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Sample records for viable bacteria including

  1. Removal of viable bacteria and endotoxins by Electro Deionization (EDI).

    Science.gov (United States)

    Harada, Norimitsu; Otomo, Teruo; Watabe, Tomoichi; Ase, Tomonobu; Takemura, Takuto; Sato, Toshio

    2011-09-01

    Viable bacteria and endotoxins in water sometimes cause problems for human health. Endotoxins are major components of the outer cell wall of gram-negative bacteria (lipopolysaccharides). In medical procedures, especially haemodialysis (HD) and related therapies (haemodiafiltration (HDF), haemofiltration (HF)), endotoxins in the water for haemodialysis can permeate through the haemodialysis membrane and cause microinflammation or various haemodialysis-related illnesses. To decrease such a biological risk, RO and UF membranes are generally used. Also, hot water disinfection or the chemical disinfection is regularly executed to kill bacteria which produce endotoxins. However, simple treatment methods and equipment may be able to decrease the biological risk more efficiently. In our experiments, we confirmed that viable bacteria and endotoxins were removed by Electro Deionization (EDI) technology and also clarified the desorption mechanisms.

  2. Profiling Total Viable Bacteria in a Hemodialysis Water Treatment System.

    Science.gov (United States)

    Chen, Lihua; Zhu, Xuan; Zhang, Menglu; Wang, Yuxin; Lv, Tianyu; Zhang, Shenghua; Yu, Xin

    2017-05-28

    Culture-dependent methods, such as heterotrophic plate counting (HPC), are usually applied to evaluate the bacteriological quality of hemodialysis water. However, these methods cannot detect the uncultured or viable but non-culturable (VBNC) bacteria, both of which may be quantitatively predominant throughout the hemodialysis water treatment system. Therefore, propidium monoazide (PMA)-qPCR associated with HPC was used together to profile the distribution of the total viable bacteria in such a system. Moreover, high-throughput sequencing of 16S rRNA gene amplicons was utilized to analyze the microbial community structure and diversity. The HPC results indicated that the total bacterial counts conformed to the standards, yet the bacteria amounts were abruptly enhanced after carbon filter treatment. Nevertheless, the bacterial counts detected by PMA-qPCR, with the highest levels of 2.14 × 10 7 copies/100 ml in softener water, were much higher than the corresponding HPC results, which demonstrated the occurrence of numerous uncultured or VBNC bacteria among the entire system before reverse osmosis (RO). In addition, the microbial community structure was very different and the diversity was enhanced after the carbon filter. Although the diversity was minimized after RO treatment, pathogens such as Escherichia could still be detected in the RO effluent. In general, both the amounts of bacteria and the complexity of microbial community in the hemodialysis water treatment system revealed by molecular approaches were much higher than by traditional method. These results suggested the higher health risk potential for hemodialysis patients from the up-to-standard water. The treatment process could also be optimized, based on the results of this study.

  3. 9 CFR 113.27 - Detection of extraneous viable bacteria and fungi in live vaccines.

    Science.gov (United States)

    2010-01-01

    ... bacteria and fungi in live vaccines. 113.27 Section 113.27 Animals and Animal Products ANIMAL AND PLANT... bacteria and fungi in live vaccines. Unless otherwise specified by the Administrator or elsewhere exempted... Seed Bacteria shall be tested for extraneous viable bacteria and fungi as prescribed in this section. A...

  4. Grazing of particle-associated bacteria-an elimination of the non-viable fraction.

    Science.gov (United States)

    Gonsalves, Maria-Judith; Fernandes, Sheryl Oliveira; Priya, Madasamy Lakshmi; LokaBharathi, Ponnapakkam Adikesavan

    Quantification of bacteria being grazed by microzooplankton is gaining importance since they serve as energy subsidies for higher trophic levels which consequently influence fish production. Hence, grazing pressure on viable and non-viable fraction of free and particle-associated bacteria in a tropical estuary controlled mainly by protist grazers was estimated using the seawater dilution technique. In vitro incubations over a period of 42h showed that at the end of 24h, growth coefficient (k) of particle-associated bacteria was 9 times higher at 0.546 than that of free forms. Further, 'k' value of viable cells on particles was double that of free forms at 0.016 and 0.007, respectively. While bacteria associated with particles were grazed (coefficient of removal (g)=0.564), the free forms were relatively less grazed indicating that particle-associated bacteria were exposed to grazers in these waters. Among the viable and non-viable forms, 'g' of non-viable fraction (particle-associated bacteria=0.615, Free=0.0086) was much greater than the viable fraction (particle-associated bacteria=0.056, Free=0.068). Thus, grazing on viable cells was relatively low in both the free and attached states. These observations suggest that non-viable forms of particle-associated bacteria were more prone to grazing and were weeded out leaving the viable cells to replenish the bacterial standing stock. Particle colonization could thus be a temporary refuge for the "persistent variants" where the viable fraction multiply and release their progeny. Copyright © 2016 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

  5. Experimental design for the optimization of propidium monoazide treatment to quantify viable and non-viable bacteria in piggery effluents.

    Science.gov (United States)

    Desneux, Jérémy; Chemaly, Marianne; Pourcher, Anne-Marie

    2015-08-16

    Distinguishing between viable and dead bacteria in animal and urban effluents is a major challenge. Among existing methods, propidium monoazide (PMA)-qPCR is a promising way to quantify viable cells. However, its efficiency depends on the composition of the effluent, particularly on total suspended solids (TSS)) and on methodological parameters. The aim of this study was evaluate the influence of three methodological factors (concentration of PMA, incubation time and photoactivation time) on the efficiency of PMA-qPCR to quantify viable and dead cells of Listeria monocytogenes used as a microorganism model, in two piggery effluents (manure and lagoon effluent containing 20 and 0.4 TSS g.kg(-1), respectively). An experimental design strategy (Doehlert design and desirability function) was used to identify the experimental conditions to achieve optimal PMA-qPCR results. The quantification of viable cells of L. monocytogenes was mainly influenced by the concentration of PMA in the manure and by the duration of photoactivation in the lagoon effluent. Optimal values differed with the matrix: 55 μM PMA, 5 min incubation and 56 min photoactivation for manure and 20 μM PMA, 20 min incubation and 30 min photoactivation for lagoon effluent. Applied to five manure and four lagoon samples, these conditions resulted in satisfactory quantification of viable and dead cells. PMA-qPCR can be used on undiluted turbid effluent with high levels of TSS, provided preliminary tests are performed to identify the optimal conditions.

