expressing cells within both overgrowth populations (Preceptor-positive cells in the total cell population analysed in overgrowth tissues (Pisoform and receptor expression by fibroblasts in gingival overgrowth that may contribute to disease pathogenesis.

  20. Gut flora and bacterial translocation in chronic liver disease

    Institute of Scientific and Technical Information of China (English)

    John Almeida; Sumedha Galhenage; Jennifer Yu; Jelica Kurtovic; Stephen M Riordan

    2006-01-01

    Increasing evidence suggests that derangement of gut flora is of substantial clinical relevance to patients with cirrhosis. Intestinal bacterial overgrowth and increased bacterial translocation of gut flora from the intestinal lumen, in particular, predispose to an increased potential for bacterial infection in this group. Recent studies suggest that, in addition to their role in the pathogenesis of overt infective episodes and the clinical consequences of sepsis, gut flora contributes to the pro-inflammatory state of cirrhosis even in the absence of overt infection.Furthermore, manipulation of gut flora to augment the intestinal content of lactic acid-type bacteria at the expense of other gut flora species with more pathogenic potential may favourably influence liver function in cirrhotic patients. Here we review current concepts of the various inter-relationships between gut flora, bacterial translocation, bacterial infection, pro-inflammatory cytokine production and liver function in this group.

  1. Bacterial colonization and gut development in preterm neonates

    DEFF Research Database (Denmark)

    Cilieborg, Malene S.; Boye, Mette; Sangild, Per Torp

    2012-01-01

    colonization may provide the clue to prevent NEC, and studies in infants must be combined with animal models to understand the mechanisms of the microbiota–epithelium interactions. Analyses of infant fecal samples show that the density and distribution of bacterial species are highly variable...... with no consistent effects of gestational age, delivery mode, diet or probiotic administration, while low bacterial diversity and bacterial overgrowth are commonly associated with NEC. A series of recent studies in preterm pigs show that the mucosa-associated microbiota is affected by delivery method, prematurity......Necrotizing enterocolitis (NEC) develops in 5–10% of preterm infants in association with enteral feeding and bacterial colonization. It remains unclear how diet and bacteria interact to protect or provoke the immature gastrointestinal tract. Understanding the factors that control bacterial...

  2. Hypoxia-inducible factor-1a contributes to dendritic overgrowth in tuberous sclerosis.

    Science.gov (United States)

    Zhang, Longbo; Feliciano, David M; Huang, Tianxiang; Zhang, Shiliang; Bordey, Angélique

    2016-01-26

    Expression of hypoxia-inducible factor 1a (HIF1a) is increased under several pathological conditions such as hyperactive mechanistic target of rapamycin complex 1 (mTORC1) in tuberous sclerosis complex (TSC). Hyperactive mTORC1 and the resulting increased dendritic complexity of neurons are shared molecular and cellular alterations in several neurological disorders associated with cognitive disabilities. Despite some evidence that HIF1a contributes to dendritic overgrowth in vitro, it remains unknown whether increased HIF1a in TSC neurons could contribute to their increased dendritic complexity. To address this use in vivo, we generated TSC neurons by deleting Tsc1 in newborn olfactory bulb (OB) neurons of conditional Tsc1 transgenic mice using neonatal electroporation. In addition to their increased dendritic complexity, Tsc1(null) neurons have been reported to display increased Hif1a mRNA level and HIF1a transcriptional activity. We found that Tsc1(null)-dependent dendritic overgrowth was prevented by knocking down HIF1a or expressing a dominant negative HIF1a. In addition, overexpressing HIF1a in wild-type developing neurons resulted in increased dendritic complexity in vivo. These data highlight that an increase in HIF1a levels contributes to abnormal dendritic patterning in developing neurons under normal conditions and hyperactive mTORC1 conditions as in TSC.

  3. Chemical Evolution of Intercumulus Liquid, as Seen in Plagioclase Overgrowth Rims from the Skaergaard Intrusion

    Science.gov (United States)

    Humphreys, M. C.

    2008-12-01

    Closed-system solidification of a crystal mush will produce a cumulate rock with strongly zoned intercumulus minerals, as a result of continual thermal and compositional change in the residual liquid. The physical properties of the residual liquid (viscosity, density) also change, which may allow compositional convection or melt migration through the cumulate pile, depending on the porosity and permeability of the mush. However, for fully solidified cumulates, 'fossil' changes in liquid composition or porosity are difficult to identify. This study investigates the changing concentration of Ti in plagioclase overgrowths from the lower parts of the Skaergaard Intrusion. Ti concentrations in plagioclase reflect the changing Ti concentration of the residual liquid during solidification. The plagioclase overgrowths record Ti increasing in the liquid until local (intercumulus) saturation of Fe-Ti oxides, when Ti contents start to fall. Ti continues to fall in the residual liquid until the most evolved plagioclase compositions (An30), which form when only approximately 4 % porosity remains. Ti in clinopyroxene oikocrysts also falls rimward, but zoning in faster diffusing species (Fe, Mg) is not observed. These results are discussed in the context of the changing porosity and permeability during solidification.

  4. Phosphorus-rich olivine overgrowths: Evidence for additional impact to the Main Group pallasite parent body

    Science.gov (United States)

    Fowler-Gerace, Neva; Tait, Kimberly

    2015-04-01

    Phosphorus-rich olivine (1-7 wt% P2O5) is a metastable phase known from fewer than a dozen meteoritic or terrestrial occurrences. We have thoroughly examined P-rich olivine in the Springwater pallasite to characterise its distribution, textural relationships, and geochemical signature. P-rich olivine is abundant in Springwater as randomly distributed millimetre-scale partial overgrowths on the nominally P-free forsterite crystals. Geochemical analyses support the substitution mechanism of P into the tetrahedral Si site with octahedral site vacancies for charge balance; observed trace element variations, on the other hand, are not related to P substitution. Element mapping reveals fine-scale oscillatory P zoning in unusual serrate patterns, indicating rapid crystal nucleation from a melt and a subsequently variable rate of crystallisation. We constrain P-rich olivine formation in Springwater to at least 10-100 Myr subsequent to the introduction of the metal but before cooling below 700°C. Because the P-rich overgrowths overprint specific host grain boundary modifications, we suggest an impact to the Main Group pallasite parent body may have triggered the episode of extremely rapid cooling necessary to crystallise and preserve this rare phase.

  5. Fabrication of quantum wires by in-situ ion etching and MBE overgrowth

    Science.gov (United States)

    Heyn, Ch; Klein, C.; Kramp, S.; Beyer, S.; Günther, S.; Heitmann, D.; Hansen, W.

    2001-07-01

    We fabricate GaAs quantum wires (QW) that are completely embedded in epitaxial material. Here we report about an in-vacuo fabrication process, in which an ex-situ pre-patterned GaAlAs/GaAs heterostructure is in-situ etched and subsequently transferred under ultra high vacuum conditions into the growth chamber for epitaxial overgrowth. The in-situ etching step involves a chemical assisted ion beam etching with subsequent chemical gas etching. The aim of our investigations is to optimize the in-vacuo process for the reduction of interface states between the etched and overgrown material. We have studied structural properties of such processed samples with cross-sectional scanning-electron microscopy and transmission-electron microscopy. The optical and electronic properties of overgrown QW are investigated with magneto-transport measurements and far-infrared transmission spectroscopy. Overgrown QW show in comparison to conventional QW without overgrowth clearly increased carrier densities and a reduced depletion zone at the QW side-walls. These results indicate the successful reduction of surface states and establish the potential of the suggested in-situ technique for the fabrication of quantum structures.

  6. Transport, Growth Mechanisms, and Material Quality in GaN Epitaxial Lateral Overgrowth

    Energy Technology Data Exchange (ETDEWEB)

    Baca, Albert G.; Bartram, M.E.; Coltrin, M.E.; Crawford, M.H.; Han, J.; Missert, N.; Willan, C.C.

    1999-01-11

    Growth kinetics, mechanisms, and material quality in GaN epitaxial lateral over-growth (ELO) were examined using a single mask of systematically varied patterns. A 2-D gas phase reaction/diffusion model describes how transport of the Ga precursor to the growth surface enhances the lateral rate in the early stages of growth. In agreement with SEM studies of truncated growth runs, the model also predicts the dramatic decrease in the lateral rate that occurs as GaN over-growth reduces the exposed area of the mask. At the point of convergence, a step-flow coalescence mechanism is observed to fill in the area between lateral growth-fronts. This alternative growth mode in which a secondary growth of GaN is nucleated along a single convergence line, may be responsible for producing smooth films observed to have uniform cathodoluminescence (CL) when using 1{micro}m nucleation zones. Although emission is comprised of both UV ({approximately}365nm) and yellow ({approximately}550nm) components, the spectra suggest these films have reduced concentrations of threading dislocations normally associated with non-radiative recombination centers and defects known to accompany growth-front convergence lines.

  7. Maternal Inflammation Contributes to Brain Overgrowth and Autism-Associated Behaviors through Altered Redox Signaling in Stem and Progenitor Cells

    Directory of Open Access Journals (Sweden)

    Janel E. Le Belle

    2014-11-01

    Full Text Available A period of mild brain overgrowth with an unknown etiology has been identified as one of the most common phenotypes in autism. Here, we test the hypothesis that maternal inflammation during critical periods of embryonic development can cause brain overgrowth and autism-associated behaviors as a result of altered neural stem cell function. Pregnant mice treated with low-dose lipopolysaccharide at embryonic day 9 had offspring with brain overgrowth, with a more pronounced effect in PTEN heterozygotes. Exposure to maternal inflammation also enhanced NADPH oxidase (NOX-PI3K pathway signaling, stimulated the hyperproliferation of neural stem and progenitor cells, increased forebrain microglia, and produced abnormal autism-associated behaviors in affected pups. Our evidence supports the idea that a prenatal neuroinflammatory dysregulation in neural stem cell redox signaling can act in concert with underlying genetic susceptibilities to affect cellular responses to environmentally altered cellular levels of reactive oxygen species.

  8. Maternal inflammation contributes to brain overgrowth and autism-associated behaviors through altered redox signaling in stem and progenitor cells.

    Science.gov (United States)

    Le Belle, Janel E; Sperry, Jantzen; Ngo, Amy; Ghochani, Yasmin; Laks, Dan R; López-Aranda, Manuel; Silva, Alcino J; Kornblum, Harley I

    2014-11-11

    A period of mild brain overgrowth with an unknown etiology has been identified as one of the most common phenotypes in autism. Here, we test the hypothesis that maternal inflammation during critical periods of embryonic development can cause brain overgrowth and autism-associated behaviors as a result of altered neural stem cell function. Pregnant mice treated with low-dose lipopolysaccharide at embryonic day 9 had offspring with brain overgrowth, with a more pronounced effect in PTEN heterozygotes. Exposure to maternal inflammation also enhanced NADPH oxidase (NOX)-PI3K pathway signaling, stimulated the hyperproliferation of neural stem and progenitor cells, increased forebrain microglia, and produced abnormal autism-associated behaviors in affected pups. Our evidence supports the idea that a prenatal neuroinflammatory dysregulation in neural stem cell redox signaling can act in concert with underlying genetic susceptibilities to affect cellular responses to environmentally altered cellular levels of reactive oxygen species.

  9. The overgrowth of Listeria monocytogenes by other Listeria spp. in food samples undergoing enrichment cultivation has a nutritional basis.

    Science.gov (United States)

    Besse, Nathalie Gnanou; Barre, Lena; Buhariwalla, Colin; Vignaud, Marie Léone; Khamissi, Elissa; Decourseulles, Emilie; Nirsimloo, Marjorie; Chelly, Minyar; Kalmokoff, Martin

    2010-01-01

    The isolation of Listeria monocytogenes from food is carried out using a double enrichment. In cases where multiple Listeria species are present within the original sample, L. monocytogenes can be overgrown during enrichment by other species of listeria present in the original sample. From a practical perspective, this can result in a false negative or complicate the ability of public health investigators to match food and clinical isolates. We have further investigated this phenomenon by analysing the growth kinetics of single species and pairs of different species over the ISO 11290-1 enrichment process. The overgrowth of a strain of L. monocytogenes by a strain of Listeria innocua resulted primarily from interactions which occurred in late exponential phase, where it was observed that growth of both strains stopped when the dominant strain reached stationary phase. In a second mixed culture, the dominant L. monocytogenes strain suppressed the exponential growth rate of the second Listeria welshimeri strain. Both findings suggest that the overgrowth could partially be explained in terms of a nutritional competition. Multi-factor analysis of Fraser broth constituents and growth temperatures using both stressed and non-stressed inoculants failed to identify any single factor in the ISO 11290-1 methodology which would contribute to the overgrowth phenomenon in our model system. Furthermore, species was not a significant factor in observed differences in growth parameters among a wider array of strains which had been stressed or not stressed prior to grown in Fraser broths, even though some strains had significantly faster growth rates than others. Limiting diffusion in Fraser broth through the addition of agar significantly reduced the extent of the overgrowth in experiments using mixtures of strains originally isolated from foods where overgrowth had been previously observed. Taken together, these findings support that the overgrowth phenomenon in most instances

  10. A novel aromatic oil compound inhibits microbial overgrowth on feet: a case study

    Directory of Open Access Journals (Sweden)

    Misner Bill D

    2007-07-01

    Full Text Available Abstract Background Athlete's Foot (Tinea pedis is a form of ringworm associated with highly contagious yeast-fungi colonies, although they look like bacteria. Foot bacteria overgrowth produces a harmless pungent odor, however, uncontrolled proliferation of yeast-fungi produces small vesicles, fissures, scaling, and maceration with eroded areas between the toes and the plantar surface of the foot, resulting in intense itching, blisters, and cracking. Painful microbial foot infection may prevent athletic participation. Keeping the feet clean and dry with the toenails trimmed reduces the incidence of skin disease of the feet. Wearing sandals in locker and shower rooms prevents intimate contact with the infecting organisms and alleviates most foot-sensitive infections. Enclosing feet in socks and shoes generates a moisture-rich environment that stimulates overgrowth of pungent both aerobic bacteria and infectious yeast-fungi. Suppression of microbial growth may be accomplished by exposing the feet to air to enhance evaporation to reduce moistures' growth-stimulating effect and is often neglected. There is an association between yeast-fungi overgrowths and disabling foot infections. Potent agents virtually exterminate some microbial growth, but the inevitable presence of infection under the nails predicts future infection. Topical antibiotics present a potent approach with the ideal agent being one that removes moisture producing antibacterial-antifungal activity. Severe infection may require costly prescription drugs, salves, and repeated treatment. Methods A 63-y female volunteered to enclose feet in shoes and socks for 48 hours. Aerobic bacteria and yeast-fungi counts were determined by swab sample incubation technique (1 after 48-hours feet enclosure, (2 after washing feet, and (3 after 8-hours socks-shoes exposure to a aromatic oil powder-compound consisting of arrowroot, baking soda, basil oil, tea tree oil, sage oil, and clove oil. Conclusion

  11. Plasma membrane overgrowth causes fibrotic collagen accumulation and immune activation in Drosophila adipocytes

    Science.gov (United States)

    Zang, Yiran; Wan, Ming; Liu, Min; Ke, Hongmei; Ma, Shuangchun; Liu, Lu-Ping; Ni, Jian-Quan; Carlos Pastor-Pareja, José

    2015-01-01

    Many chronic diseases are associated with fibrotic deposition of Collagen and other matrix proteins. Little is known about the factors that determine preferential onset of fibrosis in particular tissues. Here we show that plasma membrane (PM) overgrowth causes pericellular Collagen accumulation in Drosophila adipocytes. We found that loss of Dynamin and other endocytic components causes pericellular trapping of outgoing Collagen IV due to dramatic cortex expansion when endocytic removal of PM is prevented. Deposits also form in the absence of negative Toll immune regulator Cactus, excess PM being caused in this case by increased secretion. Finally, we show that trimeric Collagen accumulation, downstream of Toll or endocytic defects, activates a tissue damage response. Our work indicates that traffic imbalances and PM topology may contribute to fibrosis. It also places fibrotic deposits both downstream and upstream of immune signaling, consistent with the chronic character of fibrotic diseases. DOI: http://dx.doi.org/10.7554/eLife.07187.001 PMID:26090908

  12. Mullerian adenosarcoma (heterologous) of the cervix with sarcomatous overgrowth: a case report with review of literature

    Science.gov (United States)

    Nijhawan, Raje; Aggarwal, Neelam; Sikka, Pooja

    2010-01-01

    Mullerian adenosarcoma is a rare biphasic malignant neoplasm of the cervix characterized by an admixture of benign epithelial elements and a malignant sarcomatous stromal component, which may be either homologous or heterologous. An aggressive variant of adenosarcoma, mullerian adenosarcoma with sarcomatous overgrowth (MASO) is extremely rare, with only two such cases being reported in the English literature to date. In this report we present a case of MASO of uterine cervix with heterologous elements in a 15-year-old unmarried girl presenting with foul smelling menstrual bleeding and passage of fleshy masses. Because MASO with heterologous elements seems to appear at the earliest stages of reproductive lifespan in women, and have an uncertain malignant potential, gynecologists and pathologists should be aware and think about the possibility of this tumor. PMID:20613904

  13. AMLODIPIN-INDUCED GINGIVAL OVERGROWTH AND APPLICATION OF ER:YAG LASER IN THE TREATMENT PROTOCOL.

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    Elena I. Firkova

    2013-05-01

    Full Text Available Gingival overgrowth (GO is one of the most important clinical features of gingival pathology. Amlodipine is a comparatively new III generation calcium channels blocker, used for management of cardiovascular disorders. Although it is considered safe, it can also rarely induce GO. A case of severe amlodipine-induced GO, complicated by inflammatory changes due to plaque accumulation is presented in a 54 years old patient.Treatment was performed as follows: drug substitution; initial periodontal therapy –scaling and root planning (reduction of inflammatory component in the gingival tissues; Er:YAG laser-performed gingivectomy and gingivoplasty; maintenance care. The healing process went uneventful and the postoperative results were extremely esthetically and functionally satisfactory.

  14. Amlodipine-induced gingival overgrowth in a child after liver transplant

    Science.gov (United States)

    Guollo, André; Vivas, Ana Paula Molina; Lopes, Rodrigo Nascimento; Porta, Gilda

    2016-01-01

    Drug-induced gingival overgrowth (GO) has been associated with phenytoin, cyclosporine, and calcium channel blocker therapies. This study reports the case of an 11-year-old girl who was referred for evaluation of GO, which had occurred over the last 6 months. Her medical history included a liver transplant due to biliary atresia 3 years ago, immunosuppressive therapy, and hypertension, which is why she was started on a daily intake of amlodipine. The intraoral examination showed generalized GO, and the treatment consisted of a gingivectomy. Subsequently, amlodipine was replaced with captopril and oral hygiene instructions. There was no recurrence of GO after 28 months of follow-up. Although GO may be related to the chronic use of amlodipine, such an association is uncommon in pediatrics, and the treatment consists of the replacement of medication combined with a surgical approach and plaque control. PMID:27818959

  15. Stromal Overgrowth in a Brenner Tumor or Ovarian Fibroma With Minor Sex Cord Elements?

    Science.gov (United States)

    Ross, Julia A; Saglam, Ozlen

    2015-07-01

    Computed tomography obtained as part of a urinary tract assessment in a 68-year-old woman incidentally detected a solid adnexal mass. Bilateral salpingo-oophorectomy revealed a unilateral, 4-cm, white to tan-yellow colored, focally calcified, left ovarian mass. Microscopically, the tumor was composed of bland fibroblasts, abundant collagen, and areas of calcification with a minor component composed of nests of epithelial cells with nuclear clefts focally evident, some of which contained central lumens with eosinophilic secretions. The major considerations were fibromatous overgrowth in a Brenner tumor or ovarian fibroma with minor sex cord elements. Immunostains for cytokeratin 7 showed diffuse positivity in the epithelial nests, whereas cytokeratin 20 and inhibin were negative, further supporting the diagnosis of a Brenner tumor.

  16. Whole exome sequencing identifies a novel frameshift mutation in GPC3 gene in a patient with overgrowth syndrome.

    Science.gov (United States)

    Das Bhowmik, Aneek; Dalal, Ashwin

    2015-11-10

    Overgrowth syndromes are a heterogeneous group of diseases characterized by focal or generalized overgrowth. Many of the syndromes have overlapping clinical features and it is difficult to diagnose the condition based on clinical features alone. In the present study we report on a patient with overgrowth syndrome where extensive investigation did not reveal the cause of disease. Finally exome sequencing revealed a novel hemizygous single base pair deletion in exon 8 of GPC3 gene (chrX:132670203delA) resulting in a frameshift and creating a new stop codon at 62 amino acids downstream to codon 564 (c.1692delT; p.Leu565SerfsTer63) of the protein. The mutation was confirmed by Sanger sequencing. The mother was found to be heterozygous for the mutation. This variation is not reported in the 1000 Genomes, Exome Variant Server (EVS), Exome Aggregation Consortium (ExAC) and dbSNP databases and the region is conserved across primates. Exome sequencing was helpful in establishing diagnosis of Simpson-Golabi-Behmel syndrome type 1 (SGBS1) in a patient with unknown overgrowth syndrome.

  17. Germline mutations in DIS3L2 cause the Perlman syndrome of overgrowth and Wilms tumor susceptibility

    NARCIS (Netherlands)

    Astuti, Dewi; Morris, Mark R.; Cooper, Wendy N.; Staals, Raymond H. J.; Wake, Naomi C.; Fews, Graham A.; Gill, Harmeet; Gentle, Dean; Shuib, Salwati; Ricketts, Christopher J.; Cole, Trevor; van Essen, Anthonie J.; van Lingen, Richard A.; Neri, Giovanni; Opitz, John M.; Rump, Patrick; Stolte-Dijkstra, Irene; Mueller, Ferenc; Pruijn, Ger J. M.; Latif, Farida; Maher, Eamonn R.

    2012-01-01

    Perlman syndrome is a congenital overgrowth syndrome inherited in an autosomal recessive manner that is associated with Wilms tumor susceptibility. We mapped a previously unknown susceptibility locus to 2q37.1 and identified germline mutations in DIS3L2, a homolog of the Schizosaccharomyces pombe di

  18. [Qualitative and quantitative detection of bacterial flora in experimental blind loop syndrome of the rat].

    Science.gov (United States)

    Menge, H; Simes, G; Germer, C T; Wagner, J; Hahn, H; Riecken, E O

    1985-08-01

    In the blind loop syndrome bacterial overgrowth--accompanied by an increase in bile acid deconjugation--is thought to be responsible for the observed morphological alterations of the small intestinal mucosa with its concomitant malabsorption syndrome. Since in this chain of events the bacterial overgrowth is of primary importance, we have performed a complete qualitative and quantitative evaluation of the intraluminal flora in rats with surgically created self-filling blind loops. The results show a significant increase in bacteria of the aerobic growing genera E. coli and Streptococcus (Enterococcus), and of the anaerobic growing genus Bacteroides, in one single rat also of the genera Lactobacillus/Bifidobacterium. In order to elucidate which strains of bacteria are predominantly responsible for the morphological and functional alterations observed in the stagnant loop syndrome, germ-free rats with self-filling blind loops should be contaminated selectively with bacteria of these genera.

  19. Bacterial Vaginosis

    Science.gov (United States)

    ... Issues > Conditions > Sexually Transmitted > Bacterial Vaginosis Health Issues Listen Español Text Size Email Print Share Bacterial Vaginosis Page Content Bacterial vaginosis (BV) is the most common vaginal infection in sexually active teenaged girls . It appears to be caused by ...

  20. The bacterial metabolism of carbohydrates used in tests of intestinal permeability

    OpenAIRE

    Qureishy, Gulzar A.

    1984-01-01

    Carbohydrates have been used for tests of intestinal function for many years and the impaired absorption of carbohydrates in the intestinal lumen is either due to the damaged intestinal absorptive surface, as in coeliac disease etc., in some types of acute gastroenteritis , when the absorptive area is reduced by villous atrophy , or due to the bacterial overgrowth in the small intestinal lumen as in blind loop syndrome , some types of malabsorption , which possibly produce alteration in the m...

  1. Leaky gut and the liver: A role for bacterial translocation in nonalcoholic steatohepatitis

    Institute of Scientific and Technical Information of China (English)

    Yaron Ilan

    2012-01-01

    Gut flora and bacterial translocation (BT) play important roles in the pathogenesis of chronic liver disease,including cirrhosis and its complications.Intestinal bacterial overgrowth and increased bacterial translocation of gut flora from the intestinal lumen predispose patients to bacterial infections,major complications and also play a role in the pathogenesis of chronic liver disorders.Levels of bacterial lipopolysaccharide,a component of gram-negative bacteria,are increased in the portal and/or systemic circulation in several types of chronic liver disease.Impaired gut epithelial integrity due to alterations in tight junction proteins may be the pathological mechanism underlying bacterial translocation.Preclinical and clinical studies over the last decade have suggested a role for BT in the pathogenesis of nonalcoholic steatohepatitis (NASH).Bacterial overgrowth,immune dysfunction,alteration of the luminal factors,and altered intestinal permeability are all involved in the pathogenesis of NASH and its complications.A better understanding of the cell-specific recognition and intracellular signaling events involved in sensing gut-derived microbes will help in the development of means to achieve an optimal balance in the gut-liver axis and ameliorate liver diseases.These may suggest new targets for potential therapeutic interventions for the treatment of NASH.Here,we review some of the mechanisms connecting BT and NASH and potential therapeutic developments.

  2. Effect of cisapride on intestinal bacterial and endotoxin translocation in cirrhosis

    Institute of Scientific and Technical Information of China (English)

    Shun-Cai Zhang; Wei Wang; Wei-Ying Ren; Bo-Ming He; Kang Zhou; Wu-Nan Zhu

    2003-01-01

    AIM: To investigate the effects of cisapride on intestinal bacterial overgrowth (IBO), bacterial and endotoxin translocation, intestinal transit and permeability in cirrhotic rats.METHODS: All animals were assessed with variables including bacterial and endotoxin translocation, intestinal bacterial overgrowth, intestinal transit and permeability.Bacterial translocation (BT) was assessed by bacterial culture of MLN, liver and spleen, IBO by a jejunal bacterial count of the specific organism, intestinal permeability by determination of the 24-hour urinary 99mTc-DTPA excretion and intestinal transit by measurement of the distribution of 51Cr in the intestine.RESULTS: Bacterial translocation (BT) and IBO was found in 48 % and 80 % cirrhotic rats respectively and none in control rats. Urinary excretion of 99mTc-DTPA in cirrhotic rats with BT (22.2±7.8) was greater than these without BT (10.5±2.9). Intestinal transit (geometric center ratio) was significantly delayed in cirrhotic rats (0.31±0.06) and further more delayed in cirrhotic rats with BT (0.24±0.06) than these without BT (0.38±0.11). Cirrhotic rats with IBO had significantly higher rates of intestinal bacterial and endotoxin translocation, slower intestinal transit time and higher intestinal permeability than those without IBO. It was also found that BT was closely associated with IBO and the injury of intestinal barrier. Compared with the placebo group,cisapride-treated rats had lower rates of bacterial/endotoxin translocation and IBO, which was closely associated with increased intestinal transit and improved intestinal permeability by cisapride.CONCLUSION: These results indicate that endotoxin and bacterial translocation in cirrhotic rats may be attributed to IBO and increased intestinal permeability. Cisapride that accelerates intestinal transit and improve intestinal permeability might be helpful in preventing intestinal bacterial and endotoxin translocation.

  3. Growth of very large InN microcrystals by molecular beam epitaxy using epitaxial lateral overgrowth

    Energy Technology Data Exchange (ETDEWEB)

    Kamimura, J., E-mail: kamimura@pdi-berlin.de [Department of Engineering and Applied Sciences, Sophia University, 7-1 Kioicho, Chiyoda-ku, Tokyo 102-8554 (Japan); Kishino, K.; Kikuchi, A. [Department of Engineering and Applied Sciences, Sophia University, 7-1 Kioicho, Chiyoda-ku, Tokyo 102-8554 (Japan); Sophia Nanotechnology Research Center, Sophia University, 7-1 Kioicho, Chiyoda-ku, Tokyo 102-8554 (Japan)

    2015-02-28

    Very thick InN (∼40 μm) was grown by molecular beam epitaxy using the epitaxial lateral overgrowth (ELO) technique. In some regions, the ELO of InN was observed as expected, indicating an important step toward fabricating quasi-bulk InN substrates. Interestingly, most parts of the sample consist of large flat-topped microcrystals and well-faceted microstructures. This is likely due to local growth condition variations during ELO, which is supported by an experiment where ELO of InN was performed on a substrate with various stripe mask patterns. TEM characterization of a flat top InN microcrystal revealed few stacking faults and only related threading dislocations. Defect-free small faceted microcrystals were also observed. The thick InN crystals show a narrow photoluminescence spectrum with a peak at 0.679 eV and linewidth of 16.8 meV at 4 K.

  4. Heat resistive dielectric multi-layer micro-mirror array in epitaxial lateral overgrowth gallium nitride.

    Science.gov (United States)

    Huang, Chen-Yang; Ku, Hao-Min; Liao, Wei-Tsai; Chao, Chu-Li; Tsay, Jenq-Dar; Chao, Shiuh

    2009-03-30

    Ta2O5 / SiO2 dielectric multi-layer micro-mirror array (MMA) with 3mm mirror size and 6mm array period was fabricated on c-plane sapphire substrate. The MMA was subjected to 1200 degrees C high temperature annealing and remained intact with high reflectance in contrast to the continuous multi-layer for which the layers have undergone severe damage by 1200 degrees C annealing. Epitaxial lateral overgrowth (ELO) of gallium nitride (GaN) was applied to the MMA that was deposited on both sapphire and sapphire with 2:56 mm GaN template. The MMA was fully embedded in the ELO GaN and remained intact. The result implies that our MMA is compatible to the high temperature growth environment of GaN and the MMA could be incorporated into the structure of the micro-LED array as a one to one micro backlight reflector, or as the patterned structure on the large area LED for controlling the output light.

  5. Prevalence of gingival overgrowth induced by antihypertensive drugs: A hospital-based study

    Directory of Open Access Journals (Sweden)

    Saumiya Gopal

    2015-01-01

    Full Text Available Background: Gingival overgrowth (GO is a known side-effect of calcium channel blockers. Although there have been several case reports, few studies have examined the prevalence of nifedipine, diltiazem, and amlodipine. This study was conducted to determine the prevalence and risk factors for GO in patients treated with calcium channel blockers. Materials and Methods: A cross-sectional study was conducted in out patient Department of Medicine, Government Medical College, Calicut. 133 patients taking antihypertensives were examined for the presence of GO using two different indices: Vertical GO in 6 points around each tooth and horizontal Miranda-Brunet index in the interdental area. Gingival index (GI, plaque index, and probing depth were also evaluated. Results: The frequency of GO was significantly higher in nifedipine-treated cases than other drug groups. Frequency of GO was 75% for nifedipine, 31.4% for amlodipine and 25% for amlodipine + metoprolol. Higher gingival, plaque and calculus were observed in patients taking calcium channel blockers. Among the possible risk factors, only the GI showed a significant correlation with GO. Conclusions: Patients taking antihypertensives had poor oral hygiene. Patients taking nifedipine showed a higher frequency of GO. Gingival inflammation acts as a predisposing factor.

  6. Pallister Killian syndrome: unusual significant postnatal overgrowth in a girl with otherwise typical presentation.

    Science.gov (United States)

    Frković, Sanda Huljev; Durisević, Ivana Tonković; Trcić, Ruzica Lasan; Sarnavka, Vladimir; Gornik, Kristina Crkvenac; Muzinić, Dubravka; Letica, Ljiljana; Barić, Ivo; Begović, Davor

    2010-03-01

    Pallister Killian syndrome (PKS) is a rare genetic disorder caused by tetrasomy of the short arm of chromosome 12, revealed usually in mosaic distribution of an extra i (12) (p10) chromosome in fibroblasts. The syndrome presents with a recognizable pattern of findings including pigmentary skin changes, coarse face, high forehead, sparse anterior scalp hair, hypertelorism, seizures and progressive psychomotor developmental delay. It was first described independently by Pallister in 1977 and by Killian and Teschler-Nikola in 1981. We report a case of 21 month old girl with PKS and significant overgrowth. Cytogenetic analysis was performed using the GTG banding technique. The karyotype of cultured lymphocytes was normal. The karyotype from skin fibroblasts was established as mosaic tetrasomy of 12p 47,XX,+i (12) (p10)/46,XX. The origin of the extra marker chromosome was determinated by fluorescence in situ hybridization with chromosome 12 specific DNA probes confirming that supernumerary marker is chromosome i (12p) in 68% of cells. Despite the excessive postnatal growth we found low serum growth hormone levels and reduced response to pharmacological stimulation test. This is also the first report of a postnatal patient in our country.

  7. Testing Brain Overgrowth and Synaptic Models of Autism Using NPC’s and Neurons from Patient-Derived IPS Cells

    Science.gov (United States)

    2014-10-01

    interaction, and limited and repetitive interests and behavior. Recent studies have led to two major hypotheses for autism pathogenesis : early brain...interests and behavior. Recent studies have led to two major hypotheses for autism pathogenesis . First, early brain overgrowth appears to be a critical...Models of Autism Using NPC’s and Neurons from Patient- Derived IPS Cells PRINCIPAL INVESTIGATOR: Fred H. Gage, Ph.D

  8. Macrosomia, obesity, macrocephaly and ocular abnormalities (MOMO syndrome) in two unrelated patients: delineation of a newly recognized overgrowth syndrome.

    Science.gov (United States)

    Moretti-Ferreira, D; Koiffmann, C P; Listik, M; Setian, N; Wajntal, A

    1993-06-15

    We describe 2 unrelated patients, a boy and a girl, with an overgrowth syndrome and the following common characteristics: macrocrania, obesity, ocular abnormalities (retinal coloboma and nystagmus), downward slant of palpebral fissures, mental retardation, and delayed bone maturation. Both cases are of sporadic occurrence with no consanguinity between the parents. We suggest that this syndrome is due to a new autosomal dominant mutation and propose to designate it with the acronym of "MOMO syndrome" (Macrosomia, Obesity, Macrocrania, Ocular anomalities.

  9. CORRELATION OF BLOOD LEVELS OF CYCLOSPORINE AND IT'S METABOLITES AND LOCAL FACTORS WITH GINGIVAL OVERGROWTH IN IRANIAN RENAL ALLOGRAFT PATIENTS

    Directory of Open Access Journals (Sweden)

    M. Sahebjamee .

    1997-06-01

    Full Text Available Forty renal allograft patients with three months under immunosuppression by cycloserine were examined for their gingival overgrowth and it's correlation with several parameters including the trough levels of blood cyclosporine and it's metabolites measured by the fluorescence polarization immunoassay technique. No correlation was found between the scores of gingival overgrowth and both the age of patients and duration of cyclosporine therapy. Also, there was no correlation between the scores of gingival overgrowth and the levels of dental plaque. Our findings confirm the effective role of gingival inflammation as a local predisposing factor and also suggest the potential toxic action of cyclosporine metabolites on development of gingival overgrowth or it's accentuation.

  10. Activation of oxygen-mediating pathway using copper ions: fine-tuning of growth kinetics in gold nanorod overgrowth.

    Science.gov (United States)

    Liu, Wenqi; Zhang, Hui; Wen, Tao; Yan, Jiao; Hou, Shuai; Shi, Xiaowei; Hu, Zhijian; Ji, Yinglu; Wu, Xiaochun

    2014-10-21

    Growth kinetics plays an important role in the shape control of nanocrystals (NCs). Herein, we presented a unique way to fine-tune the growth kinetics via oxidative etching activated by copper ions. For the overgrowth of gold nanorods (Au NRs), competitive adsorption of dissolved oxygen on rod surface was found to slow down the overgrowth rate. Copper ions were able to remove the adsorbed oxygen species from the Au surface via oxidative etching, thus exposing more reaction sites for Au deposition. In this way, copper ions facilitated the overgrowth process. Furthermore, Cu(2+) rather than Cu(+) acted as the catalyst for the oxidative etching. Comparative study with Ag(+) indicated that Cu(2+) cannot regulate NC shapes via an underpotential deposition mechanism. In contrast, Ag(+) led to the formation of Au tetrahexahedra (THH) and a slight decrease of the growth rate at similar growth conditions. Combining the distinct roles of the two ions enabled elongated THH to be produced. Copper ions activating the O2 pathway suggested that dissolved oxygen has a strong affinity for the Au surface. Moreover, the results of NC-sensitized singlet oxygen ((1)O2) indicated that the absorbed oxygen species on the surface of Au NCs bounded with low-index facets mainly existed in the form of molecular O2.

  11. Gonadoblastoma: Case report of two young patients with isochromosome 12p found in the dysgerminoma overgrowth component in one case.

    Science.gov (United States)

    Changchien, Yi-Che; Haltrich, Irén; Micsik, Tamás; Kiss, Eszter; Fónyad, László; Papp, Gergő; Sápi, Zoltán

    2012-10-15

    Gonadoblastomas are unusual neoplasias that frequently appear in the dysgenetic gonads of women with chromosome Y anomaly. We present two cases of gonadoblastoma associated with complete gonadal dysgenesis and Turner syndrome, respectively, with dysgerminoma overgrowth found in one case. We were interested in the DNA ploidy, the presence of Y chromosome DNA sequence and the status of chromosome 12p arm among the tumor cells. We performed cytophotometry to analyze the DNA content and fluorescence in situ hybridization (FISH) to identify the Y chromosome and the isochromosome 12p within the tumor cells. The cytophotometric result showed diploid DNA content in gonadoblastoma, whereas dysgerminoma revealed aneuploid DNA. The FISH result revealed Y chromosome DNA sequence within gonadoblastoma and dysgerminoma. Isochromosome 12p was identified in dysgerminoma, but not in gonadoblastoma. We conclude that gonadoblastoma and dysgerminoma have a strong association with the Y chromosome, and dysgerminoma overgrowth is due to further chromosomal aberrations, such as isochromosome 12p. Histological, immunohistocheimcal and molecular studies should render the correct diagnosis. Identifying dysgerminoma overgrowth is crucial since it is associated with adverse prognosis and requires additional therapy.

  12. [Significance of deficient bacterial colonization in the pathogenesis of mucosal lesions in experimental blind loop syndrome].

    Science.gov (United States)

    Menge, H; Germer, C T; Stössel, R; Simes, G; Wagner, J; Hahn, H; Riecken, E O

    1985-07-20

    A complete evaluation of the bacterial flora in jejunal self-filling blind loops was performed. The results show a significant increase in bacteria of the genera E. coli, Streptococcus and Bacteroides. In further experiments, jejunal self-filling blind loops were created in germ-free animals. In spite of the germ-free state the mucosa displayed marked hyperplasia. The same was true when the blind loops had been contaminated with aerobic bacteria. These results demonstrate that other factors in addition to bacterial overgrowth contribute to the mucosal damage observed in self-filling blind loops.

  13. Diagenetic Mg-calcite overgrowths on foraminiferal tests in the vicinity of methane seeps

    Science.gov (United States)

    Panieri, Giuliana; Lepland, Aivo; Whitehouse, Martin J.; Wirth, Richard; Raanes, Morten P.; James, Rachael H.; Graves, Carolyn A.; Crémière, Antoine; Schneider, Andrea

    2017-01-01

    Methane is a potent greenhouse gas and some episodes of past global warming appear to coincide with its massive release from seafloor sediments as suggested by carbon isotope records of foraminifera. Here, we present structural, geochemical, and stable carbon isotope data from single foraminiferal calcite tests and authigenic Mg-calcite overgrowths in a sediment core recovered from an area of active methane seepage in western Svalbard at ca. 340 m water depth. The foraminifera are from intervals in the core where conventional bulk foraminiferal δ13 C values are as low as -11.3 ‰. Mg/Ca analyses of the foraminiferal tests reveal that even tests for which there is no morphological evidence for secondary authigenic carbonate can contain Mg-rich interlayers with Mg/Ca up to 220 mmol/mol. Transmission electron microscopy (TEM) of the contact point between the biogenic calcite and authigenic Mg-calcite layers shows that the two phases are structurally indistinguishable and they have the same crystallographic orientation. Secondary ion mass spectrometry (SIMS) analyses reveal that the Mg-rich layers are strongly depleted in 13C (δ13 C as low as -34.1 ‰). These very low δ13 C values indicate that the authigenic Mg-calcite precipitated from pore waters containing methane-derived dissolved inorganic carbon at the depth of the sulfate-methane transition zone (SMTZ). As the depth of the SMTZ can be located several meters below the sediment-seawater interface, interpretation of low foraminiferal δ13 C values in ancient sediments in terms of the history of methane seepage at the seafloor must be undertaken with care.

  14. Total Hemi-overgrowth in Pigmentary Mosaicism of the (Hypomelanosis of) Ito Type: Eight Case Reports.

    Science.gov (United States)

    Pavone, Vito; Signorelli, Salvatore Santo; Praticò, Andrea Domenico; Corsello, Giovanni; Savasta, Salvatore; Falsaperla, Raffaele; Pavone, Piero; Sessa, Giuseppe; Ruggieri, Martino; Ba, Martino Ruggieri

    2016-03-01

    Pigmentary mosaicism of the (hypomelanosis of) Ito type is an umbrella term, which includes phenotypes characterized by mosaic hypopigmentation in the form of streaks, whorls, patchy, or more bizarre skin configurations (running along the lines of Blaschko): these cutaneous patterns can manifest as an isolated skin disorder (pigmentary mosaicism of the Ito type) or as a complex malformation syndrome in association with extracutaneous anomalies (most often of the musculoskeletal and/or nervous systems) (hypomelanosis of Ito). Affected individuals are anecdotally reported to have also partial or total body hemi-overgrowth (HOG), which often causes moderate to severe complications.We studied the occurrence and features of HOG in the 114 children and adults with mosaic pigmentary disorders of the Ito type diagnosed and followed up (from 2 to 22 years; average follow-up 16 years) at our Institutions.Eight patients (5 M, 3 F; aged 4 to 25 years; median age 16 years) out of the 114 analyzed (7%) fulfilled the criteria for unilateral HOG, with differences in diameter ranging from 0.4 to 4.0 cm (upper limbs) and 1.0 to 9.0 cm (lower limbs). Moreover, among these 8 patients, 5/8 filled in the 75th to 90th percentile for height; 6/8 had associated kyphoscoliosis; and 5/8 showed cognitive delays. No tumour complications were recorded. Overall, 6/8 HOG patients presented with additional (extracutaneous) syndromic manifestations, apart from the HOG (ie, with a clinical phenotype of hypomelanosis of Ito).The present study, which includes children and adults with the longest follow-up so far recorded, confirms the association between pigmentary mosaicism of the Ito type and HOG lowering previous estimates (7% vs 16%) for HOG in the context of mosaic hypopigmentation. A careful examination, looking at subtle to moderate asymmetries and associated complications within the spectrum of these mosaic pigmentary disorders, is recommended.

  15. Doom and boom on a resilient reef: climate change, algal overgrowth and coral recovery.

    Directory of Open Access Journals (Sweden)

    Guillermo Diaz-Pulido

    Full Text Available BACKGROUND: Coral reefs around the world are experiencing large-scale degradation, largely due to global climate change, overfishing, diseases and eutrophication. Climate change models suggest increasing frequency and severity of warming-induced coral bleaching events, with consequent increases in coral mortality and algal overgrowth. Critically, the recovery of damaged reefs will depend on the reversibility of seaweed blooms, generally considered to depend on grazing of the seaweed, and replenishment of corals by larvae that successfully recruit to damaged reefs. These processes usually take years to decades to bring a reef back to coral dominance. METHODOLOGY/PRINCIPAL FINDINGS: In 2006, mass bleaching of corals on inshore reefs of the Great Barrier Reef caused high coral mortality. Here we show that this coral mortality was followed by an unprecedented bloom of a single species of unpalatable seaweed (Lobophora variegata, colonizing dead coral skeletons, but that corals on these reefs recovered dramatically, in less than a year. Unexpectedly, this rapid reversal did not involve reestablishment of corals by recruitment of coral larvae, as often assumed, but depended on several ecological mechanisms previously underestimated. CONCLUSIONS/SIGNIFICANCE: These mechanisms of ecological recovery included rapid regeneration rates of remnant coral tissue, very high competitive ability of the corals allowing them to out-compete the seaweed, a natural seasonal decline in the particular species of dominant seaweed, and an effective marine protected area system. Our study provides a key example of the doom and boom of a highly resilient reef, and new insights into the variability and mechanisms of reef resilience under rapid climate change.

  16. Bacterial gastroenteritis

    Science.gov (United States)

    Bacterial gastroenteritis is present when bacteria cause an infection of the stomach and intestines ... has not been treated Many different types of bacteria can cause ... Campylobacter jejuni E coli Salmonella Shigella Staphylococcus ...

  17. Cathodic and anodic behavior of steel in water with saprophytic anaerobic bacterial flora

    Energy Technology Data Exchange (ETDEWEB)

    Lubyanova, V.I.; Emets, G.P.; Norokina, Y.M.

    1986-07-01

    Saprophytic bacteria in the bacterial communities of overgrowths cause biocorrosion in hydroelectric power plants. In order to study bacteria in overgrowths in the Zaporozhskii reservoir at a depth of 2 m the authors fixed specimens - plate of steel St3 - for 30 days. The potentiodynamic (5 mV/sec) curves of cathodic and anodic polarization of steel St3 in sterile water and also in medium with Bacillus putrificus on the 34th and 57th days of the experiment are shown. The anodic curve of steel after 57 days in the medium with the bacteria containing 30 mg/liter of hydrogen sulfide, has a section with fall of process rate at potentials from -0.35 to -0.20 V; on the curves recorded after 12 and 34 days there are no such sections.

  18. Lateral epitaxial overgrowth of aluminum nitride and near ultraviolet LEDs for white lighting applications

    Science.gov (United States)

    Newman, Scott A.

    In recent years, substantial efforts have been made to develop deep ultraviolet AlGaN-based LEDs (200-280 nm) for specialized applications such as bio-detection and non-line-of-sight (NLOS) communications. One of several factors limiting the performance of these devices is the high threading dislocation (TD) density of ˜5x109 cm-2 that results from growing the required AlN base layer on either a SiC or sapphire substrate. Lateral epitaxial overgrowth (LEO) of AlN, the first topic of this dissertation, is a promising technology for growing low TD density AlN templates. Conventional LEO methods relying on selective area growth (SAG) have not been effective for AlxGa1-xN with x > 0.2, because of the high aluminum sticking coefficient for the mask materials and/or contamination of the film by the mask. Therefore, maskless AlN LEO was investigated using metal organic chemical vapor deposition (MOCVD) and hydride vapor phase epitaxy (HVPE). Cracked AlN films with TD densities of LEDs for white lighting applications. Currently, cool white LEDs consisting of a blue GaN/InGaN LED and the YAG:Ce3+ yellow phosphor are available with 107 lm/W efficacy, but have have high correlated color temperatures (CCTs) of ˜5,500 K and poor color rendering indices (CRIs) of ˜75. The alternative approach of combining a NUV LED with suitable NUV-excitation phosphors (e.g., red, green, and blue phosphors) can theoretically allow for high CRI white lighting with relatively good efficacy and a variety of CCTs. When this project began in late 2007, the lack of suitable blue-excitation phosphors suggested that this was the only viable approach to attaining very high CRI white lighting. NUV LEDs with AlN buffers on 6H-SiC substrates and AlGaN/InGaN active regions were first developed to target white phosphors with excitation peaks near 365 nm. Later, NUV LEDs with GaN buffers on sapphire substrates and GaN/InGaN active regions were developed to diagnose problems with the AlGaN/InGaN LEDs and to

  19. Small intestinal bacteria overgrowth decreases small intestinal motility in the NASH rats

    Institute of Scientific and Technical Information of China (English)

    Wan-Chun Wu; Wei Zhao; Sheng Li

    2008-01-01

    AIM: To explore the relationship between small intestinal motility and small intestinal bacteria overgrowth (SIBO) in Nonalcoholic steatohepatitis (NASH), and to investigate the effect of SIBO on the pathogenesis of NASH in rats. The effect of cidomycin in alleviating severity of NASH is also studied.METHODS: Forty eight rats were randomly divided into NASH group (n = 16), cidomycin group (n = 16)and control group (n = 16). Then each group were subdivided into small intestinal motility group (n = 8),bacteria group (n = 8) respectively. A semi-solid colored marker was used for monitoring small intestinal transit.The proximal small intestine was harvested under sterile condition and processed for quantitation for aerobes (E. coli) and anaerobes (Lactobacilli). Liver pathologic score was calculated to qualify the severity of hepatitis.Serum ALT, AST levels were detected to evaluate the severity of hepatitis.RESULTS: Small intestinal transit was inhibited in NASH group (P < 0.01). Rats treated with cidomycin had higher small intestine transit rate than rats in NASH group (P < 0.01). High fat diet resulted in quantitative alterations in the aerobes (E. coli) but not in the anoerobics (Lactobacill). There was an increase in the number of E. coli in the proximal small intestinal flora in NASH group than in control group (1.70 ± 0.12 log10 (CFU/g) vs 1.28 ± 0.07 log10 (CFU/g), P < 0.01). TNF-a concentration was significantly higher in NASH group than in control group (1.13±0.15 mmol/L vs 0.57±0.09 mmol/L, P < 0.01). TNF-α concentration was lower in cidomycin group than in NASH group (0.63±0.09 mmol/L vs 1.13 ± 0.15 mmol/L, P < 0.01). Treatment with cidomycin showed its effect by significantly lowering serum ALT, AST and TNF-α levels of NASH rats.CONCLUSION: SIBO may decrease small intestinal movement in NASH rats. SIBO may be an important pathogenesis of Nash. And treatment with cidomycin by mouth can alleviate the severity of NASH.

  20. Two-step epitaxial lateral overgrowth of a-plane GaN by MOCVD

    Science.gov (United States)

    Ni, X.; Özgür, Ü.; Morkoç, H.; Baski, A. A.; Liliental-Weber, Z.; Everitt, H. O.

    2007-02-01

    -plane epitaxial layers (<45 ps), and ratio of the slow decaying component magnitude to the fast decaying one was more than 1.5, showing considerable reduction of nonradiative centers by lateral overgrowth. In addition, room temperature near-field optical microscopy studies revealed the improved optical quality in the wing regions of the overgrown GaN. As revealed from far-field PL, the band edge luminescence at room temperature was more than two orders of magnitude weaker than the yellow luminescence. Therefore, the overall spectrally integrated near field PL was collected, and its intensity was noticeably stronger in the wing areas with both Ga and N polarity. The much weaker emission at the windows and meeting fronts of the two opposite wings were consistent with the observations of high density of dislocations in the window regions and new defects originating at the meeting boundaries from TEM.

  1. Bacterial Adhesion & Blocking Bacterial Adhesion

    DEFF Research Database (Denmark)

    Vejborg, Rebecca Munk

    2008-01-01

    tract to the microbial flocs in waste water treatment facilities. Microbial biofilms may however also cause a wide range of industrial and medical problems, and have been implicated in a wide range of persistent infectious diseases, including implantassociated microbial infections. Bacterial adhesion...... is the first committing step in biofilm formation, and has therefore been intensely scrutinized. Much however, still remains elusive. Bacterial adhesion is a highly complex process, which is influenced by a variety of factors. In this thesis, a range of physico-chemical, molecular and environmental parameters......, which influence the transition from a planktonic lifestyle to a sessile lifestyle, have been studied. Protein conditioning film formation was found to influence bacterial adhesion and subsequent biofilm formation considerable, and an aqueous extract of fish muscle tissue was shown to significantly...

  2. Bacterial lipases

    NARCIS (Netherlands)

    Jaeger, Karl-Erich; Ransac, Stéphane; Dijkstra, Bauke W.; Colson, Charles; Heuvel, Margreet van; Misset, Onno

    1994-01-01

    Many different bacterial species produce lipases which hydrolyze esters of glycerol with preferably long-chain fatty acids. They act at the interface generated by a hydrophobic lipid substrate in a hydrophilic aqueous medium. A characteristic property of lipases is called interfacial activation, mea

  3. Bacterial Ecology

    DEFF Research Database (Denmark)

    Fenchel, Tom

    2011-01-01

    Bacterial ecology is concerned with the interactions between bacteria and their biological and nonbiological environments and with the role of bacteria in biogeochemical element cycling. Many fundamental properties of bacteria are consequences of their small size. Thus, they can efficiently exploit...

  4. [Bacterial vaginosis].

    Science.gov (United States)

    Romero Herrero, Daniel; Andreu Domingo, Antonia

    2016-07-01

    Bacterial vaginosis (BV) is the main cause of vaginal dysbacteriosis in the women during the reproductive age. It is an entity in which many studies have focused for years and which is still open for discussion topics. This is due to the diversity of microorganisms that cause it and therefore, its difficult treatment. Bacterial vaginosis is probably the result of vaginal colonization by complex bacterial communities, many of them non-cultivable and with interdependent metabolism where anaerobic populations most likely play an important role in its pathogenesis. The main symptoms are an increase of vaginal discharge and the unpleasant smell of it. It can lead to serious consequences for women, such as an increased risk of contracting sexually transmitted infections including human immunodeficiency virus and upper genital tract and pregnancy complications. Gram stain is the gold standard for microbiological diagnosis of BV, but can also be diagnosed using the Amsel clinical criteria. It should not be considered a sexually transmitted disease but it is highly related to sex. Recurrence is the main problem of medical treatment. Apart from BV, there are other dysbacteriosis less characterized like aerobic vaginitis of which further studies are coming slowly but are achieving more attention and consensus among specialists.

  5. 3.2 Mb microdeletion in chromosome 7 bands q22.2-q22.3 associated with overgrowth and delayed bone age.

    Science.gov (United States)

    Uliana, Vera; Grosso, Salvatore; Cioni, Maddalena; Ariani, Francesca; Papa, Filomena T; Tamburello, Silvia; Rossi, Elisa; Katzaki, Eleni; Mucciolo, Mafalda; Marozza, Annabella; Pollazzon, Marzia; Mencarelli, Maria Antonietta; Mari, Francesca; Balestri, Paolo; Renieri, Alessandra

    2010-01-01

    We report a patient with mental retardation, epilepsy, overgrowth, delayed bone age, peculiar facial features, corpus callosum hypoplasia, enlarged cisterna magna and right cerebellar hypoplasia. Array-CGH analysis revealed the presence of a de novo 3.2 Mb interstitial deletion of the long arm of chromosome 7 involving bands q22.2-q22.3. The rearrangement includes 15 genes and encompasses a genomic region that represents a site of frequent loss of heterozygosity in myeloid malignancies. Four genes are implicated in the control of cell cycle: SRPK2, MLL5, RINT1 and LHFPL3. Haploinsufficiency of these genes might therefore be associated with overgrowth and could confer susceptibility to cancers or other tumours, so that attention to this possibility would be appropriate during regular medical review. In conclusion, array-CGH analysis should be performed in patients with overgrowth where the known causes have already been excluded, because some still unclassified overgrowth syndromes may be caused by subtle genomic imbalances.

  6. Müllerian adenosarcoma of the uterine cervix with sarcomatous overgrowth: A case report of aggressive disease in a young patient

    Directory of Open Access Journals (Sweden)

    David A. Morales F.

    2016-01-01

    Conclusion: A young woman with Müllerian adenosarcoma of the cervix with sarcomatous overgrowth presenting the risk factors for its recurrence experienced a rapid relapse after receiving radical surgery but not adjuvant therapy. Control of this aggressive disease via sequential radiotherapy and chemotherapy are recommended.

  7. Markers of bacterial translocation in end-stage liver disease

    Institute of Scientific and Technical Information of China (English)

    Ioannis; Koutsounas; Garyfallia; Kaltsa; Spyros; I; Siakavellas; Giorgos; Bamias

    2015-01-01

    Bacterial translocation(BT) refers to the passage of viable bacteria or bacterial products from the intestinal lumen, through the intestinal epithelium, into the systemic circulation and extraintestinal locations. The three principal mechanisms that are thought to be involved in BT include bacterial overgrowth, disruption of the gut mucosal barrier and an impaired host defence.BT is commonly observed in liver cirrhosis and has been shown to play an important role in the pathogenesis of the complications of end stage liver disease, including infections as well as hepatic encephalopathy and hepatorenal syndrome. Due to the importance of BT in the natural history of cirrhosis, there is intense interest for the discovery of biomarkers of BT. To date, several such candidates have been proposed, which include bacterial DNA, soluble CD14, lipopolysaccharides endotoxin, lipopolysaccharide-binding protein, calprotectin and procalcitonin. Studies on the association of these markers with BT have demonstrated not only promising data but, oftentimes, contradictory results. As a consequence, currently, there is no optimal marker that may be used in clinical practice as a surrogate for the presence of BT.

  8. Bacterial hydrodynamics

    CERN Document Server

    Lauga, Eric

    2015-01-01

    Bacteria predate plants and animals by billions of years. Today, they are the world's smallest cells yet they represent the bulk of the world's biomass, and the main reservoir of nutrients for higher organisms. Most bacteria can move on their own, and the majority of motile bacteria are able to swim in viscous fluids using slender helical appendages called flagella. Low-Reynolds-number hydrodynamics is at the heart of the ability of flagella to generate propulsion at the micron scale. In fact, fluid dynamic forces impact many aspects of bacteriology, ranging from the ability of cells to reorient and search their surroundings to their interactions within mechanically and chemically-complex environments. Using hydrodynamics as an organizing framework, we review the biomechanics of bacterial motility and look ahead to future challenges.

  9. Silver-nanoparticle-coated biliary stent inhibits bacterial adhesion in bacterial cholangitis in swine

    Institute of Scientific and Technical Information of China (English)

    Wei Wen; Li-Mei Ma; Wei He; Xiao-Wei Tang; Yin Zhang; Xiang Wang; Li Liu; Zhi-Ning Fan

    2016-01-01

    BACKGROUND: One of the major limitations of biliary stents is the stent occlusion, which is closely related to the over-growth of bacteria. This study aimed to evaluate the feasibility of a novel silver-nanoparticle-coated polyurethane (Ag/PU) stent in bacterial cholangitis model in swine. METHODS: Ag/PU was designed by coating silver nanopar-ticles on polyurethane (PU) stent. Twenty-four healthy pigs with bacterial cholangitis using Ag/PU and PU stents were ran-domly divided into an Ag/PU stent group (n=12) and a PU stent group (n=12), respectively. The stents were inserted by standard endoscopic retrograde cholangiopancreatography. Laboratory assay was performed for white blood cell (WBC) count, alanine aminotransferase (ALT), interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α) at baseline time, 8 hours, 1, 2, 3, and 7 days after stent placements. The segment of bile duct containing the stent was examined histologically ex vivo. Implanted bili-ary stents were examined by a scan electron microscope. The amount of silver release was also measured in vitro. RESULTS: The number of inflammatory cells and level of ALT, IL-1β and TNF-α were significantly lower in the Ag/PU stent group than in the PU stent group. Hyperplasia of the mucosa was more severe in the PU stent group than in the Ag/PU stent group. In contrast to the biofilm of bacteria on the PU stent, fewer bacteria adhered to the Ag/PU stent. CONCLUSIONS: PU biliary stents modified with silver nanoparticles are able to alleviate the inflammation of pigs with bacterial cholangitis. Silver-nanoparticle-coated stents are resistant to bacterial adhesion.

  10. Bacterial vaginosis -- aftercare

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000687.htm Bacterial vaginosis - aftercare To use the sharing features on this ... to back after you use the bathroom. Preventing Bacterial Vaginosis You can help prevent bacterial vaginosis by: Not ...

  11. Pregnancy Complications: Bacterial Vaginosis

    Science.gov (United States)

    ... Complications & Loss > Pregnancy complications > Bacterial vaginosis and pregnancy Bacterial vaginosis and pregnancy E-mail to a friend Please ... this page It's been added to your dashboard . Bacterial vaginosis (also called BV or vaginitis) is an infection ...

  12. Diagnosis of bacterial overgrowth of the small intestine. Comparison of the 14C-D-xylose breath test and jejunal cultures in 60 patients

    DEFF Research Database (Denmark)

    Rumessen, J J; Gudmand-Høyer, E; Bachmann, E

    1985-01-01

    the presence of BOG was ruled out (diagnoses: irritable bowel syndrome, 8; chronic diarrhoea, 6; and lactose malabsorption, 1). These patients were used as controls. The other 22 of the 60 patients could not be placed in either group owing to the presence of factors known to predispose for BOG; none of them...

  13. Bile acid malabsorption or disturbed intestinal permeability in patients treated with enzyme substitution for exocrine pancreatic insufficiency is not caused by bacterial overgrowth

    DEFF Research Database (Denmark)

    Madsen, Jan Lysgård; Graff, Jesper; Philipsen, Else Kirstine;

    2003-01-01

    INTRODUCTION: In some patients with severe exocrine pancreatic insufficiency, enzyme replacement therapy will not lead to clinical improvement or reduction of steatorrhea. Therefore, other mechanisms separately or in interplay with reduced enzyme secretion might be responsible for malabsorption...

  14. Effects of lactulose on intestinal endotoxin and bacterial translocation in cirrhotic rats

    Institute of Scientific and Technical Information of China (English)

    张顺财; 王唯; 任卫英; 戴茜; 贺伯明; 周康

    2003-01-01

    Objective To investigate the effects of lactulose on intestinal bacterial overgrowth (IBO), bacterial translocation (BT), intestinal transit and permeability in cirrhotic rats. Methods BT in all animals was assessed by bacterial culture of mesenteric lymph node (MLN), liver and spleen, and IBO was assessed by a jejunal bacterial count of the specific organism. Intestinal permeability was determined by the 24-hour urinary 99mTc-diethylenetriaminepentaacetate (99mTc-DTPA) excretion, and intestinal transit was determined by measuring the distribution of 51 Cr in the intestine. Results BT and IBO were found in 48% and 80% of the cirrhotic rats, respectively, while not in the control rats. Cirrhotic rats with IBO had significantly higher levels of intestinal endotoxin higher rates of bacterial translocation, shorter intestinal transit time and higher intestinal permeability than those without IBO. It was also found that BT was closely associated with IBO and injury of the intestinal barrier. Compared with the placebo group, lactulose-treated rats had lower rates of BT and IBO, which was closely associated with increased intestinal transit and improved intestinal permeability by lactulose. Conclusions Our study indicate that endotoxin and bacterial translocation in cirrhotic rats may attribute to IBO and increased intestinal permeability. Lactulose that accelerates intestinal transit and improves intestinal permeability might be helpful in preventing intestinal bacterial and endotoxin translocation.

  15. Defect reduction in (112_O) a-plane GaN by two-stage epitaxiallateral overgrowth

    Energy Technology Data Exchange (ETDEWEB)

    Ni, X.; Ozgur, U.; Fu, Y.; Biyikli, N.; Xie, J.; Baski, A.A.; Morkoc, H.; Liliental-Weber, Z.

    2006-10-20

    In the epitaxial lateral overgrowth (ELO) of (11{bar 2}0) a-plane GaN, the uneven growth rates of two opposing wings, Ga- and N-wings, makes the coalescence of two neighboring wings more difficult than that in c-plane GaN. We report a two-stage growth method to get uniformly coalesced epitaxial lateral overgrown a-plane GaN using metalorganic chemical vapor deposition (MOCVD) by employing relatively lower growth temperature in the first step followed by enhanced lateral growth in the second. Using this method, the height differences between Ga-polar and N-polar wings at the coalescence front could be reduced, thereby making the coalescence of two wings much easier. Transmission electron microscopy (TEM) showed that the threading dislocation density in the wing areas was 1.0x10{sup 8}cm{sup -2}, more than two orders of magnitude lower than that in the window areas (4.2x10{sup 10}cm{sup -2}). However, high density of basal stacking faults of 1.2x104 cm-1 was still observed in the wing areas as compared to c-plane GaN. Atomic force microscopy and photoluminescence measurements on the coalesced ELO a-GaN sample also indicated improved material quality.

  16. Quantitative estimation of AgNORs in inflammatory gingival overgrowth in pediatric patients and its correlation with the dental plaque status

    Directory of Open Access Journals (Sweden)

    Mukhopadhyay S

    2009-01-01

    Full Text Available Background and Objectives: Nucleolar organizer Regions (NORs are situated within the nucleolus of a cell. The proteins are selectively stained by the silver colloid technique that is known as the AgNOR technique. AgNOR stain can be visualized as a black dot under the optical microscope. The present study aimed to evaluate the cases for quantitative estimation of AgNORs in the epithelial cells in various grades of gingival overgrowth to that of normal gingival tissues. Materials and Methods: Only preadolescent and adolescent groups aged up to 14 years were selected. Twenty normal and 31 disease cases of gingival overgrowth were selected. The tissue sections were stained by the hematoxylin and eosin (HandE technique for the routine histological evaluation, while the AgNOR counts were performed through the improved one-step method of Ploton et al. Results: HandE staining revealed five different types of gingival overgrowth. The plaque index (PI, gingival index (GI, and AgNOR count were not significantly (P> 0.05 higher than that of control cases in pyogenic granuloma, puberty gingivitis, and in drug-induced gingival overgrowth cases. In gingival fibromatosis cases, for comparison of different indices t-tests were done. The PI when compared with AgNOR count was found significant at 5% level and 0.1% level for mixed and permanent dentition, respectively. The GI when compared with AgNOR count was found significant at 1% level and 0.1% level in mixed and permanent dentitions, respectively.

  17. GINGIVAL OVERGROWTH INDUCED BY IMMUNOSUPPRESSIVE TREATMENT WITH CYCLOSPORINE A AND MYCOPHENOLATE MOFETIL IN A PATIENT WITH KIDNEY TRANSPLANT – A CASE REPORT AND LITERATURE REVIEW

    Directory of Open Access Journals (Sweden)

    Daniela Trandafir

    2013-07-01

    Full Text Available Cyclosporine A, a drug that inhibits the immuneresponse, has been widely used for over 30 years in immunosuppressivetherapy protocols for patient‑recipients ofthe transplanted organs. One of the commonly reportedside effects of Cyclosporine A is gingival overgrowth, withvarying degrees of severity, which may interfere with theaesthetics and normal functions of the oral cavity. Combinationwith other drugs that can recognize the gum tissueas a secondary target organ increases the risk ofdrug‑induced gingival overgrowth. In cases where a lowerdose of Cyclosporine A or conversion to another immunosuppressiveagent (a drug not assigned to such a sideeffect are not possible, the management of severe gingivalovergrowth focuses on surgical excision of the excessivelyproliferated gingival tissue. We report the case of a youngadult with moderate drug‑induced gingival overgrowth,the beneficiary of a functional transplanted kidney about9 years ago, treated with two immunosuppressives, whohas undergone gingivectomy with electrocautery, as a necessaryintervention to improve the oral hygiene and toavoid worsening of malfunctions in the oral cavity.

  18. Loss of the Drosophila cell polarity regulator Scribbled promotes epithelial tissue overgrowth and cooperation with oncogenic Ras-Raf through impaired Hippo pathway signaling

    Directory of Open Access Journals (Sweden)

    Grusche Felix A

    2011-09-01

    Full Text Available Abstract Background Epithelial neoplasias are associated with alterations in cell polarity and excessive cell proliferation, yet how these neoplastic properties are related to one another is still poorly understood. The study of Drosophila genes that function as neoplastic tumor suppressors by regulating both of these properties has significant potential to clarify this relationship. Results Here we show in Drosophila that loss of Scribbled (Scrib, a cell polarity regulator and neoplastic tumor suppressor, results in impaired Hippo pathway signaling in the epithelial tissues of both the eye and wing imaginal disc. scrib mutant tissue overgrowth, but not the loss of cell polarity, is dependent upon defective Hippo signaling and can be rescued by knockdown of either the TEAD/TEF family transcription factor Scalloped or the transcriptional coactivator Yorkie in the eye disc, or reducing levels of Yorkie in the wing disc. Furthermore, loss of Scrib sensitizes tissue to transformation by oncogenic Ras-Raf signaling, and Yorkie-Scalloped activity is required to promote this cooperative tumor overgrowth. The inhibition of Hippo signaling in scrib mutant eye disc clones is not dependent upon JNK activity, but can be significantly rescued by reducing aPKC kinase activity, and ectopic aPKC activity is sufficient to impair Hippo signaling in the eye disc, even when JNK signaling is blocked. In contrast, warts mutant overgrowth does not require aPKC activity. Moreover, reducing endogenous levels of aPKC or increasing Scrib or Lethal giant larvae levels does not promote increased Hippo signaling, suggesting that aPKC activity is not normally rate limiting for Hippo pathway activity. Epistasis experiments suggest that Hippo pathway inhibition in scrib mutants occurs, at least in part, downstream or in parallel to both the Expanded and Fat arms of Hippo pathway regulation. Conclusions Loss of Scrib promotes Yorkie/Scalloped-dependent epithelial tissue

  19. Association of sexually transmitted infections, Candida species, gram-positive flora and perianal flora with bacterial vaginosis.

    Science.gov (United States)

    Vahidnia, Ali; Tuin, Hellen; Bliekendaal, Harry; Spaargaren, Joke

    2015-10-01

    Bacterial vaginosis (BV) is characterised by depletion of the normal Lactobacillus spp. and overgrowth of commensal anaerobic bacteria. We investigated the composition of vaginal microbiota and their association with BV in women of reproductive age. Vaginal samples from 1197 women were analysed, whereby n=451 patients had normal flora and n=614 were diagnosed with BV, the remaining patients were diagnosed with having either intermediate flora (n=42) or dysbacteriosis (n=90). The reported results show that pathogens are associated with BV. This knowledge will further expand our understanding of events leading to BV, which may lead to more effective prevention and treatment strategies.

  20. Effects of rifaximin on bacterial translocation in thioacetamide-induced liver injury in rats.

    Science.gov (United States)

    Harputluoglu, Murat M M; Demirel, Ulvi; Gul, Mehmet; Temel, Ismail; Gursoy, Sule; Selcuk, Engin Burak; Aladag, Murat; Bilgic, Yilmaz; Gunduz, Ercan; Seckin, Yuksel

    2012-08-01

    Intestinal bacterial overgrowth (IBO) and increased mucosal permeability are suggested to increase bacterial translocation (BT) in liver injury. Rifaximin (RIF) is a minimally absorbed oral antimicrobial agent that restores gut microflora imbalance. The aim of the present study was to investigate the effects of RIF on BT frequency in thioacetamide (TAA)-induced liver injury. Group 1 was the control. In group 2 (TAA), rats received TAA daily for 3 days. In group 3 (TAA + RIF), RIF was commenced on the same day as the first dose of TAA. In group 4 (RIF), rats received only RIF. Ileal aspirate Escherichia coli counts were significantly lower in the TAA + RIF group than in TAA group. There was no difference in BT frequency between the TAA and TAA + RIF groups. Our results suggest that factors such as intestinal barrier dysfunction and impaired host immune shield, apart from IBO, play an important role in BT in this model.

  1. Groundwater geochemistry observations in littoral caves of Mallorca (western Mediterranean: implications for deposition of phreatic overgrowths on speleothems

    Directory of Open Access Journals (Sweden)

    Bogdan P. Onac

    2014-05-01

    Full Text Available Phreatic overgrowths on speleothems (POS precipitate at the air-water interface in the littoral caves of Mallorca, Spain. Mainly composed of calcite, aragonite POS are also observed in specific locations. To characterize the geochemical environment of the brackish upper water column, water samples and salinity values were collected from water profiles (0-2.9 m in April 2012 and March 2013 near aragonite POS in Cova des Pas de Vallgornera and calcite POS in Coves del Drac (hereafter, Vallgornera and Drac. Degassing of CO2 from the water was evidenced by the existence of lower dissolved inorganic carbon (DIC concentration and enriched δ13CDIC values in a thin surface layer (the uppermost 0.4 m, which was observed in both profiles from Drac. This process is facilitated by the efficient exchange of cave air with the atmosphere, creating a CO2 partial pressure (pCO2 disparity between the cave water and air, resulting in the precipitation of calcite POS as CO2 degasses from the water. The degassed upper layer was not observed in either profile from Vallgornera, suggesting that less efficient cave ventilation restricts outgassing of CO2, which also results in accumulation of CO2 in the cave atmosphere. The presence of an existing uncorroded POS horizon, as well as higher concentrations and large amplitude fluctuations of cave air pCO2, may indicate that aragonite POS deposition is currently episodic in Vallgornera. Ion concentration data from monthly water samples collected in each cave between October 2012 and March 2013 indicate higher Mg:Ca, Sr:Ca, Ba:Ca and Sr:Mg ratios in Vallgornera. Salinity alone does not appear to be a viable proxy for ions that may promote aragonite precipitation or inhibit calcite precipitation. Instead, these ions may be contributed by more intense bedrock weathering or deep groundwater flow.

  2. Avoidance of Maternal Cell Contamination and Overgrowth in Isolating Fetal Chorionic Villi Mesenchymal Stem Cells from Human Term Placenta.

    Science.gov (United States)

    Sardesai, Varda S; Shafiee, Abbas; Fisk, Nicholas M; Pelekanos, Rebecca A

    2017-04-01

    Human placenta is rich in mesenchymal stem/stromal cells (MSC), with their origin widely presumed fetal. Cultured placental MSCs are confounded by a high frequency of maternal cell contamination. Our recent systematic review concluded that only a small minority of placental MSC publications report fetal/maternal origin, and failed to discern a specific methodology for isolation of fetal MSC from term villi. We determined isolation conditions to yield fetal and separately maternal MSC during ex vivo expansion from human term placenta. MSCs were isolated via a range of methods in combination; selection from various chorionic regions, different commercial media, mononuclear cell digest and/or explant culture. Fetal and maternal cell identities were quantitated in gender-discordant pregnancies by XY chromosome fluorescence in situ hybridization. We first demonstrated reproducible maternal cell contamination in MSC cultures from all chorionic anatomical locations tested. Cultures in standard media rapidly became composed entirely of maternal cells despite isolation from fetal villi. To isolate pure fetal cells, we validated a novel isolation procedure comprising focal dissection from the cotyledonary core, collagenase/dispase digestion and explant culture in endothelial growth media that selected, and provided a proliferative environment, for fetal MSC. Comparison of MSC populations within the same placenta confirmed fetal to be smaller, more osteogenic and proliferative than maternal MSC. We conclude that in standard media, fetal chorionic villi-derived MSC (CV-MSC) do not grow readily, whereas maternal MSC proliferate to result in maternal overgrowth during culture. Instead, fetal CV-MSCs require isolation under specific conditions, which has implications for clinical trials using placental MSC. Stem Cells Translational Medicine 2017;6:1070-1084.

  3. Effect of azithromycin on gingival overgrowth induced by cyclosporine A + nifedipine combination therapy: A morphometric analysis in rats

    Directory of Open Access Journals (Sweden)

    Madhu Singh Ratre

    2016-01-01

    Full Text Available Background: Drug-induced gingival overgrowth (DIGO is a well-known adverse effect of cyclosporine A (CsA and nifedipine (Nf therapy. The aim of the present morphometric study was to evaluate the effect of azithromycin (Azi on the combined GO in rats induced by CsA + Nf combination. Materials and Methods: Thirty Sprague-Dawley male rats were randomly divided equally into three groups. Group 1 (control received olive oil only; Group 2 received a combination of CsA and Nf in olive oil throughout the study period; Group 3 received CsA + Nf combination therapy, and Azi was added for 1 week in the 5th week. All the drugs were delivered by oral route. Impressions of the mandibular central incisal regions were taken, and study models were prepared at baseline and biweekly up to the 8 weeks. Statistical analysis was done by one-way analysis of variance and intergroup comparisons were made using Tukey's post hoc analysis. Results: Significant GO was evident in Group 2 and Group 3 rats when compared to Group 1. However, in Group 3 (Azi, GO was observed up to the 4th week, but a significant decrease in GO was noticed during 6–8th week after the administration of Azi in 5th week. Conclusion: Azi is an effective drug in the remission of DIGO induced by combined therapy of CsA + Nf and thereby can be considered as a useful therapeutic regimen in minimizing the DIGO in transplant patients.

  4. Deeply hidden inside introduced biogenic structures - Pacific oyster reefs reduce detrimental barnacle overgrowth on native blue mussels

    Science.gov (United States)

    Buschbaum, Christian; Cornelius, Annika; Goedknegt, M. Anouk

    2016-11-01

    In sedimentary coastal ecosystems shells of epibenthic organisms such as blue mussels (Mytilus edulis) provide the only major attachment surface for barnacle epibionts, which may cause detrimental effects on their mussel basibionts by e.g. reducing growth rate. In the European Wadden Sea, beds of native blue mussels have been invaded by Pacific oysters Crassostrea gigas, which transformed these beds into mixed reefs of oysters with mussels. In this study, we determined the spatial distribution of M. edulis and their barnacle epibionts (Semibalanus balanoides) within the reef matrix. Mean mussel density near the bottom was about twice as high compared to the mussel density near the top of an oyster reef, whereas barnacles on mussels showed a reversed pattern. Barnacle dry weight per mussel was on average 14 times higher near the top than at the bottom. This pattern was confirmed by experimentally placing clean M. edulis at the top and on the bottom of oyster reefs at two sites in the Wadden Sea (island of Texel, The Netherlands; island of Sylt, Germany). After an experimental period of five weeks (April and May 2015, the main settlement period of S. balanoides), the number of barnacles per mussel was at both sites significantly higher on mussels near the top compared to near the bottom. We conclude that the oyster reef matrix offers a refuge for M. edulis: inside reefs they are not only better protected against predators but also against detrimental barnacle overgrowth. This study shows that alien species can cause beneficial effects for native organisms and should not be generally considered as a risk for the recipient marine ecosystems.

  5. Polymer Coatings of Cochlear Implant Electrode Surface - An Option for Improving Electrode-Nerve-Interface by Blocking Fibroblast Overgrowth.

    Directory of Open Access Journals (Sweden)

    C Hadler

    Full Text Available Overgrowth of connective tissue and scar formation induced by the electrode array insertion increase the impedance and, thus, diminish the interactions between neural probes as like cochlear implants (CI and the target tissue. Therefore, it is of great clinical interest to modify the carrier material of the electrodes to improve the electrode nerve interface for selective cell adhesion. On one side connective tissue growth needs to be reduced to avoid electrode array encapsulation, on the other side the carrier material should not compromise the interaction with neuronal cells. The present in vitro-study qualitatively and quantitatively characterises the interaction of fibroblasts, glial cells and spiral ganglion neurons (SGN with ultrathin poly(N,N-dimethylacrylamide (PDMAA, poly(2-ethyloxazoline (PEtOx and poly([2-methacryloyloxyethyl]trimethylammoniumchlorid (PMTA films immobilised onto glass surfaces using a photoreactive anchor layer. The layer thickness and hydrophilicity of the polymer films were characterised by ellipsometric and water contact angle measurement. Moreover the topography of the surfaces was investigated using atomic force microscopy (AFM. The neuronal and non-neuronal cells were dissociated from spiral ganglions of postnatal rats and cultivated for 48 h on top of the polymer coatings. Immunocytochemical staining of neuronal and intermediary filaments revealed that glial cells predominantly attached on PMTA films, but not on PDMAA and PEtOx monolayers. Hereby, strong survival rates and neurite outgrowth were only found on PMTA, whereas PDMAA and PEtOx coatings significantly reduced the SG neuron survival and neuritogenesis. As also shown by scanning electron microscopy (SEM SGN strongly survived and retained their differentiated phenotype only on PMTA. In conclusion, survival and neuritogenesis of SGN may be associated with the extent of the glial cell growth. Since PMTA was the only of the polar polymers used in this study

  6. Assessment of 11p loci status of Simpson-Golabi-Behmel (SGBS) somatic overgrowth syndrome and associated embryonal tumours

    Energy Technology Data Exchange (ETDEWEB)

    Xuan, J.Y.; McKenzie, A.E. [Univ. of Ottawa (Canada); Hughes-Benzie, R. [Children`s Hospital of Eastern Ontario (Canada)

    1994-09-01

    SGBS, a somatic overgrowth syndrome which we have recently mapped to Xq25-q27, shows significant clinical overlap with the more common Beckwith-Wiedemann syndrome (BWS) including an increased risk of developing embryonal tumors. Two genes from the BWS-linked 11p15 region, IGF2 and H19, are known to undergo parental imprinting. Relaxation of this imprinting has recently been demonstrated in some BWS cases and isolated Wilm`s tumour (WT). Since SGBS and BWS have been postulated to represent distinct defects in a common pathway, we have studied the methylation pattern and transcriptional activity of IGF2 and H19 in isolated SGBS +/- WT tissue. No consistent methylation abnormalities were observed in genomic DNA isolated from SGBS WBC, placenta, fibroblast or cleft lip tissues. Genotyping of H19 cDNA polymorphisms from SGBS fibroblast revealed normal mono-allelic gene expression. IGF2 is currently being analyzed in a similar fashion. It appears that, in distinction from some cases of BWS, abberant 11p15 loci imprinting is not a factor in SGBS pathogenesis in our study population. Furthermore, genotyping with microsatellites in a large SGBS kindred did not reveal inheritance of a common 11p13-15.5 chromosomal region in the 3 children with WT. Loss of heterozygosity (LOH) secondary to a maternal allele duplication was detected in the 11p15.5 loci in the tumor tissue of both SGBS WTs assayed. Thus, while spontaneous relaxation of 11p15 loci imprinting was not observed in either SGBS or SGBS WT, a de facto LOH-based imprinting abnormality is observed in SGBS associated WT. It is unknown if SGBS predisposes renal cells to LOH or confers a cellular selective advantage following LOH or both.

  7. Effects of laxative and N-acetylcysteine on mucus accumulation, bacterial load, transit, and inflammation in the cystic fibrosis mouse small intestine.

    Science.gov (United States)

    De Lisle, Robert C; Roach, Eileen; Jansson, Kyle

    2007-09-01

    The accumulation of mucus in affected organs is characteristic of cystic fibrosis (CF). The CF mouse small intestine has dramatic mucus accumulation and exhibits slower interdigestive intestinal transit. These factors are proposed to play cooperative roles that foster small intestinal bacterial overgrowth (SIBO) and contribute to the innate immune response of the CF intestine. It was hypothesized that decreasing the mucus accumulation would reduce SIBO and might improve other aspects of the CF intestinal phenotype. To test this, solid chow-fed CF mice were treated with an osmotic laxative to improve gut hydration or liquid-fed mice were treated orally with N-acetylcysteine (NAC) to break mucin disulfide bonds. Treatment with laxative or NAC reduced mucus accumulation by 43% and 50%, respectively, as measured histologically as dilation of the intestinal crypts. Laxative and NAC also reduced bacterial overgrowth in the CF intestine by 92% and 63%, respectively. Treatment with laxative normalized small intestinal transit in CF mice, whereas NAC did not. The expression of innate immune response-related genes was significantly reduced in laxative-treated CF mice, whereas there was no significant effect in NAC-treated CF mice. In summary, laxative and NAC treatments of CF mice reduced mucus accumulation to a similar extent, but laxative was more effective than NAC at reducing bacterial load. Eradication of bacterial overgrowth by laxative treatment was associated with normalized intestinal transit and a reduction in the innate immune response. These results suggest that both mucus accumulation and slowed interdigestive small intestinal transit contribute to SIBO in the CF intestine.

  8. Comprehensive postmortem analyses of intestinal microbiota changes and bacterial translocation in human flora associated mice.

    Directory of Open Access Journals (Sweden)

    Markus M Heimesaat

    Full Text Available BACKGROUND: Postmortem microbiological examinations are performed in forensic and medical pathology for defining uncertain causes of deaths and for screening of deceased tissue donors. Interpretation of bacteriological data, however, is hampered by false-positive results due to agonal spread of microorganisms, postmortem bacterial translocation, and environmental contamination. METHODOLOGY/PRINCIPAL FINDINGS: We performed a kinetic survey of naturally occurring postmortem gut flora changes in the small and large intestines of conventional and gnotobiotic mice associated with a human microbiota (hfa applying cultural and molecular methods. Sacrificed mice were kept under ambient conditions for up to 72 hours postmortem. Intestinal microbiota changes were most pronounced in the ileal lumen where enterobacteria and enterococci increased by 3-5 orders of magnitude in conventional and hfa mice. Interestingly, comparable intestinal overgrowth was shown in acute and chronic intestinal inflammation in mice and men. In hfa mice, ileal overgrowth with enterococci and enterobacteria started 3 and 24 hours postmortem, respectively. Strikingly, intestinal bacteria translocated to extra-intestinal compartments such as mesenteric lymphnodes, spleen, liver, kidney, and cardiac blood as early as 5 min after death. Furthermore, intestinal tissue destruction was characterized by increased numbers of apoptotic cells and neutrophils within 3 hours postmortem, whereas counts of proliferative cells as well as T- and B-lymphocytes and regulatory T-cells decreased between 3 and 12 hours postmortem. CONCLUSIONS/SIGNIFICANCE: We conclude that kinetics of ileal overgrowth with enterobacteria and enterococci in hfa mice can be used as an indicator for compromized intestinal functionality and for more precisely defining the time point of death under defined ambient conditions. The rapid translocation of intestinal bacteria starting within a few minutes after death will help

  9. Pretreatment with a γ-Secretase Inhibitor Prevents Tumor-like Overgrowth in Human iPSC-Derived Transplants for Spinal Cord Injury

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    Toshiki Okubo

    2016-10-01

    Full Text Available Neural stem/progenitor cells (NS/PCs derived from human induced pluripotent stem cells (hiPSCs are considered to be a promising cell source for cell-based interventions that target CNS disorders. We previously reported that transplanting certain hiPSC-NS/PCs in the spinal cord results in tumor-like overgrowth of hiPSC-NS/PCs and subsequent deterioration of motor function. Remnant immature cells should be removed or induced into more mature cell types to avoid adverse effects of hiPSC-NS/PC transplantation. Because Notch signaling plays a role in maintaining NS/PCs, we evaluated the effects of γ-secretase inhibitor (GSI and found that pretreating hiPSC-NS/PCs with GSI promoted neuronal differentiation and maturation in vitro, and GSI pretreatment also reduced the overgrowth of transplanted hiPSC-NS/PCs and inhibited the deterioration of motor function in vivo. These results indicate that pretreatment with hiPSC-NS/PCs decreases the proliferative capacity of transplanted hiPSC-NS/PCs, triggers neuronal commitment, and improves the safety of hiPSC-based approaches in regenerative medicine.

  10. Prevention of bacterial adhesion

    DEFF Research Database (Denmark)

    Klemm, Per; Vejborg, Rebecca Munk; Hancock, Viktoria

    2010-01-01

    Management of bacterial infections is becoming increasingly difficult due to the emergence and increasing prevalence of bacterial pathogens that are resistant to available antibiotics. Conventional antibiotics generally kill bacteria by interfering with vital cellular functions, an approach...... that imposes selection pressure for resistant bacteria. New approaches are urgently needed. Targeting bacterial virulence functions directly is an attractive alternative. An obvious target is bacterial adhesion. Bacterial adhesion to surfaces is the first step in colonization, invasion, and biofilm formation....... As such, adhesion represents the Achilles heel of crucial pathogenic functions. It follows that interference with adhesion can reduce bacterial virulence. Here, we illustrate this important topic with examples of techniques being developed that can inhibit bacterial adhesion. Some of these will become...

  11. Peritonitis - spontaneous bacterial

    Science.gov (United States)

    Spontaneous bacterial peritonitis (SBP); Ascites - peritonitis; Cirrhosis - peritonitis ... who are on peritoneal dialysis for kidney failure. Peritonitis may have other causes . These include infection from ...

  12. Local Inflammation Alters MMP-2 and MMP-9 Gelatinase Expression Associated with the Severity of Nifedipine-Induced Gingival Overgrowth: a Rat Model Study.

    Science.gov (United States)

    Li, Wu-Li; Wu, Cheng-Hai; Yang, Jun; Tang, Min; Chen, Long-Jie; Zhao, Shou-Liang

    2015-08-01

    Nifedipine-induced gingival overgrowth (NIGO) is characterized by cell proliferation and extracellular matrix (ECM) component accumulation in gingival connective tissues, with varying degrees of inflammation and fibrosis. Impaired collagen and ECM homeostasis may be among the underlying molecular mechanisms that lead to the fibrotic changes that occur in drug-induced gingival overgrowth (DIGO). Because matrix metalloproteinases (MMPs) play vital roles in regulating collagen and ECM metabolism, many studies have been performed to reveal the relationship between MMPs and DIGO. It is thought that the gelatinases MMP-2 and MMP-9, both type IV collagenases, are involved in the development of tissue inflammation and organ fibrosis. However, the few studies regarding gelatinase expression in DIGO are controversial. Recent studies have demonstrated the inhibitory effect of cyclosporine A (CsA) on gelatinase expression and/or activity; however, similar changes have yet to be detected in Nif-treated gingival tissues. In this study, we verified that Nif treatment could lead to gingival overgrowth in rats and that gingival inflammation played a pro-proliferative role in NIGO development. Additionally, we examined the temporal expression of gelatinases on days 0, 7, 14, 21, 30, and 40 during NIGO development. The aim was to investigate whether MMP-2 and MMP-9 played significant roles in regulating NIGO development and progression. MMP-2 gene expression was not altered by Nif treatment alone but was significantly inhibited by Nif treatment for 30 days in the presence of local inflammation. However, no significant alterations in MMP-2 protein expression were detected in the Nif-treated gingival tissue, regardless of the presence or absence of local inflammation. Moreover, Nif treatment could lead to transient and significant increases in MMP-9 gene and protein expression levels in the presence of local inflammation. In particular, active MMP-9 expression increased significantly

  13. Bacterial translocation:the core of gut microbiota dysbiosis in patients with short bowel syndrome%肠道细菌移居:短肠综合征肠道微生态紊乱的核心

    Institute of Scientific and Technical Information of China (English)

    范圣先; 李幼生

    2015-01-01

    人体肠道定植着大量细菌,正常情况下肠道菌群处于动态平衡.短肠综合征患者肠道正常的菌群结构遭到破坏,使肠道微生态发生显著变化:结肠菌群失调、小肠细菌过度生长,导致肠道消化及吸收功能障碍、黏膜炎症,进而延长肠外营养支持治疗时间.与此同时,小肠细菌过度生长还会导致肠功能障碍相关性肝损伤,最终导致机体各种功能障碍.本文综述短肠综合征患者肠道细菌在肠道内的移居,为其治疗及预防提供理论基础.%The human gastrointestinal tract is colonized by complex and diverse microbiota which maintains an ecological balance under normal circumstances.Short bowel syndrome causes damage to the normal flora which predisposes the patient to colonic dysbacteriosis and small intestine bacterial overgrowth.Small intestine bacterial overgrowth may lead to digestive and absoptive disfunctions, mucosal inflammation, and may delay or prevent weaning from total parenteral nutrition.Moreover, small intestine bacterial overgrowth may be one of the causes of intestinal failure-associated liver disease, and eventually lead to various body dysfunctions.In this review, the bacterial translocation in short bowel syndrome were summarized, providing the theoretic proofs to treatment and prevention.

  14. Microbiota and the gut-liver axis: bacterial translocation, inflammation and infection in cirrhosis.

    Science.gov (United States)

    Giannelli, Valerio; Di Gregorio, Vincenza; Iebba, Valerio; Giusto, Michela; Schippa, Serena; Merli, Manuela; Thalheimer, Ulrich

    2014-12-07

    Liver disease is associated with qualitative and quantitative changes in the intestinal microbiota. In cirrhotic patients the alteration in gut microbiota is characterized by an overgrowth of potentially pathogenic bacteria (i.e., gram negative species) and a decrease in autochthonous familiae. Here we summarize the available literature on the risk of gut dysbiosis in liver cirrhosis and its clinical consequences. We therefore described the features of the complex interaction between gut microbiota and cirrhotic host, the so called "gut-liver axis", with a particular attention to the acquired risk of bacterial translocation, systemic inflammation and the relationship with systemic infections in the cirrhotic patient. Such knowledge might help to develop novel and innovative strategies for the prevention and therapy of gut dysbiosis and its complication in liver cirrhosis.

  15. Void Shapes Controlled by Using Interruption-Free Epitaxial Lateral Overgrowth of GaN Films on Patterned SiO2 AlN/Sapphire Template

    Directory of Open Access Journals (Sweden)

    Yu-An Chen

    2014-01-01

    Full Text Available GaN epitaxial layers with embedded air voids grown on patterned SiO2 AlN/sapphire templates were proposed. Using interruption-free epitaxial lateral overgrowth technology, we realized uninterrupted growth and controlled the shape of embedded air voids. These layers showed improved crystal quality using X-ray diffraction and measurement of etching pits density. Compared with conventional undoped-GaN film, the full width at half-maximum of the GaN (0 0 2 and (1 0 2 peaks decreased from 485 arcsec to 376 arcsec and from 600 arcsec to 322 arcsec, respectively. Transmission electron microscopy results showed that the coalesced GaN growth led to bending threading dislocation. We also proposed a growth model based on results of scanning electron microscopy.

  16. MQWs InGaN/GaN LED with embedded micro-mirror array in the epitaxial-lateral-overgrowth gallium nitride for light extraction enhancement.

    Science.gov (United States)

    Huang, Chen-Yang; Ku, Hao-Min; Liao, Chen-Zi; Chao, Shiuh

    2010-05-10

    Multi-quantum wells (MQWs) InGaN/GaN LEDs, 300 microm x 300 microm chip size, were fabricated with Ta(2)O(5) / SiO(2) dielectric multi-layer micro-mirror array (MMA) embedded in the epitaxiallateral- overgrowth (ELOG) gallium nitride (GaN) on the c-plane sapphire substrate. MQWs InGaN/GaN LEDs with ELOG embedded patterned SiO(2) array (P-SiO(2)) of the same dimension as the MMA were also fabricated for comparison. Dislocation density was reduced for the ELOG samples. 75.2% light extraction enhancement for P-SiO(2)-LED and 102.6% light extraction enhancement for MMA-LED were obtained over the standard LED. We showed that multiple-diffraction with high intensity from the MMA redirected the trap lights to escape from the LED causing the light extraction enhancement.

  17. Germline Mutations in RASA1 Are Not Found in Patients with Klippel-Trenaunay Syndrome or Capillary Malformation with Limb Overgrowth.

    Science.gov (United States)

    Revencu, N; Boon, L M; Dompmartin, A; Rieu, P; Busch, W L; Dubois, J; Forzano, F; van Hagen, J M; Halbach, S; Kuechler, A; Lachmeijer, A M A; Lähde, J; Russell, L; Simola, K O J; Mulliken, J B; Vikkula, M

    2013-04-01

    The RASA1 gene encodes p120RASGAP, a multidomain cytoplasmic protein that acts as a negative regulator of the RAS signalling pathway. Heterozygous loss-of-function RASA1 mutations were identified in patients with Parkes Weber syndrome and multifocal capillary malformations. This syndrome is characterised by a capillary blush on an extremity, arteriovenous microfistulas, and bony and soft tissue hypertrophy. The aim of this study was to test RASA1 in 2 disorders characterised by asymmetric limb enlargement and vascular malformations, namely Klippel-Trenaunay syndrome and regional capillary malformation with overgrowth. We did not identify any clear pathogenic change in these patients. Thus, besides clinical and radiological criteria, RASA1 testing constitutes an additional tool to differentiate Parkes Weber syndrome of capillary malformation-arteriovenous malformation (CM-AVM) from overlapping disorders.

  18. Prevention of bacterial adhesion

    DEFF Research Database (Denmark)

    Klemm, Per; Vejborg, Rebecca Munk; Hancock, Viktoria

    2010-01-01

    Management of bacterial infections is becoming increasingly difficult due to the emergence and increasing prevalence of bacterial pathogens that are resistant to available antibiotics. Conventional antibiotics generally kill bacteria by interfering with vital cellular functions, an approach that ...... valuable weapons for preventing pathogen contamination and fighting infectious diseases in the future....

  19. Down-regulation of transforming growth factor beta-2 expression is associated with the reduction of cyclosporin induced gingival overgrowth in rats treated with roxithromycin: an experimental study

    Directory of Open Access Journals (Sweden)

    Aarestrup Fernando

    2009-12-01

    Full Text Available Abstract Background Gingival overgrowth (GO is a common side effect of the chronic use of cyclosporine (CsA, an immunosuppressant widely used to prevent rejection in transplant patients. Recent studies have reported elevated levels of specific cytokines in gingival overgrowth tissue, particularly TGF-beta, suggesting that this growth factor plays a role in the accumulation of extracellular matrix materials. The effectiveness of azithromycin, a macrolide antibiotic, in the regression of this undesirable side effect has also been demonstrated. Methods In this study, we created an experimental model for assessing the therapeutic effect of roxithromycin in GO and the expression of transforming growth factor beta (TGF-beta2 through immunohistochemistry. We used four groups of rats totaling 32 individuals. GO was induced during five weeks and drug treatment was given on the 6th week as follows: group 1 received saline; group 2 received CsA and was treated with saline on the 6th week; group 3 received CsA and, on the 6th week, ampicilin; and group 4 received CsA during 5 weeks and, on the 6th week, was treated with roxithromycin. Results The results demonstrated that roxithromycin treatment was effective in reducing cyclosporine-induced GO in rats. Both epithelial and connective tissue showed a decrease in thickness and a significant reduction in TGF-beta2 expression, with a lower number of fibroblasts, reduction in fibrotic areas and decrease in inflammatory infiltrate. Conclusion The present data suggest that the down-regulation of TGF-beta2 expression may be an important mechanism of action by which roxithromycin inhibits GO.