  6. Viable Legionella pneumophila bacteria in natural soil and rainwater puddles

    NARCIS (Netherlands)

    van Heijnsbergen, E.; de Roda Husman, A. M.; Lodder, W. J.; Bouwknegt, M.; Docters van Leeuwen, A. E.; Bruin, J. P.; Euser, S. M.; den Boer, J. W.; Schalk, J. A C

    Aims: For the majority of sporadic Legionnaires' disease cases the source of infection remains unknown. Infection may possible result from exposure to Legionella bacteria in sources that are not yet considered in outbreak investigations. Therefore, potential sources of pathogenic Legionella

  7. Marine environmental pollution stress detection through direct viable counts of bacteria

    Digital Repository Service at National Institute of Oceanography (India)

    Ramaiah, N.; Kenkre, V.D.; Verlecar, X.N.

    Direct viable counts (DVC) of bacteria were quantified from polluted and relatively less/non-polluted coastal locations during different seasons to assess whether they can be routinely monitored for an understanding of environmental stress(es...

  8. Real-time quantification of viable bacteria in liquid medium using infrared thermography

    Science.gov (United States)

    Salaimeh, Ahmad A.; Campion, Jeffrey J.; Gharaibeh, Belal Y.; Evans, Martin E.; Saito, Kozo

    2011-11-01

    Quantifying viable bacteria in liquids is important in environmental, food processing, manufacturing, and medical applications. Since vegetative bacteria generate heat as a result of biochemical reactions associated with cellular functions, thermal sensing techniques, including infrared thermography (IRT), have been used to detect viable cells in biologic samples. We developed a novel method that extends the dynamic range and improves the sensitivity of bacterial quantification by IRT. The approach uses IRT video, thermodynamics laws, and heat transfer mechanisms to directly measure, in real-time, the amount of energy lost as heat from the surface of a liquid sample containing bacteria when the specimen cools to a lower temperature over 2 min. We show that the Energy Content ( EC) of liquid media containing as few as 120 colony-forming units (CFU) of Escherichia coli per ml was significantly higher than that of sterile media ( P method that provides real-time bacterial enumeration over a wide dynamic range without the need for sample concentration, modification, or destruction. The approach could be adapted to quantify other living cells in a liquid milieu and has the potential for automation and high throughput.

  9. Oligonucleotide microarrays for the detection and identification of viable beer spoilage bacteria.

    Science.gov (United States)

    Weber, D G; Sahm, K; Polen, T; Wendisch, V F; Antranikian, G

    2008-10-01

    The design and evaluation of an oligonucleotide microarray in order to detect and identify viable bacterial species that play a significant role in beer spoilage. These belong to the species of the genera Lactobacillus, Megasphaera, Pediococcus and Pectinatus. Oligonucleotide probes specific to beer spoilage bacteria were designed. In order to detect viable bacteria, the probes were designed to target the intergenic spacer regions (ISR) between 16S and 23S rRNA. Prior to hybridization the ISR were amplified by combining reverse transcriptase and polymerase chain reactions using a designed consenus primer. The developed oligonucleotide microarrays allows the detection of viable beer spoilage bacteria. This method allows the detection and discrimination of single bacterial species in a sample containing complex microbial community. Furthermore, microarrays using oligonucleotide probes targeting the ISR allow the distinction between viable bacteria with the potential to grow and non growing bacteria. The results demonstrate the feasibility of oligonucleotide microarrays as a contamination control in food industry for the detection and identification of spoilage micro-organisms within a mixed population.

  10. 9 CFR 113.26 - Detection of viable bacteria and fungi except in live vaccine.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Detection of viable bacteria and fungi except in live vaccine. 113.26 Section 113.26 Animals and Animal Products ANIMAL AND PLANT HEALTH... in live vaccine. Each serial and subserial of biological product except live vaccines shall be tested...

  11. An advanced PCR method for the specific detection of viable total coliform bacteria in pasteurized milk.

    Science.gov (United States)

    Soejima, Takashi; Minami, Jun-ichi; Yaeshima, Tomoko; Iwatsuki, Keiji

    2012-07-01

    Pasteurized milk is a complex food that contains various inhibitors of polymerase chain reaction (PCR) and may contain a large number of dead bacteria, depending on the milking conditions and environment. Ethidium monoazide bromide (EMA)-PCR is occasionally used to distinguish between viable and dead bacteria in foods other than pasteurized milk. EMA is a DNA-intercalating dye that selectively permeates the compromised cell membranes of dead bacteria and cleaves DNA. Usually, EMA-PCR techniques reduce the detection of dead bacteria by up to 3.5 logs compared with techniques that do not use EMA. However, this difference may still be insufficient to suppress the amplification of DNA from dead Gram-negative bacteria (e.g., total coliform bacteria) if they are present in pasteurized milk in large numbers. Thus, false positives may result. We developed a new method that uses real-time PCR targeting of a long DNA template (16S-23S rRNA gene, principally 2,451 bp) following EMA treatment to completely suppress the amplification of DNA of up to 7 logs (10(7) cells) of dead total coliforms. Furthermore, we found that a low dose of proteinase K (25 U/ml) removed PCR inhibitors and simultaneously increased the signal from viable coliform bacteria. In conclusion, our simple protocol specifically detects viable total coliforms in pasteurized milk at an initial count of ≥1 colony forming unit (CFU)/2.22 ml within 7.5 h of total testing time. This detection limit for viable cells complies with the requirements for the analysis of total coliforms in pasteurized milk set by the Japanese Sanitation Act (which specifies <1 CFU/2.22 ml).

  12. Viable bacteria associated with red blood cells and plasma in freshly drawn blood donations.

    Directory of Open Access Journals (Sweden)

    Christian Damgaard

    Full Text Available Infection remains a leading cause of post-transfusion mortality and morbidity. Bacterial contamination is, however, detected in less than 0.1% of blood units tested. The aim of the study was to identify viable bacteria in standard blood-pack units, with particular focus on bacteria from the oral cavity, and to determine the distribution of bacteria revealed in plasma and in the red blood cell (RBC-fraction.Cross-sectional study. Blood were separated into plasma and RBC-suspensions, which were incubated anaerobically or aerobically for 7 days on trypticase soy blood agar (TSA or blue lactose plates. For identification colony PCR was performed using primers targeting 16S rDNA.Blood donors attending Capital Region Blood Bank, Copenhagen University Hospital, Rigshospitalet, Hvidovre, Denmark, October 29th to December 10th 2013.60 donors (≥50 years old, self-reported medically healthy.Bacterial growth was observed on plates inoculated with plasma or RBCs from 62% of the blood donations. Growth was evident in 21 (35% of 60 RBC-fractions and in 32 (53% of 60 plasma-fractions versus 8 of 60 negative controls (p = 0.005 and p = 2.6x10-6, respectively. Propionibacterium acnes was found in 23% of the donations, and Staphylococcus epidermidis in 38%. The majority of bacteria identified in the present study were either facultative anaerobic (59.5% or anaerobic (27.8% species, which are not likely to be detected during current routine screening.Viable bacteria are present in blood from donors self-reported as medically healthy, indicating that conventional test systems employed by blood banks insufficiently detect bacteria in plasma. Further investigation is needed to determine whether routine testing for anaerobic bacteria and testing of RBC-fractions for adherent bacteria should be recommended.