  20. Ubiquitous Low-FeO Relict Grains in Type II Chondrules and Limited Overgrowths on Phenocrysts Following the Final Melting Event

    Science.gov (United States)

    Wasson, John T.; Rubin, Alan E.

    2006-01-01

    Type II porphyritic chondrules commonly contain several large (>40 microns) olivine phenocrysts; furnace-based cooling rates based on the assumption that these phenocrysts grew in a single-stage melting-cooling event yield chondrule cooling-rate estimates of 0.01-1 K/s. Because other evidence indicates much higher cooling rates, we examined type 11 chondrules in the CO3.0 chondrites that have experienced only minimal parent-body alteration. We discovered three kinds of evidence indicating that only minor (4-10 microns) olivine growth occurred after the final melting event: (1) Nearly all (>90%) type II chondrules in CO3.0 chondrites contain low-FeO relict grains; overgrowths on these relicts are narrow, in the range of 2-12 microns. (2) Most type II chondrules contain some FeO-rich olivine grains with decurved surfaces and acute angles between faces indicating that the grains are fragments from an earlier generation of chondrules; the limited overgrowth thicknesses following the last melting event are too thin to disguise the shard-like nature of these grains. (3) Most type II chondrules contain many small (40 microns) high-FeO phenocrysts are relicts from earlier generations of chondrules, and that cooling rates after the last melting event were much more rapid than indicated by models based on a single melting event. These observations are thus inconsistent with the "classic" igneous model of formation of type II porphyritic chondrules by near-total melting of a precursor mix followed by olivine nucleation on a very limited number of nuclei (say, <10) and by growth to produce the large phenocrysts during a period of monotonic (and roughly linear) cooling. Our observations that recycled chondrule materials constitute a large component of the phenocrysts of type II chondrules also imply that this kind of chondrule formed relatively late during the chondrule-forming period.

  1. Vimentin in Bacterial Infections

    DEFF Research Database (Denmark)

    Mak, Tim N; Brüggemann, Holger

    2016-01-01

    Despite well-studied bacterial strategies to target actin to subvert the host cell cytoskeleton, thus promoting bacterial survival, replication, and dissemination, relatively little is known about the bacterial interaction with other components of the host cell cytoskeleton, including intermediate...... filaments (IFs). IFs have not only roles in maintaining the structural integrity of the cell, but they are also involved in many cellular processes including cell adhesion, immune signaling, and autophagy, processes that are important in the context of bacterial infections. Here, we summarize the knowledge...... about the role of IFs in bacterial infections, focusing on the type III IF protein vimentin. Recent studies have revealed the involvement of vimentin in host cell defenses, acting as ligand for several pattern recognition receptors of the innate immune system. Two main aspects of bacteria...

  2. Interfering with bacterial gossip

    DEFF Research Database (Denmark)

    Bjarnsholt, Thomas; Tolker-Nielsen, Tim; Givskov, Michael

    2011-01-01

    defense. Antibiotics exhibit a rather limited effect on biofilms. Furthermore, antibiotics have an ‘inherent obsolescence’ because they select for development of resistance. Bacterial infections with origin in bacterial biofilms have become a serious threat in developed countries. Pseudomonas aeruginosa...... that appropriately target bacteria in their relevant habitat with the aim of mitigating their destructive impact on patients. In this review we describe molecular mechanisms involved in “bacterial gossip” (more scientifically referred to as quorum sensing (QS) and c-di-GMP signaling), virulence, biofilm formation......, resistance and QS inhibition as future antimicrobial targets, in particular those that would work to minimize selection pressures for the development of resistant bacteria....

  3. Bacterial intermediate filaments

    DEFF Research Database (Denmark)

    Charbon, Godefroid; Cabeen, M.; Jacobs-Wagner, C.

    2009-01-01

    Crescentin, which is the founding member of a rapidly growing family of bacterial cytoskeletal proteins, was previously proposed to resemble eukaryotic intermediate filament (IF) proteins based on structural prediction and in vitro polymerization properties. Here, we demonstrate that crescentin...

  4. Bacterial Wound Culture

    Science.gov (United States)

    ... Home Visit Global Sites Search Help? Bacterial Wound Culture Share this page: Was this page helpful? Also known as: Aerobic Wound Culture; Anaerobic Wound Culture Formal name: Culture, wound Related ...

  5. Bacterial surface adaptation

    Science.gov (United States)

    Utada, Andrew

    2014-03-01

    Biofilms are structured multi-cellular communities that are fundamental to the biology and ecology of bacteria. Parasitic bacterial biofilms can cause lethal infections and biofouling, but commensal bacterial biofilms, such as those found in the gut, can break down otherwise indigestible plant polysaccharides and allow us to enjoy vegetables. The first step in biofilm formation, adaptation to life on a surface, requires a working knowledge of low Reynolds number fluid physics, and the coordination of biochemical signaling, polysaccharide production, and molecular motility motors. These crucial early stages of biofilm formation are at present poorly understood. By adapting methods from soft matter physics, we dissect bacterial social behavior at the single cell level for several prototypical bacterial species, including Pseudomonas aeruginosa and Vibrio cholerae.

  6. Bacterial Meningitis in Infants

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2004-04-01

    Full Text Available A retrospective study of 80 infantile patients (ages 30-365 days; 47 male, 33 female with culture-proven bacterial meningitis seen over a 16 year period (1986-2001 is reported from Taiwan.

  7. Bacterial proteases and virulence

    DEFF Research Database (Denmark)

    Frees, Dorte; Brøndsted, Lone; Ingmer, Hanne

    2013-01-01

    Bacterial pathogens rely on proteolysis for variety of purposes during the infection process. In the cytosol, the main proteolytic players are the conserved Clp and Lon proteases that directly contribute to virulence through the timely degradation of virulence regulators and indirectly by providing....... These extracellular proteases are activated in complex cascades involving auto-processing and proteolytic maturation. Thus, proteolysis has been adopted by bacterial pathogens at multiple levels to ensure the success of the pathogen in contact with the human host....

  8. Expression of Integrins in Drug-induced Gingival Overgrowth%整合素在药物性牙龈增生中的表达研究

    Institute of Scientific and Technical Information of China (English)

    周洁

    2012-01-01

    Objective: To investigate the possible correlation between integrin al , a2 and (31 expression and excessive collagen synthesis in fibroblasts from drug-induced gingival overgrowth (DIGO) patients. Methods: Gingival fibroblasts from five DIGO patients and five healthy subjects were included. The expression of al, a2 and (31 integrin subunits was examined by immunohistochemistry and quantitative PCR. Results: Our results demonstrate that the expression of al was significantly lower in HGF fibroblasts compared with control fibroblasts (P<0. 01). No significant differences in the expression of a2 and (31 were detected. Conclusion: The decreased expression of integrin al in DIGO fibroblasts may be related to the excessive collagen deposition in DIGO patients.%目的:检测整合素α1、α2和β1在来源于药物性牙龈增生(drug-induced gingival overgrowth,DIGO)患者的牙龈成纤维细胞中的表达水平变化,探讨其与DIGO胶原聚集的相关性.方法:采用免疫组织化学法和实时定量PCR分别检测整合素α1、α2和β1在来源于DIGO和正常人群牙龈组织和成纤维细胞中的表达水平.结果:整合素α1在DIGO牙龈成纤维细胞中的表达水平显著性低于其在正常牙龈成纤维细胞中的表达水平(P<0.01).而整合索α2和β1在2组牙龈成纤维细胞中的表达水平无显著性差异.结论:整合素α1在DIGO牙龈成纤维细胞中的低表达可能与胶原聚集相关.

  9. The bacterial lipocalins.

    Science.gov (United States)

    Bishop, R E

    2000-10-18

    The lipocalins were once regarded as a eukaryotic protein family, but new members have been recently discovered in bacteria. The first bacterial lipocalin (Blc) was identified in Escherichia coli as an outer membrane lipoprotein expressed under conditions of environmental stress. Blc is distinguished from most lipocalins by the absence of intramolecular disulfide bonds, but the presence of a membrane anchor is shared with two of its closest homologues, apolipoprotein D and lazarillo. Several common features of the membrane-anchored lipocalins suggest that each may play an important role in membrane biogenesis and repair. Additionally, Blc proteins are implicated in the dissemination of antibiotic resistance genes and in the activation of immunity. Recent genome sequencing efforts reveal the existence of at least 20 bacterial lipocalins. The lipocalins appear to have originated in Gram-negative bacteria and were probably transferred horizontally to eukaryotes from the endosymbiotic alpha-proteobacterial ancestor of the mitochondrion. The genome sequences also reveal that some bacterial lipocalins exhibit disulfide bonds and alternative modes of subcellular localization, which include targeting to the periplasmic space, the cytoplasmic membrane, and the cytosol. The relationships between bacterial lipocalin structure and function further illuminate the common biochemistry of bacterial and eukaryotic cells.

  10. A genetic screen in Drosophila implicates Sex comb on midleg (Scm) in tissue overgrowth and mechanisms of Scm degradation by Wds.

    Science.gov (United States)

    Guo, Jiwei; Jin, Dan

    2015-05-01

    The sex comb on midleg (scm) gene encodes a transcriptional repressor and belongs to the Polycomb group (PcG) of genes, which regulates growth in Drosophila. Scm interacts with Polyhomeotic (a PcG protein) in vitro by recognizing its SPM domain. The homologous human protein, Sex comb on midleg-like 2 (Scml2), has been implicated in malignant brain tumors. Will die slowly (Wds) is another factor that regulates Drosophila development, and its homologous human protein, WD repeat domain 5(Wdr5), is part of the mixed lineage leukemia 1(MLL1) complex that promotes histone H3Lys4 methylation. Like Scml2, Wdr5 has been implicated in certain cancers; this protein plays an important role in leukemogenesis. In this study, we find that loss-of-function mutations in Scm result in non-autonomous tissue overgrowth in Drosophila, and determine that Scm is essential for ommatidium development and important for cell survival in Drosophila. Furthermore, our research suggests a relationship between Wds and Scm; Wds promotes Scm degradation through ubiquitination in vitro in Drosophila.

  11. High current density GaAs/Si rectifying heterojunction by defect free Epitaxial Lateral overgrowth on Tunnel Oxide from nano-seed

    Science.gov (United States)

    Renard, Charles; Molière, Timothée; Cherkashin, Nikolay; Alvarez, José; Vincent, Laetitia; Jaffré, Alexandre; Hallais, Géraldine; Connolly, James Patrick; Mencaraglia, Denis; Bouchier, Daniel

    2016-05-01

    Interest in the heteroepitaxy of GaAs on Si has never failed in the last years due to the potential for monolithic integration of GaAs-based devices with Si integrated circuits. But in spite of this effort, devices fabricated from them still use homo-epitaxy only. Here we present an epitaxial technique based on the epitaxial lateral overgrowth of micrometer scale GaAs crystals on a thin SiO2 layer from nanoscale Si seeds. This method permits the integration of high quality and defect-free crystalline GaAs on Si substrate and provides active GaAs/Si heterojunctions with efficient carrier transport through the thin SiO2 layer. The nucleation from small width openings avoids the emission of misfit dislocations and the formation of antiphase domains. With this method, we have experimentally demonstrated for the first time a monolithically integrated GaAs/Si diode with high current densities of 10 kA.cm‑2 for a forward bias of 3.7 V. This epitaxial technique paves the way to hybrid III–V/Si devices that are free from lattice-matching restrictions, and where silicon not only behaves as a substrate but also as an active medium.

  12. Spatially resolved and orientation dependent Raman mapping of epitaxial lateral overgrowth nonpolar a-plane GaN on r-plane sapphire.

    Science.gov (United States)

    Jiang, Teng; Xu, Sheng-Rui; Zhang, Jin-Cheng; Xie, Yong; Hao, Yue

    2016-01-01

    Uncoalesced a-plane GaN epitaxial lateral overgrowth (ELO) structures have been synthesized along two mask stripe orientations on a-plane GaN template by MOCVD. The morphology of two ELO GaN structures is performed by Scanning electronic microscopy. The anisotropy of crystalline quality and stress are investigated by micro-Raman spectroscopy. According to the Raman mapping spectra, the variations on the intensity, peak shift and the full width at half maximum (FWHM) of GaN E2 (high) peak indicate that the crystalline quality improvement occurs in the window region of the GaN stripes along [0001], which is caused by the dislocations bending towards the sidewalls. Conversely, the wing regions have better quality with less stress as the dislocations propagated upwards when the GaN stripes are along []. Spatial cathodoluminescence mapping results further support the explanation for the different dislocation growth mechanisms in the ELO processes with two different mask stripe orientations.

  13. Comparison of 14C and U-Th ages of two Holocene phreatic overgrowths on speleothems from Mallorca (Western Mediterranean: Environmental implications

    Directory of Open Access Journals (Sweden)

    Tuccimei Paola

    2011-01-01

    Full Text Available This investigation reports on the comparison between ICP-MS U-Th and AMS 14C ages of Phreatic Overgrowths on Speleothems (POS from two different caves on the island of Mallorca (Spain. These speleothem encrustations form at the water table of coastal caves in a low-amplitude tide-controlled microenvironment and are used to reconstruct past sea level changes. The aim of this study is to evaluate if this particular type of speleothem is datable using 14C method and to investigate possible problems connected with the incorporation of dead carbon inherited from the dissolution of 14C-free limestone. The results show that 14C ages are strongly site dependent and appear related to local residence time of water infiltration through the soil and epikarst. When short transit time and limited interaction with soil and bedrock, as in Cova de Cala Varques A, the so-called “reservoir” effect is negligible and 14C and U-Th ages corresponds within the error range. When the residence time is longer, as in Cova des Pas de Vallgornera, 14C ages are steadily 2,300-2,400 years older than the U-Th data, as shown by the mean value (25% of estimated percent dead carbon proportions and by higher and better correlated contents of major and trace elements in the vadose support of this speleothem encrustation. The potential use of this multi-method approach to paleoenvironmental studies is also suggested.

  14. STUDIES ON THE BACTERIOPHAGE OF D'HERELLE : VI. ON THE VIRULENCE OF THE OVERGROWTH IN THE LYSED CULTURES OF BACILLUS PESTIS CAVIAE (M. T. II).

    Science.gov (United States)

    Bronfenbrenner, J; Muckenfuss, R S; Korb, C

    1926-10-31

    Resistants isolated from the overgrowth of cultures of B. pestis caviae (M. T. II) lysed by various strains of specific bacteriophage proved to be avirulent when administered to mice by feeding, or by intraperitoneal injection. These cultures remained resistant to the action of bacteriophage so long as they were carried on agar. When transferred to broth, however, one group of resistants, namely, those isolated by means of "weak" phages, became susceptible to lysis after five to seven daily passages. The other group of resistants, isolated from the cultures lysed by one of the "strong" phages, failed to become susceptible to lysis even after nearly 200 passages in broth. Simultaneously with the recovery of susceptibility, the cultures of the first group regained a degree of virulence comparable to that of the parent culture of B. pestis caviae. The cultures of the second group of resistants have failed thus far to recover virulence (10 months after isolation). The latter cultures, apart from lack of both virulence and susceptibility to lysis, are identical with the parent culture of B. pestis caviae, as indicated by biochemical and antigenic properties. Our findings offer evidence in favor of the view that resistant strains result from selection among variants already existing in the parent culture and do not arise through the inheritance of specific immunity properties produced by the action of phage.

  15. Bacterial glycosyltransferase toxins.

    Science.gov (United States)

    Jank, Thomas; Belyi, Yury; Aktories, Klaus

    2015-12-01

    Mono-glycosylation of host proteins is a common mechanism by which bacterial protein toxins manipulate cellular functions of eukaryotic target host cells. Prototypic for this group of glycosyltransferase toxins are Clostridium difficile toxins A and B, which modify guanine nucleotide-binding proteins of the Rho family. However, toxin-induced glycosylation is not restricted to the Clostridia. Various types of bacterial pathogens including Escherichia coli, Yersinia, Photorhabdus and Legionella species produce glycosyltransferase toxins. Recent studies discovered novel unexpected variations in host protein targets and amino acid acceptors of toxin-catalysed glycosylation. These findings open new perspectives in toxin as well as in carbohydrate research.

  16. Seizures Complicating Bacterial Meningitis

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2004-09-01

    Full Text Available The clinical data of 116 patients, 1 month to <5 years of age, admitted for bacterial meningitis, and grouped according to those with and without seizures during hospitalization, were compared in a study at Buddhist Dalin Tzu Chi General Hospital, Chang Gung Memorial Hospital and other centers in Taiwan.

  17. Hipercrescimento femoral no tratamento cirúrgico do quadril displásico inveterado Femoral overgrowth following surgical treatment of long-established dysplasia of the hip

    Directory of Open Access Journals (Sweden)

    João Paulo Freire Martins de Moura

    2009-01-01

    Full Text Available OBJETIVO: Medir radiograficamente através de escanometria o hipercrescimento femoral em pacientes portadores de Displasia do Desenvolvimento do Quadril inveterada tratados cirurgicamente com encurtamento femoral, redução cruenta e acetabuloplastia. MÉTODOS: Avaliamos 30 crianças (33 quadris submetidas à redução cruenta pela técnica de Scaglietti e Calandriello, ostectomia para encurtamento femoral e acetabuloplastia de Salter. Haviam 29 do sexo feminino e 1 do sexo masculino, com idade média de 4 anos e 5 meses na ocasião da cirurgia. De acordo com a classificação de Zionts e MacEwen, 23 (69,6% quadris foram classificados como tipo III, 5 (15,2% como tipo I e 5 (15,2% como tipo II. O encurtamento femoral médio foi 45,12mm (variando de 30,00mm a 80,00mm. O tempo de seguimento médio foi de 10 anos e 2 meses. A discrepância femoral média mensurada nos escanogramas foi 13,48mm (variando de 0,00mm a 60,00mm após acompanhamento mínimo de 2 anos e 3 meses. RESULTADOS: Todos os pacientes evoluíram com hipercrescimento sendo que em 18 (54,6% casos a anisomelia observada foi 30mm. CONCLUSÃO: Observamos diminuição significante na diferença entre os comprimentos femorais após tratamento cirúrgico comparando com as medidas obtidas durante o seguimento ambulatorial.OBJECTIVE: To measure femoral overgrowth using radiographic scanning in patients with long-established Developmental Dysplasia of the Hip treated with femoral shaft shortening, open reduction and acetabuloplasty. METHODS: We studied 30 children (33 hips submitted to surgical treatment including femoral shaft shortening, open reduction according to Scaglietti & Calandriello's procedure and Salter acetabuloplasty without preliminary traction. There were 29 females and 1 male, with mean age = 4 years and 5 months at the time of operation. According to Zionts & MacEwen's classification, 23 hips were classified as type III (69.6%, 5 (15.2% as type I and 5 (15.2% as type II. The

  18. Effect of predatory bacteria on the gut bacterial microbiota in rats

    Science.gov (United States)

    Shatzkes, Kenneth; Tang, Chi; Singleton, Eric; Shukla, Sean; Zuena, Michael; Gupta, Shilpi; Dharani, Sonal; Rinaggio, Joseph; Connell, Nancy D.; Kadouri, Daniel E.

    2017-01-01

    Bdellovibrio bacteriovorus and Micavibrio aeruginosavorus are Gram-negative proteobacteria that are obligate predators of other Gram-negative bacteria and are considered potential alternatives to antibiotics. Most studies focusing on predatory bacteria have been performed in vitro, thus the effect of predatory bacteria on a live host, including the impact on the ecology of the native microbiota, has yet to be fully examined. In this study, intrarectal inoculations of Sprague-Dawley rats with predatory bacteria were performed. Additionally, feces were collected for seven days post-inoculation to determine the effect on gut bacterial diversity. Rat colonic tissue exhibited no abnormal histopathological effects due to predatory bacteria. A modest increase in pro-inflammatory cytokines was measured in the colons of rats inoculated with predatory bacteria by 24 and 48 hours, with all but IL-13 returning to baseline by seven days. V4 16S rRNA gene sequencing of fecal DNA demonstrated minimal shifts in taxonomic representation over the week due to predatory bacteria. Changes in bacterial populations due to exposure to B. bacteriovorus are predicted to contribute to health, however, an overgrowth of Prevotella was observed due to exposure to M. aeruginosavorus. This study further addresses safety concerns associated with the potential use of predatory bacteria to treat infections. PMID:28262674

  19. Magnesium aminoclay enhances lipid production of mixotrophic Chlorella sp. KR-1 while reducing bacterial populations.

    Science.gov (United States)

    Kim, Bohwa; Praveenkumar, Ramasamy; Lee, Jiye; Nam, Bora; Kim, Dong-Myung; Lee, Kyubock; Lee, Young-Chul; Oh, You-Kwan

    2016-11-01

    Improving lipid productivity and preventing overgrowth of contaminating bacteria are critical issues relevant to the commercialization of the mixotrophic microalgae cultivation process. In this paper, we report the use of magnesium aminoclay (MgAC) nanoparticles for enhanced lipid production from oleaginous Chlorella sp. KR-1 with simultaneous control of KR-1-associated bacterial growth in mixotrophic cultures with glucose as the model substrate. Addition of 0.01-0.1g/L MgAC promoted microalgal biomass production better than the MgAC-less control, via differential biocidal effects on microalgal and bacterial cells (the latter being more sensitive to MgAC's bio-toxicity than the former). The inhibition effect of MgAC on co-existing bacteria was, as based on density-gradient-gel-electrophoresis (DGGE) analysis, largely dosage-dependent and species-specific. MgAC also, by inducing an oxidative stress environment, increased both the cell size and lipid content of KR-1, resulting in a considerable, ∼25% improvement of mixotrophic algal lipid productivity (to ∼410mgFAME/L/d) compared with the untreated control.

  20. Seasonal Changes in Bacterial Communities Cause Foaming in a Wastewater Treatment Plant.

    Science.gov (United States)

    Wang, Ping; Yu, Zhisheng; Zhao, Jihong; Zhang, Hongxun

    2016-04-01

    Bio-foaming is a major problem in solid separation in activated sludge (AS) wastewater treatment systems. Understanding the changes in bacterial communities during sludge foaming is vital for explaining foam formation. Changes in bacterial communities in the foam, corresponding foaming AS, and non-foaming AS in a seasonal foaming wastewater treatment plant (WWTP) in Northern China were investigated by high-throughput pyrosequencing and molecular quantification-based approaches. We found that bacterial communities of the foam and the corresponding foaming AS were similar but markedly different from those of the non-foaming AS. Actinobacteria was the predominant phylum in the foam and the corresponding foaming AS, whereas Proteobacteria was predominant in the non-foaming AS. Similar to the results of most previous studies, our results showed that Candidatus "Microthrix parvicella" was the predominant filamentous bacteria in the foam and the corresponding foaming AS and was significantly enriched in the foam compared to the corresponding foaming AS. Its abundance decreased gradually with a slow disappearance of sludge foaming, indicating that its overgrowth had a direct relationship with sludge foaming. In addition to Candidatus M. parvicella, Tetrasphaera and Trichococcus might play a role in sludge foaming, because they supported the changes in AS microbial ecology for foam formation. The effluent water quality of the surveyed plant remained stable during the period of sludge foaming, but the microbial consortia responsible for nitrogen and phosphorus transformation and removal markedly changed compared to that in the non-foaming AS. This study adds to the previous understanding of bacterial communities causing foaming in WWTPs.

  1. Cooperative Bacterial Foraging Optimization

    Directory of Open Access Journals (Sweden)

    Hanning Chen

    2009-01-01

    Full Text Available Bacterial Foraging Optimization (BFO is a novel optimization algorithm based on the social foraging behavior of E. coli bacteria. This paper presents a variation on the original BFO algorithm, namely, the Cooperative Bacterial Foraging Optimization (CBFO, which significantly improve the original BFO in solving complex optimization problems. This significant improvement is achieved by applying two cooperative approaches to the original BFO, namely, the serial heterogeneous cooperation on the implicit space decomposition level and the serial heterogeneous cooperation on the hybrid space decomposition level. The experiments compare the performance of two CBFO variants with the original BFO, the standard PSO and a real-coded GA on four widely used benchmark functions. The new method shows a marked improvement in performance over the original BFO and appears to be comparable with the PSO and GA.

  2. Bacterial Colony Optimization

    Directory of Open Access Journals (Sweden)

    Ben Niu

    2012-01-01

    Full Text Available This paper investigates the behaviors at different developmental stages in Escherichia coli (E. coli lifecycle and developing a new biologically inspired optimization algorithm named bacterial colony optimization (BCO. BCO is based on a lifecycle model that simulates some typical behaviors of E. coli bacteria during their whole lifecycle, including chemotaxis, communication, elimination, reproduction, and migration. A newly created chemotaxis strategy combined with communication mechanism is developed to simplify the bacterial optimization, which is spread over the whole optimization process. However, the other behaviors such as elimination, reproduction, and migration are implemented only when the given conditions are satisfied. Two types of interactive communication schemas: individuals exchange schema and group exchange schema are designed to improve the optimization efficiency. In the simulation studies, a set of 12 benchmark functions belonging to three classes (unimodal, multimodal, and rotated problems are performed, and the performances of the proposed algorithms are compared with five recent evolutionary algorithms to demonstrate the superiority of BCO.

  3. Bacterial assays for recombinagens.

    Science.gov (United States)

    Hoffmann, G R

    1992-12-01

    Two principal strategies have been used for studying recombinagenic effects of chemicals and radiation in bacteria: (1) measurement of homologous recombination involving defined alleles in a partially diploid strain, and (2) measurement of the formation and loss of genetic duplications in the bacterial chromosome. In the former category, most methods involve one allele in the bacterial chromosome and another in a plasmid, but it is also possible to detect recombination between two chromosomal alleles or between two extrachromosomal alleles. This review summarizes methods that use each of these approaches for detecting recombination and tabulates data on agents that have been found to be recombinagenic in bacteria. The assays are discussed with respect to their effectiveness in testing for recombinagens and their potential for elucidating mechanisms underlying recombinagenic effects.

  4. Bacterial transformation of terpenoids

    Science.gov (United States)

    Grishko, V. V.; Nogovitsina, Y. M.; Ivshina, I. B.

    2014-04-01

    Data on the bacterial transformation of terpenoids published in the literature in the past decade are analyzed. Possible pathways for chemo-, regio- and stereoselective modifications of terpenoids are discussed. Considerable attention is given to new technological approaches to the synthesis of terpenoid derivatives suitable for the use in the perfume and food industry and promising as drugs and chiral intermediates for fine organic synthesis. The bibliography includes 246 references.

  5. Spontaneous bacterial peritonitis

    OpenAIRE

    Al Amri Saleh

    1995-01-01

    Spontaneous bacterial peritonitis (SBP) is an infection of the ascitic fluid without obvious intra-abdominal source of sepsis; usually complicates advanced liver disease. The pathogenesis of the disease is multifactorial: low ascitic protein-content, which reflects defi-cient ascitic fluid complement and hence, reduced opsonic activity is thought to be the most important pathogenic factor. Frequent and prolonged bacteremia has been considered as another pertinent cause of SBP. This disease is...

  6. Modelling bacterial speciation

    OpenAIRE

    2006-01-01

    A central problem in understanding bacterial speciation is how clusters of closely related strains emerge and persist in the face of recombination. We use a neutral Fisher–Wright model in which genotypes, defined by the alleles at 140 house-keeping loci, change in each generation by mutation or recombination, and examine conditions in which an initially uniform population gives rise to resolved clusters. Where recombination occurs at equal frequency between all members of the population, we o...

  7. Adaptive Bacterial Foraging Optimization

    Directory of Open Access Journals (Sweden)

    Hanning Chen

    2011-01-01

    Full Text Available Bacterial Foraging Optimization (BFO is a recently developed nature-inspired optimization algorithm, which is based on the foraging behavior of E. coli bacteria. Up to now, BFO has been applied successfully to some engineering problems due to its simplicity and ease of implementation. However, BFO possesses a poor convergence behavior over complex optimization problems as compared to other nature-inspired optimization techniques. This paper first analyzes how the run-length unit parameter of BFO controls the exploration of the whole search space and the exploitation of the promising areas. Then it presents a variation on the original BFO, called the adaptive bacterial foraging optimization (ABFO, employing the adaptive foraging strategies to improve the performance of the original BFO. This improvement is achieved by enabling the bacterial foraging algorithm to adjust the run-length unit parameter dynamically during algorithm execution in order to balance the exploration/exploitation tradeoff. The experiments compare the performance of two versions of ABFO with the original BFO, the standard particle swarm optimization (PSO and a real-coded genetic algorithm (GA on four widely-used benchmark functions. The proposed ABFO shows a marked improvement in performance over the original BFO and appears to be comparable with the PSO and GA.

  8. Neglected bacterial zoonoses.

    Science.gov (United States)

    Chikeka, I; Dumler, J S

    2015-05-01

    Bacterial zoonoses comprise a group of diseases in humans or animals acquired by direct contact with or by oral consumption of contaminated animal materials, or via arthropod vectors. Among neglected infections, bacterial zoonoses are among the most neglected given emerging data on incidence and prevalence as causes of acute febrile illness, even in areas where recognized neglected tropical diseases occur frequently. Although many other bacterial infections could also be considered in this neglected category, five distinct infections stand out because they are globally distributed, are acute febrile diseases, have high rates of morbidity and case fatality, and are reported as commonly as malaria, typhoid or dengue virus infections in carefully designed studies in which broad-spectrum diagnoses are actively sought. This review will focus attention on leptospirosis, relapsing fever borreliosis and rickettsioses, including scrub typhus, murine typhus and spotted fever group rickettsiosis. Of greatest interest is the lack of distinguishing clinical features among these infections when in humans, which confounds diagnosis where laboratory confirmation is lacking, and in regions where clinical diagnosis is often attributed to one of several perceived more common threats. As diseases such as malaria come under improved control, the real impact of these common and under-recognized infections will become evident, as will the requirement for the strategies and allocation of resources for their control.

  9. Synthesis and characterization of Pt-Pd nanoparticles with core-shell morphology: Nucleation and overgrowth of the Pd shells on the as-prepared and defined Pt seeds

    Energy Technology Data Exchange (ETDEWEB)

    Long, Nguyen Viet, E-mail: nguyenvietlong@yahoo.com [Department of Materials Scienceand Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555 (Japan); Posts and Telecommunications Institute of Technology, km 10 Nguyen Trai, Hanoi (Viet Nam); Laboratory for Nanotechnology, Vietnam National University at Ho Chi Minh, Linh Trung, Thu Duc, Ho Chi Minh (Viet Nam); Department of Molecular and Material Sciences, Interdisciplinary Graduate School of Engineering Sciences, 6-1 Kasugakouen, Kasuga, Fukuoka 861-8580 (Japan); Hien, Tong Duy [Laboratory for Nanotechnology, Vietnam National University at Ho Chi Minh, Linh Trung, Thu Duc, Ho Chi Minh (Viet Nam); Asaka, Toru [Department of Materials Scienceand Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555 (Japan); Ohtaki, Michitaka [Department of Molecular and Material Sciences, Interdisciplinary Graduate School of Engineering Sciences, 6-1 Kasugakouen, Kasuga, Fukuoka 861-8580 (Japan); Nogami, Masayuki, E-mail: nogami@nitech.ac.jp [Department of Materials Scienceand Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555 (Japan)

    2011-07-21

    Highlights: > The Pt-Pd core-shell nanoparticles based on the as-prepared Pt cores are synthesized. > Not only the Pt-Pd core-shell nanoparticles are formed, but also the separate formation of Pd nanoparticles as well. > The Pt cores without the morphological changes are protected by the Pd-shell overgrowths. > There are the co-existence of the layer-by-layer and island-on-wetting-layer growth modes of the Pd shells and the latter becomes the favorable overgrowth in the formation of core-shell structures. - Abstract: In the present research, Pt-Pd core-shell nanoparticles based on the as-prepared and defined Pt-seed cores with well-controlled size and morphology were synthesized. Their characterizations were investigated by using UV-vis spectroscopy, transmission electron microscopy (TEM), and high resolution (HR)TEM measurements. The high resolution elemental mappings were performed in the operation of high angle annular dark field (HAADF) in conjunction with scanning (S)TEM mode and X-ray energy dispersive spectroscopy (XEDS). It is found that not only the Pt-Pd core-shell nanoparticles were formed, but also the nucleation, growth, and the separate formation of single Pd nanoparticles as well. Interestingly, the as-prepared Pt cores without the morphological changes were protected by the overgrowths of the Pd shells during the successive reduction of sodium tetrachloropalladate (II) hydrate. There were the co-existence of the Frank-van der Merwe (FM) layer-by-layer and Stranski-Krastanov (SK) island-on-wetting-layer growth modes of the Pd shells on the as-prepared Pt cores. It is predicted that the SK growth became the favorable growth mode in the formation of the Pd shells in the formation Pt-Pd core-shell nanoparticles.

  10. Bacterial chromosome segregation.

    Science.gov (United States)

    Possoz, Christophe; Junier, Ivan; Espeli, Olivier

    2012-01-01

    Dividing cells have mechanisms to ensure that their genomes are faithfully segregated into daughter cells. In bacteria, the description of these mechanisms has been considerably improved in the recent years. This review focuses on the different aspects of bacterial chromosome segregation that can be understood thanks to the studies performed with model organisms: Escherichia coli, Bacillus subtilis, Caulobacter crescentus and Vibrio cholerae. We describe the global positionning of the nucleoid in the cell and the specific localization and dynamics of different chromosomal loci, kinetic and biophysic aspects of chromosome segregation are presented. Finally, a presentation of the key proteins involved in the chromosome segregation is made.

  11. Bacterial Degradation of Pesticides

    DEFF Research Database (Denmark)

    Knudsen, Berith Elkær

    This PhD project was carried out as part of the Microbial Remediation of Contaminated Soil and Water Resources (MIRESOWA) project, funded by the Danish Council for Strategic Research (grant number 2104-08-0012). The environment is contaminated with various xenobiotic compounds e.g. pesticides......D student, to construct fungal-bacterial consortia in order to potentially stimulate pesticide degradation thereby increasing the chance of successful bioaugmentation. The results of the project are reported in three article manuscripts, included in this thesis. In manuscript I, the mineralization of 2...

  12. Spontaneous bacterial peritonitis

    Directory of Open Access Journals (Sweden)

    Al Amri Saleh

    1995-01-01

    Full Text Available Spontaneous bacterial peritonitis (SBP is an infection of the ascitic fluid without obvious intra-abdominal source of sepsis; usually complicates advanced liver disease. The pathogenesis of the disease is multifactorial: low ascitic protein-content, which reflects defi-cient ascitic fluid complement and hence, reduced opsonic activity is thought to be the most important pathogenic factor. Frequent and prolonged bacteremia has been considered as another pertinent cause of SBP. This disease is associated with high mortality and recurrence. Therefore, orompt recognition and institution of therapy and plan of prophylaxis is vital.

  13. Bacterial mitotic machineries

    DEFF Research Database (Denmark)

    Gerdes, Kenn; Møller-Jensen, Jakob; Ebersbach, Gitte;

    2004-01-01

    Here, we review recent progress that yields fundamental new insight into the molecular mechanisms behind plasmid and chromosome segregation in prokaryotic cells. In particular, we describe how prokaryotic actin homologs form mitotic machineries that segregate DNA before cell division. Thus, the Par......M protein of plasmid R1 forms F actin-like filaments that separate and move plasmid DNA from mid-cell to the cell poles. Evidence from three different laboratories indicate that the morphogenetic MreB protein may be involved in segregation of the bacterial chromosome....

  14. MMP8, MMP9 AND TIMP1 LEVELS IN GCF AND GINGIVAL TISSUE OF PATIENTS WITH GINGIVAL OVERGROWTH DURING ORTHODONTIC TREATMENT

    Directory of Open Access Journals (Sweden)

    Petra Surlin

    2012-03-01

    Full Text Available Aim. Periodontal remodellng produced during dental orthodontic treatment represents a series of biologicallyactive substances, part of them playing some role in the initiation and propagation of inflammatory processes. The present study aims at demonstrating the MMP8, MMP9 and TIMP1 levels intervening in tissular periodontal remodeling produced during orthodontic treatments, accompanied by gingival overgrowth, as a reaction of the marginal periodontium to mechanical stress. Materials and Method. Selected for the study were 21 patients – 13 females and 8 males – with ages between 13 and 32 years (17.6±1.3 years affected with dento-maxillary anomalies, who received orthodontic treatment with fixed apparatus. Sampling from the gingival fluid was performed 6 times, namely: 1 hour prior to the application of the orthodontic apparatus, 4 hours after its application, again after 8 and 24 hours and then 1 and, respectively, 2 weeks later. If gingival hypertrophy was installed (HTG, the hypertrophic gingiva was removed, and an immuno-histo-chemical examination was made. The patient was weekly monitorized in the first 6 weeks – during the initial orthodontic treatment, then monthly, samples being taken over from the gingival sulcus on each visit made in the first 6 weeks. Results. MMP-9 immuno-marking was positive both at corione level and in the deep structures of the covering epithelium. The positive cells at MMP-9 evidenced different intensities at the level of each structure forming the gingival mucous membrane. In four of the cases under analysis, disorganization of the normal layering/stratification of the epithelium was evidenced, along with the presence of numerous red cells in the chorione of the mucous membrane. In such cases, immuno-marking to MMP8 showed a normal intensity, even if few positive cells, dispersed among the extravasated red cells could be observed. Immunologically, MMP8 and MMP9 obey the same pattern, registering maximum

  15. Prostatic Inflammation is Determinant for Prostate Overgrowth and Luts Severity in Men with Metabolic Syndrome: Highlights from Two Recently Published Multicentre Studies

    Directory of Open Access Journals (Sweden)

    Mauro Gacci

    2013-12-01

    BPH oxidized low-density lipoprotein (oxLDL showed the highest secretion of IL-8 (>10-folds-a surrogate marker of prostate inflammation-as well as IL-6, and bFGF. Conclusions: MetS and dyslipidaemia are associated with prostate overgrowth and inflammation. In particular, with a selective increase of prostatic AP diameter, leading to a modification of prostatic shape. Hence, MetS can be regarded as a new determinant of prostate inflammation and BPH progression in men with severe LUTS.

  16. Spontaneous bacterial peritonitis

    Institute of Scientific and Technical Information of China (English)

    Anastasios Koulaouzidis; Shivaram Bhat; Athar A Saeed

    2009-01-01

    Since its initial description in 1964, research has transformed spontaneous bacterial peritonitis (SBP) from a feared disease (with reported mortality of 90%) to a treatable complication of decompensated cirrhosis,albeit with steady prevalence and a high recurrence rate. Bacterial translocation, the key mechanism in the pathogenesis of SBP, is only possible because of the concurrent failure of defensive mechanisms in cirrhosis.Variants of SBP should be treated. Leucocyte esterase reagent strips have managed to shorten the 'tap-toshot' time, while future studies should look into their combined use with ascitic fluid pH. Third generation cephalosporins are the antibiotic of choice because they have a number of advantages. Renal dysfunction has been shown to be an independent predictor of mortality in patients with SBP. Albumin is felt to reduce the risk of renal impairment by improving effective intravascular volume, and by helping to bind proinflammatory molecules. Following a single episode of SBP, patients should have long-term antibiotic prophylaxis and be considered for liver transplantation.

  17. Antimicrobials for bacterial bioterrorism agents.

    Science.gov (United States)

    Sarkar-Tyson, Mitali; Atkins, Helen S

    2011-06-01

    The limitations of current antimicrobials for highly virulent pathogens considered as potential bioterrorism agents drives the requirement for new antimicrobials that are suitable for use in populations in the event of a deliberate release. Strategies targeting bacterial virulence offer the potential for new countermeasures to combat bacterial bioterrorism agents, including those active against a broad spectrum of pathogens. Although early in the development of antivirulence approaches, inhibitors of bacterial type III secretion systems and cell division mechanisms show promise for the future.

  18. Epigenetics and bacterial infections.

    Science.gov (United States)

    Bierne, Hélène; Hamon, Mélanie; Cossart, Pascale

    2012-12-01

    Epigenetic mechanisms regulate expression of the genome to generate various cell types during development or orchestrate cellular responses to external stimuli. Recent studies highlight that bacteria can affect the chromatin structure and transcriptional program of host cells by influencing diverse epigenetic factors (i.e., histone modifications, DNA methylation, chromatin-associated complexes, noncoding RNAs, and RNA splicing factors). In this article, we first review the molecular bases of the epigenetic language and then describe the current state of research regarding how bacteria can alter epigenetic marks and machineries. Bacterial-induced epigenetic deregulations may affect host cell function either to promote host defense or to allow pathogen persistence. Thus, pathogenic bacteria can be considered as potential epimutagens able to reshape the epigenome. Their effects might generate specific, long-lasting imprints on host cells, leading to a memory of infection that influences immunity and might be at the origin of unexplained diseases.

  19. Bacterial polyhydroxyalkanoates: Still fabulous?

    Science.gov (United States)

    Możejko-Ciesielska, Justyna; Kiewisz, Robert

    2016-11-01

    Bacterial polyhydroxyalkanoates (PHA) are polyesters accumulated as carbon and energy storage materials under limited growth conditions in the presence of excess carbon sources. They have been developed as biomaterials with unique properties for the past many years being considered as a potential substitute for conventional non-degradable plastics. Due to the increasing concern towards global climate change, depleting petroleum resource and problems with an utilization of a growing number of synthetic plastics, PHAs have gained much more attention from industry and research. These environmentally friendly microbial polymers have great potential in biomedical, agricultural, and industrial applications. However, their production on a large scale is still limited. This paper describes the backgrounds of PHAs and discussed the current state of knowledge on the polyhydroxyalkanoates. Ability of bacteria to convert different carbon sources to PHAs, the opportunities and challenges of their introduction to global market as valuable renewable products have been also discussed.

  20. Bacterial degradation of aminopyrine.

    Science.gov (United States)

    Blecher, H; Blecher, R; Wegst, W; Eberspaecher, J; Lingens, F

    1981-11-01

    1. Four strains of bacteria growing with aminopyrine as sole source of carbon were isolated from soil and were identified as strains of Phenylobacterium immobilis. 2. Strain M13 and strain E, the type species of Phenylobacterium immobilis (DSM 1986), which had been isolated by enrichment with chloridazon (5-amino-4-chloro-2-phenyl-2H-pyridazin-3-one) were used to investigate the bacterial degradation of aminopyrine. 3. Three metabolites were isolated and identified as: 4-(dimethylamino)-1,2-dihydro-1,5-dimethyl-2-(2,3-dihydro-2,3-dihydroxy-4,6-cyc lohexadien-1-yl)-3H-pyrazol-3-one, 4-(dimethylamino)-1,2-dihydro-1,5-dimethyl-2-(2,3-dihydroxyphenyl)-3H-pyrazol-3 -one and 4-(dimethylamino)-1,2-dihydro-1,5-dimethyl-3H-pyrazol-3-one. 4. An enzyme extract from cells of strain m13 was shown to further metabolize the catechol derivative of aminopyrine, with the formation of 2-pyrone-6-carboxylic acid. 5. Results indicate that the benzene ring of aminopyrine is the principal site of microbial metabolism.

  1. Electromagnetism of Bacterial Growth

    Science.gov (United States)

    Ainiwaer, Ailiyasi

    2011-10-01

    There has been increasing concern from the public about personal health due to the significant rise in the daily use of electrical devices such as cell phones, radios, computers, GPS, video games and television. All of these devices create electromagnetic (EM) fields, which are simply magnetic and electric fields surrounding the appliances that simultaneously affect the human bio-system. Although these can affect the human system, obstacles can easily shield or weaken the electrical fields; however, magnetic fields cannot be weakened and can pass through walls, human bodies and most other objects. The present study was conducted to examine the possible effects of bacteria when exposed to magnetic fields. The results indicate that a strong causal relationship is not clear, since different magnetic fields affect the bacteria differently, with some causing an increase in bacterial cells, and others causing a decrease in the same cells. This phenomenon has yet to be explained, but the current study attempts to offer a mathematical explanation for this occurrence. The researchers added cultures to the magnetic fields to examine any effects to ion transportation. Researchers discovered ions such as potassium and sodium are affected by the magnetic field. A formula is presented in the analysis section to explain this effect.

  2. Evolution of Bacterial Suicide

    Science.gov (United States)

    Tchernookov, Martin; Nemenman, Ilya

    2013-03-01

    While active, controlled cellular suicide (autolysis) in bacteria is commonly observed, it has been hard to argue that autolysis can be beneficial to an individual who commits it. We propose a theoretical model that predicts that bacterial autolysis is evolutionarily advantageous to an individualand would fixate in physically structured environments for stationary phase colonies. We perform spatially resolved agent-based simulations of the model, which predict that lower mixing in the environment results in fixation of a higher autolysis rate from a single mutated cell, regardless of the colony's genetic diversity. We argue that quorum sensing will fixate as well, even if initially rare, if it is coupled to controlling the autolysis rate. The model does not predict a strong additional competitive advantage for cells where autolysis is controlled by quorum sensing systems that distinguish self from nonself. These predictions are broadly supported by recent experimental results in B. subtilisand S. pneumoniae. Research partially supported by the James S McDonnell Foundation grant No. 220020321 and by HFSP grant No. RGY0084/2011.

  3. Bacterial endocarditis prophylaxis.

    Science.gov (United States)

    Blanco-Carrión, Andrés

    2004-01-01

    Bacterial endocarditis (BE) is a disease resulting from the association of morphological alterations of the heart and bacteraemia originating from different sources that at times can be indiscernible (infectious endocarditis). It is classified on the basis of the morphological alteration involved, depending on the clinical manifestations and course of illness, which varies according to the causative microorganism and host conditions (for example, it is characteristic in I.V. drug users). The most common microorganisms involved are: Streptococcus viridans (55%), Staphylococcus aureus (30%), Enterococcus (6%) and HACEK bacteria (corresponding to the initials: Haemophilus, Actinobacillus, Cardiobacterium, Eikenella and Kingella), although on occasions it can also be caused by fungi. The oral microbiological flora plays a very important role in the aetiopathogenesis of BE, given that the condition may be of oral or dental origin. This paper will deal with the prevention of said bacteraemia. Prophylaxis will be undertaken using amoxicillin or clindamycin according to action protocols, with special emphasis placed on oral hygiene in patients with structural defects of the heart.

  4. First genomic insights into members of a candidate bacterial phylum responsible for wastewater bulking

    Directory of Open Access Journals (Sweden)

    Yuji Sekiguchi

    2015-01-01

    Full Text Available Filamentous cells belonging to the candidate bacterial phylum KSB3 were previously identified as the causative agent of fatal filament overgrowth (bulking in a high-rate industrial anaerobic wastewater treatment bioreactor. Here, we obtained near complete genomes from two KSB3 populations in the bioreactor, including the dominant bulking filament, using differential coverage binning of metagenomic data. Fluorescence in situ hybridization with 16S rRNA-targeted probes specific for the two populations confirmed that both are filamentous organisms. Genome-based metabolic reconstruction and microscopic observation of the KSB3 filaments in the presence of sugar gradients indicate that both filament types are Gram-negative, strictly anaerobic fermenters capable of non-flagellar based gliding motility, and have a strikingly large number of sensory and response regulator genes. We propose that the KSB3 filaments are highly sensitive to their surroundings and that cellular processes, including those causing bulking, are controlled by external stimuli. The obtained genomes lay the foundation for a more detailed understanding of environmental cues used by KSB3 filaments, which may lead to more robust treatment options to prevent bulking.

  5. Meningitis bacteriana Bacterial meningitis

    Directory of Open Access Journals (Sweden)

    Ana Teresa Alvarado Guevara

    2006-03-01

    causales son virales lo cual conlleva a las diferentes sub-clasificaciones. También en ciertos casos puede ser ocasionada por hongos, bacterias atípicas, micobacterias y parásitos.In Costa Rica the bacterial meningitis had turn into a high-priority subject in which to monitoring epidemiologist. It had been talked about in the last months, to dice an increase in the attention is published of this subject, due to this phenomenon it becomes necessary to make a revision of topic. Meningitis is an inflammation of leptomeninges and colonization of the subarachnoid cerebrospinal fluid (LCR due to different agents, which produces meningeal symptoms (ex. migraine, neck rigidity, and photophobia and pleocytosis in LCR. De pending on the variables to take into account is possible to group it in different classifications, taking into account the time of evolution are possible to be divided in acute or chronic, to first with few hours or days of beginning of the symptoms, whereas the chronicle also presents a silence course but of the disease of approximately 4 weeks of instauration. There is a difference according to its etiologic agent; they can be infectious and non-infectious. Examples of common non-infectious causes include medications (ex, nonsteroidal anti-inflammatory drugs, and antibiotics and carcinomatosis. A classification exists as well according to the causal agent. The acute bacterial meningitis remarks a bacterial origin of the syndrome, which characterizes by the by an acute onset of meningeal symptoms and neutrophilic pleocytosis. Each one of the bacteriological agents, parasitic or fungus finishes by characterizing the different presentations of the clinical features (ex, meningocóccica meningitis, Cryptococcus meningitis. Finally, there is also the aseptic meningitis, denominated in this form because it’s nonpyogenic cellular response caused by many types of agents. The patients show an acute beginning of symptoms, fever and lymphocytic pleocytosis. After

  6. Bacterial Communities: Interactions to Scale

    Directory of Open Access Journals (Sweden)

    Reed M. Stubbendieck

    2016-08-01

    Full Text Available In the environment, bacteria live in complex multispecies communities. These communities span in scale from small, multicellular aggregates to billions or trillions of cells within the gastrointestinal tract of animals. The dynamics of bacterial communities are determined by pairwise interactions that occur between different species in the community. Though interactions occur between a few cells at a time, the outcomes of these interchanges have ramifications that ripple through many orders of magnitude, and ultimately affect the macroscopic world including the health of host organisms. In this review we cover how bacterial competition influences the structures of bacterial communities. We also emphasize methods and insights garnered from culture-dependent pairwise interaction studies, metagenomic analyses, and modeling experiments. Finally, we argue that the integration of multiple approaches will be instrumental to future understanding of the underlying dynamics of bacterial communities.

  7. Bacterial Chromosome Organization and Segregation

    OpenAIRE

    Toro, Esteban; Shapiro, Lucy

    2010-01-01

    Bacterial chromosomes are generally ∼1000 times longer than the cells in which they reside, and concurrent replication, segregation, and transcription/translation of this crowded mass of DNA poses a challenging organizational problem. Recent advances in cell-imaging technology with subdiffraction resolution have revealed that the bacterial nucleoid is reliably oriented and highly organized within the cell. Such organization is transmitted from one generation to the next by progressive segrega...

  8. Bacterial Protein-Tyrosine Kinases

    DEFF Research Database (Denmark)

    Shi, Lei; Kobir, Ahasanul; Jers, Carsten

    2010-01-01

    phosphorylation. Protein-tyrosine phosphorylation in bacteria is particular with respect to very low occupancy of phosphorylation sites in vivo; this has represented a major challenge for detection techniques. Only the recent breakthroughs in gel-free high resolution mass spectrometry allowed the systematic...... and highlighted their importance in bacterial physiology. Having no orthologues in Eukarya, BY-kinases are receiving a growing attention from the biomedical field, since they represent a particularly promising target for anti-bacterial drug design....

  9. Surface micropattern limits bacterial contamination

    OpenAIRE

    Mann, Ethan E.; Manna, Dipankar; Mettetal, Michael R; May, Rhea M.; Dannemiller, Elisa M; Chung, Kenneth K.; Brennan, Anthony B; Reddy, Shravanthi T

    2014-01-01

    Background Bacterial surface contamination contributes to transmission of nosocomial infections. Chemical cleansers used to control surface contamination are often toxic and incorrectly implemented. Additional non-toxic strategies should be combined with regular cleanings to mitigate risks of human error and further decrease rates of nosocomial infections. The Sharklet micropattern (MP), inspired by shark skin, is an effective tool for reducing bacterial load on surfaces without toxic additiv...

  10. Bacterial cellulose/boehmite composites

    Energy Technology Data Exchange (ETDEWEB)

    Salvi, Denise T.B. de; Barud, Hernane S.; Messaddeq, Younes; Ribeiro, Sidney J.L. [Universidade Estadual Paulista Julio de Mesquita Filho. UNESP. Instituto de Quimica de Araraquara, SP (Brazil); Caiut, Jose Mauricio A. [Universidade de Sao Paulo. Departamento de Quimica - FFCLRP/USP, Ribeirao Preto, SP (Brazil)

    2011-07-01

    Composites based on bacterial cellulose membranes and boehmite were obtained. SEM results indicate that the bacterial cellulose (BC) membranes are totally covered by boehmite and obtained XRD patterns suggest structural changes due to this boehmite addition. Thermal stability is accessed through TG curves and is dependent on boehmite content. Transparency is high comparing to pure BC as can be seen through UV-vis absorption spectroscopy. (author)

  11. A combined study of SHRIMP U-Pb dating, trace element and mineral inclusions on high-pressure metamorphic overgrowth zircon in eclogite from Qinglongshan in the Sulu terrane

    Institute of Scientific and Technical Information of China (English)

    LI Qiuli; LI Shuguang; HOU Zhenhui1; HONG Jian; YANG Wei1

    2005-01-01

    Methods recently advanced for discrimination on the genesis of metamorphic zircon, such as analysis of mineral inclusions and trace elements, provide us powerful means to distinguish zircon overgrowth during high-pressure metamorphism. Zircons in ultrahigh-pressure eclogite from Qinglongshan in the Sulu terrane were studied by the SHRIMP U-Pb method in combining with trace element and mineral inclusion analyses. No inherited core was identified in the analyzed zircons by means of cathodoluminescence images. The occurrence of high-pressure metamorphic mineral inclusions in zircon, such as garnet, omphacite, rutile, and the flat HREE pattern in zircon indicate that the zircon formed at high-pressure metamorphic conditions. Therefore, a weighted average U-Pb age of 227.4 ± 3.5 Ma obtained from such a kind of zircon is interpreted to represent the timing of peak metamorphism for the Qinglongshan eclogite.

  12. The Human Vaginal Bacterial Biota and Bacterial Vaginosis

    Directory of Open Access Journals (Sweden)

    Sujatha Srinivasan

    2008-01-01

    Full Text Available The bacterial biota of the human vagina can have a profound impact on the health of women and their neonates. Changes in the vaginal microbiota have been associated with several adverse health outcomes including premature birth, pelvic inflammatory disease, and acquisition of HIV infection. Cultivation-independent molecular methods have provided new insights regarding bacterial diversity in this important niche, particularly in women with the common condition bacterial vaginosis (BV. PCR methods have shown that women with BV have complex communities of vaginal bacteria that include many fastidious species, particularly from the phyla Bacteroidetes and Actinobacteria. Healthy women are mostly colonized with lactobacilli such as Lactobacillus crispatus, Lactobacillus jensenii, and Lactobacillus iners, though a variety of other bacteria may be present. The microbiology of BV is heterogeneous. The presence of Gardnerella vaginalis and Atopobium vaginae coating the vaginal epithelium in some subjects with BV suggests that biofilms may contribute to this condition.

  13. New Treatments for Bacterial Keratitis

    Directory of Open Access Journals (Sweden)

    Raymond L. M. Wong

    2012-01-01

    Full Text Available Purpose. To review the newer treatments for bacterial keratitis. Data Sources. PubMed literature search up to April 2012. Study Selection. Key words used for literature search: “infectious keratitis”, “microbial keratitis”, “infective keratitis”, “new treatments for infectious keratitis”, “fourth generation fluoroquinolones”, “moxifloxacin”, “gatifloxacin”, “collagen cross-linking”, and “photodynamic therapy”. Data Extraction. Over 2400 articles were retrieved. Large scale studies or publications at more recent dates were selected. Data Synthesis. Broad spectrum antibiotics have been the main stay of treatment for bacterial keratitis but with the emergence of bacterial resistance; there is a need for newer antimicrobial agents and treatment methods. Fourth-generation fluoroquinolones and corneal collagen cross-linking are amongst the new treatments. In vitro studies and prospective clinical trials have shown that fourth-generation fluoroquinolones are better than the older generation fluoroquinolones and are as potent as combined fortified antibiotics against common pathogens that cause bacterial keratitis. Collagen cross-linking was shown to improve healing of infectious corneal ulcer in treatment-resistant cases or as an adjunct to antibiotics treatment. Conclusion. Fourth-generation fluoroquinolones are good alternatives to standard treatment of bacterial keratitis using combined fortified topical antibiotics. Collagen cross-linking may be considered in treatment-resistant infectious keratitis or as an adjunct to antibiotics therapy.

  14. Bacterial carbonatogenesis; La carbonatogenese bacterienne

    Energy Technology Data Exchange (ETDEWEB)

    Castanier, S. [Angers Univ., 49 (France). Faculte des Sciences; Le Metayer-Levrel, G.; Perthuisot, J.P. [Nantes Univ., 44 (France). Laboratoire de Biogeologie, Faculte des Sciences et des Techniques

    1998-12-31

    Several series of experiments in the laboratory as well as in natural conditions teach that the production of carbonate particles by heterotrophic bacteria follows different ways. The `passive` carbonatogenesis is generated by modifications of the medium that lead to the accumulation of carbonate and bicarbonate ions and to the precipitation of solid particles. The `active` carbonatogenesis is independent of the metabolic pathways. The carbonate particles are produced by ionic exchanges through the cell membrane following still poorly known mechanisms. Carbonatogenesis appears to be the response of heterotrophic bacterial communities to an enrichment of the milieu in organic matter. The active carbonatogenesis seems to start first. It is followed by the passive one which induces the growth of initially produced particles. The yield of heterotrophic bacterial carbonatogenesis and the amounts of solid carbonates production by bacteria are potentially very high as compared to autotrophic or chemical sedimentation from marine, paralic or continental waters. Furthermore, the bacterial processes are environmentally very ubiquitous; they just require organic matter enrichment. Thus, apart from purely evaporite and autotrophic ones, all Ca and/or Mg carbonates must be considered as from heterotrophic bacterial origin. By the way, the carbon of carbonates comes from primary organic matter. Such considerations ask questions about some interpretations from isotopic data on carbonates. Finally, bacterial heterotrophic carbonatogenesis appears as a fundamental phase in the relationships between atmosphere and lithosphere and in the geo-biological evolution of Earth. (author) 43 refs.

  15. Bacterial Degradation of Aromatic Compounds

    Directory of Open Access Journals (Sweden)

    Qing X. Li

    2009-01-01

    Full Text Available Aromatic compounds are among the most prevalent and persistent pollutants in the environment. Petroleum-contaminated soil and sediment commonly contain a mixture of polycyclic aromatic hydrocarbons (PAHs and heterocyclic aromatics. Aromatics derived from industrial activities often have functional groups such as alkyls, halogens and nitro groups. Biodegradation is a major mechanism of removal of organic pollutants from a contaminated site. This review focuses on bacterial degradation pathways of selected aromatic compounds. Catabolic pathways of naphthalene, fluorene, phenanthrene, fluoranthene, pyrene, and benzo[a]pyrene are described in detail. Bacterial catabolism of the heterocycles dibenzofuran, carbazole, dibenzothiophene, and dibenzodioxin is discussed. Bacterial catabolism of alkylated PAHs is summarized, followed by a brief discussion of proteomics and metabolomics as powerful tools for elucidation of biodegradation mechanisms.

  16. Molecular mechanisms underlying bacterial persisters

    DEFF Research Database (Denmark)

    Maisonneuve, Etienne; Gerdes, Kenn

    2014-01-01

    All bacteria form persisters, cells that are multidrug tolerant and therefore able to survive antibiotic treatment. Due to the low frequencies of persisters in growing bacterial cultures and the complex underlying molecular mechanisms, the phenomenon has been challenging to study. However, recent...

  17. Bacterial Cytotoxins Target Rho GTPases

    Science.gov (United States)

    Schmidt, Gudula; Aktories, Klaus

    1998-06-01

    Low molecular mass GTPases of the Rho family, which are involved in the regulation of the actin cytoskeleton and in various signal transduction processes, are the eukaryotic targets of bacterial protein toxins. The toxins covalently modify Rho proteins by ADP ribosylation, glucosylation, and deamidation, thereby inactivating and activating the GTPases.

  18. Disease notes - Bacterial root rot

    Science.gov (United States)

    Bacterial root rot initiated by lactic acid bacteria, particularly Leuconostoc, occurs every year in Idaho sugarbeet fields. Hot fall weather seems to make the problem worse. Although Leuconostoc initiates the rot, other bacteria and yeast frequently invade the tissue as well. The acetic acid bac...

  19. Bacterial canker resistance in tomato

    NARCIS (Netherlands)

    Sen, Y.

    2014-01-01

    Clavibacter michiganensis subsp. michiganensis (Cmm) is the pathogen causing bacterial  canker in tomato. The disease was described for the first time in 1910 in Michigan, USA. Cmmis considered the most harmful bacteria threatening tomato. Disease transmission occurs via seed and symptoms becom

  20. Biotechnological applications of bacterial cellulases

    Directory of Open Access Journals (Sweden)

    Esther Menendez

    2015-08-01

    Full Text Available Cellulases have numerous applications in several industries, including biofuel production, food and feed industry, brewing, pulp and paper, textile, laundry, and agriculture.Cellulose-degrading bacteria are widely spread in nature, being isolated from quite different environments. Cellulose degradation is the result of a synergic process between an endoglucanase, an exoglucanase and a,β-glucosidase. Bacterial endoglucanases degrade ß-1,4-glucan linkages of cellulose amorphous zones, meanwhile exoglucanases cleave the remaining oligosaccharide chains, originating cellobiose, which is hydrolyzed by ß-glucanases. Bacterial cellulases (EC 3.2.1.4 are comprised in fourteen Glycosil Hydrolase families. Several advantages, such as higher growth rates and genetic versatility, emphasize the suitability and advantages of bacterial cellulases over other sources for this group of enzymes. This review summarizes the main known cellulolytic bacteria and the best strategies to optimize their cellulase production, focusing on endoglucanases, as well as it reviews the main biotechnological applications of bacterial cellulases in several industries, medicine and agriculture.

  1. Food irradiation and bacterial toxins

    Energy Technology Data Exchange (ETDEWEB)

    Tranter, H.S.; Modi, N.K.; Hambleton, P.; Melling, J.; Rose, S.; Stringer, M.F.

    1987-07-04

    The authors' findings indicate that irradiation confers no advantage over heat processing in respect of bacterial toxins (clostridium botulinum, neurotoxin A and staphylococcal enterotoxin A). It follows that irradiation at doses less than the ACINF recommended upper limit of 10 kGy could not be used to improve the ambient temperature shelf life on non-acid foods.

  2. Extracardiac manifestations of bacterial endocarditis.

    Science.gov (United States)

    Heffner, J E

    1979-08-01

    Bacterial endocarditis is an elusive disease that challenges clinicians' diagnostic capabilities. Because it can present with various combinations of extravalvular signs and symptoms, the underlying primary disease can go unnoticed.A review of the various extracardiac manifestations of bacterial endocarditis suggests three main patterns by which the valvular infection can be obscured. (1) A major clinical event may be so dramatic that subtle evidence of endocarditis is overlooked. The rupture of a mycotic aneurysm may simulate a subarachnoid hemorrhage from a congenital aneurysm. (2) The symptoms of bacterial endocarditis may be constitutional complaints easily attributable to a routine, trivial illness. Symptoms of low-grade fever, myalgias, back pain and anorexia may mimic a viral syndrome. (3) Endocarditis poses a difficult diagnostic dilemma when it generates constellations of findings that are classic for other disorders. Complaints of arthritis and arthralgias accompanied by hematuria and antinuclear antibody may suggest systemic lupus erythematosus; a renal biopsy study showing diffuse proliferative glomerulonephritis may support this diagnosis. The combination of fever, petechiae, altered mental status, thrombocytopenia, azotemia and anemia may promote the diagnosis of thrombotic thrombocytopenic purpura. When the protean guises of bacterial endocarditis create these clinical difficulties, errors in diagnosis occur and appropriate therapy is delayed. Keen awareness of the varied disease presentations will improve success in managing endocarditis by fostering rapid diagnosis and prompt therapy.

  3. Conjuntivite bacteriana secundária à doença dentária em chinchilas (Chinchilla lanigera Bacterial conjunctivitis secondary to dental disease in chinchillas (Chinchilla lanigera

    Directory of Open Access Journals (Sweden)

    Ricardo Barbosa Lucena

    2012-11-01

    Full Text Available São relatados três casos de conjuntivite bacteriana associada à doença dentária grave em chinchilas. Todas as chinchilas afetadas tinham histórico de emagrecimento, hipersalivação e epífora, que progrediu para exsudação ocular purulenta. Durante a necropsia, foi constatado marcado alongamento da coroa clínica dos incisivos e molares, e crescimento do ápice dentário, causando deformação óssea e compressão do canal lacrimal. Histologicamente, observou-se infiltrado de neutrófilos na conjuntiva e pálpebras. Cultivo microbiológico do exsudato ocular revelou crescimento de Staphylococcus coagulase-positiva . Uma compressão do canal lacrimal pelo crescimento dentário excessivo impediu a drenagem das lágrimas, resultando em epífora. Esse é um importante fator predisponente para infecção bacteriana ocular em chinchilas.Three cases of bacterial conjunctivitis associated with severe dental disease in chinchillas are described. All affected chinchillas had a history of weight loss, ptyalism, and epiphora which progressed to suppurative ocular exsudation. At necropsy incisor and molar teeth revealed marked elongation of the clinical crown and overgrowth of the dental apexes resulting in deformation of the tear ducts. Histologically, there was neutrophilic infiltrate in the conjunctiva and eyelid skin. Microbiological culture carried out in samples from the ocular exsudate yielded Staphylococcus coagulase-positive. Compression of the lacrimal duct by dental overgrowth compromised tear draining and resulting in epiphora. This is a major predisposing factor inducing bacterial ocular infection in chinchillas.

  4. Superinfecting microorganisms in patients under treatment with cyclosporin-A and its correlation to gingival overgrowth Microrganismos superinfectantes em pacientes submetidos a terapia com ciclosporina-A e sua correlação com crescimento gengival

    Directory of Open Access Journals (Sweden)

    Giuseppe Alexandre Romito

    2003-03-01

    Full Text Available The aim of this study was to identify the presence of superinfecting microorganisms (Gram-negative enteric rods and Candida sp. in heart transplant patients and correlate this with gingival overgrowth. Thirty patients (10 females, 20 males - mean age 45 years were examined. All were under cyclosporin-A (CsA therapy. Patients who had taken any antibiotics 3 months prior the study or had been submitted to periodontal therapy were not enrolled. Patients were required to have at least 6 teeth. The plaque index (PI, gingival index (GI, pocket depth (PD and clinical attachment level (CAL were recorded. Microbiological samples were taken from sulcus/pocket (s/p and from stimulated saliva (ss and submitted to analysis. Patients were divided into two groups: the ones with gingival overgrowth (GO and those without gingival overgrowth (WGO. After statistical analysis (chi-square test, Student's t-test, Fisher test, p A proposta deste trabalho foi identificar a presença de microrganismos superinfectantes (bastonetes entéricos Gram-negativos e Candida sp. em pacientes transplantados cardíacos e correlacioná-la com a presença de crescimento gengival. Foram examinados 30 pacientes (10 mulheres e 20 homens - média de idade: 45 anos. Todos os pacientes estavam sob terapia com ciclosporina-A (CsA sem terem sido submetidos a antibioticoterapia e nem a tratamento periodontal prévio, por pelo menos três meses antes do início do estudo. O paciente deveria ter, no mínimo, seis dentes. Foram registrados os índices de placa bacteriana (IP, índice gengival (IG, valores de profundidade clínica de sondagem (PCS e nível clínico de inserção (NCI. Análise microbiológica foi realizada a partir de amostras coletadas de sulco/bolsa gengival (s/b e da saliva estimulada (se. Os pacientes foram divididos em dois grupos: com crescimento gengival (CCG e sem crescimento gengival (SCG. Após análise estatística (teste do qui-quadrado; teste t de Student; prova

  5. Prostatitis-bacterial - self-care

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000395.htm Prostatitis- bacterial - self-care To use the sharing features ... enable JavaScript. You have been diagnosed with bacterial prostatitis . This is an infection of the prostate gland. ...

  6. Cognitive outcome in adults after bacterial meningitis.

    NARCIS (Netherlands)

    Hoogman, M.; Beek, D. van de; Weisfelt, M.; Gans, J. de; Schmand, B.

    2007-01-01

    OBJECTIVE: To evaluate cognitive outcome in adult survivors of bacterial meningitis. METHODS: Data from three prospective multicentre studies were pooled and reanalysed, involving 155 adults surviving bacterial meningitis (79 after pneumococcal and 76 after meningococcal meningitis) and 72 healthy c

  7. The bacterial lux reporter system: applications in bacterial localisation studies.

    Science.gov (United States)

    Gahan, Cormac G M

    2012-02-01

    Bacterial production of visible light is a natural phenomenon occurring in marine (Vibrio and Photobacterium) and terrestrial (Photorhabdus) species. The mechanism underpinning light production in these organisms is similar and involves the oxidation of an aldehyde substrate in a reaction catalysed by the bacterial luciferase enzyme. The genes encoding the luciferase and a fatty acid reductase complex which synthesizes the substrate are contained in a single operon (the lux operon). This provides a useful reporter system as cloning the operon into a recipient host bacterium will generate visible light without the requirement to add exogenous substrate. The light can be detected in vivo in the living animal using a sensitive detection system and is therefore ideally suited to bioluminescence imaging protocols. The system has therefore been widely used to track bacteria during infection or colonisation of the host. As bacteria are currently being examined as bactofection vectors for gene delivery, particularly to tumour tissue, the use of bioluminescence imaging offers a powerful means to investigate vector amplification in situ. The implications of this technology for bacterial localization, tumour targeting and gene transfer (bactofection) studies are discussed.

  8. Actividad sialidasa en mujeres con vaginosis bacteriana Sialidase activity in women with bacterial vaginosis

    Directory of Open Access Journals (Sweden)

    Adriana M. Ombrella

    2006-04-01

    Full Text Available La vaginosis bacteriana (VB es un síndrome caracterizado por el sobrecrecimiento bacteriano de flora endógena Gram negativa, que desplaza a la flora lactobacilar normal. Dentro de las enzimas bacterianas, las sialidasas han sido consideradas factores de virulencia de muchos microorganismos patógenos que colonizan las distintas mucosas. Su presencia en fluidos vaginales puede estar correlacionada con VB. El propósito de este estudio fue comprobar la actividad de dicha enzima en mujeres con este síndrome y sin evidencia clínica de infección genital. Se estudiaron 112 mujeres (51 fueron pacientes con VB y 61 mujeres con flora colonizante habitual. Para la cuantificación de la actividad sialidasa se empleó la técnica basada en la hidrólisis enzimática de un derivado ácido del ácido metoxifenil acetil murámico. En la población estudiada se encontró que ambos grupos mostraron valores comprendidos entre 0.5 a 5.1 nmoles de metoxifenol, mientras que 11 de 52 pacientes con VB (21.17%, registraron valores superiores a 5.1 nmoles. La presencia de actividad sialidasa solamente no es índice de VB, excepto para valores mayores de 5.5 nmoles de metoxifenol, producidos en la reacción enzimática.Bacterial vaginosis (VB is a syndrome characterized by overgrowth of endogenous Gram negative bacterial flora and the lack of the normal flora. Within bacterial enzymes, sialidases have been considered a virulence factor of many pathogenic microorganisms colonizing the different mucous membranes. Their presence in vaginal discharges can be correlated with VB. The aim of this study was to detect the activity of this enzyme in women with this syndrome and without clinical evidence of genital infection. Out of a total 112 women studied, 51 were patients with VB and the other 61 women presented normal vaginal flora. For the quantification of enzyme activity, the technique based on the enzymatic hydrolysis of a derivative acid of the acetyl metoxifenil

  9. Distribution of Triplet Separators in Bacterial Genomes

    Institute of Scientific and Technical Information of China (English)

    HU Rui; ZHENG Wei-Mou

    2001-01-01

    Distributions of triplet separator lengths for two bacterial complete genomes are analyzed. The theoretical distributions for the independent random sequence and the first-order Markov chain are derived and compared with the distributions of the bacterial genomes. A prominent double band structure, which does not exist in the theoretical distributions, is observed in the bacterial distributions for most triplets.``

  10. Antibiotic drugs targeting bacterial RNAs

    Directory of Open Access Journals (Sweden)

    Weiling Hong

    2014-08-01

    Full Text Available RNAs have diverse structures that include bulges and internal loops able to form tertiary contacts or serve as ligand binding sites. The recent increase in structural and functional information related to RNAs has put them in the limelight as a drug target for small molecule therapy. In addition, the recognition of the marked difference between prokaryotic and eukaryotic rRNA has led to the development of antibiotics that specifically target bacterial rRNA, reduce protein translation and thereby inhibit bacterial growth. To facilitate the development of new antibiotics targeting RNA, we here review the literature concerning such antibiotics, mRNA, riboswitch and tRNA and the key methodologies used for their screening.

  11. Electromagnetic Signals from Bacterial DNA

    CERN Document Server

    Widom, A; Srivastava, Y N; Sivasubramanian, S

    2011-01-01

    Chemical reactions can be induced at a distance due to the propagation of electromagnetic signals during intermediate chemical stages. Although is is well known at optical frequencies, e.g. photosynthetic reactions, electromagnetic signals hold true for muck lower frequencies. In E. coli bacteria such electromagnetic signals can be generated by electric transitions between energy levels describing electrons moving around DNA loops. The electromagnetic signals between different bacteria within a community is a "wireless" version of intercellular communication found in bacterial communities connected by "nanowires". The wireless broadcasts can in principle be of both the AM and FM variety due to the magnetic flux periodicity in electron energy spectra in bacterial DNA orbital motions.

  12. Bacterial survival in Martian conditions

    CERN Document Server

    D'Alessandro, Giuseppe Galletta; Giulio Bertoloni; Maurizio

    2010-01-01

    We shortly discuss the observable consequences of the two hypotheses about the origin of life on Earth and Mars: the Lithopanspermia (Mars to Earth or viceversa) and the origin from a unique progenitor, that for Earth is called LUCA (the LUCA hypothesis). To test the possibility that some lifeforms similar to the terrestrial ones may survive on Mars, we designed and built two simulators of Martian environments where to perform experiments with different bacterial strains: LISA and mini-LISA. Our LISA environmental chambers can reproduce the conditions of many Martian locations near the surface trough changes of temperature, pressure, UV fluence and atmospheric composition. Both simulators are open to collaboration with other laboratories interested in performing experiments on many kind of samples (biological, minerals, electronic) in situations similar to that of the red planet. Inside LISA we have studied the survival of several bacterial strains and endospores. We verified that the UV light is the major re...

  13. Bacterial streamers in curved microchannels

    Science.gov (United States)

    Rusconi, Roberto; Lecuyer, Sigolene; Guglielmini, Laura; Stone, Howard

    2009-11-01

    Biofilms, generally identified as microbial communities embedded in a self-produced matrix of extracellular polymeric substances, are involved in a wide variety of health-related problems ranging from implant-associated infections to disease transmissions and dental plaque. The usual picture of these bacterial films is that they grow and develop on surfaces. However, suspended biofilm structures, or streamers, have been found in natural environments (e.g., rivers, acid mines, hydrothermal hot springs) and are always suggested to stem from a turbulent flow. We report the formation of bacterial streamers in curved microfluidic channels. By using confocal laser microscopy we are able to directly image and characterize the spatial and temporal evolution of these filamentous structures. Such streamers, which always connect the inner corners of opposite sides of the channel, are always located in the middle plane. Numerical simulations of the flow provide evidences for an underlying hydrodynamic mechanism behind the formation of the streamers.

  14. Bacterial chromosome organization and segregation.

    Science.gov (United States)

    Badrinarayanan, Anjana; Le, Tung B K; Laub, Michael T

    2015-01-01

    If fully stretched out, a typical bacterial chromosome would be nearly 1 mm long, approximately 1,000 times the length of a cell. Not only must cells massively compact their genetic material, but they must also organize their DNA in a manner that is compatible with a range of cellular processes, including DNA replication, DNA repair, homologous recombination, and horizontal gene transfer. Recent work, driven in part by technological advances, has begun to reveal the general principles of chromosome organization in bacteria. Here, drawing on studies of many different organisms, we review the emerging picture of how bacterial chromosomes are structured at multiple length scales, highlighting the functions of various DNA-binding proteins and the impact of physical forces. Additionally, we discuss the spatial dynamics of chromosomes, particularly during their segregation to daughter cells. Although there has been tremendous progress, we also highlight gaps that remain in understanding chromosome organization and segregation.

  15. Dynamics of bacterial gene regulation

    Science.gov (United States)

    Narang, Atul

    2009-03-01

    The phenomenon of diauxic growth is a classical problem of bacterial gene regulation. The most well studied example of this phenomenon is the glucose-lactose diauxie, which occurs because the expression of the lac operon is strongly repressed in the presence of glucose. This repression is often explained by appealing to molecular mechanisms such as cAMP activation and inducer exclusion. I will begin by analyzing data showing that these molecular mechanisms cannot explain the strong lac repression because they exert a relatively weak effect. I will then present a minimal model accounting only for enzyme induction and dilution, which yields strong repression despite the absence of catabolite repression and inducer exclusion. The model also explains the growth patterns observed in batch and continuous cultures of various bacterial strains and substrate mixtures. The talk will conclude with a discussion of the experimental evidence regarding positive feedback, the key component of the minimal model.

  16. Collective Functionality through Bacterial Individuality

    Science.gov (United States)

    Ackermann, Martin

    According to the conventional view, the properties of an organism are a product of nature and nurture - of its genes and the environment it lives in. Recent experiments with unicellular organisms have challenged this view: several molecular mechanisms generate phenotypic variation independently of environmental signals, leading to variation in clonal groups. My presentation will focus on the causes and consequences of this microbial individuality. Using examples from bacterial genetic model systems, I will first discuss different molecular and cellular mechanisms that give rise to bacterial individuality. Then, I will discuss the consequences of individuality, and focus on how phenotypic variation in clonal populations of bacteria can promote interactions between individuals, lead to the division of labor, and allow clonal groups of bacteria to cope with environmental uncertainty. Variation between individuals thus provides clonal groups with collective functionality.

  17. Bacterial Interstitial Nephritis in Children

    OpenAIRE

    Bobadilla Chang, Fernando; Departamento de Ciencias Dinámicas Facultad de Medicina Universidad Nacional Mayor de San Marcos Lima, Perú; Villanueva, Dolores; Departamento de Ciencias Dinámicas Facultad de Medicina Universidad Nacional Mayor de San Marcos Lima, Perú

    2014-01-01

    OBJECTIVE: To assess the diagnosis approach to urinary tract infections in children. MATERIAL AND METHODS: Medical records from 103 children with diagnosis of interstitial bacterial nephritis were retrospectively reviewed. Diagnosis was supported by the dramatic involvement of renal parenquima, which is not addressed as "urinary tract infection". RESULTS: From all 103 patients, 49 were 2-years-old or younger, 33 were between 2 and 5-years-old, and 21 were between 6 to 10. Clinical picture inc...

  18. Bacterial canker resistance in tomato

    OpenAIRE

    Sen, Y.

    2014-01-01

    Clavibacter michiganensis subsp. michiganensis (Cmm) is the pathogen causing bacterial  canker in tomato. The disease was described for the first time in 1910 in Michigan, USA. Cmmis considered the most harmful bacteria threatening tomato. Disease transmission occurs via seed and symptoms become visible at least 20 days after infection. Due to its complex strategy and transmission, Cmm is under quarantine regulation in EU and other countries. There is no method to stop disease progress i...

  19. Biotechnological applications of bacterial cellulases

    OpenAIRE

    Esther Menendez; Paula Garcia-Fraile; Raul Rivas

    2015-01-01

    Cellulases have numerous applications in several industries, including biofuel production, food and feed industry, brewing, pulp and paper, textile, laundry, and agriculture.Cellulose-degrading bacteria are widely spread in nature, being isolated from quite different environments. Cellulose degradation is the result of a synergic process between an endoglucanase, an exoglucanase and a,β-glucosidase. Bacterial endoglucanases degrade ß-1,4-glucan linkages of cellulose amorphous zones, mean...

  20. Bacterial motility on abiotic surfaces

    OpenAIRE

    Gibiansky, Maxsim

    2013-01-01

    Bacterial biofilms are structured microbial communities which are widespread both in nature and in clinical settings. When organized into a biofilm, bacteria are extremely resistant to many forms of stress, including a greatly heightened antibiotic resistance. In the early stages of biofilm formation on an abiotic surface, many bacteria make use of their motility to explore the surface, finding areas of high nutrition or other bacteria to form microcolonies. They use motility appendages, incl...

  1. Cytochemical Differences in Bacterial Glycocalyx

    Science.gov (United States)

    Krautgartner, Wolf Dietrich; Vitkov, Ljubomir; Hannig, Matthias; Pelz, Klaus; Stoiber, Walter

    2005-02-01

    To examine new cytochemical aspects of the bacterial adhesion, a strain 41452/01 of the oral commensal Streptococcus sanguis and a wild strain of Staphylococcus aureus were grown with and without sucrose supplementation for 6 days. Osmiumtetraoxyde (OsO4), uranyl acetate (UA), ruthenium red (RR), cupromeronic blue (CB) staining with critical electrolytic concentrations (CECs), and the tannic acid-metal salt technique (TAMST) were applied for electron microscopy. Cytochemically, only RR-positive fimbriae in S. sanguis were visualized. By contrast, some types of fimbriae staining were observed in S. aureus glycocalyx: RR-positive, OsO4-positive, tannophilic and CB-positive with ceasing point at 0.3 M MgCl2. The CB staining with CEC, used for the first time for visualization of glycoproteins of bacterial glycocalyx, also reveals intacellular CB-positive substances-probably the monomeric molecules, that is, subunits forming the fimbriae via extracellular assembly. Thus, glycosylated components of the biofilm matrix can be reliably related to single cells. The visualization of intracellular components by CB with CEC enables clear distinction between S. aureus and other bacteria, which do not produce CB-positive substances. The small quantities of tannophilic substances found in S. aureus makes the use of TAMST for the same purpose difficult. The present work protocol enables, for the first time, a partial cytochemical differentiation of the bacterial glycocalyx.

  2. DIAGNOSTIC DIFFICULTIES IN BACTERIAL SPONDYLODISCITIS

    Directory of Open Access Journals (Sweden)

    Vinicius Orso

    2015-12-01

    Full Text Available Objective : To analyze aspects related to the diagnostic difficulty in patients with bacterial spondylodiscitis. Methods : Cross-sectional observational study with retrospective data collected in the period from March 2004 to January 2014.Twenty-one patients diagnosed with bacterial spondylodiscitis were analyzed. Results : Women were the most affected, as well as older individuals. Pain in the affected region was the initial symptom in 52% of patients, and 45.5% of the patients had low back pain, and those with dorsal discitis had back pain as the main complaint; the patients with thoracolumbar discitis had pain in that region, and only one patient had sacroiliac discitis. The average time between onset of symptoms and treatment was five months. The lumbar segment was the most affected with 11 cases (52%, followed by thoracolumbar in 24%, dorsal in 19% of cases and a case in the sacroiliac segment. Only seven patients had fever. Pain in the affected level was coincidentally the most common symptom. Conclusions : Early diagnosis of bacterial spondylodiscitis remains a challenge due to the nonspecific signs and symptoms reported by the patient and the wide variability of laboratory results and imaging. The basis for early diagnosis remains the clinical suspicion at the time of initial treatment.

  3. Detergent-compatible bacterial amylases.

    Science.gov (United States)

    Niyonzima, Francois N; More, Sunil S

    2014-10-01

    Proteases, lipases, amylases, and cellulases are enzymes used in detergent formulation to improve the detergency. The amylases are specifically supplemented to the detergent to digest starchy stains. Most of the solid and liquid detergents that are currently manufactured contain alkaline enzymes. The advantages of using alkaline enzymes in the detergent formulation are that they aid in removing tough stains and the process is environmentally friendly since they reduce the use of toxic detergent ingredients. Amylases active at low temperature are preferred as the energy consumption gets reduced, and the whole process becomes cost-effective. Most microbial alkaline amylases are used as detergent ingredients. Various reviews report on the production, purification, characterization, and application of amylases in different industry sectors, but there is no specific review on bacterial or fungal alkaline amylases or detergent-compatible amylases. In this mini-review, an overview on the production and property studies of the detergent bacterial amylases is given, and the stability and compatibility of the alkaline bacterial amylases in the presence of the detergents and the detergent components are highlighted.

  4. The restoration of the vaginal microbiota after treatment for bacterial vaginosis with metronidazole or probiotics.

    Science.gov (United States)

    Ling, Zongxin; Liu, Xia; Chen, Weiguang; Luo, Yueqiu; Yuan, Li; Xia, Yaxian; Nelson, Karen E; Huang, Shaolei; Zhang, Shaoen; Wang, Yuezhu; Yuan, Jieli; Li, Lanjuan; Xiang, Charlie

    2013-04-01

    Whether or not treatment with antibiotics or probiotics for bacterial vaginosis (BV) is associated with a change in the diversity of vaginal microbiota in women was investigated. One hundred fifteen women, consisting of 30 healthy subjects, 30 BV-positive control subjects, 30 subjects with BV treated with a 7-day metronidazole regimen, and 25 subjects with BV treated with a 10-day probiotics regimen, were analyzed to determine the efficacy and disparity of diversity and richness of vaginal microbiota using 454 pyrosequencing. Follow-up visits at days 5 and 30 showed a greater BV cure rate in the probiotics-treated subjects (88.0 and 96 %, respectively) compared to the metronidazole-treated subjects (83.3 and 70 %, respectively [p = 0.625 at day 5 and p = 0.013 at day 30]). Treatment with metronidazole reduced the taxa diversity and eradicated most of the BV-associated phylotypes, while probiotics only suppressed the overgrowth and re-established vaginal homeostasis gradually and steadily. Despite significant interindividual variation, the microbiota of the actively treated groups or participants constituted a unique profile. Along with the decrease in pathogenic bacteria, such as Gardnerella, Atopobium, Prevotella, Megasphaera, Coriobacteriaceae, Lachnospiraceae, Mycoplasma, and Sneathia, a Lactobacillus-dominated vaginal microbiota was recovered. Acting as vaginal sentinels and biomarkers, the relative abundance of Lactobacillus and pathogenic bacteria determined the consistency of the BV clinical and microbiologic cure rates, as well as recurrent BV. Both 7-day intravaginal metronidazole and 10-day intravaginal probiotics have good efficacy against BV, while probiotics maintained normal vaginal microbiota longer due to effective and steady vaginal microbiota restoration, which provide new insights into BV treatment.

  5. Bacterial adhesion and biofilms on surfaces

    Institute of Scientific and Technical Information of China (English)

    Trevor Roger Garrett; Manmohan Bhakoo; Zhibing Zhang

    2008-01-01

    Bacterial adhesion has become a significant problem in industry and in the domicile,and much research has been done for deeper understanding of the processes involved.A generic biological model of bacterial adhesion and population growth called the bacterial biofilm growth cycle,has been described and modified many times.The biofilm growth cycle encompasses bacterial adhesion at all levels,starting with the initial physical attraction of bacteria to a substrate,and ending with the eventual liberation of cell dusters from the biofilm matrix.When describing bacterial adhesion one is simply describing one or more stages of biofilm development,neglecting the fact that the population may not reach maturity.This article provides an overview of bacterial adhesion.cites examples of how bac-terial adhesion affects industry and summarises methods and instrumentation used to improve our understanding of the adhesive prop-erties of bacteria.

  6. Bacterial meningitis and diseases caused by bacterial toxins.

    Science.gov (United States)

    Rings, D M

    1987-03-01

    Bacterial meningitis most commonly occurs in young calves secondary to septicemia. Clinical signs of hyperirritability are usually seen. Meningitis can be confirmed by cerebrospinal fluid analysis and culture or by necropsy. Intoxications by the exotoxins of Clostridium perfringens types C and D, C. botulinum, and C. tetani are difficult to confirm. The clinical signs of these intoxications vary from flaccid paralysis (botulism) to muscular rigidity (tetanus). Treatment of affected cattle has been unrewarding in botulism and enterotoxemia, whereas early aggressive treatment of tetanus cases can often be successfully resolved. Botulism and enterotoxemia can be proved using mouse inoculation tests, whereas tetanus is diagnosed largely by ruling out other diseases.

  7. Propionibacterium acnes CAMP factor and host acid sphingomyelinase contribute to bacterial virulence: potential targets for inflammatory acne treatment.

    Directory of Open Access Journals (Sweden)

    Teruaki Nakatsuji

    Full Text Available BACKGROUND: In the progression of acne vulgaris, the disruption of follicular epithelia by an over-growth of Propionibacterium acnes (P. acnes permits the bacteria to spread and become in contact with various skin and immune cells. METHODOLOGY/PRINCIPAL FINDINGS: We have demonstrated in the present study that the Christie, Atkins, Munch-Peterson (CAMP factor of P. acnes is a secretory protein with co-hemolytic activity with sphingomyelinase that can confer cytotoxicity to HaCaT keratinocytes and RAW264.7 macrophages. The CAMP factor from bacteria and acid sphingomyelinase (ASMase from the host cells were simultaneously present in the culture supernatant only when the cells were co-cultured with P. acnes. Either anti-CAMP factor serum or desipramine, a selective ASMase inhibitor, significantly abrogated the P. acnes-induced cell death of HaCaT and RAW264.7 cells. Intradermal injection of ICR mouse ears with live P. acnes induced considerable ear inflammation, macrophage infiltration, and an increase in cellular soluble ASMase. Suppression of ASMase by systemic treatment with desipramine significantly reduced inflammatory reaction induced by intradermal injection with P. acnes, suggesting the contribution of host ASMase in P. acnes-induced inflammatory reaction in vivo. Vaccination of mice with CAMP factor elicited a protective immunity against P. acnes-induced ear inflammation, indicating the involvement of CAMP factor in P. acnes-induced inflammation. Most notably, suppression of both bacterial CAMP factor and host ASMase using vaccination and specific antibody injection, respectively, cooperatively alleviated P. acnes-induced inflammation. CONCLUSIONS/SIGNIFICANCE: These findings envision a novel infectious mechanism by which P. acnes CAMP factor may hijack host ASMase to amplify bacterial virulence to degrade and invade host cells. This work has identified both CAMP factor and ASMase as potential molecular targets for the development of drugs

  8. BACTERIAL DESEASES IN SEA FISH

    Directory of Open Access Journals (Sweden)

    Ivančica Strunjak-Perović

    1997-10-01

    Full Text Available With development of the fish culturing in the sea, the interest in their health also increased. The reason for this are diseases or rather mortality that occur in such controlled cultures and cause great economic losses. By growing large quantities of fish in rather small species, natural conditions are changed, so fish is more sensitive and prone to infection agents (viruses, bacteria, parasites. Besides, a large fish density in the cultural process accelerates spreading if the diseases, but also enables a better perception of them. In wild populations sick specimen very quickly become predator’s prey, witch makes it difficult to note any pathological changes in such fish. There are lots of articles on viral, bacterial and parasitic diseases nowdays, but this work deals exclusively with bacterial deseases that occur in the controlled sea cultures (vibriosis, furunculosis, pastherelosis, nocardiosis, mycobaceriosis, edwardsielosis, yersiniosis, deseases caused by bacteria of genera Flexibacter, Pseudomonas, Aeromonas, Streptococus and bacteria nephryithis. Yet, the knowledge of these deseases vary, depending on wether a fish species is being cultured for a longer period of time or is only being introduced in the controlled culture.

  9. Bacterial Culture of Neonatal Sepsis

    Directory of Open Access Journals (Sweden)

    AH Movahedian

    2006-08-01

    Full Text Available Neonatal bacterial sepsis is one of the major cause of morbidity and mortality in neonates. This retrospective study was performed to determine the incidence of bacterial sepsis with focus on Gram negative organisms in neonates admitted at Beheshti Hospital in Kashan, during a 3-yr period, from September 2002 to September 2005. Blood culture was performed on all neonates with risk factors or signs of suggestive sepsis. Blood samples were cultured using brain heart infusion (BHI broth according to standard method. From the 1680 neonates 36% had positive blood culture for Pseudomans aeruginosa, 20.7% for Coagulase negative Staphylococci, and 17% for Klebsiella spp. Gram-negative organisms accounted for 72.1% of all positive cultures. The overall mortality rate was 19.8% (22 /111 of whom 63.6% (14 /22 were preterm. Pseudomona aeruginosa and Klebsiella spp. showed a high degree of resistance to commonly used antibiotics (ampicillin, gentamicin as well as third generation cephalosporins. Continued local surveillance studies are urged to monitor emerging antimicrobial resistance and to guide interventions to minimize its occurrence.

  10. Periodontal diseases as bacterial infection

    Directory of Open Access Journals (Sweden)

    A. Bascones Martínez

    Full Text Available The periodontal disease is conformed by a group of illnesses affecting the gums and dental support structures. They are caused by certain bacteria found in the bacterial plaque. These bacteria are essential to the onset of illness; however, there are predisposing factors in both the host and the microorganisms that will have an effect on the pathogenesis of the illness. Periodontopathogenic bacterial microbiota is needed, but by itself, it is not enough to cause the illness, requiring the presence of a susceptible host. These diseases have been classified as gingivitis, when limited to the gums, and periodontitis, when they spread to deeper tissues. Classification of periodontal disease has varied over the years.The one used in this work was approved at the International Workshop for a Classification of Periodontal Diseases and Conditions, held in 1999. This study is an overview of the different periodontal disease syndromes. Later, the systematic use of antibiotic treatment consisting of amoxicillin, amoxicillinclavulanic acid, and metronidazole as first line coadjuvant treatment of these illnesses will be reviewed.

  11. Bioinformatic Comparison of Bacterial Secretomes

    Institute of Scientific and Technical Information of China (English)

    Catharine Song; Aseem Kumar; Mazen Saleh

    2009-01-01

    The rapid increasing number of completed bacterial genomes provides a good op-portunity to compare their proteomes. This study was undertaken to specifically compare and contrast their secretomes-the fraction of the proteome with pre-dicted N-terminal signal sequences, both type Ⅰ and type Ⅱ. A total of 176 theoreti-cal bacterial proteomes were examined using the ExProt program. Compared with the Gram-positives, the Gram-negative bacteria were found, on average, to con-tain a larger number of potential Sec-dependent sequences. In the Gram-negative bacteria but not in the others, there was a positive correlation between proteome size and secretome size, while there was no correlation between secretome size and pathogenicity. Within the Gram-negative bacteria, intracellular pathogens were found to have the smallest secretomes. However, the secretomes of certain bacte-ria did not fit into the observed pattern. Specifically, the secretome of Borrelia burgdoferi has an unusually large number of putative lipoproteins, and the signal peptides of mycoplasmas show closer sequence similarity to those of the Gram-negative bacteria. Our analysis also suggests that even for a theoretical minimal genome of 300 open reading frames, a fraction of this gene pool (up to a maximum of 20%) may code for proteins with Sec-dependent signal sequences.

  12. Bacterial pericarditis in a cat

    Directory of Open Access Journals (Sweden)

    Nicole LeBlanc

    2015-09-01

    Full Text Available Case summary A 4-year-old male neutered domestic shorthair cat was presented to the Oregon State University cardiology service for suspected pericardial effusion. Cardiac tamponade was documented and pericardiocentesis yielded purulent fluid with cytologic results supportive of bacterial pericarditis. The microbial population consisted of Pasteurella multocida, Actinomyces canis, Fusobacterium and Bacteroides species. Conservative management was elected consisting of intravenous antibiotic therapy with ampicillin sodium/sulbactam sodium and metronidazole for 48 h followed by 4 weeks of oral antibiotics. Re-examination 3 months after the initial incident indicated no recurrence of effusion and the cat remained free of clinical signs 2 years after presentation. Relevance and novel information Bacterial pericarditis is a rare cause of pericardial effusion in cats. Growth of P multocida, A canis, Fusobacterium and Bacteroides species has not previously been documented in feline septic pericarditis. Conservative management with broad-spectrum antibiotics may be considered when further diagnostic imaging or exploratory surgery to search for a primary nidus of infection is not feasible or elected.