  13. A direct viable count method for the enumeration of attached bacteria and assessment of biofilm disinfection

    Science.gov (United States)

    Yu, F. P.; Pyle, B. H.; McFeters, G. A.

    1993-01-01

    This report describes the adaptation of an in situ direct viable count (in situ DVC) method in biofilm disinfection studies. The results obtained with this technique were compared to two other enumeration methods, the plate count (PC) and conventional direct viable count (c-DVC). An environmental isolate (Klebsiella pneumoniae Kp1) was used to form biofilms on stainless steel coupons in a stirred batch reactor. The in situ DVC method was applied to directly assess the viability of bacteria in biofilms without disturbing the integrity of the interfacial community. As additional advantages, the results were observed after 4 h instead of the 24 h incubation time required for colony formation and total cell numbers that remained on the substratum were enumerated. Chlorine and monochloramine were used to determine the susceptibilities of attached and planktonic bacteria to disinfection treatment using this novel analytical approach. The planktonic cells in the reactor showed no significant change in susceptibility to disinfectants during the period of biofilm formation. In addition, the attached cells did not reveal any more resistance to disinfection than planktonic cells. The disinfection studies of young biofilms indicated that 0.25 mg/l free chlorine (at pH 7.2) and 1 mg/l monochloramine (at pH 9.0) have comparable disinfection efficiencies at 25 degrees C. Although being a weaker disinfectant, monochloramine was more effective in removing attached bacteria from the substratum than free chlorine. The in situ DVC method always showed at least one log higher viable cell densities than the PC method, suggesting that the in situ DVC method is more efficient in the enumeration of biofilm bacteria. The results also indicated that the in situ DVC method can provide more accurate information regarding the cell numbers and viability of bacteria within biofilms following disinfection.

  14. Isolation of Viable but Non-culturable Bacteria from Printing and Dyeing Wastewater Bioreactor Based on Resuscitation Promoting Factor.

    Science.gov (United States)

    Jin, Yi; Gan, Guojuan; Yu, Xiaoyun; Wu, Dongdong; Zhang, Li; Yang, Na; Hu, Jiadan; Liu, Zhiheng; Zhang, Lixin; Hong, Huachang; Yan, Xiaoqing; Liang, Yan; Ding, Linxian; Pan, Yonglong

    2017-07-01

    Printing and dyeing wastewater with high content of organic matters, high colority, and poor biochemical performance is hard to be degraded. In this study, we isolated viable but non-culturable (VBNC) bacteria from printing and dyeing wastewater with the culture media contained resuscitation promoting factor (Rpf) protein secreted by Micrococcus luteus, counted the culturable cells number with the most probable number, sequenced 16S rRNA genes, and performed polymerase chain reaction-denaturing gradient gel electrophoresis. It is obviously that the addition of Rpf in the enrichment culture could promote growth and resuscitation of bacteria in VBNC state to obtain more fastidious bacteria significantly. The identified bacteria were assigned to nine genera in the treatment group, while the two strains of Ochrobactrum anthropi and Microbacterium sp. could not be isolated from the control group. The function of isolated strains was explored and these strains could degrade the dye of Congo red. This study provides a new sight into the further study including the present state, composition, formation mechanism, and recovery mechanism about VBNC bacteria in printing and dyeing wastewater, which would promote to understand bacterial community in printing and dyeing wastewater, and to obtain VBNC bacteria from ecological environment.

  15. Biofilms in Full-Scale Drinking Water Ozone Contactors Contribute Viable Bacteria to Ozonated Water.

    Science.gov (United States)

    Kotlarz, Nadine; Rockey, Nicole; Olson, Terese M; Haig, Sarah-Jane; Sanford, Larry; LiPuma, John J; Raskin, Lutgarde

    2018-02-13

    Concentrations of viable microbial cells were monitored using culture-based and culture-independent methods across multichamber ozone contactors in a full-scale drinking water treatment plant. Membrane-intact and culturable cell concentrations in ozone contactor effluents ranged from 1200 to 3750 cells/mL and from 200 to 3850 colony forming units/mL, respectively. Viable cell concentrations decreased significantly in the first ozone contact chamber, but rose, even as ozone exposure increased, in subsequent chambers. Our results implicate microbial detachment from biofilms on contactor surfaces, and from biomass present within lime softening sediments in a hydraulic dead zone, as a possible reason for increasing cell concentrations in water samples from sequential ozone chambers. Biofilm community structures on baffle walls upstream and downstream from the dead zone were significantly different from each other (p = 0.017). The biofilms downstream of the dead zone contained a significantly (p = 0.036) higher relative abundance of bacteria of the genera Mycobacterium and Legionella than the upstream biofilms. These results have important implications as the effluent from ozone contactors is often treated further in biologically active filters and bacteria in ozonated water continuously seed filter microbial communities.

  16. Factors affecting the numbers of expected viable lactic acid bacteria in inoculant applicator tanks.

    Science.gov (United States)

    Windle, M C; Kung, L

    2016-11-01

    The application of correct numbers of viable microorganisms to forages at the time of ensiling is one of the most important factors affecting the probability of a beneficial effect from an inoculant. The objective of this study was to determine relationships between numbers of expected lactic acid bacteria (LAB) from silage inoculants in application tanks and various factors that might affect their viability. The pH and temperature of inoculant-water mixes were measured in applicator tanks (n=53) on farms in Wisconsin, Minnesota, South Dakota, and California during the corn harvest season of 2012. Samples were collected on-farm and plated on de Man, Rogosa, and Sharpe agar to enumerate LAB and establish the number of viable LAB (cfu/mL). Expected numbers of LAB were calculated from the minimum label guarantees for viable bacteria and mixing rates with water. In addition, the pH of the inoculant-water mixes at sampling, the ambient temperature at sampling, and the length of time that the samples had been in the tank were measured and obtained. The log difference between the measured and expected numbers of LAB was calculated and expressed as ΔM - E in log scale. Ambient temperature at sampling had no relationship with time in the tank or ΔM - E. Most (83%) of the inoculants had been mixed with water in the applicator tanks for <10h. For these samples, a negative linear correlation (R2=0.36) existed between time that the inoculant-water mixes were in the applicators tanks and ΔM - E. The pH of the inoculant-water mixes was also negatively correlated (R2=0.28) with time in the applicator tank, but pH was not related to ΔM - E. The temperatures of the inoculant-water mixtures were negatively correlated with ΔM - E (R2=0.39). Seven of 8 samples whose ΔM - E were at least -0.95 or more lower than expected (equivalent of about 1 or more log concentration less than expected) had water temperatures above 35°C. These data support our previous laboratory findings and