  13. Interaction between resource identity and bacterial community composition regulates bacterial respiration in aquatic ecosystems

    Directory of Open Access Journals (Sweden)

    A. P. F. Pires

    Full Text Available Abstract Resource identity and composition structure bacterial community, which in turn determines the magnitude of bacterial processes and ecological services. However, the complex interaction between resource identity and bacterial community composition (BCC has been poorly understood so far. Using aquatic microcosms, we tested whether and how resource identity interacts with BCC in regulating bacterial respiration and bacterial functional diversity. Different aquatic macrophyte leachates were used as different carbon resources while BCC was manipulated through successional changes of bacterial populations in batch cultures. We observed that the same BCC treatment respired differently on each carbon resource; these resources also supported different amounts of bacterial functional diversity. There was no clear linear pattern of bacterial respiration in relation to time succession of bacterial communities in all leachates, i.e. differences on bacterial respiration between different BCC were rather idiosyncratic. Resource identity regulated the magnitude of respiration of each BCC, e.g. Ultricularia foliosa leachate sustained the greatest bacterial functional diversity and lowest rates of bacterial respiration in all BCC. We conclude that both resource identity and the BCC interact affecting the pattern and the magnitude of bacterial respiration in aquatic ecosystems.

  14. 钙离子拮抗剂致药物性牙龈增生的危险因素分析%Analysis of the risk factors for drug-induced gingival overgrowth

    Institute of Scientific and Technical Information of China (English)

    刘卓; 高津福

    2014-01-01

    AIM:To explore the relationship between calcium channel blockers and gingival hyperplasia. METHODS:459 subjects with high blood pressure were included.262 of them taking calcium channel blockers (CCB)were in CCB group,197 without use of CCB were in control group.All the subjects were investigated by a questionnaire and oral examination.Gingiva hyperplasia was assessed according to the diagnostic criteria of periodontal hperplasia index(HI).RESULTS:Gingival overgrowth was found in 20.23% of the subjects in CCB group and in 2.54% in control group(χ2 =32.276,P<0.05).Single factor analysis showed that age,dosage and duration of the drug use were the risk factors of gingival hyperplasia (P<0.05).There was a negative correlation between prevalence rate of gingival hyperplasia and the age of patients who took CCB(r=-0.155,P=0.012).There is close relationship between gingival overgrowth and periodontal local factors.CONCLUSION:The gingival hyperplasia is associated with the factors of CCB age,duration,administration method ,dosage of CCB and oral hygiene.%目的:探讨高血压患者服用钙离子拮抗剂后出现牙龈增生的患病率。方法:对我院查体中心和心血管内科门诊服用钙离子拮抗剂抗高血压类药物的262和未服用钙离子拮抗剂的197例患者进行横断面调查。方法包括问卷调查和口腔牙周检查,其中牙龈增生的判定以牙龈增生指数(HI )为诊断标准。对调查结果进行统计学分析。结果:服用钙离子拮抗剂类药物患者的牙龈增生患病率为20.23%,显著高于对照组的2.54%(χ2=32.276,P<0.05)。随年龄增大,药物性牙龈增生的患病率降低(r=-0.155,P<0.05);单一用药者较联合用药者患病率高;服药时间越长患病率降低;随服药剂量的增加,患病率明显增长;口腔卫生状况差者可加重牙龈增生程度。结论:药物性牙龈增生是多方面作用的结果,其主

  15. Forensic identification using skin bacterial communities

    OpenAIRE

    FIERER Noah; Lauber, Christian L.; Zhou, Nick; McDonald, Daniel; Costello, Elizabeth K.; Knight, Rob

    2010-01-01

    Recent work has demonstrated that the diversity of skin-associated bacterial communities is far higher than previously recognized, with a high degree of interindividual variability in the composition of bacterial communities. Given that skin bacterial communities are personalized, we hypothesized that we could use the residual skin bacteria left on objects for forensic identification, matching the bacteria on the object to the skin-associated bacteria of the individual who touched the object....

  16. Drag Reduction of Bacterial Cellulose Suspensions

    Directory of Open Access Journals (Sweden)

    Satoshi Ogata

    2011-01-01

    Full Text Available Drag reduction due to bacterial cellulose suspensions with small environmental loading was investigated. Experiments were carried out by measuring the pressure drop in pipe flow. It was found that bacterial cellulose suspensions give rise to drag reduction in the turbulent flow range. We observed a maximum drag reduction ratio of 11% and found that it increased with the concentration of the bacterial cellulose suspension. However, the drag reduction effect decreased in the presence of mechanical shear.

  17. In vivo bacterial morphogenetic protein interactions

    OpenAIRE

    van der Ploeg, R.; den Blaauwen, T.; Meghea, A.

    2012-01-01

    This chapter will discuss none-invasive techniques that are widely used to study protein-protein interactions. As an example, their application in exploring interactions between proteins involved in bacterial cell division will be evaluated. First, bacterial morphology and cell division of the rod-shaped bacterium Escherichia coli will be introduced. Next, three bacterial two-hybrid methods and three Förster resonance energy transfer detection methods that are frequently applied to detect int...

  18. Bacterial contamination of hospital physicians' stethoscopes.

    Science.gov (United States)

    Bernard, L; Kereveur, A; Durand, D; Gonot, J; Goldstein, F; Mainardi, J L; Acar, J; Carlet, J

    1999-09-01

    Because stethoscopes might be potential vectors of nosocomial infections, this study, conducted in a 450-bed general hospital, was devised to evaluate the bacterial contamination of stethoscopes; bacterial survival on stethoscope membranes; the kinetics of the bacterial load on stethoscope membranes during clinical use; and the efficacy of 70% alcohol or liquid soap for membrane disinfection. Among the 355 stethoscopes tested, 234 carried > or =2 different bacterial species; 31 carried potentially pathogenic bacteria. Although some bacteria deposited onto membranes could survive 6 to 18 hours, none survived after disinfection.

  19. Bacterial Nanocellulose as a Microbiological Derived Nanomaterial

    Directory of Open Access Journals (Sweden)

    Stanisławska A.

    2016-12-01

    Full Text Available Bacterial nanocellulose (BNC is a nanofibrilar polymer produced by strains such as Gluconacetobacter xylinus, one of the best bacterial species which given the highest efficiency in cellulose production. Bacterial cellulose is a biomaterial having unique properties such as: chemical purity, good mechanical strength, high flexibility, high absorbency, possibility of forming any shape and size and many others. Such a large number of advantages contributes to the widespread use of the BNC in food technology, paper, electronic industry, but also the architecture in use. However, the greatest hopes are using the BNC in medicine. This text contains information about bacterial nanocellulose, its specific mechanical and biological properties and current applications.

  20. Extended recombinant bacterial ghost system.

    Science.gov (United States)

    Lubitz, W; Witte, A; Eko, F O; Kamal, M; Jechlinger, W; Brand, E; Marchart, J; Haidinger, W; Huter, V; Felnerova, D; Stralis-Alves, N; Lechleitner, S; Melzer, H; Szostak, M P; Resch, S; Mader, H; Kuen, B; Mayr, B; Mayrhofer, P; Geretschläger, R; Haslberger, A; Hensel, A

    1999-08-20

    Controlled expression of cloned PhiX174 gene E in Gram-negative bacteria results in lysis of the bacteria by formation of an E-specific transmembrane tunnel structure built through the cell envelope complex. Bacterial ghosts from a variety of bacteria are used as non-living candidate vaccines. In the recombinant ghost system, foreign proteins are attached on the inside of the inner membrane as fusions with specific anchor sequences. Ghosts have a sealed periplasmic space and the export of proteins into this space vastly extends the capacity of ghosts or recombinant ghosts to function as carriers of foreign antigens. In addition, S-layer proteins forming shell-like self assembly structures can be expressed in candidate vaccine strains prior to E-mediated lysis. Such recombinant S-layer proteins carrying foreign epitopes further extend the possibilities of ghosts as carriers of foreign epitopes. As ghosts have inherent adjuvant properties, they can be used as adjuvants in combination with subunit vaccines. Subunits or other ligands can also be coupled to matrixes like dextran which are used to fill the internal lumen of ghosts. Oral, aerogenic or parenteral immunization of experimental animals with recombinant ghosts induced specific humoral and cellular immune responses against bacterial and target components including protective mucosal immunity. The most relevant advantage of recombinant bacterial ghosts as immunogens is that no inactivation procedures that denature relevant immunogenic determinants are employed in this production. This fact explains the superior quality of ghosts when compared to other inactivated vaccines. The endotoxic component of the outer membrane does not limit the use of ghosts as vaccine candidates but triggers the release of several potent immunoregulatory cytokines. As carriers, there is no limitation in the size of foreign antigens that can be inserted in the membrane and the capacity of all spaces including the membranes, peri

  1. New pathways for bacterial polythioesters.

    Science.gov (United States)

    Wübbeler, Jan Hendrik; Steinbüchel, Alexander

    2014-10-01

    Polythioesters (PTE) contain sulfur in the backbone and represent persistent biopolymers, which are produced by certain chemical procedures as well as biotechnological in vitro and in vivo techniques. Different building blocks can be incorporated, resulting in PTE with variable features that could become interesting for special purposes. Particularly, the option to produce PTE in large-scale and in accordance with the methods of white biotechnology or green chemistry is valuable due to economical potentials and public environmental consciousness. This review is focused on the synthesis of PTE by the three established bacterial production strains Ralstonia eutropha, Escherichia coli and Advenella mimigardefordensis. In addition, an overview of the in vitro production and degradation of PTE is depicted.

  2. Cooperative Model of Bacterial Sensing

    CERN Document Server

    Shi, Y; Shi, Yu; Duke, Thomas

    1998-01-01

    Bacterial chemotaxis is controlled by the signalling of a cluster of receptors. A cooperative model is presented, in which coupling between neighbouring receptor dimers enhances the sensitivity with which stimuli can be detected, without diminishing the range of chemoeffector concentration over which chemotaxis can operate. Individual receptor dimers have two stable conformational states: one active, one inactive. Noise gives rise to a distribution between these states, with the probability influenced by ligand binding, and also by the conformational states of adjacent receptor dimers. The two-state model is solved, based on an equivalence with the Ising model in a randomly distributed magnetic field. The model has only two effective parameters, and unifies a number of experimental findings. According to the value of the parameter comparing coupling and noise, the signal can be arbitrarily sensitive to changes in the fraction of receptor dimers to which ligand is bound. The counteracting effect of a change of...

  3. Antigenic Variation in Bacterial Pathogens.

    Science.gov (United States)

    Palmer, Guy H; Bankhead, Troy; Seifert, H Steven

    2016-02-01

    Antigenic variation is a strategy used by a broad diversity of microbial pathogens to persist within the mammalian host. Whereas viruses make use of a minimal proofreading capacity combined with large amounts of progeny to use random mutation for variant generation, antigenically variant bacteria have evolved mechanisms which use a stable genome, which aids in protecting the fitness of the progeny. Here, three well-characterized and highly antigenically variant bacterial pathogens are discussed: Anaplasma, Borrelia, and Neisseria. These three pathogens display a variety of mechanisms used to create the structural and antigenic variation needed for immune escape and long-term persistence. Intrahost antigenic variation is the focus; however, the role of these immune escape mechanisms at the population level is also presented.

  4. Bacterial interactions in dental biofilm.

    Science.gov (United States)

    Huang, Ruijie; Li, Mingyun; Gregory, Richard L

    2011-01-01

    Biofilms are masses of microorganisms that bind to and multiply on a solid surface, typically with a fluid bathing the microbes. The microorganisms that are not attached but are free floating in an aqueous environment are termed planktonic cells. Traditionally, microbiology research has addressed results from planktonic bacterial cells. However, many recent studies have indicated that biofilms are the preferred form of growth of most microbes and particularly those of a pathogenic nature. Biofilms on animal hosts have significantly increased resistance to various antimicrobials compared to planktonic cells. These microbial communities form microcolonies that interact with each other using very sophisticated communication methods (i.e., quorum-sensing). The development of unique microbiological tools to detect and assess the various biofilms around us is a tremendously important focus of research in many laboratories. In the present review, we discuss the major biofilm mechanisms and the interactions among oral bacteria.

  5. Autoproteolytic Activation of Bacterial Toxins

    Directory of Open Access Journals (Sweden)

    Aimee Shen

    2010-05-01

    Full Text Available Protease domains within toxins typically act as the primary effector domain within target cells. By contrast, the primary function of the cysteine protease domain (CPD in Multifunctional Autoprocessing RTX-like (MARTX and Clostridium sp. glucosylating toxin families is to proteolytically cleave the toxin and release its cognate effector domains. The CPD becomes activated upon binding to the eukaryotic-specific small molecule, inositol hexakisphosphate (InsP6, which is found abundantly in the eukaryotic cytosol. This property allows the CPD to spatially and temporally regulate toxin activation, making it a prime candidate for developing anti-toxin therapeutics. In this review, we summarize recent findings related to defining the regulation of toxin function by the CPD and the development of inhibitors to prevent CPD-mediated activation of bacterial toxins.

  6. Bacterial Ice Crystal Controlling Proteins

    Directory of Open Access Journals (Sweden)

    Janet S. H. Lorv

    2014-01-01

    Full Text Available Across the world, many ice active bacteria utilize ice crystal controlling proteins for aid in freezing tolerance at subzero temperatures. Ice crystal controlling proteins include both antifreeze and ice nucleation proteins. Antifreeze proteins minimize freezing damage by inhibiting growth of large ice crystals, while ice nucleation proteins induce formation of embryonic ice crystals. Although both protein classes have differing functions, these proteins use the same ice binding mechanisms. Rather than direct binding, it is probable that these protein classes create an ice surface prior to ice crystal surface adsorption. Function is differentiated by molecular size of the protein. This paper reviews the similar and different aspects of bacterial antifreeze and ice nucleation proteins, the role of these proteins in freezing tolerance, prevalence of these proteins in psychrophiles, and current mechanisms of protein-ice interactions.

  7. Multiple bacterial species reside in chronic wounds

    DEFF Research Database (Denmark)

    Gjødsbøl, Kristine; Christensen, Jens Jørgen; Karlsmark, Tonny;

    2006-01-01

    The aim of the study was to investigate the bacterial profile of chronic venous leg ulcers and the importance of the profile to ulcer development. Patients with persisting venous leg ulcers were included and followed for 8 weeks. Every second week, ulcer samples were collected and the bacterial s...

  8. Bacterial biofilms: prokaryotic adventures in multicellularity

    DEFF Research Database (Denmark)

    Webb, J.S.; Givskov, Michael Christian; Kjelleberg, S.

    2003-01-01

    The development of bacterial biofilms includes both the initial social behavior of undifferentiated cells, as well as cell death and differentiation in the mature biofilm, and displays several striking similarities with higher organisms. Recent advances in the field provide new insight...... into differentiation and cell death events in bacterial biofilm development and propose that biofilms have an unexpected level of multicellularity....

  9. Bacterial Flora of the Female Genital Tract

    Directory of Open Access Journals (Sweden)

    Pongsakdi Chaisilwattana

    1995-01-01

    Full Text Available Objective: The purpose of this study was to analyze the ability of septicemic and nonsepticemic isolates of group B streptococci (GBS to inhibit in vitro the principal bacterial groups found in the normal bacterial flora of the female genital tract.

  10. Use of Bacteriophages to control bacterial pathogens

    Science.gov (United States)

    Lytic bacteriophages can provide a natural method and an effective alternative to antibiotics to reduce bacterial pathogens in animals, foods, and other environments. Bacteriophages (phages) are viruses which infect bacterial cells and eventually kill them through lysis, and represent the most abun...

  11. Cerebral infarction in childhood bacterial meningitis

    OpenAIRE

    Snyder, R.D.; Stovring, J; Cushing, A H; Davis, L. E.; Hardy, T. L.

    1981-01-01

    Forty-nine children with complicated bacterial meningitis were studied. Thirteen had abnormalities on computed tomography compatible with the diagnosis of brain infarction; one had a brain biopsy with the histological appearance of infarction. Factors exist in childhood bacterial meningitis which are associated with the development of brain infraction.

  12. In vivo bacterial morphogenetic protein interactions

    NARCIS (Netherlands)

    van der Ploeg, R.; den Blaauwen, T.; Meghea, A.

    2012-01-01

    This chapter will discuss none-invasive techniques that are widely used to study protein-protein interactions. As an example, their application in exploring interactions between proteins involved in bacterial cell division will be evaluated. First, bacterial morphology and cell division of the rod-s

  13. Structural biology of bacterial RNA polymerase.

    Science.gov (United States)

    Murakami, Katsuhiko S

    2015-05-11

    Since its discovery and characterization in the early 1960s (Hurwitz, J. The discovery of RNA polymerase. J. Biol. Chem. 2005, 280, 42477-42485), an enormous amount of biochemical, biophysical and genetic data has been collected on bacterial RNA polymerase (RNAP). In the late 1990s, structural information pertaining to bacterial RNAP has emerged that provided unprecedented insights into the function and mechanism of RNA transcription. In this review, I list all structures related to bacterial RNAP (as determined by X-ray crystallography and NMR methods available from the Protein Data Bank), describe their contributions to bacterial transcription research and discuss the role that small molecules play in inhibiting bacterial RNA transcription.

  14. Oral bacterial DNA findings in pericardial fluid

    Directory of Open Access Journals (Sweden)

    Anne-Mari Louhelainen

    2014-11-01

    Full Text Available Background: We recently reported that large amounts of oral bacterial DNA can be found in thrombus aspirates of myocardial infarction patients. Some case reports describe bacterial findings in pericardial fluid, mostly done with conventional culturing and a few with PCR; in purulent pericarditis, nevertheless, bacterial PCR has not been used as a diagnostic method before. Objective: To find out whether bacterial DNA can be measured in the pericardial fluid and if it correlates with pathologic–anatomic findings linked to cardiovascular diseases. Methods: Twenty-two pericardial aspirates were collected aseptically prior to forensic autopsy at Tampere University Hospital during 2009–2010. Of the autopsies, 10 (45.5% were free of coronary artery disease (CAD, 7 (31.8% had mild and 5 (22.7% had severe CAD. Bacterial DNA amounts were determined using real-time quantitative PCR with specific primers and probes for all bacterial strains associated with endodontic disease (Streptococcus mitis group, Streptococcus anginosus group, Staphylococcus aureus/Staphylococcus epidermidis, Prevotella intermedia, Parvimonas micra and periodontal disease (Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Treponema denticola, Fusobacterium nucleatus, and Dialister pneumosintes. Results: Of 22 cases, 14 (63.6% were positive for endodontic and 8 (36.4% for periodontal-disease-associated bacteria. Only one case was positive for bacterial culturing. There was a statistically significant association between the relative amount of bacterial DNA in the pericardial fluid and the severity of CAD (p=0.035. Conclusions: Oral bacterial DNA was detectable in pericardial fluid and an association between the severity of CAD and the total amount of bacterial DNA in pericardial fluid was found, suggesting that this kind of measurement might be useful for clinical purposes.

  15. The effect of glutamine infusion on the inflammatory response and HSP70 during human experimental endotoxaemia

    DEFF Research Database (Denmark)

    Andreasen, Anne Sofie; Pedersen-Skovsgaard, Theis; Mortensen, Ole Hartvig;

    2009-01-01

    INTRODUCTION: Glutamine supplementation has beneficial effects on morbidity and mortality in critically ill patients, possibly in part through an attenuation of the proinflammatory cytokine response and a stimulation of heat shock protein (HSP)70. We infused either alanine-glutamine or saline dur...

  16. Acute Escherichia coli endotoxaemia decreases the plasma l-arginine/asymmetrical dimethylarginine ratio in humans.

    Science.gov (United States)

    Mittermayer, Friedrich; Namiranian, Khodadad; Pleiner, Johannes; Schaller, Georg; Wolzt, Michael

    2004-06-01

    Acute inflammation impairs vascular function. Based on the association between endothelial dysfunction and plasma concentrations of L-arginine and the endogenous nitric oxide synthase inhibitor ADMA (asymmetrical dimethylarginine), we hypothesized that the ratio between L-arginine and ADMA could be affected by experimental inflammation. Plasma concentrations of L-arginine, ADMA and SDMA (symmetrical dimethylarginine) were studied at baseline and 3.5 h after intravenous administration of Escherichia coli endotoxin [LPS (lipopolysaccharide), 20 units/kg of body mass; n =8] or placebo ( n =9) in healthy males. L-Arginine and dimethylarginines were quantified after solid-phase extraction by reversed-phase HPLC. Body temperature, heart rate and leucocyte count increased after LPS administration ( P <0.01 for all). LPS administration decreased plasma concentrations of L-arginine from 66 micromol/l [95% CI (confidence interval): 56, 88] at baseline to 48 micromol/l (CI: 40, 60) after 3.5 h ( P <0.02), but did not affect ADMA and SDMA concentrations. Consequently, the L-arginine/ADMA ratio declined significantly from a median of 159 (CI: 137, 193) to 135 (CI: 103, 146); a decrease of 25 (CI: -68, -13; P <0.02). L-Arginine, ADMA, SDMA and the L-arginine/ADMA ratio remained constant over time in controls. Acute inflammation reduces the L-arginine/ADMA ratio which could contribute to impaired vascular function.

  17. Cardiac troponin I release and cytokine response during experimental human endotoxaemia

    NARCIS (Netherlands)

    van Bockel, EAP; Tulleken, JE; Kobold, ACM; Ligtenberg, JJM; van der Werf, TS; Spanjersberg, R; Zijlstra, JG

    2003-01-01

    Objective. To study the relationship between cytokine levels and cardiac troponin I (cTnI). Design. Prospective experimental study. Setting. Intensive care unit of a university hospital. Participants. Six healthy male volunteers. Interventions. Endotoxin, 4 ng/kg, was given as a 1-min intravenous in

  18. Bacterial Histidine Kinases as Novel Antibacterial Drug Targets

    NARCIS (Netherlands)

    Bem, A.E.; Velikova, N.R.; Pellicer, M.T.; Baarlen, van P.; Marina, A.; Wells, J.M.

    2015-01-01

    Bacterial histidine kinases (HKs) are promising targets for novel antibacterials. Bacterial HKs are part of bacterial two-component systems (TCSs), the main signal transduction pathways in bacteria, regulating various processes including virulence, secretion systems and antibiotic resistance. In thi

  19. BIOSYNTHESIS OF BACTERIAL CELLULOSE BY МEDUSOMYCES GISEVII

    OpenAIRE

    E. K. Gladysheva; E. A. Skiba

    2015-01-01

    Summary: Bacterial cellulose is an organic material that is synthesized by microorganisms extracellularly. Bacterial cellulose can be used in various industries. Especially, bacterial cellulose has found its application basically in medicine. The production of bacterial cellulose is a complicated and long process. The principal criterion for the process to be successful is bacterial cellulose to be obtained in a higher yield. Russia is lacking an operating facility to produce bacterial cellul...

  20. BACTERIAL FLORA IN DIABETIC ULCER

    Directory of Open Access Journals (Sweden)

    Anitha Lavanya

    2015-04-01

    Full Text Available BACKGROUND : Diabetic foot infections are one of the most feared complications of diabetes. This study was undertaken to determine the common etiological agents of diabetic foot infections and their in vitro antibiotic susceptibility. METHODS : A prospective study was p erformed over a period of two years in a tertiary care hospital. The aerobic and anaerobic bacterial agents were isolated and their antibiotic susceptibility pattern was determined . RESULTS : One hundred patients with Diabetic ulcer were studied, of which 6 5 were males and 35 were females. Majority of patients were in the age group of 51 to 60 years (37% and polymicrobial etiology was 64 % and monomicrobial etiology was 36%. A total of 187 organisms were isolated of which 165 were aerobic and 22 were anaero bic. Most frequently isolated aerobic organisms were Pseudomonas Sp., Klebsiella Sp., E coli Sp., and Staphylococcus aureus. The common anaerobic organisms isolated were Peptostreptococcus Sp. And Bacterioids Sp. CONCLUSION : High prevalence of multi - drug r esistant pathogens was observed. Amikacin, Imipenem were active against gram - negative bacilli, while vancomycin was found to be active against gram - positive bacteria.

  1. Initiation of bacterial spore germination.

    Science.gov (United States)

    Vary, J C; Halvorson, H O

    1968-04-01

    To investigate the problem of initiation in bacterial spore germination, we isolated, from extracts of dormant spores of Bacillus cereus strain T and B. licheniformis, a protein that initiated spore germination when added to a suspension of heat-activated spores. The optimal conditions for initiatory activity of this protein (the initiator) were 30 C in 0.01 to 0.04 m NaCl and 0.01 m tris(hydroxymethyl)aminomethane (pH 8.5). The initiator was inhibited by phosphate but required two co-factors, l-alanine (1/7 of K(m) for l-alanine-inhibited germination) and nicotinamide adenine dinucleotide (1.25 x 10(-4)m). In the crude extract, the initiator activity was increased 3.5-fold by heating the extract at 65 C for 10 min, but the partially purified initiator preparation was completely heat-sensitive (65 C for 5 min). Heat stability could be conferred on the purified initiator by adding 10(-3)m dipicolinic acid. A fractionation of this protein that excluded l-alanine dehydrogenase and adenosine deaminase from the initiator activity was developed. The molecular weight of the initiator was estimated as 7 x 10(4). The kinetics of germination in the presence of initiator were examined at various concentrations of l-alanine and nicotinamide adenine dinucleotide.

  2. Phenotypic plasticity in bacterial plasmids.

    Science.gov (United States)

    Turner, Paul E

    2004-01-01

    Plasmid pB15 was previously shown to evolve increased horizontal (infectious) transfer at the expense of reduced vertical (intergenerational) transfer and vice versa, a key trade-off assumed in theories of parasite virulence. Whereas the models predict that susceptible host abundance should determine which mode of transfer is selectively favored, host density failed to mediate the trade-off in pB15. One possibility is that the plasmid's transfer deviates from the assumption that horizontal spread (conjugation) occurs in direct proportion to cell density. I tested this hypothesis using Escherichia coli/pB15 associations in laboratory serial culture. Contrary to most models of plasmid transfer kinetics, my data show that pB15 invades static (nonshaking) bacterial cultures only at intermediate densities. The results can be explained by phenotypic plasticity in traits governing plasmid transfer. As cells become more numerous, the plasmid's conjugative transfer unexpectedly declines, while the trade-off between transmission routes causes vertical transfer to increase. Thus, at intermediate densities the plasmid's horizontal transfer can offset selection against plasmid-bearing cells, but at high densities pB15 conjugates so poorly that it cannot invade. I discuss adaptive vs. nonadaptive causes for the phenotypic plasticity, as well as potential mechanisms that may lead to complex transfer dynamics of plasmids in liquid environments. PMID:15166133

  3. Acute bacterial sinusitis in children.

    Science.gov (United States)

    DeMuri, Gregory; Wald, Ellen R

    2013-10-01

    On the basis of strong research evidence, the pathogenesis of sinusitis involves 3 key factors: sinusostia obstruction, ciliary dysfunction, and thickening of sinus secretions. On the basis of studies of the microbiology of otitis media, H influenzae is playing an increasingly important role in the etiology of sinusitis, exceeding that of S pneumoniae in some areas, and b-lactamase production by H influenzae is increasing in respiratory isolates in the United States. On the basis of some research evidence and consensus,the presentation of acute bacterial sinusitis conforms to 1 of 3 predicable patterns; persistent, severe, and worsening symptoms. On the basis of some research evidence and consensus,the diagnosis of sinusitis should be made by applying strict clinical criteria. This approach will select children with upper respiratory infection symptoms who are most likely to benefit from an antibiotic. On the basis of some research evidence and consensus,imaging is not indicated routinely in the diagnosis of sinusitis. Computed tomography or magnetic resonance imaging provides useful information when complications of sinusitis are suspected. On the basis of some research evidence and consensus,amoxicillin-clavulanate should be considered asa first-line agent for the treatment of sinusitis.

  4. Marine mesocosm bacterial colonisation of volcanic ash

    Science.gov (United States)

    Witt, Verena; Cimarelli, Corrado; Ayris, Paul; Kueppers, Ulrich; Erpenbeck, Dirk; Dingwell, Donald; Woerheide, Gert

    2015-04-01

    Volcanic eruptions regularly eject large quantities of ash particles into the atmosphere, which can be deposited via fallout into oceanic environments. Such fallout has the potential to alter pH, light and nutrient availability at local scales. Shallow-water coral reef ecosystems - "rainforests of the sea" - are highly sensitive to disturbances, such as ocean acidification, sedimentation and eutrophication. Therefore, wind-delivered volcanic ash may lead to burial and mortality of such reefs. Coral reef ecosystem resilience may depend on pioneer bacterial colonisation of the ash layer, supporting subsequent establishment of the micro- and ultimately the macro-community. However, which bacteria are involved in pioneer colonisation remain unknown. We hypothesize that physico-chemical properties (i.e., morphology, mineralogy) of the ash may dictate bacterial colonisation. The effect of substrate properties on bacterial colonisation was tested by exposing five substrates: i) quartz sand ii) crystalline ash (Sakurajima, Japan) iii) volcanic glass iv) carbonate reef sand and v) calcite sand of similar grain size, in controlled marine coral reef aquaria under low light conditions for six months. Bacterial communities were screened every month by Automated Ribosomal Intergenic Spacer Analysis of the 16S-23S rRNA Internal Transcribed Spacer region. Multivariate statistics revealed discrete groupings of bacterial communities on substrates of volcanic origin (ash and glass) and reef origin (three sands). Analysis of Similarity supported significantly different communities associated with all substrates (p=0.0001), only quartz did not differ from both carbonate and calcite sands. The ash substrate exhibited the most diverse bacterial community with the most substrate-specific bacterial operational taxonomic units. Our findings suggest that bacterial diversity and community composition during colonisation of volcanic ash in a coral reef-like environment is controlled by the

  5. Bacterial binding to extracellular proteins - in vitro adhesion

    DEFF Research Database (Denmark)

    Schou, C.; Fiehn, N.-E.

    1999-01-01

    Viridans streptococci, bacterial adherence, extracellular matrix proteins, surface receptors, endocarditis......Viridans streptococci, bacterial adherence, extracellular matrix proteins, surface receptors, endocarditis...

  6. Tobacco use increases susceptibility to bacterial infection

    Directory of Open Access Journals (Sweden)

    Demuth Donald R

    2008-12-01

    Full Text Available Abstract Active smokers and those exposed to secondhand smoke are at increased risk of bacterial infection. Tobacco smoke exposure increases susceptibility to respiratory tract infections, including tuberculosis, pneumonia and Legionnaires disease; bacterial vaginosis and sexually transmitted diseases, such as chlamydia and gonorrhoea; Helicobacter pylori infection; periodontitis; meningitis; otitis media; and post-surgical and nosocomial infections. Tobacco smoke compromises the anti-bacterial function of leukocytes, including neutrophils, monocytes, T cells and B cells, providing a mechanistic explanation for increased infection risk. Further epidemiological, clinical and mechanistic research into this important area is warranted.

  7. Spontaneous Bacterial Peritonitis in Subclinical Hypothyroidism

    Directory of Open Access Journals (Sweden)

    Dalip Gupta

    2013-11-01

    Full Text Available Hypothyroidism is an uncommon cause of ascites. Here we describe a case of a 75 year-old female patient with spontaneous bacterial peritonitis and subclinical hypothyroidism that resolved with thyroid replacement and antibiotic therapy respectively. Ascitic fluid analysis revealed a gram-positive bacterium on gram staining. A review of the literature revealed just one other reported case of myxoedema ascites with concomitant spontaneous bacterial peritonitis and no case has till been reported of spontaneous bacterial peritonitis in subclinical hypothyroidism.

  8. Biochemistry of Bacterial Multidrug Efflux Pumps

    Directory of Open Access Journals (Sweden)

    Sanath Kumar

    2012-04-01

    Full Text Available Bacterial pathogens that are multi-drug resistant compromise the effectiveness of treatment when they are the causative agents of infectious disease. These multi-drug resistance mechanisms allow bacteria to survive in the presence of clinically useful antimicrobial agents, thus reducing the efficacy of chemotherapy towards infectious disease. Importantly, active multi-drug efflux is a major mechanism for bacterial pathogen drug resistance. Therefore, because of their overwhelming presence in bacterial pathogens, these active multi-drug efflux mechanisms remain a major area of intense study, so that ultimately measures may be discovered to inhibit these active multi-drug efflux pumps.

  9. Bacterial gasotransmitters: an innate defense against antibiotics.

    Science.gov (United States)

    Luhachack, Lyly; Nudler, Evgeny

    2014-10-01

    In recent decades, there has been growing interest in the field of gasotransmitters, endogenous gaseous signaling molecules (NO, H2S, and CO), as regulators of a multitude of biochemical pathways and physiological processes. Most of the concerted effort has been on eukaryotic gasotransmitters until the subsequent discovery of bacterial counterparts. While the fundamental aspects of bacterial gasotransmitters remain undefined and necessitate further research, we will discuss a known specific role they play in defense against antibiotics. Considering the current dilemma of multidrug-resistant bacteria we consider it particularly prudent to exploring novel targets and approaches, of which the bacterial gasotransmitters, nitric oxide and hydrogen sulfide represent.

  10. 环孢素A所致牙龈增生的治疗以及增生牙龈组织的病理观察%Clinical therapy and pathological observation of cyclosporine A-induced gingival overgrowth

    Institute of Scientific and Technical Information of China (English)

    马净植; 李明; 曹颖光

    2008-01-01

    Objective To explore the clinical therapy for cyclosporine A(CsA)-induced gingival overgrowth (GO) and the pathological changes in gingival overgrowth tissues.Methods Nine cases of CsA-induced GO after renal transplantation were subjected to periodontal non-surgical treatment and surgical treatment.Under light and electron microscopy,the pathological changes in CO tissues were observed.Results The bleeding index(BI) and the plaque index(PLI) of patients were declined after periodontal treatment.GO recurred in 2 patients 6 months later and happened to recur in all 9 patients 12 months later(GOD≤1).At 18th month after transplantation,an obvioUS GO(GOD≥2)occurred in one patient,and re-operation was done to cut hyperplastic gingiva.At 48th month during the observation period,GO existed continuously but no more than 2 in GOD.There were 3 other patients who had their GO(GOD≥2)at 24th month after peridental treatment and re-operation was carried out to remove the hyperplasic gingivaL Under a light microscope,epithelial pegs constituted of basal cells and prickle cells elongated and presented as cancellation structure;spinus layer thickened:hyperkeratosis or parakeratosis occurred in cuticular layer where inflammatory cells infiltrated:collagen increased in proper layer.Under the transmission electron microscopy,the volume of fibroblasts in hyperplastic gingival tissues was increased,rough endoplansmic reticula in the intracytoplasm were abundant and expanded slightly,and there were a few of the apoptotic fibroblasts in the early stage.Conclusion BI and PLl were declined in patients taking CyA for a long-term who were subjected to periodontal and surgical treatments.GO recurred in some patients.The proliferation and differentiation of fibroblasts was not observed in hyperplastic gingival tissues.%目的 探讨环孢素A(CsA)所致牙龈增生(GO)的临床治疗方法以及增生牙龈的组织学变化.方法 9例肾移植患者因服用CsA导致GO,采取牙周基

  11. Positively regulated bacterial expression systems.

    Science.gov (United States)

    Brautaset, Trygve; Lale, Rahmi; Valla, Svein

    2009-01-01

    Regulated promoters are useful tools for many aspects related to recombinant gene expression in bacteria, including for high-level expression of heterologous proteins and for expression at physiological levels in metabolic engineering applications. In general, it is common to express the genes of interest from an inducible promoter controlled either by a positive regulator or by a repressor protein. In this review, we discuss established and potentially useful positively regulated bacterial promoter systems, with a particular emphasis on those that are controlled by the AraC-XylS family of transcriptional activators. The systems function in a wide range of microorganisms, including enterobacteria, soil bacteria, lactic bacteria and streptomycetes. The available systems that have been applied to express heterologous genes are regulated either by sugars (L-arabinose, L-rhamnose, xylose and sucrose), substituted benzenes, cyclohexanone-related compounds, ε-caprolactam, propionate, thiostrepton, alkanes or peptides. It is of applied interest that some of the inducers require the presence of transport systems, some are more prone than others to become metabolized by the host and some have been applied mainly in one or a limited number of species. Based on bioinformatics analyses, the AraC-XylS family of regulators contains a large number of different members (currently over 300), but only a small fraction of these, the XylS/Pm, AraC/P(BAD), RhaR-RhaS/rhaBAD, NitR/PnitA and ChnR/Pb regulator/promoter systems, have so far been explored for biotechnological applications.

  12. Endolymphatic sac involvement in bacterial meningitis

    DEFF Research Database (Denmark)

    Møller, Martin Nue; Brandt, Christian; Andersen, Christian Østergaard;

    2015-01-01

    The commonest sequelae of bacterial meningitis are related to the inner ear. Little is known about the inner ear immune defense. Evidence suggests that the endolymphatic sac provides some protection against infection. A potential involvement of the endolymphatic sac in bacterial meningitis......-inoculated. The rats were killed when reaching terminal illness or on day 7, followed by light microscopy preparation and PAS-Alcian blue staining. The endolymphatic sac was examined for bacterial invasion and leukocyte infiltration. Neither bacteria nor leukocytes infiltrated the endolymphatic sac during the first...... days. Bacteria invaded the inner ear through the cochlear aquaduct. On days 5-6, the bacteria invaded the endolymphatic sac through the endolymphatic duct subsequent to invasion of the vestibular endolymphatic compartment. No evidence of direct bacterial invasion of the sac through the meninges...

  13. Bacterial bioluminescence in marine pollution assessment

    Digital Repository Service at National Institute of Oceanography (India)

    Ramaiah, N.; Chandramohan, D.

    Warm water marine luminous bacterial species, particularly Vibrio harveyi, V. fischeri and Photobacterium leiognathi, are easy to isolate, maintain and handle in the laboratories without strict temperature requirements, which is an important...

  14. The bacterial microbiota in inflammatory lung diseases.

    Science.gov (United States)

    Huffnagle, Gary B; Dickson, Robert P

    2015-08-01

    Numerous lines of evidence, ranging from recent studies back to those in the 1920s, have demonstrated that the lungs are NOT bacteria-free during health. We have recently proposed that the entire respiratory tract should be considered a single ecosystem extending from the nasal and oral cavities to the alveoli, which includes gradients and niches that modulate microbiome dispersion, retention, survival and proliferation. Bacterial exposure and colonization of the lungs during health is most likely constant and transient, respectively. Host microanatomy, cell biology and innate defenses are altered during chronic lung disease, which in turn, alters the dynamics of bacterial turnover in the lungs and can lead to longer term bacterial colonization, as well as blooms of well-recognized respiratory bacterial pathogens. A few new respiratory colonizers have been identified by culture-independent methods, such as Pseudomonas fluorescens; however, the role of these bacteria in respiratory disease remains to be determined.

  15. Respiratory bacterial infections in cystic fibrosis

    DEFF Research Database (Denmark)

    Ciofu, Oana; Hansen, Christine R; Høiby, Niels

    2013-01-01

    Bacterial respiratory infections are the main cause of morbidity and mortality in patients with cystic fibrosis (CF). Pseudomonas aeruginosa remains the main pathogen in adults, but other Gram-negative bacteria such as Achromobacter xylosoxidans and Stenotrophomonas maltophilia as well...

  16. The Bacterial Microbiota in Inflammatory Lung Diseases

    Science.gov (United States)

    Huffnagle, Gary B.; Dickson, Robert P.

    2016-01-01

    Numerous lines of evidence, ranging from recent studies back to those in the 1920's, have demonstrated that the lungs are NOT bacteria-free during health. We have recently proposed that the entire respiratory tract should be considered a single ecosystem extending from the nasal and oral cavities to the alveoli, which includes gradients and niches that modulate microbiome dispersion, retention, survival and proliferation. Bacterial exposure and colonization of the lungs during health is most likely constant and transient, respectively. Host microanatomy, cell biology and innate defenses are altered during chronic lung disease, which in turn, alters the dynamics of bacterial turnover in the lungs and can lead to longer term bacterial colonization, as well as blooms of well-recognized respiratory bacterial pathogens. A few new respiratory colonizers have been identified by culture-independent methods, such as Pseudomonas fluorescens; however, the role of these bacteria in respiratory disease remains to be determined. PMID:26122174

  17. Plant growth-promoting bacterial endophytes.

    Science.gov (United States)

    Santoyo, Gustavo; Moreno-Hagelsieb, Gabriel; Orozco-Mosqueda, Ma del Carmen; Glick, Bernard R

    2016-02-01

    Bacterial endophytes ubiquitously colonize the internal tissues of plants, being found in nearly every plant worldwide. Some endophytes are able to promote the growth of plants. For those strains the mechanisms of plant growth-promotion known to be employed by bacterial endophytes are similar to the mechanisms used by rhizospheric bacteria, e.g., the acquisition of resources needed for plant growth and modulation of plant growth and development. Similar to rhizospheric plant growth-promoting bacteria, endophytic plant growth-promoting bacteria can act to facilitate plant growth in agriculture, horticulture and silviculture as well as in strategies for environmental cleanup (i.e., phytoremediation). Genome comparisons between bacterial endophytes and the genomes of rhizospheric plant growth-promoting bacteria are starting to unveil potential genetic factors involved in an endophytic lifestyle, which should facilitate a better understanding of the functioning of bacterial endophytes.

  18. [Combination therapy of chronic bacterial prostatitis].

    Science.gov (United States)

    Khryanin, A A; Reshetnikov, O V

    2016-08-01

    The article discusses the possible etiological factors in the development of chronic bacterial prostatitis. The authors presented a comparative long-term analysis of morbidity from non-viral sexually transmitted infections (STIs) in Russia. Against the background of general decline in STIs incidence, a significant percentage of them is made up by urogenital trichomoniasis. The findings substantiated the advantages of combination therapy (ornidazole and ofloxacin) for bacterial urinary tract infections.

  19. Jellyfish modulate bacterial dynamic and community structure.

    Science.gov (United States)

    Tinta, Tinkara; Kogovšek, Tjaša; Malej, Alenka; Turk, Valentina

    2012-01-01

    Jellyfish blooms have increased in coastal areas around the world and the outbreaks have become longer and more frequent over the past few decades. The Mediterranean Sea is among the heavily affected regions and the common bloom-forming taxa are scyphozoans Aurelia aurita s.l., Pelagia noctiluca, and Rhizostoma pulmo. Jellyfish have few natural predators, therefore their carcasses at the termination of a bloom represent an organic-rich substrate that supports rapid bacterial growth, and may have a large impact on the surrounding environment. The focus of this study was to explore whether jellyfish substrate have an impact on bacterial community phylotype selection. We conducted in situ jellyfish-enrichment experiment with three different jellyfish species. Bacterial dynamic together with nutrients were monitored to assess decaying jellyfish-bacteria dynamics. Our results show that jellyfish biomass is characterized by protein rich organic matter, which is highly bioavailable to 'jellyfish-associated' and 'free-living' bacteria, and triggers rapid shifts in bacterial population dynamics and composition. Based on 16S rRNA clone libraries and denaturing gradient gel electrophoresis (DGGE) analysis, we observed a rapid shift in community composition from unculturable Alphaproteobacteria to culturable species of Gammaproteobacteria and Flavobacteria. The results of sequence analyses of bacterial isolates and of total bacterial community determined by culture independent genetic analysis showed the dominance of the Pseudoalteromonadaceae and the Vibrionaceae families. Elevated levels of dissolved proteins, dissolved organic and inorganic nutrient release, bacterial abundance and carbon production as well as ammonium concentrations characterized the degradation process. The biochemical composition of jellyfish species may influence changes in the amount of accumulated dissolved organic and inorganic nutrients. Our results can contribute insights into possible changes in

  20. Jellyfish modulate bacterial dynamic and community structure.

    Directory of Open Access Journals (Sweden)

    Tinkara Tinta

    Full Text Available Jellyfish blooms have increased in coastal areas around the world and the outbreaks have become longer and more frequent over the past few decades. The Mediterranean Sea is among the heavily affected regions and the common bloom-forming taxa are scyphozoans Aurelia aurita s.l., Pelagia noctiluca, and Rhizostoma pulmo. Jellyfish have few natural predators, therefore their carcasses at the termination of a bloom represent an organic-rich substrate that supports rapid bacterial growth, and may have a large impact on the surrounding environment. The focus of this study was to explore whether jellyfish substrate have an impact on bacterial community phylotype selection. We conducted in situ jellyfish-enrichment experiment with three different jellyfish species. Bacterial dynamic together with nutrients were monitored to assess decaying jellyfish-bacteria dynamics. Our results show that jellyfish biomass is characterized by protein rich organic matter, which is highly bioavailable to 'jellyfish-associated' and 'free-living' bacteria, and triggers rapid shifts in bacterial population dynamics and composition. Based on 16S rRNA clone libraries and denaturing gradient gel electrophoresis (DGGE analysis, we observed a rapid shift in community composition from unculturable Alphaproteobacteria to culturable species of Gammaproteobacteria and Flavobacteria. The results of sequence analyses of bacterial isolates and of total bacterial community determined by culture independent genetic analysis showed the dominance of the Pseudoalteromonadaceae and the Vibrionaceae families. Elevated levels of dissolved proteins, dissolved organic and inorganic nutrient release, bacterial abundance and carbon production as well as ammonium concentrations characterized the degradation process. The biochemical composition of jellyfish species may influence changes in the amount of accumulated dissolved organic and inorganic nutrients. Our results can contribute insights into

  1. Pattern Formation in a Bacterial Colony Model

    Directory of Open Access Journals (Sweden)

    Xinze Lian

    2014-01-01

    Full Text Available We investigate the spatiotemporal dynamics of a bacterial colony model. Based on the stability analysis, we derive the conditions for Hopf and Turing bifurcations. Furthermore, we present novel numerical evidence of time evolution of patterns controlled by parameters in the model and find that the model dynamics exhibit a diffusion controlled formation growth to spots, holes and stripes pattern replication, which show that the bacterial colony model is useful in revealing the spatial predation dynamics in the real world.

  2. Asynchronous exponential growth of a bacterial population

    Directory of Open Access Journals (Sweden)

    Mohamed Boulanouar

    2014-01-01

    Full Text Available In this work, we complete a study started earlier in [1,2] wherein a model of growing bacterial population has been the matter of a mathematical analysis. We show that the full model is governed by a strongly continuous semigroup. Beside the positivity and the irreducibility of the generated semigroup, we describe its asymptotic behavior in the uniform topology which leads to the asynchronous exponential growth of the bacterial population.

  3. Volatiles in Inter-Specific Bacterial Interactions.

    Science.gov (United States)

    Tyc, Olaf; Zweers, Hans; de Boer, Wietse; Garbeva, Paolina

    2015-01-01

    The importance of volatile organic compounds for functioning of microbes is receiving increased research attention. However, to date very little is known on how inter-specific bacterial interactions effect volatiles production as most studies have been focused on volatiles produced by monocultures of well-described bacterial genera. In this study we aimed to understand how inter-specific bacterial interactions affect the composition, production and activity of volatiles. Four phylogenetically different bacterial species namely: Chryseobacterium, Dyella, Janthinobacterium, and Tsukamurella were selected. Earlier results had shown that pairwise combinations of these bacteria induced antimicrobial activity in agar media whereas this was not the case for monocultures. In the current study, we examined if these observations were also reflected by the production of antimicrobial volatiles. Thus, the identity and antimicrobial activity of volatiles produced by the bacteria were determined in monoculture as well in pairwise combinations. Antimicrobial activity of the volatiles was assessed against fungal, oomycetal, and bacterial model organisms. Our results revealed that inter-specific bacterial interactions affected volatiles blend composition. Fungi and oomycetes showed high sensitivity to bacterial volatiles whereas the effect of volatiles on bacteria varied between no effects, growth inhibition to growth promotion depending on the volatile blend composition. In total 35 volatile compounds were detected most of which were sulfur-containing compounds. Two commonly produced sulfur-containing volatile compounds (dimethyl disulfide and dimethyl trisulfide) were tested for their effect on three target bacteria. Here, we display the importance of inter-specific interactions on bacterial volatiles production and their antimicrobial activities.

  4. Rho-modifying bacterial protein toxins.

    Science.gov (United States)

    Aktories, Klaus

    2015-12-01

    Rho proteins are targets of numerous bacterial protein toxins, which manipulate the GTP-binding proteins by covalent modifications, including ADP ribosylation, glycosylation, adenylylation, proteolytic cleavage and deamidation. Bacterial toxins are important virulence factors but are also potent and efficient pharmacological tools to study the physiological functions of their eukaryotic targets. Recent studies indicate that amazing variations exist in the molecular mechanisms by which toxins attack Rho proteins, which are discussed here.

  5. Mechanistic investigations on six bacterial terpene cyclases

    Directory of Open Access Journals (Sweden)

    Patrick Rabe

    2016-08-01

    Full Text Available The products obtained by incubation of farnesyl diphosphate (FPP with six purified bacterial terpene cyclases were characterised by one- and two-dimensional NMR spectroscopic methods, allowing for a full structure elucidation. The absolute configurations of four terpenes were determined based on their optical rotary powers. Incubation experiments with 13C-labelled isotopomers of FPP in buffers containing water or deuterium oxide allowed for detailed insights into the cyclisation mechanisms of the bacterial terpene cyclases.

  6. Recombination and the nature of bacterial speciation

    OpenAIRE

    2007-01-01

    Genetic surveys are uncovering the diversity of bacteria, and are causing the species concepts used to categorize these to be questioned. One difficulty in defining bacterial species arises from the high rates of recombination that results in the transfer of DNA between relatively distantly related bacteria. Barriers to this process, which could be used to define species naturally, are not apparent. Here, we have reviewed conceptual models of bacterial speciation and simulate speciation in si...

  7. Soil carbon quality and nitrogen fertilization structure bacterial communities with predictable responses of major bacterial phyla

    OpenAIRE

    2014-01-01

    Agricultural practices affect the soil ecosystem in multiple ways and the soil microbial communities represent an integrated and dynamic measure of soil status. Our aim was to test whether the soil bacterial community and the relative abundance of major bacterial phyla responded predictably to long-term organic amendments representing different carbon qualities (peat and straw) in combination with nitrogen fertilization levels and if certain bacterial groups were indicative of specific treatm...

  8. Comprehensive phylogenetic analysis of bacterial reverse transcriptases.

    Directory of Open Access Journals (Sweden)

    Nicolás Toro

    Full Text Available Much less is known about reverse transcriptases (RTs in prokaryotes than in eukaryotes, with most prokaryotic enzymes still uncharacterized. Two surveys involving BLAST searches for RT genes in prokaryotic genomes revealed the presence of large numbers of diverse, uncharacterized RTs and RT-like sequences. Here, using consistent annotation across all sequenced bacterial species from GenBank and other sources via RAST, available from the PATRIC (Pathogenic Resource Integration Center platform, we have compiled the data for currently annotated reverse transcriptases from completely sequenced bacterial genomes. RT sequences are broadly distributed across bacterial phyla, but green sulfur bacteria and cyanobacteria have the highest levels of RT sequence diversity (≤85% identity per genome. By contrast, phylum Actinobacteria, for which a large number of genomes have been sequenced, was found to have a low RT sequence diversity. Phylogenetic analyses revealed that bacterial RTs could be classified into 17 main groups: group II introns, retrons/retron-like RTs, diversity-generating retroelements (DGRs, Abi-like RTs, CRISPR-Cas-associated RTs, group II-like RTs (G2L, and 11 other groups of RTs of unknown function. Proteobacteria had the highest potential functional diversity, as they possessed most of the RT groups. Group II introns and DGRs were the most widely distributed RTs in bacterial phyla. Our results provide insights into bacterial RT phylogeny and the basis for an update of annotation systems based on sequence/domain homology.

  9. Role of quorum sensing in bacterial infections

    Science.gov (United States)

    Castillo-Juárez, Israel; Maeda, Toshinari; Mandujano-Tinoco, Edna Ayerim; Tomás, María; Pérez-Eretza, Berenice; García-Contreras, Silvia Julieta; Wood, Thomas K; García-Contreras, Rodolfo

    2015-01-01

    Quorum sensing (QS) is cell communication that is widely used by bacterial pathogens to coordinate the expression of several collective traits, including the production of multiple virulence factors, biofilm formation, and swarming motility once a population threshold is reached. Several lines of evidence indicate that QS enhances virulence of bacterial pathogens in animal models as well as in human infections; however, its relative importance for bacterial pathogenesis is still incomplete. In this review, we discuss the present evidence from in vitro and in vivo experiments in animal models, as well as from clinical studies, that link QS systems with human infections. We focus on two major QS bacterial models, the opportunistic Gram negative bacteria Pseudomonas aeruginosa and the Gram positive Staphylococcus aureus, which are also two of the main agents responsible of nosocomial and wound infections. In addition, QS communication systems in other bacterial, eukaryotic pathogens, and even immune and cancer cells are also reviewed, and finally, the new approaches proposed to combat bacterial infections by the attenuation of their QS communication systems and virulence are also discussed. PMID:26244150

  10. Antibiotics promote aggregation within aquatic bacterial communities

    Directory of Open Access Journals (Sweden)

    Gianluca eCorno

    2014-07-01

    Full Text Available The release of antibiotics (AB into the environment poses several threats for human health due to potential development of ABresistant natural bacteria. Even though the use of low-dose antibiotics has been promoted in health care and farming, significant amounts of AB are observed in aquatic environments. Knowledge on the impact of AB on natural bacterial communities is missing both in terms of spread and evolution of resistance mechanisms, and of modifications of community composition and productivity. New approaches are required to study the response of microbial communities rather than individual resistance genes. In this study a chemostat-based experiment with 4 coexisting bacterial strains has been performed to mimicking the response of a freshwater bacterial community to the presence of antibiotics in low and high doses. Bacterial abundance rapidly decreased by 75% in the presence of AB, independently of their concentration, and remained constant until the end of the experiment. The bacterial community was mainly dominated by Aeromonas hydrophila and Brevundimonas intermedia while the other two strains, Micrococcus luteus and Rhodococcus sp. never exceed 10%. Interestingly, the bacterial strains, which were isolated at the end of the experiment, were not AB-resistant, while reassembled communities composed of the 4 strains, isolated from treatments under AB stress, significantly raised their performance (growth rate, abundance in the presence of AB compared to the communities reassembled with strains isolated from the treatment without AB. By investigating the phenotypic adaptations of the communities subjected to the different treatments, we found that the presence of AB significantly increased co-aggregation by 5-6 fold.These results represent the first observation of co-aggregation as a successful strategy of AB resistance based on phenotype in aquatic bacterial communities, and can represent a fundamental step in the understanding of

  11. Photoinactivation of major bacterial pathogens in aquaculture

    Directory of Open Access Journals (Sweden)

    Heyong Jin Roh

    2016-08-01

    Full Text Available Abstract Background Significant increases in the bacterial resistance to various antibiotics have been found in fish farms. Non-antibiotic therapies for infectious diseases in aquaculture are needed. In recent years, light-emitting diode technology has been applied to the inactivation of pathogens, especially those affecting humans. The purpose of this study was to assess the effect of blue light (wavelengths 405 and 465 nm on seven major bacterial pathogens that affect fish and shellfish important in aquaculture. Results We successfully demonstrate inactivation activity of a 405/465-nm LED on selected bacterial pathogens. Although some bacteria were not fully inactivated by the 465-nm light, the 405-nm light had a bactericidal effect against all seven pathogens, indicating that blue light can be effective without the addition of a photosensitizer. Photobacterium damselae, Vibrio anguillarum, and Edwardsiella tarda were the most susceptible to the 405-nm light (36.1, 41.2, and 68.4 J cm−2, respectively, produced one log reduction in the bacterial populations, whereas Streptococcus parauberis was the least susceptible (153.8 J cm−2 per one log reduction. In general, optical density (OD values indicated that higher bacterial densities were associated with lower inactivating efficacy, with the exception of P. damselae and Vibrio harveyi. In conclusion, growth of the bacterial fish and shellfish pathogens evaluated in this study was inactivated by exposure to either the 405- or 465-nm light. In addition, inactivation was dependent on exposure time. Conclusions This study presents that blue LED has potentially alternative therapy for treating fish and shellfish bacterial pathogens. It has great advantages in aspect of eco-friendly treating methods differed from antimicrobial methods.

  12. Molecular diagnosis of bacterial vaginosis: Does adjustment for total bacterial load or human cellular content improve diagnostic performance?

    Science.gov (United States)

    Plummer, E L; Garland, S M; Bradshaw, C S; Law, M G; Vodstrcil, L A; Hocking, J S; Fairley, C K; Tabrizi, S N

    2017-02-01

    We investigated the utility of quantitative PCR assays for diagnosis of bacterial vaginosis and found that while the best model utilized bacterial copy number adjusted for total bacterial load (sensitivity=98%, specificity=93%, AUC=0.95[95%CI=0.93,0.97]), adjusting for total bacterial or human cell load did not consistently increase the diagnostic performance of the assays.

  13. Microbial Degradation of Aniline by Bacterial Consortium

    Institute of Scientific and Technical Information of China (English)

    JIAN-LONG WANG; ZE-YU MAO; WEI-ZHONG WU

    2003-01-01

    Objective To investigate the characteristics of microbial degradation of aniline by a stable bacterial consortium. Methods The bacterial consortium was isolated from activated sludge treating chemical wastewater using aniline as the sole source of carbon and nitrogen by enrichment and isolation technique. The biomass was measured as optical density (OD) at 510 nm using a spectrophotometer. Aniline concentrations were determined by spectrophotometer. The intermediates of aniline degradation were identified by GC/MS method. Results The bacterial consortium could grow at a range of aniline concentrations between 50 and 500 mg/L. The optimal pH and temperature for aniline degradation were determined to be 7.0 and 30, respectively. The presence of NH4NO3 as an additional nitrogen source (100-500 mg/L) had no adverse effect on bacterial growth and aniline degradation. The presence of heavy metal ions, such as Co2+, Zn2+, Ni2+, Mn2+ and Cu2+ had an inhibitory effect on aniline degradation. Conclusions The isolated bacterial consortium candegrade aniline up to 500 mg/L effectively and tolerate some heavy metal ions that commonly exist in chemical wastewater. It has a potential to be applied in the practical treatment of aniline-containingwastewater.

  14. Bacterial infections in patients with liver cirrhosis

    Directory of Open Access Journals (Sweden)

    Giacomo Zaccherini

    2011-07-01

    Full Text Available Bacterial infections represent a frequent complication of liver cirrhosis carrying a significantly greater risk of morbidity and mortality as compared to that observed in non-cirrhotic patients. Such unfavourable prognosis is related to the systemic complications (liver and renal failure, shock, coagulopathy, multiple organ failure induced by a series of pro-inflammatory and immunological systems which are activated by bacteria and their pathogenetic products.The epidemiology of bacterial infections in cirrhosis has changed in the last years with a marked increase of Gram+ infections and the emergence of multi-resistant bacteria.The severity of liver disease represents the major clinical factor predisposing to bacterial infections, which are asymptomatic or paucisymptomatic at presentation in almost half of the cases. Aim of this review is to summarise the clinical and therapeutic aspects of bacterial infections in cirrhotic patients. The most common sites of infection are the urinary tract, ascites, blood, lungs and soft tissues.Beside antibiotics, it has been proposed the administration of human albumin to prevent the development of renal failure in patients with spontaneous bacterial peritonitis and, more recently, the use of hydrocortisone to treat cirrhotic patients with septic shock.

  15. Bacterial coinfections in children with viral wheezing.

    Science.gov (United States)

    Lehtinen, P; Jartti, T; Virkki, R; Vuorinen, T; Leinonen, M; Peltola, V; Ruohola, A; Ruuskanen, O

    2006-07-01

    Bacterial coinfections occur in respiratory viral infections, but the attack rates and the clinical profile are not clear. The aim of this study was to determine bacterial coinfections in children hospitalized for acute expiratory wheezing with defined viral etiology. A total of 220 children aged 3 months to 16 years were investigated. The viral etiology of wheezing was confirmed by viral culture, antigen detection, serologic investigation, and/or PCR. Specific antibodies to common respiratory bacteria were measured from acute and convalescent serum samples. All children were examined clinically for acute otitis media, and subgroups of children were examined radiologically for sinusitis and pneumonia. Rhinovirus (32%), respiratory syncytial virus (31%), and enteroviruses (31%) were the most common causative viruses. Serologic evidence of bacterial coinfection was found in 18% of the children. Streptococcus pneumoniae (8%) and Mycoplasma pneumoniae (5%) were the most common causative bacteria. Acute otitis media was diagnosed in 44% of the children. Chest radiographs showed alveolar infiltrates in 10%, and paranasal radiographs and clinical signs showed sinusitis in 17% of the older children studied. Leukocyte counts and serum C-reactive protein levels were low in a great majority of patients. Viral lower respiratory tract infection in children is often associated with bacterial-type upper respiratory tract infections. However, coexisting bacterial lower respiratory tract infections that induce systemic inflammatory response are seldom detected.

  16. Bacterial communities associated with the lichen symbiosis.

    Science.gov (United States)

    Bates, Scott T; Cropsey, Garrett W G; Caporaso, J Gregory; Knight, Rob; Fierer, Noah

    2011-02-01

    Lichens are commonly described as a mutualistic symbiosis between fungi and "algae" (Chlorophyta or Cyanobacteria); however, they also have internal bacterial communities. Recent research suggests that lichen-associated microbes are an integral component of lichen thalli and that the classical view of this symbiotic relationship should be expanded to include bacteria. However, we still have a limited understanding of the phylogenetic structure of these communities and their variability across lichen species. To address these knowledge gaps, we used bar-coded pyrosequencing to survey the bacterial communities associated with lichens. Bacterial sequences obtained from four lichen species at multiple locations on rock outcrops suggested that each lichen species harbored a distinct community and that all communities were dominated by Alphaproteobacteria. Across all samples, we recovered numerous bacterial phylotypes that were closely related to sequences isolated from lichens in prior investigations, including those from a lichen-associated Rhizobiales lineage (LAR1; putative N(2) fixers). LAR1-related phylotypes were relatively abundant and were found in all four lichen species, and many sequences closely related to other known N(2) fixers (e.g., Azospirillum, Bradyrhizobium, and Frankia) were recovered. Our findings confirm the presence of highly structured bacterial communities within lichens and provide additional evidence that these bacteria may serve distinct functional roles within lichen symbioses.

  17. Emerging bacterial pathogens: the past and beyond.

    Science.gov (United States)

    Vouga, M; Greub, G

    2016-01-01

    Since the 1950s, medical communities have been facing with emerging and reemerging infectious diseases, and emerging pathogens are now considered to be a major microbiologic public health threat. In this review, we focus on bacterial emerging diseases and explore factors involved in their emergence as well as future challenges. We identified 26 major emerging and reemerging infectious diseases of bacterial origin; most of them originated either from an animal and are considered to be zoonoses or from water sources. Major contributing factors in the emergence of these bacterial infections are: (1) development of new diagnostic tools, such as improvements in culture methods, development of molecular techniques and implementation of mass spectrometry in microbiology; (2) increase in human exposure to bacterial pathogens as a result of sociodemographic and environmental changes; and (3) emergence of more virulent bacterial strains and opportunistic infections, especially affecting immunocompromised populations. A precise definition of their implications in human disease is challenging and requires the comprehensive integration of microbiological, clinical and epidemiologic aspects as well as the use of experimental models. It is now urgent to allocate financial resources to gather international data to provide a better understanding of the clinical relevance of these waterborne and zoonotic emerging diseases.

  18. Synthetic analogs of bacterial quorum sensors

    Energy Technology Data Exchange (ETDEWEB)

    Iyer, Rashi (Los Alamos, NM); Ganguly, Kumkum (Los Alamos, NM); Silks, Louis A. (Los Alamos, NM)

    2011-12-06

    Bacterial quorum-sensing molecule analogs having the following structures: ##STR00001## and methods of reducing bacterial pathogenicity, comprising providing a biological system comprising pathogenic bacteria which produce natural quorum-sensing molecule; providing a synthetic bacterial quorum-sensing molecule having the above structures and introducing the synthetic quorum-sensing molecule into the biological system comprising pathogenic bacteria. Further is provided a method of targeted delivery of an antibiotic, comprising providing a synthetic quorum-sensing molecule; chemically linking the synthetic quorum-sensing molecule to an antibiotic to produce a quorum-sensing molecule-antibiotic conjugate; and introducing the conjugate into a biological system comprising pathogenic bacteria susceptible to the antibiotic.

  19. Bacterial degradation of monocyclic aromatic amines

    Directory of Open Access Journals (Sweden)

    Pankaj Kumar Arora

    2015-08-01

    Full Text Available Aromatic amines are an important group of industrial chemicals, which are widely used for manufacturing of dyes, pesticides, drugs, pigments, and other industrial products. These compounds have been considered highly toxic to human beings due to their carcinogenic nature. Three groups of aromatic amines have been recognized: monocyclic, polycyclic and heterocyclic aromatic amines. Bacterial degradation of several monocyclic aromatic compounds has been studied in a variety of bacteria, which utilizes monocyclic aromatic amines as their sole source of carbon and energy. Several degradation pathways have been proposed and the related enzymes and genes have also been characterized. Many reviews have been reviewed toxicity of monocyclic aromatic amines; however, there is lack of review on biodegradation of monocyclic aromatic amines. The aim of this review is to summarize bacterial degradation of monocyclic aromatic amines. This review will increase our current understanding of biochemical and molecular basis of bacterial degradation of monocyclic aromatic amines.

  20. Mesoscopic modeling of bacterial flagellar microhydrodynamics.

    Science.gov (United States)

    Gebremichael, Yeshitila; Ayton, Gary S; Voth, Gregory A

    2006-11-15

    A particle-based hybrid method of elastic network model and smooth-particle hydrodynamics has been employed to describe the propulsion of bacterial flagella in a viscous hydrodynamic environment. The method explicitly models the two aspects of bacterial propulsion that involve flagellar flexibility and long-range hydrodynamic interaction of low-Reynolds-number flow. The model further incorporates the molecular organization of the flagellar filament at a coarse-grained level in terms of the 11 protofilaments. Each of these protofilaments is represented by a collection of material points that represent the flagellin proteins. A computational model of a single flexible helical segment representing the filament of a bacterial flagellum is presented. The propulsive dynamics and the flow fields generated by the motion of the model filament are examined. The nature of flagellar deformation and the influence of hydrodynamics in determining the shape of deformations are examined based on the helical filament.

  1. Comprehensive characterization of indoor airborne bacterial profile

    Institute of Scientific and Technical Information of China (English)

    P.L.Chan; P.H.F.Yu; Y.W.Cheng; C.Y.Chan; P.K.Wong

    2009-01-01

    This is the first detailed characterization of the air-borne bacterial profiles in indoor environments and two restaurants were selected for this study.Fifteen genera of bacteria were isolated from each restaurant and identified by three different bacterial identification systems including MIDI, Biolog and Riboprinter?.The dominant bacteria of both restaurants were Gram-positive bacteria in which Micrococcus and Bacillus species were the most abundant species.Most bacteria identified were representative species of skin and respiratory tract of human, and soil.Although the bacterial levels in these restaurants were below the limit of the Hong Kong Indoor Air Quality Objective (HKIAQO) Level 1 standard (i.e., < 500 cfu/m3), the majority of these bacteria were opportunistic pathogens.These results suggested that the identity of airborne bacteria should also be included in the IAQ to ensure there is a safety guideline for the public.

  2. Citrobacter rodentium mouse model of bacterial infection.

    Science.gov (United States)

    Crepin, Valerie F; Collins, James W; Habibzay, Maryam; Frankel, Gad

    2016-10-01

    Infection of mice with Citrobacter rodentium is a robust model to study bacterial pathogenesis, mucosal immunology, the health benefits of probiotics and the role of the microbiota during infection. C. rodentium was first isolated by Barthold from an outbreak of mouse diarrhea in Yale University in 1972 and was 'rediscovered' by Falkow and Schauer in 1993. Since then the use of the model has proliferated, and it is now the gold standard for studying virulence of the closely related human pathogens enteropathogenic and enterohemorrhagic Escherichia coli (EPEC and EHEC, respectively). Here we provide a detailed protocol for various applications of the model, including bacterial growth, site-directed mutagenesis, mouse inoculation (from cultured cells and after cohabitation), monitoring of bacterial colonization, tissue extraction and analysis, immune responses, probiotic treatment and microbiota analysis. The main protocol, from mouse infection to clearance and analysis of tissues and host responses, takes ∼5 weeks to complete.

  3. Value of a newly sequenced bacterial genome

    DEFF Research Database (Denmark)

    Barbosa, Eudes; Aburjaile, Flavia F; Ramos, Rommel Tj;

    2014-01-01

    Next-generation sequencing (NGS) technologies have made high-throughput sequencing available to medium- and small-size laboratories, culminating in a tidal wave of genomic information. The quantity of sequenced bacterial genomes has not only brought excitement to the field of genomics but also...... in an exponential increase in draft (partial data) genome deposits in public databases. If no further interests are expressed for a particular bacterial genome, it is more likely that the sequencing of its genome will be limited to a draft stage, and the painstaking tasks of completing the sequencing of its genome...

  4. Neurosonographic findings of bacterial meningitis in Infants

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Moon Chul; Lee, Sung Sik; Lee, Hong Kue; Lee, Soon Il [Sowa Children' s Hospital, Seoul (Korea, Republic of)

    1989-02-15

    44 infants under 1 year were studied retrospectively during these illness and follow up after 1 week intervals. The spectrum of sonographic features of bacterial meningitis in acute stage included normal scan (20 patients), echogenic sulci (10 patients), echogenic lining of epandymas (8 patients), Abnormal parenchymal echogenecity (6 patients). On follow up examination with 1 week intervals, variety of complications was found in 14 patients (32%) of the infants. There were ventriculomegaly in 7 patients, extraaxial fluid collection in 4 patients, brain abscess in 2 patients and poor encephalic cyst in 1 patient. We conclude that ultrasound was an effective method for evaluation of progression and complications of bacterial meningitis.

  5. CT scan of bacterial and aseptic meningitis

    Energy Technology Data Exchange (ETDEWEB)

    Takemoto, Kazumasa; Saiwai, Shigeo; Tamaoka, Koichi (Kobe Central Municipal Hospital (Japan))

    1983-01-01

    CT scans of the patients with aseptic and bacterial meningitis were reviewed and compared to previous reports. In aseptic meningitis, no abnormal CT findings were observed. In bacterial meningitis, CT findings were ventricular dilatation, subdural fluid collection, parenchymal low density, intracerebral hematoma and meningeal enhancement after contrast injection. Three patients among 48 suffered from status epileptics during the course of the illness. All of the 3 patients developed parenchymal inhomogeneous low density and progressive ventricular dilatation which did not improve after ventricular peritoneal shunt surgery. We believe that these changes are most likely due to hypoxic hypoxemia during epileptic seizure and meningitis itself seems to play a little role.

  6. Horizontal gene transfer and bacterial diversity

    Indian Academy of Sciences (India)

    Chitra Dutta; Archana Pan

    2002-02-01

    Bacterial genomes are extremely dynamic and mosaic in nature. A substantial amount of genetic information is inserted into or deleted from such genomes through the process of horizontal transfer. Through the introduction of novel physiological traits from distantly related organisms, horizontal gene transfer often causes drastic changes in the ecological and pathogenic character of bacterial species and thereby promotes microbial diversification and speciation. This review discusses how the recent influx of complete chromosomal sequences of various microorganisms has allowed for a quantitative assessment of the scope, rate and impact of horizontally transmitted information on microbial evolution.

  7. Glucocorticosteroids: as Adjuvant Therapy for Bacterial Infections

    Directory of Open Access Journals (Sweden)

    WONDIM MELKAM

    2015-01-01

    Full Text Available Glucocorticoids (GCs, synthetic analogues of the natural steroid hormones, are well known for their antiinflammatory and immunosuppressive properties in the periphery. They are widely and successfully used in the treatment of autoimmune diseases, chronic inflammation, and transplant rejection. Nowadays, GCs are claimed to have a beneficial role being as adjunct therapy in various infections. Different studies have been conducted to investigate their use as adjuvant therapy for different bacterial infection. This review, therefore, summarizes various bacterial infections for which glucocorticoids are reported to be used as adjuvant therapy, strategies for administration of glucocorticoids, and challenges of using glucocorticoids as adjuvant therapy.

  8. GTPases involved in bacterial ribosome maturation.

    Science.gov (United States)

    Goto, Simon; Muto, Akira; Himeno, Hyouta

    2013-05-01

    The ribosome is an RNA- and protein-based macromolecule having multiple functional domains to facilitate protein synthesis, and it is synthesized through multiple steps including transcription, stepwise cleavages of the primary transcript, modifications of ribosomal proteins and RNAs and assemblies of ribosomal proteins with rRNAs. This process requires dozens of trans-acting factors including GTP- and ATP-binding proteins to overcome several energy-consuming steps. Despite accumulation of genetic, biochemical and structural data, the entire process of bacterial ribosome synthesis remains elusive. Here, we review GTPases involved in bacterial ribosome maturation.

  9. Inhibiting bacterial toxins by channel blockage.

    Science.gov (United States)

    Bezrukov, Sergey M; Nestorovich, Ekaterina M

    2016-03-01

    Emergent rational drug design techniques explore individual properties of target biomolecules, small and macromolecule drug candidates, and the physical forces governing their interactions. In this minireview, we focus on the single-molecule biophysical studies of channel-forming bacterial toxins that suggest new approaches for their inhibition. We discuss several examples of blockage of bacterial pore-forming and AB-type toxins by the tailor-made compounds. In the concluding remarks, the most effective rationally designed pore-blocking antitoxins are compared with the small-molecule inhibitors of ion-selective channels of neurophysiology.

  10. Fungal and bacterial killing by neutrophils.

    Science.gov (United States)

    Ermert, David; Zychlinsky, Arturo; Urban, Constantin

    2009-01-01

    Neutrophils are professional phagocytes of the innate immune system that are essential to control bacterial and fungal infections. These cells engulf and kill invading microbes. Additionally, activated neutrophils are able to release neutrophil extracellular traps (NETs). These fibers consist of chromatin decorated with antimicrobial proteins to trap and kill microbes. Appropriate quantitative methods are required to understand the nature of interactions of neutrophils with pathogens. Here we present assays to measure killing mediated by phagocytosis, by NETs, by a combination of both, and by granular extract. As examples, we use Candida albicans for fungal and Shigella flexneri for bacterial pathogens.

  11. Bacterial endocarditis due to Kingella kingae.

    Science.gov (United States)

    Sage, M J; Maslowski, A H; MacCulloch, D

    1983-10-26

    A case of infective bacterial endocarditis due to Kingella kingae in a 26 year old male involving a prosthetic mitral valve is described. Microbiological features of this organism are outlined, and the treatment of this endocarditis is discussed with reference to the four previously reported cases.

  12. Bacterial endosymbionts of Pyrodinium bahamense var. compressum.

    Science.gov (United States)

    Azanza, Ma Patricia V; Azanza, Rhodora V; Vargas, Vanessa Mercee D; Hedreyda, Cynthia T

    2006-11-01

    The study presents evidence in support of the bacterial theory associated with the toxicity of Pyrodinium bahamense var. compressum. Bacterial endosymbionts from Philippine P. bahamense var. compressum strain Pbc MZRVA 042595 were isolated and identified via 16S rDNA sequence analysis. Taxonomic diversity of the identified culturable intracellular microbiota associated with Philippine P. bahamense var. compressum was established to be limited to the Phyla Proteobacteria, Actinobacteria, and Firmicutes. Major endosymbionts identified included Moraxella spp., Erythrobacter spp., and Bacillus spp., whereas Pseudomonas putida, Micrococcus spp., and Dietzia maris were identified as minor isolates. All identified strains except D. maris, P. putida, and Micrococcus spp. were shown to contain either saxitoxin or neo saxitoxin or both at levels < or =73 ng/10(7) bacterial cells based on high-performance liquid chromatography analysis. Paralytic shellfish poisoning-like physiologic reactions in test animals used in the mouse assay were recorded for the endosymbionts except for P. putida. The study is the first to elucidate the possible contribution of bacterial endosymbionts in the toxicity of P. bahamense var. compressum isolated in the Philippines.

  13. Increasing complexity of the bacterial cytoskeleton

    DEFF Research Database (Denmark)

    Møller-Jensen, Jakob; Löwe, Jan

    2005-01-01

    Bacteria contain cytoskeletal elements involved in major cellular processes including DNA segregation and cell morphogenesis and division. Distant bacterial homologues of tubulin (FtsZ) and actin (MreB and ParM) not only resemble their eukaryotic counterparts structurally but also show similar...

  14. Bacterial ice nucleation: significance and molecular basis.

    Science.gov (United States)

    Gurian-Sherman, D; Lindow, S E

    1993-11-01

    Several bacterial species are able to catalyze ice formation at temperatures as warm as -2 degrees C. These microorganisms efficiently catalyze ice formation at temperatures much higher than most organic or inorganic substances. Because of their ubiquity on the surfaces of frost-sensitive plants, they are responsible for initiating ice formation, which results in frost injury. The high temperature of ice catalysis conferred by bacterial ice nuclei makes them useful in ice nucleation-limited processes such as artificial snow production, the freezing of some food products, and possibly in future whether modification schemes. The rarity of other ice nuclei active at high subfreezing temperature, and the ease and sensitivity with which ice nuclei can be quantified, have made the use of a promoterless bacterial ice nucleation gene valuable as a reporter of transcription. Target genes to which this promoter is fused can be used in cells in natural habitats. Warm-temperature ice nucleation sites have also been extensively studied at a molecular level. Nucleation sites active at high temperatures (above -5 degrees C) are probably composed of bacterial ice nucleation protein molecules that form functionally aligned aggregates. Models of ice nucleation proteins predict that they form a planar array of hydrogen binding groups that closely complement that of an ice crystal face. Moreover, interdigitation of these molecules may produce a large contiguous template for ice formation.

  15. Prediction of bacterial growth on xenobiotics

    DEFF Research Database (Denmark)

    Brock, Andreas Libonati; Kästner, Matthias; Trapp, Stefan

    2016-01-01

    The utilisation of a given substrate leads to bacterial growth and the associated yield is normally determined experimentally. Different yield estimation methods exist based on knowledge of the Gibbs energy of reaction and the energy needed for synthesis of new biomass [1-4]. Estimating yield fro...

  16. The 'Swiss cheese' instability of bacterial biofilms

    CERN Document Server

    Jang, Hongchul; Stocker, Roman

    2012-01-01

    We demonstrate a novel pattern that results in bacterial biofilms as a result of the competition between hydrodynamic forces and adhesion forces. After the passage of an air plug, the break up of the residual thin liquid film scrapes and rearranges bacteria on the surface, such that a Swiss cheese pattern of holes is left in the residual biofilm.

  17. Corticosteroids for acute adult bacterial meningitis

    NARCIS (Netherlands)

    D. van de Beek

    2009-01-01

    Bacterial meningitis in adults is a severe disease, with high fatality and morbidity rates. Experimental studies showed that the inflammatory response in the subarachnoid space is associated with unfavorable outcome. In these experiments, corticosteroids, and in particular dexamethasone, were able t

  18. Bacterial cell biology outside the streetlight.

    Science.gov (United States)

    Bulgheresi, Silvia

    2016-09-01

    As much as vertical transmission of microbial symbionts requires their deep integration into the host reproductive and developmental biology, symbiotic lifestyle might profoundly affect bacterial growth and proliferation. This review describes the reproductive oddities displayed by bacteria associated - more or less intimately - with multicellular eukaryotes.

  19. Immunotolerance during bacterial pneumonia and sepsis

    NARCIS (Netherlands)

    Hoogerwerf, J.J.

    2010-01-01

    Bacterial pneumonia and sepsis are a major cause of morbidity and mortality worldwide. Massive use of antibiotics promotes pathogen resistance, and, as a consequence, the incidence of drug-resistant bacteria is increasing. Therefore, it is of the utmost importance to expand our comprehension of host

  20. Bacterial Acclimation Inside an Aqueous Battery.

    Directory of Open Access Journals (Sweden)

    Dexian Dong

    Full Text Available Specific environmental stresses may lead to induced genomic instability in bacteria, generating beneficial mutants and potentially accelerating the breeding of industrial microorganisms. The environmental stresses inside the aqueous battery may be derived from such conditions as ion shuttle, pH gradient, free radical reaction and electric field. In most industrial and medical applications, electric fields and direct currents are used to kill bacteria and yeast. However, the present study focused on increasing bacterial survival inside an operating battery. Using a bacterial acclimation strategy, both Escherichia coli and Bacillus subtilis were acclimated for 10 battery operation cycles and survived in the battery for over 3 days. The acclimated bacteria changed in cell shape, growth rate and colony color. Further analysis indicated that electrolyte concentration could be one of the major factors determining bacterial survival inside an aqueous battery. The acclimation process significantly improved the viability of both bacteria E. coli and B. subtilis. The viability of acclimated strains was not affected under battery cycle conditions of 0.18-0.80 mA cm(-2 and 1.4-2.1 V. Bacterial addition within 1.0×10(10 cells mL(-1 did not significantly affect battery performance. Because the environmental stress inside the aqueous battery is specific, the use of this battery acclimation strategy may be of great potential for the breeding of industrial microorganisms.

  1. Optimising Antibiotic Usage to Treat Bacterial Infections

    Science.gov (United States)

    Paterson, Iona K.; Hoyle, Andy; Ochoa, Gabriela; Baker-Austin, Craig; Taylor, Nick G. H.

    2016-11-01

    The increase in antibiotic resistant bacteria poses a threat to the continued use of antibiotics to treat bacterial infections. The overuse and misuse of antibiotics has been identified as a significant driver in the emergence of resistance. Finding optimal treatment regimens is therefore critical in ensuring the prolonged effectiveness of these antibiotics. This study uses mathematical modelling to analyse the effect traditional treatment regimens have on the dynamics of a bacterial infection. Using a novel approach, a genetic algorithm, the study then identifies improved treatment regimens. Using a single antibiotic the genetic algorithm identifies regimens which minimise the amount of antibiotic used while maximising bacterial eradication. Although exact treatments are highly dependent on parameter values and initial bacterial load, a significant common trend is identified throughout the results. A treatment regimen consisting of a high initial dose followed by an extended tapering of doses is found to optimise the use of antibiotics. This consistently improves the success of eradicating infections, uses less antibiotic than traditional regimens and reduces the time to eradication. The use of genetic algorithms to optimise treatment regimens enables an extensive search of possible regimens, with previous regimens directing the search into regions of better performance.

  2. Multiple bacterial species reside in chronic wounds

    DEFF Research Database (Denmark)

    Gjødsbøl, Kristine; Christensen, Jens Jørgen; Karlsmark, Tonny;

    2006-01-01

    species present were identified. More than one bacterial species were detected in all the ulcers. The most common bacteria found were Staphylococcus aureus (found in 93.5% of the ulcers), Enterococcus faecalis (71.7%), Pseudomonas aeruginosa (52.2%), coagulase-negative staphylococci (45.7%), Proteus...

  3. Bacterial proteases: targets for diagnostics and therapy

    NARCIS (Netherlands)

    Kaman, W.E.; Hays, J.P.; Endtz, H.P.; Bikker, F.J.

    2014-01-01

    Proteases are essential for the proliferation and growth of bacteria, and are also known to contribute to bacterial virulence. This makes them interesting candidates as diagnostic and therapeutic targets for infectious diseases. In this review, the authors discuss the most recent developments and po

  4. Bacterial meningitis: Mechanisms of disease and therapy

    NARCIS (Netherlands)

    R.F. Kornelisse (René); R. de Groot (Ronald); H.J. Neijens (Herman)

    1995-01-01

    textabstractBacterial meningitis continues to be a serious infectious disease with a high morbidity and mortality in young children. Early recognition and initiation of adequate treatment are the major determinants for a good outcome. Recent advances in our understanding of the host inflammatory res

  5. Forensic identification using skin bacterial communities.

    Science.gov (United States)

    Fierer, Noah; Lauber, Christian L; Zhou, Nick; McDonald, Daniel; Costello, Elizabeth K; Knight, Rob

    2010-04-06

    Recent work has demonstrated that the diversity of skin-associated bacterial communities is far higher than previously recognized, with a high degree of interindividual variability in the composition of bacterial communities. Given that skin bacterial communities are personalized, we hypothesized that we could use the residual skin bacteria left on objects for forensic identification, matching the bacteria on the object to the skin-associated bacteria of the individual who touched the object. Here we describe a series of studies de-monstrating the validity of this approach. We show that skin-associated bacteria can be readily recovered from surfaces (including single computer keys and computer mice) and that the structure of these communities can be used to differentiate objects handled by different individuals, even if those objects have been left untouched for up to 2 weeks at room temperature. Furthermore, we demonstrate that we can use a high-throughput pyrosequencing-based ap-proach to quantitatively compare the bacterial communities on objects and skin to match the object to the individual with a high degree of certainty. Although additional work is needed to further establish the utility of this approach, this series of studies introduces a forensics approach that could eventually be used to independently evaluate results obtained using more traditional forensic practices.

  6. Bacterial community reconstruction using compressed sensing.

    Science.gov (United States)

    Amir, Amnon; Zuk, Or

    2011-11-01

    Bacteria are the unseen majority on our planet, with millions of species and comprising most of the living protoplasm. We propose a novel approach for reconstruction of the composition of an unknown mixture of bacteria using a single Sanger-sequencing reaction of the mixture. Our method is based on compressive sensing theory, which deals with reconstruction of a sparse signal using a small number of measurements. Utilizing the fact that in many cases each bacterial community is comprised of a small subset of all known bacterial species, we show the feasibility of this approach for determining the composition of a bacterial mixture. Using simulations, we show that sequencing a few hundred base-pairs of the 16S rRNA gene sequence may provide enough information for reconstruction of mixtures containing tens of species, out of tens of thousands, even in the presence of realistic measurement noise. Finally, we show initial promising results when applying our method for the reconstruction of a toy experimental mixture with five species. Our approach may have a potential for a simple and efficient way for identifying bacterial species compositions in biological samples. All supplementary data and the MATLAB code are available at www.broadinstitute.org/?orzuk/publications/BCS/.

  7. C-reactive protein and bacterial meningitis

    DEFF Research Database (Denmark)

    Gerdes, Lars Ulrik; Jørgensen, P E; Nexø, E;

    1998-01-01

    The aim of the study was to review published articles on the diagnostic accuracy of C-reactive protein (CRP) tests with cerebrospinal fluid and serum in diagnosing bacterial meningitis. The literature from 1980 and onwards was searched using the electronic databases of MEDLINE, and we used summary...

  8. Removal of triphenylmethane dyes by bacterial consortium.

    Science.gov (United States)

    Cheriaa, Jihane; Khaireddine, Monia; Rouabhia, Mahmoud; Bakhrouf, Amina

    2012-01-01

    A new consortium of four bacterial isolates (Agrobacterium radiobacter; Bacillus spp.; Sphingomonas paucimobilis, and Aeromonas hydrophila)-(CM-4) was used to degrade and to decolorize triphenylmethane dyes. All bacteria were isolated from activated sludge extracted from a wastewater treatment station of a dyeing industry plant. Individual bacterial isolates exhibited a remarkable color-removal capability against crystal violet (50 mg/L) and malachite green (50 mg/L) dyes within 24 h. Interestingly, the microbial consortium CM-4 shows a high decolorizing percentage for crystal violet and malachite green, respectively, 91% and 99% within 2 h. The rate of chemical oxygen demand (COD) removal increases after 24 h, reaching 61.5% and 84.2% for crystal violet and malachite green, respectively. UV-Visible absorption spectra, FTIR analysis and the inspection of bacterial cells growth indicated that color removal by the CM-4 was due to biodegradation. Evaluation of mutagenicity by using Salmonella typhimurium test strains, TA98 and TA100 studies revealed that the degradation of crystal violet and malachite green by CM-4 did not lead to mutagenic products. Altogether, these results demonstrated the usefulness of the bacterial consortium in the treatment of the textile dyes.

  9. Bacterial successions in the Broiler Gastrointestinal tract

    DEFF Research Database (Denmark)

    Ranjitkar, Samir; Lawley, Blair; Tannock, Gerald

    2016-01-01

    feeding trial was performed with broilers receiving diets based on wheat (WBF), maize (MBF), and maize-based concentrates supplemented with 15% (CKMS-15) or 30% (CKMS-30) crimped kernel maize silage. The aim of the study was to investigate the bacterial community compositions in the contents...

  10. Bacterial mutants for enhanced succinate production

    NARCIS (Netherlands)

    Baart, G.J.E.; Beauprez, J.J.R.; Foulquie, M.M.R.; Heijnen, J.J.; Maertens, J.

    2010-01-01

    The present invention relates to a method for obtaining enhanced metabolite production in micro-organisms, and to mutants and/or transformants obtained with said method. More particularly, it relates to bacterial mutants and/or transformants for enhanced succinate production, especially mutants and/

  11. Volatiles in inter-specific bacterial interactions

    NARCIS (Netherlands)

    Tyc, O.; Zweers, H.; De Boer, W.; Garbeva, P.V.

    2015-01-01

    The importance of volatile organic compounds for functioning of microbes is receiving increased research attention. However, to date very little is known on how inter-specific bacterial interactions effect volatiles production as most studies have been focused on volatiles produced by monocultures o

  12. Bacterial Paleontology and Studies of Carbonaceous Chondrites

    Science.gov (United States)

    Gerasimenko, L. M.; Hoover, Richard B.; Rozanov, Alexei Y.; Zhegallo, E. A.; Zhmur, S. I.

    1999-01-01

    The study of the fossilization processes of modern cyanobacteria provides insights needed to recognize bacterial microfossils. The fossilization of cyanobacteria is discussed and images of recent and fossil bacteria and cyanobacteria from the Early Proterozoic to Neogene carbonaceous rocks (kerites, shungites, and black shales) and phosphorites are provided. These are compared with biomorphic microstructures and possible microfossils encountered in-situ in carbonaceous meteorites.

  13. Removal of Triphenylmethane Dyes by Bacterial Consortium

    Directory of Open Access Journals (Sweden)

    Jihane Cheriaa

    2012-01-01

    Full Text Available A new consortium of four bacterial isolates (Agrobacterium radiobacter; Bacillus spp.; Sphingomonas paucimobilis, and Aeromonas hydrophila-(CM-4 was used to degrade and to decolorize triphenylmethane dyes. All bacteria were isolated from activated sludge extracted from a wastewater treatment station of a dyeing industry plant. Individual bacterial isolates exhibited a remarkable color-removal capability against crystal violet (50 mg/L and malachite green (50 mg/L dyes within 24 h. Interestingly, the microbial consortium CM-4 shows a high decolorizing percentage for crystal violet and malachite green, respectively, 91% and 99% within 2 h. The rate of chemical oxygen demand (COD removal increases after 24 h, reaching 61.5% and 84.2% for crystal violet and malachite green, respectively. UV-Visible absorption spectra, FTIR analysis and the inspection of bacterial cells growth indicated that color removal by the CM-4 was due to biodegradation. Evaluation of mutagenicity by using Salmonella typhimurium test strains, TA98 and TA100 studies revealed that the degradation of crystal violet and malachite green by CM-4 did not lead to mutagenic products. Altogether, these results demonstrated the usefulness of the bacterial consortium in the treatment of the textile dyes.

  14. Bacterial and parasitic zoonoses of exotic pets.

    Science.gov (United States)

    Souza, Marcy J

    2009-09-01

    Zoonoses are estimated to make up to 75% of today's emerging infectious diseases. Many of these diseases are carried and transmitted by exotic pets and wildlife. Exotic animal practitioners must be aware of these risks not only to protect their health but also to safeguard the health of staff and clients. This article reviews selected bacterial and parasitic zoonoses associated with exotic animals.

  15. Discovery of inhibitors of bacterial histidine kinases

    NARCIS (Netherlands)

    Velikova, N.R.

    2014-01-01

    Discovery of Inhibitors of Bacterial Histidine Kinases

    Summary

    The thesis is on novel antibacterial drug discovery (http://youtu.be/NRMWOGgeysM). Using structure-based and fragment-based dru

  16. Meningococcal Disease (Bacterial Meningitis) Vaccine and Pregnancy

    Science.gov (United States)

    Meningococcal Disease (Bacterial meningitis) Vaccine and Pregnancy In every pregnancy, a woman starts out with a 3-5% chance of having a baby ... advice from your health care provider. What is meningitis? Meningitis is an infection of the lining that ...

  17. Bacterial Cell Wall Growth, Shape and Division

    NARCIS (Netherlands)

    Derouaux, A.; Terrak, M.; den Blaauwen, T.; Vollmer, W.; Remaut, H.; Fronzes, R.

    2014-01-01

    The shape of a bacterial cell is maintained by its peptidoglycan sacculus that completely surrounds the cytoplasmic membrane. During growth the sacculus is enlarged by peptidoglycan synthesis complexes that are controlled by components linked to the cytoskeleton and, in Gram-negative bacteria, by ou

  18. Effect of isolate of ruminal fibrolytic bacterial culture supplementation on fibrolytic bacterial population and survivability of inoculated bacterial strain in lactating Murrah buffaloes

    Directory of Open Access Journals (Sweden)

    Brishketu Kumar

    2013-02-01

    Full Text Available Aim: The present study was conducted to evaluate the effect of bacterial culture supplementation on ruminal fibrolytic bacterial population as well as on survivability of inoculated bacterial strain in lactating Murrah buffaloes kept on high fibre diet. Materials and Methods: Fibrolytic bacterial strains were isolated from rumen liquor of fistulated Murrah buffaloes and live bacterial culture were supplemented orally in treatment group of lactating Murrah buffaloes fed on high fibre diet to see it's effect on ruminal fibrolytic bacterial population as well as to see the effect of survivability of the inoculated bacterial strain at three different time interval in comparison to control group. Results: It has been shown by real time quantification study that supplementation of bacterial culture orally increases the population of major fibre degrading bacteria i.e. Ruminococcus flavefaciens, Ruminococcus albus as well as Fibrobacter succinogenes whereas there was decrease in secondary fibre degrading bacterial population i.e. Butyrivibrio fibrisolvens over the different time periods. However, the inoculated strain of Ruminococcus flavefaciens survived significantly over the period of time, which was shown in stability of increased inoculated bacterial population. Conclusion: The isolates of fibrolytic bacterial strains are found to be useful in increasing the number of major ruminal fibre degrading bacteria in lactating buffaloes and may act as probiotic in large ruminants on fibre-based diets. [Vet World 2013; 6(1.000: 14-17

  19. Urban greenness influences airborne bacterial community composition.

    Science.gov (United States)

    Mhuireach, Gwynne; Johnson, Bart R; Altrichter, Adam E; Ladau, Joshua; Meadow, James F; Pollard, Katherine S; Green, Jessica L

    2016-11-15

    Urban green space provides health benefits for city dwellers, and new evidence suggests that microorganisms associated with soil and vegetation could play a role. While airborne microorganisms are ubiquitous in urban areas, the influence of nearby vegetation on airborne microbial communities remains poorly understood. We examined airborne microbial communities in parks and parking lots in Eugene, Oregon, using high-throughput sequencing of the bacterial 16S rRNA gene on the Illumina MiSeq platform to identify bacterial taxa, and GIS to measure vegetation cover in buffer zones of different diameters. Our goal was to explore variation among highly vegetated (parks) versus non-vegetated (parking lots) urban environments. A secondary objective was to evaluate passive versus active collection methods for outdoor airborne microbial sampling. Airborne bacterial communities from five parks were different from those of five parking lots (p=0.023), although alpha diversity was similar. Direct gradient analysis showed that the proportion of vegetated area within a 50m radius of the sampling station explained 15% of the variation in bacterial community composition. A number of key taxa, including several Acidobacteriaceae were substantially more abundant in parks, while parking lots had higher relative abundance of Acetobacteraceae. Parks had greater beta diversity than parking lots, i.e. individual parks were characterized by unique bacterial signatures, whereas parking lot communities tended to be similar to each other. Although parks and parking lots were selected to form pairs of nearby sites, spatial proximity did not appear to affect compositional similarity. Our results also showed that passive and active collection methods gave comparable results, indicating the "settling dish" method is effective for outdoor airborne sampling. This work sets a foundation for understanding how urban vegetation may impact microbial communities, with potential implications for designing

  20. Bacterial vaginosis in pregnant adolescents: proinflammatory cytokine and bacterial sialidase profile. Cross-sectional study

    Directory of Open Access Journals (Sweden)

    Carolina Sanitá Tafner Ferreira

    Full Text Available ABSTRACT CONTEXT AND OBJECTIVE: Bacterial vaginosis occurs frequently in pregnancy and increases susceptibility to sexually transmitted infections (STI. Considering that adolescents are disproportionally affected by STI, the aim of this study was to evaluate the cervicovaginal levels of interleukin (IL-1 beta, IL-6, IL-8 and bacterial sialidase in pregnant adolescents with bacterial vaginosis. DESIGN AND SETTING: Cross-sectional study at mother and child referral units in Belém, Pará, Brazil. METHODS: Vaginal samples from 168 pregnant adolescents enrolled were tested for trichomoniasis and candidiasis. Their vaginal microbiota was classified according to the Nugent criteria (1991 as normal, intermediate or bacterial vaginosis. Cervical infection due to Chlamydia trachomatisand Neisseria gonorrhoeae was also assessed. Cytokine and sialidase levels were measured, respectively, using enzyme-linked immunosorbent assays and MUAN conversion in cervicovaginal lavages. Forty-eight adolescents (28.6% were excluded because they tested positive for some of the infections investigated. The remaining 120 adolescents were grouped according to vaginal flora type: normal (n = 68 or bacterial vaginosis (n = 52. Their cytokine and sialidase levels were compared between the groups using the Mann-Whitney test (P < 0.05. RESULTS: The pregnant adolescents with bacterial vaginosis had higher levels of IL-1 beta, IL-6 and IL-8 (P < 0.05. Sialidase was solely detected in 35 adolescents (67.2% with bacterial vaginosis. CONCLUSIONS: Not only IL-1 beta and sialidase levels, but also IL-6 and IL-8 levels are higher in pregnant adolescents with bacterial vaginosis, thus indicating that this condition elicits a more pronounced inflammatory response in this population, which potentially increases vulnerability to STI acquisition.