  17. Efficacy evaluation of bifidobacterium tetragenous viable bacteria tablets-assisted blu-ray irradiation in treatment of neonatal jaundice

    Directory of Open Access Journals (Sweden)

    Qun-Ying Ma

    2016-02-01

    Full Text Available Objective: To investigate the efficacy of bifidobacterium tetragenous viable bacteria tabletsassisted blu-ray irradiation in treatment of neonatal jaundice. Methods: A total of 118 cases of children with neonatal jaundice were randomly divided into observation group (n=59 and control group (n=59, control group received blu-ray irradiation treatment alone, observation group received bifidobacterium tetragenous viable bacteria tablets-assisted blu-ray irradiation treatment and then levels of bilirubin-related indicators, nerve damage indexes and liver function indexes of two groups were compared. Results: 3 d after treatment, total serum bilirubin (TSB, direct bilirubin (DB and transcutaneous bilirubin (TCB levels of observation group were lower than those of control group and differences were statistically significant; 3 d after treatment, serum neuron specific enolase (NSE, amyloid β-protein (A β and astrocytederived protein (S100 β levels of observation group were lower than those of control group and differences were statistically significant; 3 d after treatment, alanine aminotransferase (ALT and aspartate aminotransferase (AST levels of observation group were lower than those of control group and differences were statistically significant. Conclusion: Bifidobacterium tetragenous viable bacteria tablets-assisted blu-ray irradiation has better effect in treatment of neonatal jaundice and has advantages in reducing bilirubin level, protecting nerve function and liver function and other aspects.

  18. Persistence and potential Viable but Non-culturable state of pathogenic bacteria during storage of digestates from agricultural biogas plants

    Directory of Open Access Journals (Sweden)

    Geraldine Maynaud

    2016-09-01

    Full Text Available Despite the development of on-farm anaerobic digestion as a process for making profitable use of animal by-products, factors leading to the inactivation of pathogenic bacteria during storage of digestates remain poorly described. Here, a microcosm approach was used to evaluate the persistence of three pathogenic bacteria (Salmonella enterica Derby, Campylobacter coli and Listeria monocytogenes in digestates from farms, stored for later land spreading. Nine samples, including raw digestates, liquid fractions of digestate and composted digestates, were inoculated with each pathogen and maintained for 40 days at 24°C. Concentrations of pathogens were monitored using culture and qPCR methods. The persistence of L. monocytogenes, detected up to 20 days after inoculation, was higher than that of Salmonella Derby, detected for 7-20 days, and of C. coli (not detected after 7 days. In some digestates, the concentration of the pathogens by qPCR assay was several orders of magnitude higher than the concentration of culturable cells, suggesting a potential loss of culturability and induction of Viable but Non-Culturable (VBNC state. The potential VBNC state which was generally not observed in the same digestate for the three pathogens, occurred more frequently for C. coli and L. monocytogenes than for Salmonella Derby. Composting a digestate reduced the persistence of seeded L. monocytogenes but promoted the maintenance of Salmonella Derby. The effect of NH4+/NH3 on the culturability of C. coli and Salmonella Derby was also shown.The loss of culturability may be the underlying mechanism for the regrowth of pathogens. We have also demonstrated the importance of using molecular tools to monitor pathogens in environmental samples since culture methods may underestimate cell concentration. Our results underline the importance of considering VBNC cells when evaluating the sanitary effect of an anaerobic digestion process and the persistence of pathogens during

  19. Visual and sensitive detection of viable pathogenic bacteria by sensing of RNA markers in gold nanoparticles based paper platform.

    Science.gov (United States)

    Liu, Hongxing; Zhan, Fangfang; Liu, Fang; Zhu, Minjun; Zhou, Xiaoming; Xing, Da

    2014-12-15

    Food-borne pathogens have been recognized as a major cause of human infections worldwide. Their identification needs to be simpler, cheaper and more reliable than the traditional methods. Here, we constructed a low-cost paper platform for viable pathogenic bacteria detection with the naked eye. In this study, an effective isothermal amplification method was used to amplify the hlyA mRNA gene, a specific RNA marker in Listeria monocytogenes. The amplification products were applied to the paper-based platform to perform a visual test using sandwich hybridization assays. When the RNA products migrated along the platform by capillary action, the gold nanoparticles accumulated at the designated area. Under optimized experimental conditions, as little as 0.5 pg/μL genomic RNA from L. monocytogenes could be detected. It could also be used to specifically detect 20 CFU/mL L. monocytogenes from actual samples. The whole assay process, including RNA extraction, amplification, and visualization, can be completed within several hours. This method is suitable for point-of-care applications to detect food-borne pathogens, as it can overcome the false-positive results caused by amplifying nonviable L. monocytogenes. Furthermore, the results can be imaged and transformed into a two-dimensional bar code through an Android-based smart phone for further analysis or in-field food safety tracking. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Changes in the relative population size of selected ruminal bacteria following an induced episode of acidosis in beef heifers receiving viable and non-viable active dried yeast.

    Science.gov (United States)

    Mohammed, R; Vyas, D; Yang, W Z; Beauchemin, K A

    2017-06-01

    To characterize the changes in the relative population size (RPS) of select ruminal bacteria and rumen fermentation variables in beef heifers supplemented with a strain of Saccharomyces cerevisiae as viable active dried (ADY) or killed dried (KDY) yeast following an induced episode of ruminal acidosis. Six ruminally cannulated beef heifers fed a diet consisting of 50% forage and 50% grain (dry matter basis) were used in a replicated 3 × 3 Latin square design with three 28-day periods. Treatments were: (i) control (CTRL; no yeast); (ii) ADY (4 g day-1 providing 1010  CFU per g; AB Vista, UK); and (iii) KDY (4 g day-1 autoclaved ADY). The acidosis challenge was induced on day 22 and rumen samples were collected on day 15 (baseline; BASE), day 22 (challenge day; CHAL), and on day 29 (168th hour post acid challenge or recovery, REC) of each period. Over the study, duration of pH acidosis) was less for ADY and KDY than CTRL, with ADY less than KDY. No treatment effects were observed on relative abundance of ruminal bacteria, but the day effect was significant. The RPS of lactate producers and utilizers was greater while RPS of fibrolytic bacteria was lower during CHAL than BASE and REC. Yeast supplementation, irrespective of its viability, showed beneficial effects on ruminal pH variables in animals more susceptible to acidosis. Rumen microbial population was altered with the induction of severe acidosis. Most of the changes reverted back to baseline values during the recovery phase. Yeast supplementation reduced subacute rumen acidosis in the most susceptible cattle, but failed to attenuate severe acidosis induced by a grain challenge. The study provided valuable insight into the mechanism by which acidosis affects cattle performance. Individual animal variation in ruminal fermentation partly explained the variability in response to yeast supplementation in the study. © 2017 Her Majesty the Queen in Right of Canada. Journal of Applied Microbiology © 2017 The

  1. Different impact of heat-inactivated and viable lactic acid bacteria of aquatic origin on turbot (Scophthalmus maximus L.) head-kidney leucocytes.