  1. How Do Health Care Providers Diagnose Bacterial Vaginosis (BV)?

    Science.gov (United States)

    ... and Publications How do health care providers diagnose bacterial vaginosis (BV)? Skip sharing on social media links Share ... menstruating. Centers for Disease Control and Prevention. (2010). Bacterial vaginosis: CDC fact sheet . Retrieved May 10, 2012, from ...

  2. What Are the Treatments for Bacterial Vaginosis (BV)?

    Science.gov (United States)

    ... Resources and Publications What are the treatments for bacterial vaginosis (BV)? Skip sharing on social media links Share ... and Human Services, Office on Women's Health. (2008). Bacterial vaginosis fact sheet . Retrieved May 10, 2012, from http:// ...

  3. A study of bacterial contamination of rattlesnake venom

    Directory of Open Access Journals (Sweden)

    E. Garcia-Lima

    1987-03-01

    Full Text Available The authors studied the bacterial contamination of rattlesnake venom isolated from snakes in captivity and wild snakes caught recently. The captive snakes showed a relatively high incidence of bacterial contamination of their venom.

  4. Targeted imaging of bacterial infections : advances, hurdles and hopes

    NARCIS (Netherlands)

    van Oosten, Marleen; Hahn, Markus; Crane, Lucia M. A.; Pleijhuis, Rick G.; Francis, Kevin P.; van Dijl, Jan Maarten; van Dam, Gooitzen M.

    2015-01-01

    Bacterial infections represent an increasing problem in modern health care, in particular due to ageing populations and accumulating bacterial resistance to antibiotics. Diagnosis is rarely straightforward and consequently treatment is often delayed or indefinite. Therefore, novel tools that can be

  5. Cholinesterase modulations in patients with acute bacterial meningitis

    DEFF Research Database (Denmark)

    Berg, Ronan M G; Ofek, Keren; Qvist, Tavs;

    2011-01-01

    The circulating cholinesterases acetyl- and butyrylcholinesterase may be suppressed and subsequently released from the brain in acute bacterial meningitis.......The circulating cholinesterases acetyl- and butyrylcholinesterase may be suppressed and subsequently released from the brain in acute bacterial meningitis....

  6. Bacterial adhesion of porphyromonas gingivalis on provisional fixed prosthetic materials

    Directory of Open Access Journals (Sweden)

    Mustafa Zortuk

    2010-01-01

    Conclusion : The quantity of bacterial adhesion and surface roughness differed among the assessed provisional fixed prosthodontic materials. The light-polymerized provisional material Revotek LC had rougher surface and more bacterial adhesion compared with the others.

  7. Risk of Bacterial Meningitis in Children with Cochlear Implants

    Science.gov (United States)

    ... Information For... Media Policy Makers Risk of Bacterial Meningitis in Children with Cochlear Implants Language: English Español ( ... Compartir 2002 Study of the Risk of Bacterial Meningitis in Children with Cochlear Implants Many people have ...

  8. New methods to assess bacterial injury in water.

    OpenAIRE

    Zaske, S K; Dockins, W S; Schillinger, J. E.; McFeters, G A

    1980-01-01

    Two methods are described for measurement of bacterial injury in water. Laboratory time preceding cell division measured with slide cultures and spheroplast formation after lysozyme treatment were accurate and rapid measurements of bacterial damage.

  9. Calpains promote neutrophil recruitment and bacterial clearance in an acute bacterial peritonitis model.

    Science.gov (United States)

    Kumar, Vijay; Everingham, Stephanie; Hall, Christine; Greer, Peter A; Craig, Andrew W B

    2014-03-01

    Activation of the innate immune system is critical for clearance of bacterial pathogens to limit systemic infections and host tissue damage. Here, we report a key role for calpain proteases in bacterial clearance in mice with acute peritonitis. Using transgenic mice expressing Cre recombinase primarily in innate immune cells (fes-Cre), we generated conditional capns1 knockout mice. Consistent with capns1 being essential for stability and function of the ubiquitous calpains (calpain-1, calpain-2), peritoneal cells from these mice had reduced levels of calpain-2/capns1, and reduced proteolysis of their substrate selenoprotein K. Using an acute bacterial peritonitis model, we observed impaired bacterial killing within the peritoneum and development of bacteremia in calpain knockout mice. These defects correlated with significant reductions in IL-1α release, neutrophil recruitment, and generation of reactive oxygen species in calpain knockout mice with acute bacterial peritonitis. Peritoneal macrophages from calpain knockout mice infected with enterobacteria ex vivo, were competent in phagocytosis of bacteria, but showed impaired clearance of intracellular bacteria compared with control macrophages. Together, these results implicate calpains as key mediators of effective innate immune responses to acute bacterial infections, to prevent systemic dissemination of bacteria that can lead to sepsis.

  10. [3] Diseases Caused By Bacterial Pathogens In Inland Water

    OpenAIRE

    若林, 久嗣; 吉田, 照豊; 野村, 哲一; 中井, 敏博; 高野, 倫一

    2016-01-01

    Bacterial diseases cause huge damages in fish farms worldwide, and numerous bacterial pathogens from inland and saline waters have been identified and studied for their characterization, diagnosis, prevention and control. In this chapter, eight important fish diseases viz. 1) streptococcosis (inland water), 2) furunculosis, 3) bacterial gill disease, 4) columnaris disease, 5) bacterial cold-water disease, 6) red spot disease, 7) edwardsiellosis (Edwardsiella ictaluri), and 8) motile aeromonad...

  11. Childhood asthma after bacterial colonization of the airway in neonates

    DEFF Research Database (Denmark)

    Bisgaard, Hans; Hermansen, Mette Northman; Buchvald, Frederik;

    2007-01-01

    Pathological features of the airway in young children with severe recurrent wheeze suggest an association between bacterial colonization and the initiating events of early asthma. We conducted a study to investigate a possible association between bacterial colonization of the hypopharynx in asymp......Pathological features of the airway in young children with severe recurrent wheeze suggest an association between bacterial colonization and the initiating events of early asthma. We conducted a study to investigate a possible association between bacterial colonization of the hypopharynx...

  12. Oral bacterial DNAs in synovial fluids of arthritis patients

    OpenAIRE

    Moen, Ketil; Johan G. Brun; Eribe, Emenike R.K.; Olsen, Ingar; Jonsson, Roland

    2011-01-01

    Arthritis may be triggered by microbial constituents, more specifically, bacterial cell wall fragments, or bacterial DNA. The aim of this study was to analyze the amount of oral bacterial DNA in synovial fluids (SF) of arthritis patients. SF from 15 rheumatoid arthritis (RA) patients, 15 arthritides (non-RA) patients and 9 osteoarthritis (control) patients were extracted for oral bacterial DNA. DNA was used in a checkerboard DNA/DNA hybridization set-up, in order to identify 40 different spec...

  13. Bacterial foodborne infections after hematopoietic cell transplantation.

    Science.gov (United States)

    Boyle, Nicole M; Podczervinski, Sara; Jordan, Kim; Stednick, Zach; Butler-Wu, Susan; McMillen, Kerry; Pergam, Steven A

    2014-11-01

    Diarrhea, abdominal pain, and fever are common among patients undergoing hematopoietic cell transplantation (HCT), but such symptoms are also typical with foodborne infections. The burden of disease caused by foodborne infections in patients undergoing HCT is unknown. We sought to describe bacterial foodborne infection incidence after transplantation within a single-center population of HCT recipients. All HCT recipients who underwent transplantation from 2001 through 2011 at the Fred Hutchinson Cancer Research Center in Seattle, Washington were followed for 1 year after transplantation. Data were collected retrospectively using center databases, which include information from transplantation, on-site examinations, outside records, and collected laboratory data. Patients were considered to have a bacterial foodborne infection if Campylobacter jejuni/coli, Listeria monocytogenes, E. coli O157:H7, Salmonella species, Shigella species, Vibrio species, or Yersinia species were isolated in culture within 1 year after transplantation. Nonfoodborne infections with these agents and patients with pre-existing bacterial foodborne infection (within 30 days of transplantation) were excluded from analyses. A total of 12 of 4069 (.3%) patients developed a bacterial foodborne infection within 1 year after transplantation. Patients with infections had a median age at transplantation of 50.5 years (interquartile range [IQR], 35 to 57), and the majority were adults ≥18 years of age (9 of 12 [75%]), male gender (8 of 12 [67%]) and had allogeneic transplantation (8 of 12 [67%]). Infectious episodes occurred at an incidence rate of 1.0 per 100,000 patient-days (95% confidence interval, .5 to 1.7) and at a median of 50.5 days after transplantation (IQR, 26 to 58.5). The most frequent pathogen detected was C. jejuni/coli (5 of 12 [42%]) followed by Yersinia (3 of 12 [25%]), although Salmonella (2 of 12 [17%]) and Listeria (2 of 12 [17%]) showed equal frequencies; no cases of Shigella

  14. 21 CFR 1210.16 - Method of bacterial count.

    Science.gov (United States)

    2010-04-01

    ... FEDERAL IMPORT MILK ACT Inspection and Testing § 1210.16 Method of bacterial count. The bacterial count of milk and cream refers to the number of viable bacteria as determined by the standard plate method of... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Method of bacterial count. 1210.16 Section...

  15. Discovery of New Substrates for LuxAB Bacterial Bioluminescence.

    Science.gov (United States)

    Jiang, Tianyu; Wang, Weishan; Wu, Xingkang; Wu, Wenxiao; Bai, Haixiu; Ma, Zhao; Shen, Yuemao; Yang, Keqian; Li, Minyong

    2016-08-01

    In this article, four novel substrates with long halftime have been designed and synthesized successfully for luxAB bacterial bioluminescence. After in vitro and in vivo biological evaluation, these molecules can emit obvious bioluminescence emission with known bacterial luciferase, thus indicating a new promising approach to developing the bacterial bioluminescent system.

  16. Bacterial protein toxins : tools to study mammalian molecular cell biology

    NARCIS (Netherlands)

    Wüthrich, I.W.

    2014-01-01

    Bacterial protein toxins are genetically encoded proteinaceous macromolecules that upon exposure causes perturbation of cellular metabolism in a susceptible host. A bacterial toxin can work at a distance from the site of infection, and has direct and quantifiable actions. Bacterial protein toxins ca

  17. Metabolism links bacterial biofilms and colon carcinogenesis.

    Science.gov (United States)

    Johnson, Caroline H; Dejea, Christine M; Edler, David; Hoang, Linh T; Santidrian, Antonio F; Felding, Brunhilde H; Ivanisevic, Julijana; Cho, Kevin; Wick, Elizabeth C; Hechenbleikner, Elizabeth M; Uritboonthai, Winnie; Goetz, Laura; Casero, Robert A; Pardoll, Drew M; White, James R; Patti, Gary J; Sears, Cynthia L; Siuzdak, Gary

    2015-06-02

    Bacterial biofilms in the colon alter the host tissue microenvironment. A role for biofilms in colon cancer metabolism has been suggested but to date has not been evaluated. Using metabolomics, we investigated the metabolic influence that microbial biofilms have on colon tissues and the related occurrence of cancer. Patient-matched colon cancers and histologically normal tissues, with or without biofilms, were examined. We show the upregulation of polyamine metabolites in tissues from cancer hosts with significant enhancement of N(1), N(12)-diacetylspermine in both biofilm-positive cancer and normal tissues. Antibiotic treatment, which cleared biofilms, decreased N(1), N(12)-diacetylspermine levels to those seen in biofilm-negative tissues, indicating that host cancer and bacterial biofilm structures contribute to the polyamine metabolite pool. These results show that colonic mucosal biofilms alter the cancer metabolome to produce a regulator of cellular proliferation and colon cancer growth potentially affecting cancer development and progression.

  18. Metabolism links bacterial biofilms and colon carcinogenesis

    Science.gov (United States)

    Johnson, Caroline H.; Dejea, Christine M.; Edler, David; Hoang, Linh T.; Santidrian, Antonio F.; Felding, Brunhilde H.; Cho, Kevin; Wick, Elizabeth C.; Hechenbleikner, Elizabeth M.; Uritboonthai, Winnie; Goetz, Laura; Casero, Robert A.; Pardoll, Drew M.; White, James R.; Patti, Gary J.; Sears, Cynthia L.; Siuzdak, Gary

    2015-01-01

    SUMMARY Bacterial biofilms in the colon alter the host tissue microenvironment. A role for biofilms in colon cancer metabolism has been suggested but to date has not been evaluated. Using metabolomics, we investigated the metabolic influence that microbial biofilms have on colon tissues and the related occurrence of cancer. Patient-matched colon cancers and histologically normal tissues, with or without biofilms, were examined. We show the upregulation of polyamine metabolites in tissues from cancer hosts with significant enhancement of N1, N12-diacetylspermine in both biofilm positive cancer and normal tissues. Antibiotic treatment, which cleared biofilms, decreased N1, N12-diacetylspermine levels to those seen in biofilm negative tissues, indicating that host cancer and bacterial biofilm structures contribute to the polyamine metabolite pool. These results show that colonic mucosal biofilms alter the cancer metabolome, to produce a regulator of cellular proliferation and colon cancer growth potentially affecting cancer development and progression. PMID:25959674

  19. Bacterial microbiome of lungs in COPD.

    Science.gov (United States)

    Sze, Marc A; Hogg, James C; Sin, Don D

    2014-01-01

    Chronic obstructive pulmonary disease (COPD) is currently the third leading cause of death in the world. Although smoking is the main risk factor for this disease, only a minority of smokers develop COPD. Why this happens is largely unknown. Recent discoveries by the human microbiome project have shed new light on the importance and richness of the bacterial microbiota at different body sites in human beings. The microbiota plays a particularly important role in the development and functional integrity of the immune system. Shifts or perturbations in the microbiota can lead to disease. COPD is in part mediated by dysregulated immune responses to cigarette smoke and other environmental insults. Although traditionally the lung has been viewed as a sterile organ, by using highly sensitive genomic techniques, recent reports have identified diverse bacterial communities in the human lung that may change in COPD. This review summarizes the current knowledge concerning the lung microbiota in COPD and its potential implications for pathogenesis of the disease.

  20. Probing bacterial cell biology using image cytometry.

    Science.gov (United States)

    Cass, Julie A; Stylianidou, Stella; Kuwada, Nathan J; Traxler, Beth; Wiggins, Paul A

    2017-03-01

    Advances in automated fluorescence microscopy have made snapshot and time-lapse imaging of bacterial cells commonplace, yet fundamental challenges remain in analysis. The vast quantity of data collected in high-throughput experiments requires a fast and reliable automated method to analyze fluorescence intensity and localization, cell morphology and proliferation as well as other descriptors. Inspired by effective yet tractable methods of population-level analysis using flow cytometry, we have developed a framework and tools for facilitating analogous analyses in image cytometry. These tools can both visualize and gate (generate subpopulations) more than 70 cell descriptors, including cell size, age and fluorescence. The method is well suited to multi-well imaging, analysis of bacterial cultures with high cell density (thousands of cells per frame) and complete cell cycle imaging. We give a brief description of the analysis of four distinct applications to emphasize the broad applicability of the tool.

  1. Bacterial alginates: from biosynthesis to applications.

    Science.gov (United States)

    Remminghorst, Uwe; Rehm, Bernd H A

    2006-11-01

    Alginate is a polysaccharide belonging to the family of linear (unbranched), non-repeating copolymers, consisting of variable amounts of beta-D-mannuronic acid and its C5-epimer alpha- L-guluronic acid linked via beta-1,4-glycosidic bonds. Like DNA, alginate is a negatively charged polymer, imparting material properties ranging from viscous solutions to gel-like structures in the presence of divalent cations. Bacterial alginates are synthesized by only two bacterial genera, Pseudomonas and Azotobacter, and have been extensively studied over the last 40 years. While primarily synthesized in form of polymannuronic acid, alginate undergoes chemical modifications comprising acetylation and epimerization, which occurs during periplasmic transfer and before final export through the outer membrane. Alginate with its unique material properties and characteristics has been increasingly considered as biomaterial for medical applications. The genetic modification of alginate producing microorganisms could enable biotechnological production of new alginates with unique, tailor-made properties, suitable for medical and industrial applications.

  2. The Bacterial Microflora of Fish, Revised

    Directory of Open Access Journals (Sweden)

    B. Austin

    2006-01-01

    Full Text Available The results of numerous studies indicate that fish possess bacterial populations on or in their skin, gills, digestive tract, and light-emitting organs. In addition, the internal organs (kidney, liver, and spleen of healthy fish may contain bacteria, but there is debate about whether or not muscle is actually sterile. Using traditional culture-dependent techniques, the numbers and taxonomic composition of the bacterial populations generally reflect those of the surrounding water. More modern culture-independent approaches have permitted the recognition of previously uncultured bacteria. The role of the organisms includes the ability to degrade complex molecules (therefore exercising a potential benefit in nutrition, to produce vitamins and polymers, and to be responsible for the emission of light by the light-emitting organs of deep-sea fish. Taxa, including Pseudomonas, may contribute to spoilage by the production of histamines in fish tissue.

  3. Future of Bacterial Therapy of Cancer.

    Science.gov (United States)

    Hoffman, Robert M

    2016-01-01

    Bacterial therapy of cancer has a centuries-long history and was first-line therapy at the hospital in New York City that would become Memorial Sloan-Kettering Cancer Center, under Dr. William B. Coley. However, after Coley's death in 1936, bacterial therapy of cancer ceased in the clinic until the present century. Clinical trials have been recently carried out for strains of the obligate anaerobe Clostridium novyi with the toxin gene deleted, and on an attenuated strain of Salmonella typhimurium (S. typhimurium), which is a facultative anaerobe that can grow in viable, as well as necrotic, areas of tumors, unlike Clostridium, which can only grow in the hypoxic areas. Our laboratory has developed the novel strain S. typhimurium A1-R that is effective against all tumor types in clinically-relevant mouse models, including patient-derived orthotopic xenograft (PDOX) mouse models. This chapter suggests future clinical applications for S. typhimurium A1-R.

  4. Marine sequestration of carbon in bacterial metabolites.

    Science.gov (United States)

    Lechtenfeld, Oliver J; Hertkorn, Norbert; Shen, Yuan; Witt, Matthias; Benner, Ronald

    2015-03-31

    Linking microbial metabolomics and carbon sequestration in the ocean via refractory organic molecules has been hampered by the chemical complexity of dissolved organic matter (DOM). Here, using bioassay experiments and ultra-high resolution metabolic profiling, we demonstrate that marine bacteria rapidly utilize simple organic molecules and produce exometabolites of remarkable molecular and structural diversity. Bacterial DOM is similar in chemical composition and structural complexity to naturally occurring DOM in sea water. An appreciable fraction of bacterial DOM has molecular and structural properties that are consistent with those of refractory molecules in the ocean, indicating a dominant role for bacteria in shaping the refractory nature of marine DOM. The rapid production of chemically complex and persistent molecules from simple biochemicals demonstrates a positive feedback between primary production and refractory DOM formation. It appears that carbon sequestration in diverse and structurally complex dissolved molecules that persist in the environment is largely driven by bacteria.

  5. A study of bacterial gene regulatory mechanisms

    DEFF Research Database (Denmark)

    Hansen, Sabine

    the different regulatory mechanisms affect system dynamics. We have designed a synthetic gene regulatory network (GRN) in bacterial cells that enables us to study the dynamics of GRNs. The results presented in this PhD thesis show that model equations based on the established mechanisms of action of each...... of a particular type of regulatory mechanism. The synthetic system presented in this thesis is, to our knowledge, the first of its kind to allow a direct comparison of the dynamic behaviors of gene regulatory networks that employ different mechanisms of regulation. In addition to studying the dynamic behavior...... of GRNs this thesis also provided the first evidence of the sensor histidine kinase VC1831 being an additional player in the Vibrio cholerae quorum sensing (QS) GRN. Bacteria use a process of cell-cell communication called QS which enable the bacterial cells to collectively control their gene expression...

  6. Formaldehyde stress responses in bacterial pathogens

    Directory of Open Access Journals (Sweden)

    Nathan Houqian Chen

    2016-03-01

    Full Text Available Formaldehyde is the simplest of all aldehydes and is highly cytotoxic. Its use and associated dangers from environmental exposure have been well documented. Detoxification systems for formaldehyde are found throughout the biological world and they are especially important in methylotrophic bacteria, which generate this compound as part of their metabolism of methanol. Formaldehyde metabolizing systems can be divided into those dependent upon pterin cofactors, sugar phosphates and those dependent upon glutathione. The more prevalent thiol-dependent formaldehyde detoxification system is found in many bacterial pathogens, almost all of which do not metabolize methane or methanol. This review describes the endogenous and exogenous sources of formaldehyde, its toxic effects and mechanisms of detoxification. The methods of formaldehyde sensing are also described with a focus on the formaldehyde responsive transcription factors HxlR, FrmR and NmlR. Finally, the physiological relevance of detoxification systems for formaldehyde in bacterial pathogens is discussed.

  7. Novel Nitrocellulose Made from Bacterial Cellulose

    Science.gov (United States)

    Sun, Dong-Ping; Ma, Bo; Zhu, Chun-Lin; Liu, Chang-Sheng; Yang, Jia-Zhi

    2010-04-01

    Nitrocellulose (NC) is useful in several industrial segments, especially in the production of gun, rocket, and missile propellants. The conventional way to prepare NC is done through the nitration of plant cellulose with nitric acid. In this work, bacterial cellulose nitrate (NBC) is synthesized by bacterial cellulose (BC) and nitro-sulfric acid under heterogeneous conditions. NBC with the degree of substitution (DS) of 1-2.85 was obtained, and the effects of sulfuric to nitric ratio, reaction temperature, and reaction time on the value of DS of NBC are discussed. The samples are also characterized by elemental analysis, thermal analysis, Fourier transform infrared (FT-IR) spectroscopy, and X-ray diffraction.

  8. Effects of hydrodynamic interactions in bacterial swimming.

    Science.gov (United States)

    Chattopadhyay, Suddhashil; Lun Wu, Xiao

    2008-03-01

    The lack of precise experimental data has prevented the investigation of the effects of long range hydrodynamic interactions in bacterial swimming. We perform measurements on various strains of bacteria with the aid of optical tweezers to shed light on this aspect of bacterial motility. Geometrical parameters recorded by fluorescence microscopy are used with theories which model flagella propulsion (Resistive force theory & Lighthill's formulation which includes long range interactions). Comparison of the predictions of these theories with experimental data, observed directly from swimming bacterium, led to the conclusion that while long range inetractions were important for single polar flagellated strains (Vibrio Alginolyticus & Caulobacter Crescentus), local force theory was adequate to describe the swimming of multi-flagellated Esherichia Coli. We performed additional measurements on E. Coli minicells (miniature cells with single polar flagellum) to try and determine the cause of this apparent effect of shielding of long range interactions in multiple flagellated bacteria.

  9. Measuring bacterial cells size with AFM.

    Science.gov (United States)

    Osiro, Denise; Filho, Rubens Bernardes; Assis, Odilio Benedito Garrido; Jorge, Lúcio André de Castro; Colnago, Luiz Alberto

    2012-01-01

    Atomic Force Microscopy (AFM) can be used to obtain high-resolution topographical images of bacteria revealing surface details and cell integrity. During scanning however, the interactions between the AFM probe and the membrane results in distortion of the images. Such distortions or artifacts are the result of geometrical effects related to bacterial cell height, specimen curvature and the AFM probe geometry. The most common artifact in imaging is surface broadening, what can lead to errors in bacterial sizing. Several methods of correction have been proposed to compensate for these artifacts and in this study we describe a simple geometric model for the interaction between the tip (a pyramidal shaped AFM probe) and the bacterium (Escherichia coli JM-109 strain) to minimize the enlarging effect. Approaches to bacteria immobilization and examples of AFM images analysis are also described.

  10. Bursting the bubble on bacterial biofilms

    DEFF Research Database (Denmark)

    Crusz, Shanika A; Popat, Roman; Rybtke, Morten Theil;

    2012-01-01

    The flow cell biofilm system is an important and widely used tool for the in vitro cultivation and evaluation of bacterial biofilms under hydrodynamic conditions of flow. This paper provides an introduction to the background and use of such systems, accompanied by a detailed guide to the assembly...... of the apparatus including the description of new modifications which enhance its performance. As such, this is an essential guide for the novice biofilm researcher as well as providing valuable trouble-shooting techniques for even the most experienced laboratories. The adoption of a common and reliable...... methodology amongst researchers would enable findings to be shared and replicated amongst the biofilm research community, with the overall aim of advancing understanding and management of these complex and widespread bacterial communities....

  11. Bacterial Toxins as Pathogen Weapons Against Phagocytes.

    Science.gov (United States)

    do Vale, Ana; Cabanes, Didier; Sousa, Sandra

    2016-01-01

    Bacterial toxins are virulence factors that manipulate host cell functions and take over the control of vital processes of living organisms to favor microbial infection. Some toxins directly target innate immune cells, thereby annihilating a major branch of the host immune response. In this review we will focus on bacterial toxins that act from the extracellular milieu and hinder the function of macrophages and neutrophils. In particular, we will concentrate on toxins from Gram-positive and Gram-negative bacteria that manipulate cell signaling or induce cell death by either imposing direct damage to the host cells cytoplasmic membrane or enzymatically modifying key eukaryotic targets. Outcomes regarding pathogen dissemination, host damage and disease progression will be discussed.

  12. Bacterial protein toxins in human cancers.

    Science.gov (United States)

    Rosadi, Francesca; Fiorentini, Carla; Fabbri, Alessia

    2016-02-01

    Many bacteria causing persistent infections produce toxins whose mechanisms of action indicate that they could have a role in carcinogenesis. Some toxins, like CDT and colibactin, directly attack the genome by damaging DNA whereas others, as for example CNF1, CagA and BFT, impinge on key eukaryotic processes, such as cellular signalling and cell death. These bacterial toxins, together with other less known toxins, mimic carcinogens and tumour promoters. The aim of this review is to fulfil an up-to-date analysis of toxins with carcinogenic potential that have been already correlated to human cancers. Bacterial toxins-induced carcinogenesis represents an emerging aspect in bacteriology, and its significance is increasingly recognized.

  13. Bacterial Modulation of Plant Ethylene Levels.

    Science.gov (United States)

    Gamalero, Elisa; Glick, Bernard R

    2015-09-01

    A focus on the mechanisms by which ACC deaminase-containing bacteria facilitate plant growth.Bacteria that produce the enzyme 1-aminocyclopropane-1-carboxylate (ACC) deaminase, when present either on the surface of plant roots (rhizospheric) or within plant tissues (endophytic), play an active role in modulating ethylene levels in plants. This enzyme activity facilitates plant growth especially in the presence of various environmental stresses. Thus, plant growth-promoting bacteria that express ACC deaminase activity protect plants from growth inhibition by flooding and anoxia, drought, high salt, the presence of fungal and bacterial pathogens, nematodes, and the presence of metals and organic contaminants. Bacteria that express ACC deaminase activity also decrease the rate of flower wilting, promote the rooting of cuttings, and facilitate the nodulation of legumes. Here, the mechanisms behind bacterial ACC deaminase facilitation of plant growth and development are discussed, and numerous examples of the use of bacteria with this activity are summarized.

  14. Research on magnetic metallization of bacterial cells

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A multidisciplinary approach to the fabrication of biologically based magnetic monomers for biolimited forming is described. Rod-like Bacilli cereus about 0.5 μm in diameter and 3-5 μm in length, were used as templates on which the ferromagnetic material was deposited by an electroless deposition method. Different electroless plating solutions were compared in detail and CoNiP solution was selected. During the deposition process, both dispersant and mechanical stirring were used to solve the problem of aggregation of bacterial cells so as to obtain a uniform plating layer. The CoNiP film on Bacilli cereus was a mixture of crystalline and non-crystalline in the phase structure and showed a good magnetism. The magnetic metallized bacterial cells could be manipulated with a magnetic field. Parallel arrays of these micro magnetic particles were achieved and they could rotate along with the magnetic field.

  15. Structure and operation of bacterial tripartite pumps.

    Science.gov (United States)

    Hinchliffe, Philip; Symmons, Martyn F; Hughes, Colin; Koronakis, Vassilis

    2013-01-01

    In bacteria such as Pseudomonas aeruginosa and Escherichia coli, tripartite membrane machineries, or pumps, determine the efflux of small noxious molecules, such as detergents, heavy metals, and antibiotics, and the export of large proteins including toxins. They are therefore influential in bacterial survival, particularly during infections caused by multidrug-resistant pathogens. In these tripartite pumps an inner membrane transporter, typically an ATPase or proton antiporter, binds and translocates export or efflux substrates. In cooperation with a periplasmic adaptor protein it recruits and opens a TolC family cell exit duct, which is anchored in the outer membrane and projects across the periplasmic space between inner and outer membranes. Assembled tripartite pumps thus span the entire bacterial cell envelope. We review the atomic structures of each of the three pump components and discuss how these have allowed high-resolution views of tripartite pump assembly, operation, and possible inhibition.

  16. Bacterial toxins as pathogen weapons against phagocytes

    Directory of Open Access Journals (Sweden)

    Ana edo Vale

    2016-02-01

    Full Text Available Bacterial toxins are virulence factors that manipulate host cell functions and take over the control of vital processes of living organisms to favour microbial infection. Some toxins directly target innate immune cells, thereby annihilating a major branch of the host immune response. In this review we will focus on bacterial toxins that act from the extracellular milieu and hinder the function of macrophages and neutrophils. In particular, we will concentrate on toxins from Gram-positive and Gram-negative bacteria that manipulate cell signalling or induce cell death by either imposing direct damage to the host cells cytoplasmic membrane or enzymatically modifying key eukaryotic targets. Outcomes regarding pathogen dissemination, host damage and disease progression will be discussed.

  17. ANTIMICROBIAL ACTIVITY OF LACTIC ACID BACTERIAL ISOLATES

    Directory of Open Access Journals (Sweden)

    Utkarsha S. Shivsharan

    2013-08-01

    Full Text Available Micro-organisms have tendency to produce antimicrobial substances which show biological activity against other kind of micro-organisms. This phenomenon of bacterial antagonism is observed in lactic acid bacteria with competitive advantages. The lactic acid bacteria are commonly present in many fermented products, fruits and milk products. The variety of antimicrobial substances produced by lactic acid bacteria showing good inhibition capacity include production of lactic acid, acetic acid, hydrogen peroxide, carbon dioxide, diacetyl and bacteriocin. Bacteriocins produced by lactic acid bacteria are the subject of intense research because of their antimicrobial activity against food born bacteria such as Listeria monocytogenes, staphylococcus aureus, Bacillus cereus, Clostridium botulinum and several others .Bacteriocins may be bacteriostatic or bactericidal with narrow or broad range of activity. The main of the study was to study the antimicrobial activity of such lactic acid bacterial isolates.

  18. Discrete modelling of bacterial conjugation dynamics

    CERN Document Server

    Goni-Moreno, Angel

    2012-01-01

    In bacterial populations, cells are able to cooperate in order to yield complex collective functionalities. Interest in population-level cellular behaviour is increasing, due to both our expanding knowledge of the underlying biological principles, and the growing range of possible applications for engineered microbial consortia. Researchers in the field of synthetic biology - the application of engineering principles to living systems - have, for example, recently shown how useful decision-making circuits may be distributed across a bacterial population. The ability of cells to interact through small signalling molecules (a mechanism known as it quorum sensing) is the basis for the majority of existing engineered systems. However, horizontal gene transfer (or conjugation) offers the possibility of cells exchanging messages (using DNA) that are much more information-rich. The potential of engineering this conjugation mechanism to suit specific goals will guide future developments in this area. Motivated by a l...

  19. Intermittency measurement in two dimensional bacterial turbulence

    CERN Document Server

    Qiu, Xiang; Huang, Yongxiang; Chen, Ming; Lu, Zhiming; Liu, Yulu; Zhou, Quan

    2016-01-01

    In this paper, an experimental velocity database of a bacterial collective motion , e.g., \\textit{B. subtilis}, in turbulent phase with volume filling fraction $84\\%$ provided by Professor Goldstein at the Cambridge University UK, was analyzed to emphasize the scaling behavior of this active turbulence system. This was accomplished by performing a Hilbert-based methodology analysis to retrieve the scaling property without the $\\beta-$limitation. A dual-power-law behavior separated by the viscosity scale $\\ell_{\

  20. Diagnosis of bacterial hepatic abscess by CT

    Institute of Scientific and Technical Information of China (English)

    Cheng-Lin Wang; Xue-Jun Guo; Shui-Bo Qiu; Yi Lei; Zhi-Dong Yuan; Han-Bin Dong; Hui-An Liu

    2007-01-01

    BACKGROUND: Bacterial hepatic abscess usually is acute and progressive, often resulting in sepsis, impairment of liver function and disseminated intravascular coagulation. The mortality rate was as high as 80%in the past. For the purpose of early diagnosis and differential diagnosis of this disease, we probed the imaging manifestations and their characteristics in bacterial hepatic abscesses by CT scan. METHODS:Twenty-four lesions from 21 patients with bacterial hepatic abscesses that were conifrmed by clinical features, puncture and culture were reviewed for CT manifestations. Fourteen patients were male and 7 were female, with an average age of 56.2 years. All lesions underwent CT plain scan and three-phase enhanced scan and 15 patients underwent delayed-phase imaging. Three senior radiologists read the iflms in accordance with a standard. RESULTS: Among 24 lesions, 18 (75%) were situated in the right liver with diameters of 1.4-9.3 cm (average 4.5 cm). Nineteen (79.2%) lesions were round or sub-round in shape, and 22 (91.7%) had smooth, uninterrupted and sharp edges. All lesions showed low attenuation of less than 20 Hu. Twenty-two enhanced lesions (91.7%) had rim-shaped enhancement in the abscess wall, and 13 (54.2%) showed single or double-ring signs. Eighteen (75%) displayed honeycomb-like, grid-like or strip-like enhancement. Eighteen (75%) were regionally enhanced in the surroundings or upper or lower layers. Only 2 (8.3%) displayed a gas-liquid surface sign. CONCLUSIONS:  The CT ifndings of bacterial hepatic abscess are usually typical, and the diagnosis of the abscess is not dififcult. To precisely diagnose atypical cases, it is necessary to combine CT with clinical observations and follow-up.

  1. Dye Fluorescence Analysis from Bacterial Metabolism.

    Science.gov (United States)

    1984-04-01

    M were reported for the cell-free extracts of the cultured mouse lymphoma cells mentioned above and an in vitAo solution of porcine pancreas lipase ...fluorescence Fluorescent product Diacetyl fluorescein Lipase Bacterial metabolism 20. ABTRACT fCauhw a o de dif rNooeel md ~Id1)fp by block number) A...nonfluorescing dye is metabolized intracel- lularly by an organism through an enzyme-specific reaction . This produces a fluorescent product which when

  2. Dielectrophoretic assay of bacterial resistance to antibiotics

    Energy Technology Data Exchange (ETDEWEB)

    Johari, Juliana [School of Engineering, University of Surrey, Guildford, Surrey, GU2 7XH, UK (United Kingdom); Huebner, Yvonne [School of Engineering, University of Surrey, Guildford, Surrey, GU2 7XH, UK (United Kingdom); Hull, Judith C [School of Engineering, University of Surrey, Guildford, Surrey, GU2 7XH, UK (United Kingdom); Dale, Jeremy W [School of Biomedical and Life Sciences, University of Surrey, Guildford, Surrey, GU2 7XH, UK (United Kingdom); Hughes, Michael P [School of Engineering, University of Surrey, Guildford, Surrey, GU2 7XH, UK (United Kingdom)

    2003-07-21

    The dielectrophoretic collection spectra of antibiotic-sensitive and antibiotic-resistant strains of Staphylococcus epidermidis have been determined. These indicate that in the absence of antibiotic treatment there is a strong similarity between the dielectric properties of sensitive and resistant strains, and that there is a significant difference between the sensitive strains before and after treatment with the antibiotic streptomycin after 24 h exposure. This method offers possibilities for the assessment of bacterial resistance to antibiotics. (note)

  3. Molecular Kinetics of Reviving Bacterial Spores

    OpenAIRE

    2013-01-01

    Bacterial spores can remain dormant for years, yet they possess a remarkable potential to rapidly resume a vegetative life form. Here, we identified a distinct phase at the onset of spore outgrowth, designated the ripening period. This transition phase is exploited by the germinating spore for molecular reorganization toward elongation and subsequent cell division. We have previously shown that spores of different ages, kept under various temperatures, harbor dissimilar molecular reservoirs (...

  4. Phosphoproteome dynamics mediate revival of bacterial spores

    OpenAIRE

    2015-01-01

    Background Bacterial spores can remain dormant for decades, yet harbor the exceptional capacity to rapidly resume metabolic activity and recommence life. Although germinants and their corresponding receptors have been known for more than 30 years, the molecular events underlying this remarkable cellular transition from dormancy to full metabolic activity are only partially defined. Results Here, we examined whether protein phospho-modifications occur during germination, the first step of exit...

  5. Kinetics of dimethoate biodegradation in bacterial system

    OpenAIRE

    Manisha DebMandal; Shyamapada Mandal; Nishith Kumar Pal

    2011-01-01

    The present study is an investigation on the kinetics of dimethoate biodegradation and an estimation of residual dimethoate in bacterial culture by spectrophotometry. The methylene chloride extract of the culture medium was used for determination of dimethoate through its reaction with 1 chloro-2, 4 dinitrobenzene to produce methylamine whose absorbance at 505 nm gave an estimation of dimethoate content. The dimethoate standard curve follows Beer’s law at 505 nm with a slope of 0.0129 absorba...

  6. Tinidazole in the treatment of bacterial vaginosis

    Directory of Open Access Journals (Sweden)

    Nicola R Armstrong

    2009-06-01

    Full Text Available Nicola R Armstrong1, Janet D Wilson21Department of Infectious Diseases and Sexual Health, Trinity Centre, Bradford, UK; 2The Centre for Sexual Health, The General Infirmary at Leeds, Leeds, UKAbstract: Bacterial vaginosis (BV is the commonest cause of vaginal discharge in women of childbearing age. Oral metronidazole has long been established as an effective therapy in the treatment of BV. However, adverse effects due to metronidazole are frequent and this may lead to problems with adherence to a 7-day course of treatment and subsequently result in treatment failure. Oral tinidazole has been used to treat bacterial vaginosis for over 25 years but in a number of different dosage regimens. Placebo controlled trials have consistently shown increases in cure rate with tinidazole. Longer courses of treatment (eg, 1 g daily for 5 days appear to be more effective than a 2 g oral single dose. Comparative studies suggest that oral tinidazole is equivalent to oral metronidazole, intravaginal clindamycin cream, and intravaginal metronidazole tablets, in efficacy in treating BV. However, tinidazole has a more favorable side effect profile than oral metronidazole notably with better gastrointestinal tolerability and less metallic taste. Bacterial vaginosis is associated with high rates of recurrence and appropriate management of such recurrences can prove difficult. Recurrent BV has been linked with persistence of Gardnerella vaginalis after treatment; however the clinical implications of the possible greater activity of tinidazole against G. vaginalis are not yet clear. Repeated courses of oral metronidazole may be poorly tolerated and an alternative but equally effective treatment that is better tolerated may be preferable. In comparison to oral metronidazole, cost is clearly an issue as oral metronidazole is considerably cheaper and available in generic form. However where avoidance of oral metronidazole is necessary because of side effects, oral

  7. Clinical Practice Guidelines for Bacterial Meningoencephalitis.

    Directory of Open Access Journals (Sweden)

    Belkys Rodríguez Llerena

    2009-03-01

    Full Text Available Clinical Practice Guidelines for Bacterial Meningoencephalitis. It has been defined as an acute inflammatory process caused by bacteria, often purulent, which involves the meninges, subarachnoid space around the brain, spinal cord and usually includes the ventricles. It is caused in the 80% of the patients by three bacteria: Haemophilus influenzae, Neisseria meningitides and Streptococcus pneumonia. Concepts, classification, diagnosis and treatment were reviewed. It includes assessment guidelines focused on the most important aspects to be accomplished.

  8. Mechanisms of bacterial resistance to chromium compounds.

    Science.gov (United States)

    Ramírez-Díaz, Martha I; Díaz-Pérez, César; Vargas, Eréndira; Riveros-Rosas, Héctor; Campos-García, Jesús; Cervantes, Carlos

    2008-06-01

    Chromium is a non-essential and well-known toxic metal for microorganisms and plants. The widespread industrial use of this heavy metal has caused it to be considered as a serious environmental pollutant. Chromium exists in nature as two main species, the trivalent form, Cr(III), which is relatively innocuous, and the hexavalent form, Cr(VI), considered a more toxic species. At the intracellular level, however, Cr(III) seems to be responsible for most toxic effects of chromium. Cr(VI) is usually present as the oxyanion chromate. Inhibition of sulfate membrane transport and oxidative damage to biomolecules are associated with the toxic effects of chromate in bacteria. Several bacterial mechanisms of resistance to chromate have been reported. The best characterized mechanisms comprise efflux of chromate ions from the cell cytoplasm and reduction of Cr(VI) to Cr(III). Chromate efflux by the ChrA transporter has been established in Pseudomonas aeruginosa and Cupriavidus metallidurans (formerly Alcaligenes eutrophus) and consists of an energy-dependent process driven by the membrane potential. The CHR protein family, which includes putative ChrA orthologs, currently contains about 135 sequences from all three domains of life. Chromate reduction is carried out by chromate reductases from diverse bacterial species generating Cr(III) that may be detoxified by other mechanisms. Most characterized enzymes belong to the widespread NAD(P)H-dependent flavoprotein family of reductases. Several examples of bacterial systems protecting from the oxidative stress caused by chromate have been described. Other mechanisms of bacterial resistance to chromate involve the expression of components of the machinery for repair of DNA damage, and systems related to the homeostasis of iron and sulfur.

  9. Spontaneous bacterial peritonitis: Few additional points

    Institute of Scientific and Technical Information of China (English)

    Pankaj Jain

    2009-01-01

    Spontaneous bacterial peritonitis (SBP) is a treatable complication of decompensated cirrhosis. Coagulopathy with evidence of hyperfibrinolysis or clinically evident disseminated intravascular coagulation precludes paracentesis. Alcoholic hepatitis with fever, leucocytosis and abdominal pain should be evaluated for SBP. Oral ofloxacin is as effective as parenteral cefotaxime in treatment of SBP except for inpatients with vomiting,encephalopathy, or renal failure. Albumin is superior to hydroxyethyl starch in treatment of SBP.

  10. Biocompatibility of Bacterial Cellulose Based Biomaterials

    OpenAIRE

    2012-01-01

    Some bacteria can synthesize cellulose when they are cultivated under adequate conditions. These bacteria produce a mat of cellulose on the top of the culture medium, which is formed by a three-dimensional coherent network of pure cellulose nanofibers. Bacterial cellulose (BC) has been widely used in different fields, such as the paper industry, electronics and tissue engineering due to its remarkable mechanical properties, conformability and porosity. Nanocomposites based on BC have received...

  11. Impact of recombination on bacterial evolution

    OpenAIRE

    2010-01-01

    Genetic exchange plays a defining role in the evolution of many bacteria. The recent accumulation of nucleotide sequence data from multiple members of diverse bacterial genera has facilitated comparative studies that have revealed many features of this process. Here we focus on genetic exchange that has involved homologous recombination and illustrate how nucleotide sequence data have furthered our understanding of: (i) the frequency of recombination; (ii) the impact of recombination in diffe...

  12. Bacterial Contamination of Iranian Paper Currency

    Directory of Open Access Journals (Sweden)

    Mir-Hassan Moosavy

    2013-09-01

    Full Text Available Background: Transmission of human pathogens can be occurred via inert objects. Paper currency is a further common contact surface whereby pathogens can be transferred within a population although the significance remains unknown. Hence, the aim of the present study was to investigate microbial populations associated with Iranian paper currency.Methods: This study was carried out by getting 108 samples of the Iranian currency notes (1000, 2000, 5000, 10000, 20000 and 50000 RIALS from food-related shops that included food service outlets, greengrocery, supermarket, bakery, confectionary and poultry meat retail outlets. All currency notes were examined for total bacterial count and identification of pathogenic bacteria.Results: The average total bacterial count that was recovered from currency notes was found to be 3.27±0.31 colony forming unites. 2000R had the highest total bacterial count, followed by 5000R, 10000R and the lowest in 50000R. In this study, the isolated bacteria recovered were Bacillus cereus (8.33%, E. coli (48.14%, Staphylococcus aureus (28.7%, Salmonella (0.92%, Listeria monocytogenes (0.92%, Yersinia entrocolitica (6.48%. It was revealed that all the pathogens screened for where encountered on currency notes were recovered from one sample. There were no significant (P>0.05 correlations between the carriage of pathogens/fecal indicator bacteria and currency note condition.Conclusion: Our findings demonstrate that Iranian currency notes represent a significant vehicle for human pathogens.

  13. Insights from genomics into bacterial pathogen populations.

    Directory of Open Access Journals (Sweden)

    Daniel J Wilson

    2012-09-01

    Full Text Available Bacterial pathogens impose a heavy burden of disease on human populations worldwide. The gravest threats are posed by highly virulent respiratory pathogens, enteric pathogens, and HIV-associated infections. Tuberculosis alone is responsible for the deaths of 1.5 million people annually. Treatment options for bacterial pathogens are being steadily eroded by the evolution and spread of drug resistance. However, population-level whole genome sequencing offers new hope in the fight against pathogenic bacteria. By providing insights into bacterial evolution and disease etiology, these approaches pave the way for novel interventions and therapeutic targets. Sequencing populations of bacteria across the whole genome provides unprecedented resolution to investigate (i within-host evolution, (ii transmission history, and (iii population structure. Moreover, advances in rapid benchtop sequencing herald a new era of real-time genomics in which sequencing and analysis can be deployed within hours in response to rapidly changing public health emergencies. The purpose of this review is to highlight the transformative effect of population genomics on bacteriology, and to consider the prospects for answering abiding questions such as why bacteria cause disease.

  14. Patterning bacterial communities on epithelial cells.

    Directory of Open Access Journals (Sweden)

    Mohammed Dwidar

    Full Text Available Micropatterning of bacteria using aqueous two phase system (ATPS enables the localized culture and formation of physically separated bacterial communities on human epithelial cell sheets. This method was used to compare the effects of Escherichia coli strain MG1655 and an isogenic invasive counterpart that expresses the invasin (inv gene from Yersinia pseudotuberculosis on the underlying epithelial cell layer. Large portions of the cell layer beneath the invasive strain were killed or detached while the non-invasive E. coli had no apparent effect on the epithelial cell layer over a 24 h observation period. In addition, simultaneous testing of the localized effects of three different bacterial species; E. coli MG1655, Shigella boydii KACC 10792 and Pseudomonas sp DSM 50906 on an epithelial cell layer is also demonstrated. The paper further shows the ability to use a bacterial predator, Bdellovibriobacteriovorus HD 100, to selectively remove the E. coli, S. boydii and P. sp communities from this bacteria-patterned epithelial cell layer. Importantly, predation and removal of the P. Sp was critical for maintaining viability of the underlying epithelial cells. Although this paper focuses on a few specific cell types, the technique should be broadly applicable to understand a variety of bacteria-epithelial cell interactions.