    Science.gov (United States)

    Muñoz-Atienza, Estefanía; Araújo, Carlos; Lluch, Nuria; Hernández, Pablo E; Herranz, Carmen; Cintas, Luis M; Magadán, Susana

    2015-05-01

    In aquaculture, several criteria should be considered to select an appropriate probiotic, including the aquatic origin and safety of the strain and its ability to modulate the host immune response. The properties and effects of probiotics are strain-specific and some factors such as viability, dose and duration of diet supplementation may regulate their immunomodulatory activities. In this study, we assessed the in vitro effect of eight heat-inactivated and viable lactic acid bacteria (LAB) of aquatic origin belonging to the genera Enterococcus, Lactobacillus, Lactococcus, Leuconostoc, Pediococcus and Weissella on the viability and innate immune response of turbot (Scophthalmus maximus L.) leucocytes. Head-kidney leucocytes were incubated with viable and heat-inactivated LAB at different concentrations. After incubation, the viability of leucocytes was evaluated using colorimetric assays (MTT and LDH) and flow cytometry (annexin V/propidium iodide). Heat-inactivated LAB showed no cytotoxic effect while viable LAB exerted variable influence on apoptosis of turbot phagocytes and lymphocytes. Leucocyte respiratory burst activity and phagocytosis were also differentially activated, as viable LAB stimulated leucocytes more efficiently than the heat-inactivated LAB. Our results suggest diverse strain-specific mechanisms of interaction between the evaluated LAB and turbot leucocytes. Furthermore, our work sets up in vitro systems to evaluate the effect of LAB as potential probiotics, which will be useful to develop efficient screening. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Viable Bacteria Associated with Red Blood Cells and Plasma in Freshly Drawn Blood Donations

    DEFF Research Database (Denmark)

    Damgaard, Christian; Magnussen, Karin; Enevold, Christian

    2015-01-01

    the oral cavity, and to determine the distribution of bacteria revealed in plasma and in the red blood cell (RBC)-fraction. DESIGN: Cross-sectional study. Blood were separated into plasma and RBC-suspensions, which were incubated anaerobically or aerobically for 7 days on trypticase soy blood agar (TSA......), self-reported medically healthy. RESULTS: Bacterial growth was observed on plates inoculated with plasma or RBCs from 62% of the blood donations. Growth was evident in 21 (35%) of 60 RBC-fractions and in 32 (53%) of 60 plasma-fractions versus 8 of 60 negative controls (p = 0.005 and p = 2.6x10...... of RBC-fractions for adherent bacteria should be recommended....

  3. Reduction of viable bacteria in dentinal tubules treated with a novel medicament (Z-Mix)

    OpenAIRE

    Parinda Tasanarong; Thaweephol Dechatiwongse Na Ayudhya; Tipawan Techanitiswad; Sittichai Koontongkaew

    2016-01-01

    Background/purpose: The 3Mix-MP formulation (a mixture of metronidazole, ciprofloxacin, and minocycline; macrogol and propylene glycol) has been used to kill residual bacteria in dentin caries. This study aimed to investigate the dentin disinfection and cytotoxicity of a novel zinc oxide (ZnO) based medicament, Z-Mix. Materials and methods: Z-Mix was prepared as a prefilled syringe of materials containing mainly ZnO, incorporated with amoxicillin, ciprofloxacin, and metronidazole (1 g% of ...

  4. Probiotic bacteria: a viable adjuvant therapy for relieving symptoms of rheumatoid arthritis.

    Science.gov (United States)

    Wang, Peng; Tao, Jin-Hui; Pan, Hai-Feng

    2016-10-01

    The burgeoning use of probiotics has proliferated during the past two decades. However, the effect of probiotic administration for either the prevention or treatment of rheumatoid arthritis (RA) has been investigated in a limited number of studies. Randomized controlled clinical trials have provided evidences that specific probiotics supplementation exhibit anti-inflammatory effects, help to increase daily activities and alleviate symptoms in patients with RA. Therefore, using probiotic bacteria as an adjuvant therapy may be considered as a promising treatment option for RA. This review summarizes the available data about the therapeutic and preventive effect of probiotics in RA, together with probiotic supplement as a possible therapy in clinical treatment.

  5. Hydrogen production by model systems including hydrogenases from phototrophic bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Gogotov, I.N.; Zorin, N.A.; Serebriakova, L.T. (AN SSSR, Pushchino (SU). Inst. of Soil Science and Photosynthesis)

    1991-01-01

    Hydrogenases of purple (Rhodobacter capsulatus, Thiocapsa roseopersicina) and green (Chlorobium limicola, Chloroflexus aurantiacus) bacteria catalyse the reactions of H{sub 2} evolution (uptake) and isotopic exchange in the system D{sub 2}-H{sub 2}O at a high rate (20-60 units mg{sup -1} protein; 30{sup o}C). The enzyme active center includes a proton-accepting group, an (FeS) cluster and nickel. The data proving the direct participation of nickel in H{sub 2} activation are obtained. The hydrogenases from phototrophic bacteria are characterized by a high stability to denaturing factors. Thiocapsa roseopersicina hydrogenase absorbed at the carbon electrode accelerates electrochemical H{sub 2} oxidation and evolution. Biocatalytic systems containing chloroplasts, ferredoxin and hydrogenase produce H{sub 2} at a rate up to 100{mu}mol (h mg Chl){sup -1} but exhibit low stability. Thiocapsa roseopersicina hydrogenase adsorbed on the particles of inorganic semiconductor TiO{sub 2} carries out H{sub 2} photoproduction. (author).

  6. Rapid quantification of viable Campylobacter bacteria on chicken carcasses, using real-time PCR and propidium monoazide treatment, as a tool for quantitative risk assessment.