  15. Acute otitis media and acute bacterial sinusitis.

    Science.gov (United States)

    Wald, Ellen R

    2011-05-01

    Acute otitis media and acute bacterial sinusitis are 2 of the most common indications for antimicrobial agents in children. Together, they are responsible for billions of dollars of health care expenditures. The pathogenesis of the 2 conditions is identical. In the majority of children with each condition, a preceding viral upper respiratory tract infection predisposes to the development of the acute bacterial complication. It has been shown that viral upper respiratory tract infection predisposes to the development of acute otitis media in 37% of cases. Currently, precise microbiologic diagnosis of acute otitis media and acute bacterial sinusitis requires performance of tympanocentesis in the former and sinus aspiration in the latter. The identification of a virus from the nasopharynx in either case does not obviate the need for antimicrobial therapy. Furthermore, nasal and nasopharyngeal swabs are not useful in predicting the results of culture of the middle ear or paranasal sinus. However, it is possible that a combination of information regarding nasopharyngeal colonization with bacteria and infection with specific viruses may inform treatment decisions in the future.

  16. Carbon nanotubes as in vivo bacterial probes

    Science.gov (United States)

    Bardhan, Neelkanth M.; Ghosh, Debadyuti; Belcher, Angela M.

    2014-09-01

    With the rise in antibiotic-resistant infections, non-invasive sensing of infectious diseases is increasingly important. Optical imaging, although safer and simpler, is less developed than other modalities such as radioimaging, due to low availability of target-specific molecular probes. Here we report carbon nanotubes (SWNTs) as bacterial probes for fluorescence imaging of pathogenic infections. We demonstrate that SWNTs functionalized using M13 bacteriophage (M13-SWNT) can distinguish between F‧-positive and F‧-negative bacterial strains. Moreover, through one-step modification, we attach an anti-bacterial antibody on M13-SWNT, making it easily tunable for sensing specific F‧-negative bacteria. We illustrate detection of Staphylococcus aureus intramuscular infections, with ~3.4 × enhancement in fluorescence intensity over background. SWNT imaging presents lower signal spread ~0.08 × and higher signal amplification ~1.4 × , compared with conventional dyes. We show the probe offers greater ~5.7 × enhancement in imaging of S. aureus infective endocarditis. These biologically functionalized, aqueous-dispersed, actively targeted, modularly tunable SWNT probes offer new avenues for exploration of deeply buried infections.

  17. Bacterial ferrous iron transport: the Feo system.

    Science.gov (United States)

    Lau, Cheryl K Y; Krewulak, Karla D; Vogel, Hans J

    2016-03-01

    To maintain iron homeostasis within the cell, bacteria have evolved various types of iron acquisition systems. Ferric iron (Fe(3+)) is the dominant species in an oxygenated environment, while ferrous iron (Fe(2+)) is more abundant under anaerobic conditions or at low pH. For organisms that must combat oxygen limitation for their everyday survival, pathways for the uptake of ferrous iron are essential. Several bacterial ferrous iron transport systems have been described; however, only the Feo system appears to be widely distributed and is exclusively dedicated to the transport of iron. In recent years, many studies have explored the role of the FeoB and FeoA proteins in ferrous iron transport and their contribution toward bacterial virulence. The three-dimensional structures for the Feo proteins have recently been determined and provide insight into the molecular details of the transport system. A highly select group of bacteria also express the FeoC protein from the same operon. This review will provide a comprehensive look at the structural and functional aspects of the Feo system. In addition, bioinformatics analyses of the feo operon and the Feo proteins have been performed to complement our understanding of this ubiquitous bacterial uptake system, providing a new outlook for future studies.

  18. Corruption of Innate Immunity by Bacterial Proteases

    Science.gov (United States)

    Potempa, Jan; Pike, Robert N.

    2009-01-01

    The innate immune system of the human body has developed numerous mechanisms to control endogenous and exogenous bacteria and thus prevent infections by these microorganisms. These mechanisms range from physical barriers such as the skin or mucosal epithelium to a sophisticated array of molecules and cells that function to suppress or prevent bacterial infection. Many bacteria express a variety of proteases, ranging from non-specific and powerful enzymes that degrade many proteins involved in innate immunity to proteases that are extremely precise and specific in their mode of action. Here we have assembled a comprehensive picture of how bacterial proteases affect the host’s innate immune system to gain advantage and cause infection. This picture is far from being complete since the numbers of mechanisms utilized are as astonishing as they are diverse, ranging from degradation of molecules vital to innate immune mechanisms to subversion of the mechanisms to allow the bacterium to hide from the system or take advantage of it. It is vital that such mechanisms are elucidated to allow strategies to be developed to aid the innate immune system in controlling bacterial infections. PMID:19756242

  19. Collective decision making in bacterial viruses.

    Science.gov (United States)

    Weitz, Joshua S; Mileyko, Yuriy; Joh, Richard I; Voit, Eberhard O

    2008-09-15

    For many bacterial viruses, the choice of whether to kill host cells or enter a latent state depends on the multiplicity of coinfection. Here, we present a mathematical theory of how bacterial viruses can make collective decisions concerning the fate of infected cells. We base our theory on mechanistic models of gene regulatory dynamics. Unlike most previous work, we treat the copy number of viral genes as variable. Increasing the viral copy number increases the rate of transcription of viral mRNAs. When viral regulation of cell fate includes nonlinear feedback loops, very small changes in transcriptional rates can lead to dramatic changes in steady-state gene expression. Hence, we prove that deterministic decisions can be reached, e.g., lysis or latency, depending on the cellular multiplicity of infection within a broad class of gene regulatory models of viral decision-making. Comparisons of a parameterized version of the model with molecular studies of the decision structure in the temperate bacteriophage lambda are consistent with our conclusions. Because the model is general, it suggests that bacterial viruses can respond adaptively to changes in population dynamics, and that features of collective decision-making in viruses are evolvable life history traits.

  20. 3D printing of microscopic bacterial communities

    Science.gov (United States)

    Connell, Jodi L.; Ritschdorff, Eric T.; Whiteley, Marvin; Shear, Jason B.

    2013-01-01

    Bacteria communicate via short-range physical and chemical signals, interactions known to mediate quorum sensing, sporulation, and other adaptive phenotypes. Although most in vitro studies examine bacterial properties averaged over large populations, the levels of key molecular determinants of bacterial fitness and pathogenicity (e.g., oxygen, quorum-sensing signals) may vary over micrometer scales within small, dense cellular aggregates believed to play key roles in disease transmission. A detailed understanding of how cell–cell interactions contribute to pathogenicity in natural, complex environments will require a new level of control in constructing more relevant cellular models for assessing bacterial phenotypes. Here, we describe a microscopic three-dimensional (3D) printing strategy that enables multiple populations of bacteria to be organized within essentially any 3D geometry, including adjacent, nested, and free-floating colonies. In this laser-based lithographic technique, microscopic containers are formed around selected bacteria suspended in gelatin via focal cross-linking of polypeptide molecules. After excess reagent is removed, trapped bacteria are localized within sealed cavities formed by the cross-linked gelatin, a highly porous material that supports rapid growth of fully enclosed cellular populations and readily transmits numerous biologically active species, including polypeptides, antibiotics, and quorum-sensing signals. Using this approach, we show that a picoliter-volume aggregate of Staphylococcus aureus can display substantial resistance to β-lactam antibiotics by enclosure within a shell composed of Pseudomonas aeruginosa. PMID:24101503

  1. Bacterial microbiome of lungs in COPD

    Directory of Open Access Journals (Sweden)

    Sze MA

    2014-02-01

    Full Text Available Marc A Sze,1 James C Hogg,2 Don D Sin1 1Department of Medicine, 2Department of Pathology and Laboratory Medicine, The James Hogg Research Centre, Providence Heart-Lung Institute, St Paul's Hospital, University of British Columbia, Vancouver, BC, Canada Abstract: Chronic obstructive pulmonary disease (COPD is currently the third leading cause of death in the world. Although smoking is the main risk factor for this disease, only a minority of smokers develop COPD. Why this happens is largely unknown. Recent discoveries by the human microbiome project have shed new light on the importance and richness of the bacterial microbiota at different body sites in human beings. The microbiota plays a particularly important role in the development and functional integrity of the immune system. Shifts or perturbations in the microbiota can lead to disease. COPD is in part mediated by dysregulated immune responses to cigarette smoke and other environmental insults. Although traditionally the lung has been viewed as a sterile organ, by using highly sensitive genomic techniques, recent reports have identified diverse bacterial communities in the human lung that may change in COPD. This review summarizes the current knowledge concerning the lung microbiota in COPD and its potential implications for pathogenesis of the disease. Keywords: chronic obstructive pulmonary disease, bacterial microbiome, lungs

  2. Carbon and phosphorus regulating bacterial metabolism in oligotrophic boreal lakes

    DEFF Research Database (Denmark)

    Vidal, L. O.; Graneli, W.; Daniel, C. B.;

    2011-01-01

    -P and glucose-C alone or in combination (0.01 and 0.3 mg L(-1), respectively) was added to 1.0 mu m filtered lake water and incubated in darkness at 20 degrees C. Additions of glucose (C) and phosphorus (P) alone did not lead to changes in the rates of bacterial metabolic processes, whereas bacterial...... respiration and bacterial production responded positively to C + P enrichment for most of the lakes sampled. Bacterial growth efficiency showed a wide range (2.5-28.7%) and low mean value (12%). These variations were not correlated with the DOC concentration. Our results show that heterotrophic bacterial...

  3. Bacterial utilization of size-fractionated dissolved organic matter

    Digital Repository Service at National Institute of Oceanography (India)

    Khodse, V.B.; Bhosle, N.B.

    was 12 %. BA was estimated following the DAPI (4,6 diamidino- 2 phenylindole) staining method (Porter & Feig 1980). Briefly, a known volume of seawater (2 to 5 ml) was stained with DAPI (final concentration 0.01%) for 5 min, and filtered onto 0.22 μm... bacterial cells following the procedure described by Porter & Feig (1980). Bacterial biomass (BB) was calculated from bacterial cell numbers and assuming a bacterial carbon content of 15 fg C cell -1 (Caron et al. 1995). Bacterial production...

  4. Propionibacterium acidipropionici CRL1198 influences the production of acids and the growth of bacterial genera stimulated by inulin in a murine model of cecal slurries.

    Science.gov (United States)

    Lorenzo-Pisarello, M J; Gultemirian, M L; Nieto-Peñalver, C; Perez Chaia, A

    2010-08-01

    Different attempts have been made to improve the health status of humans and animals by increasing the intestinal production of short-chain fatty acids (SCFA) derived from non-digestible carbohydrates fermentation. In this paper we investigate the in vitro production of short-chain fatty acids (SCFA) after addition of inulin, propionibacteria or a combination of both in an experimental model of mice cecal slurries. The development of bacterial genera which are usually stimulated by inulin addition was also investigated. According to our experimental data, acetic acid and butyric acids concentrations increased after incubation in slurries that had no supplements. By contrast, butyric acid concentrations remained in the basal value when supplements were used. Fermentation of only inulin did not increase the concentration of total SCFA. Propionibacterium acidipropionici CRL1198 improved the production of propionic acid in cecal slurries when it was added alone, but the effect was more noticeable in the combination with inulin. A modulation of the global fermentative activity of the cecal microbiota was evidenced by the increase on the ratio propionic acid/SCFA in supplementations with propionibacteria. Statistical analysis of data demonstrated that samples from homogenates with propionibacteria alone or combined with inulin belong to the same cluster. The presence of propionibacteria limited the growth of Bacteroides fragilis and Clostridium hystoliticum groups in slurries with and without inulin. The growth of Bifidobacterium was not modified and the stimulating effect of inulin on lactobacilli disappeared in the presence of propionibacteria. In conclusion, dairy propionibacteria are potential candidates to develop new functional foods helpful to ensure the intestinal production of SCFA during inulin supplementation and to control the overgrowth of bacteria belonging to Bacteroides and Clostridium genera.

  5. Bacterial melanin promotes recovery after sciatic nerve injury in rats

    Institute of Scientific and Technical Information of China (English)

    Olga V Gevorkyan; Irina B Meliksetyan; Tigran R Petrosyan; Anichka S Hovsepyan

    2015-01-01

    Bacterial melanin, obtained from the mutant strain ofBacillus Thuringiensis, has been shown to promote recovery after central nervous system injury. It is hypothesized, in this study, that bacterial melanin can promote structural and functional recovery after peripheral nerve injury. Rats subjected to sciatic nerve transection were intramuscularly administered bacterial melanin. The sciatic nerve transected rats that did not receive intramuscular administration of bacterial melanin served as controls. Behavior tests showed that compared to control rats, the time taken for instrumental conditioned relfex recovery was signiifcantly shorter and the ability to keep the balance on the rotating bar was signiifcantly better in bacterial melanin-treated rats. Histomor-phological tests showed that bacterial melanin promoted axon regeneration after sciatic nerve injury. These ifndings suggest that bacterial melanin exhibits neuroprotective effects on injured sciatic nerve, contributes to limb motor function recovery, and therefore can be used for rehabil-itation treatment of peripheral nerve injury.

  6. Exploration and mining of the bacterial terpenome.

    Science.gov (United States)

    Cane, David E; Ikeda, Haruo

    2012-03-20

    Tens of thousands of terpenoids are present in both terrestrial and marine plants, as well as fungi. In the last 5-10 years, however, it has become evident that terpenes are also produced by numerous bacteria, especially soil-dwelling Gram-positive organisms such as Streptomyces and other Actinomycetes. Although some microbial terpenes, such as geosmin, the degraded sesquiterpene responsible for the smell of moist soil, the characteristic odor of the earth itself, have been known for over 100 years, few terpenoids have been identified by classical structure- or activity-guided screening of bacterial culture extracts. In fact, the majority of cyclic terpenes from bacterial species have only recently been uncovered by the newly developed techniques of "genome mining". In this new paradigm for biochemical discovery, bacterial genome sequences are first analyzed with powerful bioinformatic tools, such as the BLASTP program or Profile Hidden Markov models, to screen for and identify conserved protein sequences harboring a characteristic set of universally conserved functional domains typical of all terpene synthases. Of particular importance is the presence of variants of two universally conserved domains, the aspartate-rich DDXX(D/E) motif and the NSE/DTE triad, (N/D)DXX(S/T)XX(K/R)(D/E). Both domains have been implicated in the binding of the essential divalent cation, typically Mg(2+), that is required for cyclization of the universal acyclic terpene precursors, such as farnesyl and geranyl diphosphate. The low level of overall sequence similarity among terpene synthases, however, has so far precluded any simple correlation of protein sequence with the structure of the cyclized terpene product. The actual biochemical function of a cryptic bacterial (or indeed any) terpene synthase must therefore be determined by direct experiment. Two common approaches are (i) incubation of the expressed recombinant protein with acyclic allylic diphosphate substrates and

  7. BIOSYNTHESIS OF BACTERIAL CELLULOSE BY МEDUSOMYCES GISEVII

    Directory of Open Access Journals (Sweden)

    E. K. Gladysheva

    2015-01-01

    Full Text Available Summary: Bacterial cellulose is an organic material that is synthesized by microorganisms extracellularly. Bacterial cellulose can be used in various industries. Especially, bacterial cellulose has found its application basically in medicine. The production of bacterial cellulose is a complicated and long process. The principal criterion for the process to be successful is bacterial cellulose to be obtained in a higher yield. Russia is lacking an operating facility to produce bacterial cellulose; therefore, research in this art is the hottest topic. This paper reports details on the biosynthesis of bacterial cellulose by the Мedusomyces gisevii microbe and investigates the effect of active acidity level on the bacterial cellulose synthesis. It was found that the synthesis of bacterial cellulose by the symbiosis of Мedusomyces gisevii does not require pH to be artificially maintained. The substrate concentration effect on the bacterial cellulose yield was also examined. The bacterial cellulose synthesis was witnessed to be conjugated with the acetic-acid bacterium growth, and conditions corresponding to a maximal bacterial cells number correspond to a maximum microbial cellulose yield. The maximal bacterial cell number was observed when the glucose concentration in the broth was 20 g/l; as the glucose concentration was increased to 55 g/L, the acetic-acid bacterial cell number diminished in inverse proportion to the substrate concentration, which is likely due to the substrate inhibition. A glucose concentration of 15 g/l and lower is not enough, causing a decrease in the cell number, which is directly proportional to a decline in the substrate concentration. The maximum bacterial cellulose yield (8.7-9.0 % was achieved at an initial glucose concentration of 20-25 g/l in the broth. The conditions providing the maximum bacterial cellulose yield gave an enlarged bacterial cellulose specimen 605 g in weight. The physicochemical properties of the

  8. Tracking bacterial growth in liquid media and a new bacterial life model

    Institute of Scientific and Technical Information of China (English)

    刘实

    1999-01-01

    By increasing viscosity of liquid media above 8.4 centipoise (cp) i.e. 0.084 g·cm-1·S-1 individual growth and family formation of Escherichia coli was continuously observed in real-time for up to 6 h. The observations showed primarily unidirectional growth and reproduction of E. coli and suggested more than one reproduction in the observed portion of E. coli life span. A new bacterial life model is proposed: each bacterium has a stable cell polarity that ultimately transforms into two bacteria of different generations; the life cycle of a bacterium can contain more than one reproduction cycle; and the age of a bacterium should be defined by its experienced chronological time. This new bacterial life model differs from the dominant concepts of bacterial life but complies with all basic life principles based on direct observation of macroorganisms.

  9. Bacterial community structure and predicted alginate metabolic pathway in an alginate-degrading bacterial consortium.

    Science.gov (United States)

    Kita, Akihisa; Miura, Toyokazu; Kawata, Satoshi; Yamaguchi, Takeshi; Okamura, Yoshiko; Aki, Tsunehiro; Matsumura, Yukihiko; Tajima, Takahisa; Kato, Junichi; Nishio, Naomichi; Nakashimada, Yutaka

    2016-03-01

    Methane fermentation is one of the effective approaches for utilization of brown algae; however, this process is limited by the microbial capability to degrade alginate, a main polysaccharide found in these algae. Despite its potential, little is known about anaerobic microbial degradation of alginate. Here we constructed a bacterial consortium able to anaerobically degrade alginate. Taxonomic classification of 16S rRNA gene, based on high-throughput sequencing data, revealed that this consortium included two dominant strains, designated HUA-1 and HUA-2; these strains were related to Clostridiaceae bacterium SK082 (99%) and Dysgonomonas capnocytophagoides (95%), respectively. Alginate lyase activity and metagenomic analyses, based on high-throughput sequencing data, revealed that this bacterial consortium possessed putative genes related to a predicted alginate metabolic pathway. However, HUA-1 and 2 did not grow on agar medium with alginate by using roll-tube method, suggesting the existence of bacterial interactions like symbiosis for anaerobic alginate degradation.

  10. Bacterial invasion reconstructed molecule by molecule

    Energy Technology Data Exchange (ETDEWEB)

    Werner, James H [Los Alamos National Laboratory

    2009-01-01

    We propose to visualize the initial stages of bacterial infection of a human host cell with unmatched spatial and temporal resolution. This work will develop a new capability for the laboratory (super-resolution optical imaging), will test unresolved scientific hypotheses regarding host-pathogen interaction dynamics, and leverages state of the art 3D molecular tracking instrumentation developed recently by our group. There is much to be gained by applying new single molecule tools to the important and familiar problem of pathogen entry into a host cell. For example, conventional fluorescence microscopy has identified key host receptors, such as CD44 and {alpha}5{beta}1 integrin, that aggregate near the site of Salmonella typhimurium infection of human cells. However, due to the small size of the bacteria ({approx} 2 {micro}m) and the diffraction of the emitted light, one just sees a fluorescent 'blob' of host receptors that aggregate at the site of attachment, making it difficult to determine the exact number of receptors present or whether there is any particular spatial arrangement of the receptors that facilitates bacterial adhesion/entry. Using newly developed single molecule based super-resolution imaging methods, we will visualize how host receptors are directed to the site of pathogen adhesion and whether host receptors adopt a specific spatial arrangement for successful infection. Furthermore, we will employ our 3D molecular tracking methods to follow the injection of virulence proteins, or effectors, into the host cell by the pathogen Type III secretion system (TTSS). We expect these studies to provide mechanistic insights into the early events of pathogen infection that have here-to-fore been technically beyond our reach. Our Research Goals are: Goal 1--Construct a super-resolution fluorescence microscope and use this new capability to image the spatial distribution of different host receptors (e.g. CD44, as {alpha}5{beta}1 integrin) at the

  11. Water Microbiology. Bacterial Pathogens and Water

    Directory of Open Access Journals (Sweden)

    João P. S. Cabral

    2010-10-01

    Full Text Available Water is essential to life, but many people do not have access to clean and safe drinking water and many die of waterborne bacterial infections. In this review a general characterization of the most important bacterial diseases transmitted through water—cholera, typhoid fever and bacillary dysentery—is presented, focusing on the biology and ecology of the causal agents and on the diseases’ characteristics and their life cycles in the environment. The importance of pathogenic Escherichia coli strains and emerging pathogens in drinking water-transmitted diseases is also briefly discussed. Microbiological water analysis is mainly based on the concept of fecal indicator bacteria. The main bacteria present in human and animal feces (focusing on their behavior in their hosts and in the environment and the most important fecal indicator bacteria are presented and discussed (focusing on the advantages and limitations of their use as markers. Important sources of bacterial fecal pollution of environmental waters are also briefly indicated. In the last topic it is discussed which indicators of fecal pollution should be used in current drinking water microbiological analysis. It was concluded that safe drinking water for all is one of the major challenges of the 21st century and that microbiological control of drinking water should be the norm everywhere. Routine basic microbiological analysis of drinking water should be carried out by assaying the presence of Escherichia coli by culture methods. Whenever financial resources are available, fecal coliform determinations should be complemented with the quantification of enterococci. More studies are needed in order to check if ammonia is reliable for a preliminary screening for emergency fecal pollution outbreaks. Financial resources should be devoted to a better understanding of the ecology and behavior of human and animal fecal bacteria in environmental waters.

  12. Sensitive, Rapid Detection of Bacterial Spores

    Science.gov (United States)

    Kern, Roger G.; Venkateswaran, Kasthuri; Chen, Fei; Pickett, Molly; Matsuyama, Asahi

    2009-01-01

    A method of sensitive detection of bacterial spores within delays of no more than a few hours has been developed to provide an alternative to a prior three-day NASA standard culture-based assay. A capability for relatively rapid detection of bacterial spores would be beneficial for many endeavors, a few examples being agriculture, medicine, public health, defense against biowarfare, water supply, sanitation, hygiene, and the food-packaging and medical-equipment industries. The method involves the use of a commercial rapid microbial detection system (RMDS) that utilizes a combination of membrane filtration, adenosine triphosphate (ATP) bioluminescence chemistry, and analysis of luminescence images detected by a charge-coupled-device camera. This RMDS has been demonstrated to be highly sensitive in enumerating microbes (it can detect as little as one colony-forming unit per sample) and has been found to yield data in excellent correlation with those of culture-based methods. What makes the present method necessary is that the specific RMDS and the original protocols for its use are not designed for discriminating between bacterial spores and other microbes. In this method, a heat-shock procedure is added prior to an incubation procedure that is specified in the original RMDS protocols. In this heat-shock procedure (which was also described in a prior NASA Tech Briefs article on enumerating sporeforming bacteria), a sample is exposed to a temperature of 80 C for 15 minutes. Spores can survive the heat shock, but nonspore- forming bacteria and spore-forming bacteria that are not in spore form cannot survive. Therefore, any colonies that grow during incubation after the heat shock are deemed to have originated as spores.

  13. Water microbiology. Bacterial pathogens and water.

    Science.gov (United States)

    Cabral, João P S

    2010-10-01

    Water is essential to life, but many people do not have access to clean and safe drinking water and many die of waterborne bacterial infections. In this review a general characterization of the most important bacterial diseases transmitted through water-cholera, typhoid fever and bacillary dysentery-is presented, focusing on the biology and ecology of the causal agents and on the diseases' characteristics and their life cycles in the environment. The importance of pathogenic Escherichia coli strains and emerging pathogens in drinking water-transmitted diseases is also briefly discussed. Microbiological water analysis is mainly based on the concept of fecal indicator bacteria. The main bacteria present in human and animal feces (focusing on their behavior in their hosts and in the environment) and the most important fecal indicator bacteria are presented and discussed (focusing on the advantages and limitations of their use as markers). Important sources of bacterial fecal pollution of environmental waters are also briefly indicated. In the last topic it is discussed which indicators of fecal pollution should be used in current drinking water microbiological analysis. It was concluded that safe drinking water for all is one of the major challenges of the 21st century and that microbiological control of drinking water should be the norm everywhere. Routine basic microbiological analysis of drinking water should be carried out by assaying the presence of Escherichia coli by culture methods. Whenever financial resources are available, fecal coliform determinations should be complemented with the quantification of enterococci. More studies are needed in order to check if ammonia is reliable for a preliminary screening for emergency fecal pollution outbreaks. Financial resources should be devoted to a better understanding of the ecology and behavior of human and animal fecal bacteria in environmental waters.

  14. 脑源性神经营养因子/酪氨酸激酶受体B信号通路抑制剂K252a逆转丙戊酸引起的神经元过度生长%BDNF/TrkB pathway inhibitor K252a reverses the neuronal overgrowth induced by valproic acid in vitro

    Institute of Scientific and Technical Information of China (English)

    王中平; 熊小琴; 崔卫刚; 张应花; 李瑞锡

    2013-01-01

    目的:探讨脑源性神经营养因子(BDNF)/酪氨酸激酶受体B(TrkB)信号通路抑制剂K252a是否对丙戊酸引起的神经元过度生长有逆转作用.方法:用丙戊酸及K252a分别或共处理大鼠大脑皮层原代培养神经元,定量RT-PCR及免疫印迹检测BDNF/TrkB通路蛋白BDNF及TrkB的表达变化,同时以免疫荧光技术观测神经元形态变化.结果:丙戊酸处理后,显著增加神经元BDNF mRNA的表达,TrkB mRNA的表达则未见明显变化;丙戊酸处理也导致BDNF蛋白表达上调.而用K252a处理后,神经元BDNF及TrkB表达与对照组相比,无明显变化.形态学结果显示,丙戊酸处理后,神经元过度生长,表现为神经元突起数目及总长度显著增加;而K252a处理后,丙戊酸引起的神经元突起过度生长受到明显抑制.结论:BDNF/TrkB通路抑制剂K252a可逆转丙戊酸导致的神经元过度生长.该结果为丙戊酸及K252a应用于临床治疗某些神经发育与退行性疾病如自闭症及阿尔茨海默病等提供了实验依据.%Objective:To investigate the reverse effect of K252a, an inhibitor of BDNF/TrkB pathway which plays an important role in the neuronal proliferation, differentiation and neurite growth, on the neuronal overgrowth induced by valproic acid (VPA). Methods: The primary cultured neurons from the rat cortex were exposed to VPA, VPA plus K252a or the control. The expressions of BDNF and TrkB were tested by quantitative RT-PCR and Western blotting, and the morphological changes of the neurons were observed by immunofluorescence. Results: VPA exposure, in comparison with the control, increased the expression of both mRNA and protein of BDNF, but not of TrkB. However, K252a treatment did not affect the expression of BDNF and TrkB in the cultured neurons. The results also showed that VPA treatment promoted neuronal growth, manifesting as a significant increment of the number of the neurite branches and total neurite length. Furthermore, the

  15. Cryo-electron tomography of bacterial viruses

    Energy Technology Data Exchange (ETDEWEB)

    Guerrero-Ferreira, Ricardo C. [Division of Pediatric Infectious Diseases, Emory University School of Medicine, Children' s Healthcare of Atlanta, Atlanta, GA 30322 (United States); Wright, Elizabeth R., E-mail: erwrigh@emory.edu [Division of Pediatric Infectious Diseases, Emory University School of Medicine, Children' s Healthcare of Atlanta, Atlanta, GA 30322 (United States)

    2013-01-05

    Bacteriophage particles contain both simple and complex macromolecular assemblages and machines that enable them to regulate the infection process under diverse environmental conditions with a broad range of bacterial hosts. Recent developments in cryo-electron tomography (cryo-ET) make it possible to observe the interactions of bacteriophages with their host cells under native-state conditions at unprecedented resolution and in three-dimensions. This review describes the application of cryo-ET to studies of bacteriophage attachment, genome ejection, assembly and egress. Current topics of investigation and future directions in the field are also discussed.

  16. The Carboxysome and Other Bacterial Microcompartments

    Energy Technology Data Exchange (ETDEWEB)

    Kerfeld, Cheryl A.; Greenleaf, William B.; Kinney, James N.

    2010-06-23

    - Carboxysomes are part of the carbon concentrating mechanism in cyanobacteria and chemoautotrophs. - Carboxysomes are a subclass of bacterial microcompartments (BMCs); BMCs can encapsulate a range of metabolic processes. - Like some viral particles, the carboxysome can be modeled as an icosahedron-in its case, having 4,000-5,000 hexameric shell subunits and 12 surface pentamers to generate curvature. - The threefold axis of symmetry of the CsoS1D protein in carboxysomes forms a pore that can open and close, allowing for selective diffusion. - Genetic modules encoding BMC shell proteins and the enzymes that they encapsulate are horizontally transferable, suggesting they enable bacteria to adapt to diverse environments.

  17. Bacterial Morphologies Supporting Cometary Panspermia: a Reappraisal

    Science.gov (United States)

    Wickramasinghe, Chandra

    It is nearly 30 years since the first decisive evidence of microbial morphologies in carbonaceous chondrites was discovered and reported by Hans Dieter Pflug. In addition to morphology other data, notably laser mass spectroscopy, served to confirm the identification of such structures as putative bacterial fossils. Recent examinations of cometary dust collected in the stratosphere and further studies of carbonaceous meteorites reaffirm the presence of putative microbial fossils. Since carbonaceous chondrites (particularly Type 1 chondrites) are thought to be extinct comets the data reviewed in this article provide strong support for theories of cometary panspermia.

  18. Russian vaccines against especially dangerous bacterial pathogens

    Science.gov (United States)

    Feodorova, Valentina A; Sayapina, Lidiya V; Corbel, Michael J; Motin, Vladimir L

    2014-01-01

    In response to the epidemiological situation, live attenuated or killed vaccines against anthrax, brucellosis, cholera, glanders, plague and tularemia were developed and used for immunization of at-risk populations in the Former Soviet Union. Certain of these vaccines have been updated and currently they are used on a selective basis, mainly for high risk occupations, in the Russian Federation. Except for anthrax and cholera these vaccines currently are the only licensed products available for protection against the most dangerous bacterial pathogens. Development of improved formulations and new products is ongoing. PMID:26038506

  19. The enzymes of bacterial census and censorship.

    Science.gov (United States)

    Fast, Walter; Tipton, Peter A

    2012-01-01

    N-Acyl-L-homoserine lactones (AHLs) are a major class of quorum-sensing signals used by Gram-negative bacteria to regulate gene expression in a population-dependent manner, thereby enabling group behavior. Enzymes capable of generating and catabolizing AHL signals are of significant interest for the study of microbial ecology and quorum-sensing pathways, for understanding the systems that bacteria have evolved to interact with small-molecule signals, and for their possible use in therapeutic and industrial applications. The recent structural and functional studies reviewed here provide a detailed insight into the chemistry and enzymology of bacterial communication.

  20. [Cerebral salt wasting syndrome in bacterial meningitis].

    Science.gov (United States)

    Attout, H; Guez, S; Seriès, C

    2007-10-01

    Subarachnoid hemorrhage is the most common cause of cerebral salt wasting syndrome. There are few reports of this condition in infectious meningitis. We describe a patient with hyponatremia and bacterial meningitis. Hyponatremia rapidly improved after administration of sodium chloride. The purpose of this report is to alert clinicians to the fact that hyponatremic patients with central nervous system disease do not necessarily have a syndrome of inappropriate secretion of antidiuretic hormone (SIADH), but may have cerebral salt wasting syndrome. By contrast with SIADH, the treatment requires saline administration.

  1. Applications of Bacterial Magnetic Nanoparticles in Nanobiotechnology.

    Science.gov (United States)

    Chen, Chuanfang; Wang, Pingping; Li, Linlin

    2016-03-01

    The bacterial magnetic nanoparticle (BMP) has been well researched in nanobiotechnology as a new magnetic crystal. The BMPs are extracted from magnetotactic bacteria and under precise biological control. Compared with engineered magnetic nanoparticles synthesized by chemical approaches, BMPs have the properties of large production, monodispersity, high crystallinity, and close-to-bulk magnetization, which enable BMPs to be the highly promising magnetic nanoparticles for nanobiotechnology. In this paper, we review the biomedical applications of BMPs in magnetic hyperthermia, drug treatment with tumour and bioseparation. In addition, the biodistribution and toxicity are also reviewed.

  2. The role of metabolism in bacterial persistence

    Directory of Open Access Journals (Sweden)

    Stephanie M. Amato

    2014-03-01

    Full Text Available Bacterial persisters are phenotypic variants with extraordinary tolerances toward antibiotics. Persister survival has been attributed to inhibition of essential cell functions during antibiotic stress, followed by reversal of the process and resumption of growth upon removal of the antibiotic. Metabolism plays a critical role in this process, since it participates in the entry, maintenance, and exit from the persister phenotype. Here, we review the experimental evidence that demonstrates the importance of metabolism to persistence, highlight the successes and potential for targeting metabolism in the search for anti-persister therapies, and discuss the current methods and challenges to understand persister physiology.

  3. Bacterial Association with Particles: Aggregation to Dissolution

    Digital Repository Service at National Institute of Oceanography (India)

    DeSouza, M.J.B.D.

    that are orders of magnitude higher than in the ambient water (Caron, 1987; Caron et al., 1986; Turley and Mackie, 1994). They are the ?microchip? of the vast oceans realms, be it in the deep ocean vents or the pelagic ecosystems; bacteria attached to particles... to the deep sea floor. Contribution by PAB to total bacterial production in the deep waters is about 48% (Turley and Stutt, 2000). Macroscopic organic aggregates in the ocean as well as in lakes are decomposed by microorganisms. Traditionally marine...

  4. Experimental assessment of bacterial storage yield

    DEFF Research Database (Denmark)

    Karahan-Gül, Ö.; Artan, N.; Orhon, D.;

    2002-01-01

    An experimental procedure was developed for the respirometric determination of bacterial storage yield as defined in the Activated Sludge Model No. 3. The proposed approach is based on the oxygen utilization rate (OUR) profile obtained from a batch test and correlates the area under the OUR curve...... to the amount of oxygen associated with substrate storage. Model simulation was used to evaluate the procedure for different initial experimental conditions. The procedure was tested on acetate. The same storage yield value of 0.76 gCOD/gCOD was calculated for two experiments, starting with different F/M ratios...

  5. Recombinant protein production in bacterial hosts.

    Science.gov (United States)

    Overton, Tim W

    2014-05-01

    The production of recombinant proteins is crucial for both the development of new protein drugs and the structural determination of drug targets. As such, recombinant protein production has a major role in drug development. Bacterial hosts are commonly used for the production of recombinant proteins, accounting for approximately 30% of current biopharmaceuticals on the market. In this review, I introduce fundamental concepts in recombinant protein production in bacteria, from drug development to production scales. Recombinant protein production processes can often fail, but how can this failure be minimised to rapidly deliver maximum yields of high-quality protein and so accelerate drug discovery?

  6. Bacterial Ventures into Multicellularity: Collectivism through Individuality.

    Science.gov (United States)

    van Vliet, Simon; Ackermann, Martin

    2015-06-01

    Multicellular eukaryotes can perform functions that exceed the possibilities of an individual cell. These functions emerge through interactions between differentiated cells that are precisely arranged in space. Bacteria also form multicellular collectives that consist of differentiated but genetically identical cells. How does the functionality of these collectives depend on the spatial arrangement of the differentiated bacteria? In a previous issue of PLOS Biology, van Gestel and colleagues reported an elegant example of how the spatial arrangement of differentiated cells gives rise to collective behavior in Bacillus subtilus colonies, further demonstrating the similarity of bacterial collectives to higher multicellular organisms.

  7. Bacterial Ventures into Multicellularity: Collectivism through Individuality.

    Directory of Open Access Journals (Sweden)

    Simon van Vliet

    2015-06-01

    Full Text Available Multicellular eukaryotes can perform functions that exceed the possibilities of an individual cell. These functions emerge through interactions between differentiated cells that are precisely arranged in space. Bacteria also form multicellular collectives that consist of differentiated but genetically identical cells. How does the functionality of these collectives depend on the spatial arrangement of the differentiated bacteria? In a previous issue of PLOS Biology, van Gestel and colleagues reported an elegant example of how the spatial arrangement of differentiated cells gives rise to collective behavior in Bacillus subtilus colonies, further demonstrating the similarity of bacterial collectives to higher multicellular organisms.

  8. Novel receptors for bacterial protein toxins.

    Science.gov (United States)

    Schmidt, Gudula; Papatheodorou, Panagiotis; Aktories, Klaus

    2015-02-01

    While bacterial effectors are often directly introduced into eukaryotic target cells by various types of injection machines, toxins enter the cytosol of host cells from endosomal compartments or after retrograde transport via Golgi from the ER. A first crucial step of toxin-host interaction is receptor binding. Using optimized protocols and new methods novel toxin receptors have been identified, including metalloprotease ADAM 10 for Staphylococcus aureus α-toxin, laminin receptor Lu/BCAM for Escherichia coli cytotoxic necrotizing factor CNF1, lipolysis stimulated lipoprotein receptor (LSR) for Clostridium difficile transferase CDT and low-density lipoprotein receptor-related protein (LRP) 1 for Clostridium perfringens TpeL toxin.

  9. The clinical impact of bacterial biofilms

    DEFF Research Database (Denmark)

    Høiby, Niels; Ciofu, Oana; Johansen, Helle Krogh

    2011-01-01

    . Bacterial biofilms are resistant to antibiotics, disinfectant chemicals and to phagocytosis and other components of the innate and adaptive inflammatory defense system of the body. It is known, for example, that persistence of staphylococcal infections related to foreign bodies is due to biofilm formation...... and increased doubling times. These more or less dormant cells are therefore responsible for some of the tolerance to antibiotics. Biofilm growth is associated with an increased level of mutations. Bacteria in biofilms communicate by means of molecules, which activates certain genes responsible for production...

  10. Biodegradation of crude oil by individual bacterial strains and a mixed bacterial consortium

    Directory of Open Access Journals (Sweden)

    Santina Santisi

    2015-06-01

    Full Text Available Three bacterial isolates identified as Alcanivorax borkumensis SK2, Rhodococcus erythropolis HS4 and Pseudomonas stutzeri SDM, based on 16S rRNA gene sequences, were isolated from crude oil enrichments of natural seawater. Single strains and four bacterial consortia designed by mixing the single bacterial cultures respectively in the following ratios: (Alcanivorax: Pseudomonas, 1:1, (Alcanivorax: Rhodococcus, 1:1, (Pseudomonas: Rhodococcus, 1:1, and (Alcanivorax: Pseudomonas: Rhodococcus, 1:1:1, were analyzed in order to evaluate their oil degrading capability. All experiments were carried out in microcosms systems containing seawater (with and without addition of inorganic nutrients and crude oil (unique carbon source. Measures of total and live bacterial abundance, Card-FISH and quali-, quantitative analysis of hydrocarbons (GC-FID were carried out in order to elucidate the co-operative action of mixed microbial populations in the process of biodegradation of crude oil. All data obtained confirmed the fundamental role of bacteria belonging to Alcanivorax genus in the degradation of linear hydrocarbons in oil polluted environments.

  11. Bacterial spores in food : how phenotypic variability complicates prediction of spore properties and bacterial behavior

    NARCIS (Netherlands)

    Eijlander, Robyn T.; Abee, Tjakko; Kuipers, Oscar P.

    2011-01-01

    Bacillus spores are a known cause of food spoilage and their increased resistance poses a major challenge in efficient elimination. Recent studies on bacterial cultures at the single cell level have revealed how minor differences in essential spore properties, such as core water content or germinant

  12. Bacterial spores in food: how phenotypic variability complicates prediction of spore properties and bacterial behavior

    NARCIS (Netherlands)

    Eijlander, R.T.; Abee, T.; Kuipers, O.P.

    2011-01-01

    Bacillus spores are a known cause of food spoilage and their increased resistance poses a major challenge in efficient elimination. Recent studies on bacterial cultures at the single cell level have revealed how minor differences in essential spore properties, such as core water content or germinant

  13. High prevalence of biofilm synergy among bacterial soil isolates in cocultures indicates bacterial interspecific cooperation

    DEFF Research Database (Denmark)

    Ren, Dawei; Madsen, Jonas Stenløkke; Sørensen, Søren Johannes;

    2015-01-01

    of single-species biofilms, indicating that all the individual strains benefit from inclusion in the multispecies community. Our results show a high prevalence of synergy in biofilm formation in multispecies consortia isolated from a natural bacterial habitat and suggest that interspecific cooperation...

  14. Bacterial communities of two ubiquitous Great Barrier Reef corals reveals both site- and species-specificity of common bacterial associates.

    Directory of Open Access Journals (Sweden)

    E Charlotte E Kvennefors

    Full Text Available BACKGROUND: Coral-associated bacteria are increasingly considered to be important in coral health, and altered bacterial community structures have been linked to both coral disease and bleaching. Despite this, assessments of bacterial communities on corals rarely apply sufficient replication to adequately describe the natural variability. Replicated data such as these are crucial in determining potential roles of bacteria on coral. METHODOLOGY/PRINCIPAL FINDINGS: Denaturing Gradient Gel Electrophoresis (DGGE of the V3 region of the 16S ribosomal DNA was used in a highly replicated approach to analyse bacterial communities on both healthy and diseased corals. Although site-specific variations in the bacterial communities of healthy corals were present, host species-specific bacterial associates within a distinct cluster of gamma-proteobacteria could be identified, which are potentially linked to coral health. Corals affected by "White Syndrome" (WS underwent pronounced changes in their bacterial communities in comparison to healthy colonies. However, the community structure and bacterial ribotypes identified in diseased corals did not support the previously suggested theory of a bacterial pathogen as the causative agent of the syndrome. CONCLUSIONS/SIGNIFICANCE: This is the first study to employ large numbers of replicated samples to assess the bacterial communities of healthy and diseased corals, and the first culture-independent assessment of bacterial communities on WS affected Acroporid corals on the GBR. Results indicate that a minimum of 6 replicate samples are required in order to draw inferences on species, spatial or health-related changes in community composition, as a set of clearly distinct bacterial community profiles exist in healthy corals. Coral bacterial communities may be both site and species specific. Furthermore, a cluster of gamma-proteobacterial ribotypes may represent a group of specific common coral and marine

  15. Vulvovaginal Health

    Science.gov (United States)

    ... vagina or by taking a pill. What causes bacterial vaginosis? Bacterial vaginosis is caused by an overgrowth of the bacteria ... certain types of infections. Bacteria: One-celled organisms. Bacterial Vaginosis: A type of vaginal infection caused by the ...

  16. Metallization of bacterial cellulose for electrical and electronic device manufacture

    Science.gov (United States)

    Evans, Barbara R.; O'Neill, Hugh M.; Jansen, Valerie Malyvanh; Woodward, Jonathan

    2011-06-07

    A method for the deposition of metals in bacterial cellulose and for the employment of the metallized bacterial cellulose in the construction of fuel cells and other electronic devices is disclosed. The method for impregnating bacterial cellulose with a metal comprises placing a bacterial cellulose matrix in a solution of a metal salt such that the metal salt is reduced to metallic form and the metal precipitates in or on the matrix. The method for the construction of a fuel cell comprises placing a hydrated bacterial cellulose support structure in a solution of a metal salt such that the metal precipitates in or on the support structure, inserting contact wires into two pieces of the metal impregnated support structure, placing the two pieces of metal impregnated support structure on opposite sides of a layer of hydrated bacterial cellulose, and dehydrating the three layer structure to create a fuel cell.

  17. Value of a newly sequenced bacterial genome

    Institute of Scientific and Technical Information of China (English)

    Eudes; GV; Barbosa; Flavia; F; Aburjaile; Rommel; TJ; Ramos; Adriana; R; Carneiro; Yves; Le; Loir; Jan; Baumbach; Anderson; Miyoshi; Artur; Silva; Vasco; Azevedo

    2014-01-01

    Next-generation sequencing(NGS) technologies have made high-throughput sequencing available to medium- and small-size laboratories, culminating in a tidal wave of genomic information. The quantity of sequenced bacterial genomes has not only brought excitement to the field of genomics but also heightened expectations that NGS would boost antibacterial discovery and vaccine development. Although many possible drug and vaccine targets have been discovered, the success rate of genome-based analysis has remained below expectations. Furthermore, NGS has had consequences for genome quality, resulting in an exponential increase in draft(partial data) genome deposits in public databases. If no further interests are expressed for a particular bacterial genome, it is more likely that the sequencing of its genome will be limited to a draft stage, and the painstaking tasks of completing the sequencing of its genome and annotation will not be undertaken. It is important to know what is lost when we settle for a draft genome and to determine the "scientific value" of a newly sequenced genome. This review addresses the expected impact of newly sequenced genomes on antibacterial discovery and vaccinology. Also, it discusses the factors that could be leading to the increase in the number of draft deposits and the consequent loss of relevant biological information.

  18. High temperature bacterial leaching: HIOX project

    Energy Technology Data Exchange (ETDEWEB)

    Morin, D.; D' Hugues, P.; Bonney, C. F.; Norris, P.; Shwab, W.; Sundkvist, J-E.; Bridges, P. [Bureau de Recherhes Geologiques et Minieres, Orleans (France)

    2001-07-01

    The HIOX project was designed to investigate the use of thermophilic bacterial cultures for the leaching of chalcopyrite (CuFeS{sub 2}, the natural source of copper). Beyond bacterial leaching, the study also encompassed the downstream processing steps in an effort to develop a new method for the recovery of copper in an economical and environmentally-friendly process. Using the HIOX process copper recovery was increased to better than 90 per cent within 5 days with a 12 per cent solids culture, although some potentially limiting factors such as foam generation, nutrient concentrations and mixing/aeration efficiency were also identified. The study resulted in the establishment of a mass balance based on a simplified flowsheet of the process. Techno-economic evaluation carried out at three sites indicated technical feasibility using relatively conventional equipment and capital and operating costs in ranges that suggest that bioleaching with high temperature bacteria is an attractive alternative for the treatment of chalcopyrite concentrate. 5 tabs.

  19. Clostridium difficile is an autotrophic bacterial pathogen.

    Directory of Open Access Journals (Sweden)

    Michael Köpke

    Full Text Available During the last decade, Clostridium difficile infection showed a dramatic increase in incidence and virulence in the Northern hemisphere. This incessantly challenging disease is the leading cause of antibiotic-associated and nosocomial infectious diarrhea and became life-threatening especially among elderly people. It is generally assumed that all human bacterial pathogens are heterotrophic organisms, being either saccharolytic or proteolytic. So far, this has not been questioned as colonization of the human gut gives access to an environment, rich in organic nutrients. Here, we present data that C. difficile (both clinical and rumen isolates is also able to grow on CO2+H2 as sole carbon and energy source, thus representing the first identified autotrophic bacterial pathogen. Comparison of several different strains revealed high conservation of genes for autotrophic growth and showed that the ability to use gas mixtures for growth decreases or is lost upon prolonged culturing under heterotrophic conditions. The metabolic flexibility of C. difficile (heterotrophic growth on various substrates as well as autotrophy could allow the organism in the gut to avoid competition by niche differentiation and contribute to its survival when stressed or in unfavorable conditions that cause death to other bacteria. This may be an important trait for the pathogenicity of C. difficile.

  20. Steps in the bacterial flagellar motor.

    Directory of Open Access Journals (Sweden)

    Thierry Mora

    2009-10-01

    Full Text Available The bacterial flagellar motor is a highly efficient rotary machine used by many bacteria to propel themselves. It has recently been shown that at low speeds its rotation proceeds in steps. Here we propose a simple physical model, based on the storage of energy in protein springs, that accounts for this stepping behavior as a random walk in a tilted corrugated potential that combines torque and contact forces. We argue that the absolute angular position of the rotor is crucial for understanding step properties and show this hypothesis to be consistent with the available data, in particular the observation that backward steps are smaller on average than forward steps. We also predict a sublinear speed versus torque relationship for fixed load at low torque, and a peak in rotor diffusion as a function of torque. Our model provides a comprehensive framework for understanding and analyzing stepping behavior in the bacterial flagellar motor and proposes novel, testable predictions. More broadly, the storage of energy in protein springs by the flagellar motor may provide useful general insights into the design of highly efficient molecular machines.