    Science.gov (United States)

    Josefsen, M H; Löfström, C; Hansen, T B; Christensen, L S; Olsen, J E; Hoorfar, J

    2010-08-01

    A number of intervention strategies against Campylobacter-contaminated poultry focus on postslaughter reduction of the number of cells, emphasizing the need for rapid and reliable quantitative detection of only viable Campylobacter bacteria. We present a new and rapid quantitative approach to the enumeration of food-borne Campylobacter bacteria that combines real-time quantitative PCR (Q-PCR) with simple propidium monoazide (PMA) sample treatment. In less than 3 h, this method generates a signal from only viable and viable but nonculturable (VBNC) Campylobacter bacteria with an intact membrane. The method's performance was evaluated by assessing the contributions to variability by individual chicken carcass rinse matrices, species of Campylobacter, and differences in efficiency of DNA extraction with differing cell inputs. The method was compared with culture-based enumeration on 50 naturally infected chickens. The cell contents correlated with cycle threshold (C(T)) values (R(2) = 0.993), with a quantification range of 1 x 10(2) to 1 x 10(7) CFU/ml. The correlation between the Campylobacter counts obtained by PMA-PCR and culture on naturally contaminated chickens was high (R(2) = 0.844). The amplification efficiency of the Q-PCR method was not affected by the chicken rinse matrix or by the species of Campylobacter. No Q-PCR signals were obtained from artificially inoculated chicken rinse when PMA sample treatment was applied. In conclusion, this study presents a rapid tool for producing reliable quantitative data on viable Campylobacter bacteria in chicken carcass rinse. The proposed method does not detect DNA from dead Campylobacter bacteria but recognizes the infectious potential of the VBNC state and is thereby able to assess the effect of control strategies and provide trustworthy data for risk assessment.

  7. Electrochemical reduction of oxygen catalyzed by a wide range of bacteria including Gram-positive

    Energy Technology Data Exchange (ETDEWEB)

    Cournet, Amandine [Universite de Toulouse, UPS, LU49, Adhesion Bacterienne et Formation de Biofilms, 35 chemin des Maraichers, 31 062 Toulouse cedex 09 (France); Laboratoire de Genie Chimique CNRS, Universite de Toulouse, 4 allee Emile Monso, BP 84234, 31432 Toulouse cedex 04 (France); Delia, Marie-Line; Bergel, Alain [Laboratoire de Genie Chimique CNRS, Universite de Toulouse, 4 allee Emile Monso, BP 84234, 31432 Toulouse cedex 04 (France); Roques, Christine; Berge, Mathieu [Universite de Toulouse, UPS, LU49, Adhesion Bacterienne et Formation de Biofilms, 35 chemin des Maraichers, 31 062 Toulouse cedex 09 (France)

    2010-04-15

    Most bacteria known to be electrochemically active have been harvested in the anodic compartments of microbial fuel cells (MFCs) and are able to use electrodes as electron acceptors. The reverse phenomenon, i.e. using solid electrodes as electron donors, is not so widely studied. To our knowledge, most of the electrochemically active bacteria are Gram-negative. The present study implements a transitory electrochemical technique (cyclic voltammetry) to study the microbial catalysis of the electrochemical reduction of oxygen. It is demonstrated that a wide range of aerobic and facultative anaerobic bacteria are able to catalyze oxygen reduction. Among these electroactive bacteria, several were Gram-positive. The transfer of electrons was direct since no activity was obtained with the filtrate. These findings, showing a widespread property among bacteria including Gram-positive ones, open new and interesting routes in the field of electroactive bacteria research. (author)

  8. The susceptibility of dental plaque bacteria to the herbs included in Longo Vital®

    DEFF Research Database (Denmark)

    Larsen, T.; Fiehn, N. E.; Østergaard, E.

    1996-01-01

    the in vitro susceptibility of 12 dental plaque bacteria to six individual herbs included in Longo Vital® was determined by a broth dilution method. Paprika, rosemary leaves and peppermint inhibited two thirds of the tested bacteria at 2.8-45 mg/ml, 0.75-12 mg/ml and 3-24 mg/ml corresponding to 0.8-12.5 per...

  9. Long-term effects of antibiotics on the elimination of chemical oxygen demand, nitrification, and viable bacteria in laboratory-scale wastewater treatment plants.

    Science.gov (United States)

    Schmidt, Susan; Winter, Josef; Gallert, Claudia

    2012-10-01

    Antibiotics and other pharmaceuticals are contaminants of the environment because of their widespread use and incomplete removal by microorganisms during wastewater treatment. The influence of a mixture of ciprofloxacin (CIP), gentamicin (GM), sulfamethoxazole (SMZ)/trimethoprim (TMP), and vancomycin (VA), up to a final concentration of 40 mg/L, on the elimination of chemical oxygen demand (COD), nitrification, and survival of bacteria, as well as the elimination of the antibiotics, was assessed in a long-term study in laboratory treatment plants (LTPs). In the presence of 30 mg/L antibiotics, nitrification of artificial sewage by activated sludge ended at nitrite. Nitrate formation was almost completely inhibited. No nitrification at all was possible in the presence of 40 mg/L antibiotics. The nitrifiers were more sensitive to antibiotics than heterotrophic bacteria. COD elimination in antibiotic-stressed LTPs was not influenced by ≤20 mg/L antibiotics. Addition of 30 mg/L antibiotic mixture decreased COD removal efficiency for a period, but the LTPs recovered. Similar results were obtained with 40 mg/L antibiotic mixture. The total viable count of bacteria was not affected negatively by the antibiotics. It ranged from 2.2 × 10(6) to 8.2 × 10(6) colony-forming units per milliliter (CFU/mL) compared with the control at 1.4 × 10(6)-6.3 × 10(6) CFU/mL. Elimination of the four antibiotics during phases of 2.4-30 mg/L from the liquid was high for GM (70-90 %), much lower for VA, TMP, and CIP (0-50 %), and highly fluctuating for SMZ (0-95 %). The antibiotics were mainly adsorbed to the sludge and not biodegraded.

  10. Development of a rapid real-time PCR method as a tool to quantify viable Photobacterium phosphoreum bacteria in salmon (Salmo salar) steaks.

    Science.gov (United States)

    Macé, Sabrina; Mamlouk, Kelthoum; Chipchakova, Stoyka; Prévost, Hervé; Joffraud, Jean-Jacques; Dalgaard, Paw; Pilet, Marie-France; Dousset, Xavier

    2013-04-01

    A specific real-time PCR quantification method combined with a propidium monoazide sample treatment step was developed to determine quantitatively the viable population of the Photobacterium phosphoreum species group in raw modified-atmosphere-packed salmon. Primers were designed to amplify a 350-bp fragment of the gyrase subunit B gene (gyrB) of P. phosphoreum. The specificity of the two primers was demonstrated by using purified DNA from 81 strains of 52 different bacterial species. When these primers were used for real-time PCR in pure culture, a good correlation (R(2) of 0.99) was obtained between this method and conventional enumeration on marine agar (MA). Quantification was linear over 5 log units as confirmed by using inoculated salmon samples. On naturally contaminated fresh salmon, the new real-time PCR method performed successfully with a quantification limit of 3 log CFU/g. A correlation coefficient (R(2)) of 0.963 was obtained between the PCR method and classic enumeration on MA, followed by identification of colonies (290 isolates identified by real-time PCR or by 16S rRNA gene sequencing). A good correlation with an R(2) of 0.940 was found between the new PCR method and an available specific conductance method for P. phosphoreum. This study presents a rapid tool for producing reliable quantitative data on viable P. phosphoreum bacteria in fresh salmon in 6 h. This new culture-independent method will be valuable for future fish inspection, the assessment of raw material quality in fish processing plants, and studies on the ecology of this important specific spoilage microorganism.

  11. Development of a Rapid Real-Time PCR Method as a Tool To Quantify Viable Photobacterium phosphoreum Bacteria in Salmon (Salmo salar) Steaks

    Science.gov (United States)

    Macé, Sabrina; Mamlouk, Kelthoum; Chipchakova, Stoyka; Prévost, Hervé; Joffraud, Jean-Jacques; Dalgaard, Paw; Pilet, Marie-France

    2013-01-01

    A specific real-time PCR quantification method combined with a propidium monoazide sample treatment step was developed to determine quantitatively the viable population of the Photobacterium phosphoreum species group in raw modified-atmosphere-packed salmon. Primers were designed to amplify a 350-bp fragment of the gyrase subunit B gene (gyrB) of P. phosphoreum. The specificity of the two primers was demonstrated by using purified DNA from 81 strains of 52 different bacterial species. When these primers were used for real-time PCR in pure culture, a good correlation (R2 of 0.99) was obtained between this method and conventional enumeration on marine agar (MA). Quantification was linear over 5 log units as confirmed by using inoculated salmon samples. On naturally contaminated fresh salmon, the new real-time PCR method performed successfully with a quantification limit of 3 log CFU/g. A correlation coefficient (R2) of 0.963 was obtained between the PCR method and classic enumeration on MA, followed by identification of colonies (290 isolates identified by real-time PCR or by 16S rRNA gene sequencing). A good correlation with an R2 of 0.940 was found between the new PCR method and an available specific conductance method for P. phosphoreum. This study presents a rapid tool for producing reliable quantitative data on viable P. phosphoreum bacteria in fresh salmon in 6 h. This new culture-independent method will be valuable for future fish inspection, the assessment of raw material quality in fish processing plants, and studies on the ecology of this important specific spoilage microorganism. PMID:23396343

  12. Examination of equine glandular stomach lesions for bacteria, including Helicobacter spp by fluorescence in situ hybridisation

    DEFF Research Database (Denmark)

    husted, Louise; Jensen, Tim Kåre; Olsen, Susanne N.

    2010-01-01

    Background: The equine glandular stomach is commonly affected by erosion and ulceration. The aim of this study was to assess whether bacteria, including Helicobacter, could be involved in the aetiology of gastric glandular lesions seen in horses. Results: Stomach lesions, as well as normal...

  13. Survival or revival: long-term preservation induces a reversible viable but non-culturable state in methane-oxidizing bacteria.

    Directory of Open Access Journals (Sweden)

    Sven Hoefman

    Full Text Available Knowledge on long-term preservation of micro-organisms is limited and research in the field is scarce despite its importance for microbial biodiversity and biotechnological innovation. Preservation of fastidious organisms such as methane-oxidizing bacteria (MOB has proven difficult. Most MOB do not survive lyophilization and only some can be cryopreserved successfully for short periods. A large-scale study was designed for a diverse set of MOB applying fifteen cryopreservation or lyophilization conditions. After three, six and twelve months of preservation, the viability (via live-dead flow cytometry and culturability (via most-probable number analysis and plating of the cells were assessed. All strains could be cryopreserved without a significant loss in culturability using 1% trehalose in 10-fold diluted TSB (TT as preservation medium and 5% DMSO as cryoprotectant. Several other cryopreservation and lyophilization conditions, all of which involved the use of TT medium, also allowed successful preservation but showed a considerable loss in culturability. We demonstrate here that most of these non-culturables survived preservation according to viability assessment indicating that preservation induces a viable but non-culturable (VBNC state in a significant fraction of cells. Since this state is reversible, these findings have major implications shifting the emphasis from survival to revival of cells in a preservation protocol. We showed that MOB cells could be significantly resuscitated from the VBNC state using the TT preservation medium.

  14. Toxicity of tetracyclines and tetracycline degradation products to environmentally relevant bacteria, including selected tetracycline-resistant bacteria

    DEFF Research Database (Denmark)

    Halling-Sørensen, B.; Sengeløv, G.; Tjørnelund, J.

    2002-01-01

    Tetracyclines used in veterinary therapy invariably will find their way as parent compound and degradation products to the agricultural field. Major degradation products formed due to the limited stability of parent tetracyclines (tetracycline, chlortetracycline, and oxytetracycline) in aqueous...... solution were theoretically identified at various environmental conditions, such as pH, presence of chelating, metals, and fight. Their potency was assessed on sludge bacteria, tetracycline-sensitive soil bacteria, and tetracycline-resistant strains. Several of the degradation products had potency...... at the same concentration level as tetracycline, chlortetracycline, and oxytetracycline on both the sludge and the tetracycline-sensitive soil bacteria. Further, both 5a,6-anhydrotetracychne and 5a,6-anhydrochlortetracycline had potency on tetracycline-resistant bacteria supporting a mode of action different...

  15. Examination of equine glandular stomach lesions for bacteria, including Helicobacter spp by fluorescence in situ hybridisation

    Directory of Open Access Journals (Sweden)

    Olsen Susanne N

    2010-03-01

    Full Text Available Abstract Background The equine glandular stomach is commonly affected by erosion and ulceration. The aim of this study was to assess whether bacteria, including Helicobacter, could be involved in the aetiology of gastric glandular lesions seen in horses. Results Stomach lesions, as well as normal appearing mucosa were obtained from horses slaughtered for human consumption. All samples were tested for urease activity using the Pyloritek® assay, while mucosal bacterial content was evaluated using Fluorescence In Situ Hybridisation. In selected sub samples, bacteria characterisation was pursued further by cloning and sequencing. Mucosal lesions were found in 36/63 stomachs and included hyperplastic rugae, polypoid structures and focal erosions. None of the samples were tested positive for urease activity or for FISH using the Helicobacter genus specific probe. In samples of lesions, as well as normal samples, clones with 99% similarities to Lactobacillus salivarius and Sarcina ventriculi were found. Escherichia like bacterium clones and Enterococcus clones were demonstrated in one focal erosion. Based on a phylogenetic tree these clones had 100% similarity to Escherichia fergusonii and Enterococcus faecium. The Enterococcus were found colonising the mucosal surface, while E. fergusonii organisms were also demonstrated intraepithelial. Conclusion Gastric Helicobacter spp. could not be verified as being involved in lesions of the glandular stomach of the horse. Since E. fergusonii has been described as an emerging pathogen in both humans and animals, the finding of this bacterium in gastric erosion warrants further clarification to whether gastric infection with this type bacterium is important for horses.

  16. Rapid Quantification of Viable Campylobacter Bacteria on Chicken Carcasses, Using Real-Time PCR and Propidium Monoazide Treatment, as a Tool for Quantitative Risk Assessment

    DEFF Research Database (Denmark)

    Josefsen, Mathilde Hartmann; Löfström, Charlotta; Hansen, Tina Beck

    2010-01-01

    of foodborne Campylobacter, combining real-time PCR (Q-PCR) with a simple propidium monoazide (PMA) sample treatment. In less than 3 hours, this method generates a signal from only viable and viable but non-culturable (VBNC) Campylobacter with an intact membrane. The method performance was evaluated......-values (R(2) = 0.993), with a quantification range from 1x10(2)-1x10(7) CFU/ml. The correlation between the Campylobacter counts obtained by PMA-PCR and culture on naturally contaminated chickens was high (R(2) = 0.844). The amplification efficiency of the Q-PCR method was not affected by chicken rinse...... matrix or by species of Campylobacter. No Q-PCR signals were obtained from artificially inoculated chicken rinse when PMA sample treatment was applied. In conclusion, this study presents a rapid tool for producing reliable quantitative data on viable Campylobacter in chicken carcass rinse. The proposed...

  17. Comparison of viable cell counts and fluorescence in situ hybridization using specific rRNA-based probes for the quantification of human fecal bacteria

    NARCIS (Netherlands)

    Harmsen, HJM; Gibson, GR; Elfferich, P; Raangs, GC; Wildeboer-Veloo, ACM; Argaiz, A; Roberfroid, MB; Welling, GW

    2000-01-01

    Conventional cultivation and fluorescence in situ hybridization (FISH) using 16S rRNA-based probes were compared for the enumeration of human colonic bacteria. Groups of common intestinal anaerobic bacteria were enumerated in slurries prepared From fecal samples of three healthy volunteers. To

  18. Beverages obtained from soda fountain machines in the U.S. contain microorganisms, including coliform bacteria.

    Science.gov (United States)

    White, Amy S; Godard, Renee D; Belling, Carolyn; Kasza, Victoria; Beach, Rebecca L

    2010-01-31

    Ninety beverages of three types (sugar sodas, diet sodas and water) were obtained from 20 self-service and 10 personnel-dispensed soda fountains, analyzed for microbial contamination, and evaluated with respect to U.S. drinking water regulations. A follow-up study compared the concentration and composition of microbial populations in 27 beverages collected from 9 soda fountain machines in the morning as well as in the afternoon. Ice dispensed from these machines was also examined for microbial contamination. While none of the ice samples exceeded U.S. drinking water standards, coliform bacteria was detected in 48% of the beverages and 20% had a heterotrophic plate count greater than 500cfu/ml. Statistical analyses revealed no difference in levels of microbial contamination between beverage types or between those dispensed from self-service and personnel-dispensed soda fountains. More than 11% of the beverages analyzed contained Escherichia coli and over 17% contained Chryseobacterium meningosepticum. Other opportunistic pathogenic microorganisms isolated from the beverages included species of Klebsiella, Staphylococcus, Stenotrophomonas, Candida, and Serratia. Most of the identified bacteria showed resistance to one or more of the 11 antibiotics tested. These findings suggest that soda fountain machines may harbor persistent communities of potentially pathogenic microorganisms which may contribute to episodic gastric distress in the general population and could pose a more significant health risk to immunocompromised individuals. These findings have important public health implications and signal the need for regulations enforcing hygienic practices associated with these beverage dispensers. Copyright 2009 Elsevier B.V. All rights reserved.

  19. The effects of a new therapeutic triclosan/copolymer/sodium-fluoride dentifrice on oral bacteria, including odorigenic species.

    Science.gov (United States)

    Furgang, David; Sreenivasan, Prem K; Zhang, Yun Po; Fine, Daniel H; Cummins, Diane

    2003-09-01

    This investigation examined the in vitro and ex vivo antimicrobial effects of a new dentifrice, Colgate Total Advanced Fresh, formulated with triclosan/copolymer/sodium fluoride, on oral bacteria, including those odorigenic bacteria implicated in bad breath. The effects of Colgate Total Advanced Fresh were compared to commercially available fluoride dentifrices that served as controls. Three experimental approaches were undertaken for these studies. In the first approach, the dentifrice formulations were tested in vitro against 13 species of oral bacteria implicated in bad breath. The second approach examined the antimicrobial activity derived from dentifrice that was adsorbed to and released from hydroxyapatite disks. In this approach, dentifrice-treated hydroxyapatite disks were immersed in a suspension of bacteria, and reduction in bacterial viability from the release of bioactive agents from hydroxyapatite was determined. The third approach examined the effect of treating bacteria immediately after their removal from the oral cavity of 11 adult human volunteers. This ex vivo study examined the viability of cultivable oral bacteria after dentifrice treatment for 2 minutes. Antimicrobial effects were determined by plating Colgate Total Advanced Fresh and control-dentifrice-treated samples on enriched media (for all cultivable oral bacteria) and indicator media (for hydrogen-sulfide-producing organisms), respectively. Results indicated that the antimicrobial effects of Colgate Total Advanced Fresh were significantly greater than either of the other dentifrices for all 13 oral odorigenic bacterial strains tested in vitro (P Colgate Total Advanced Fresh-treated hydroxyapatite disks were significantly more active in reducing bacterial growth than the other dentifrices tested (P oral bacteria with Colgate Total Advanced Fresh demonstrated a 90.9% reduction of all oral cultivable bacteria and a 91.5% reduction of oral bacteria producing hydrogen sulfide compared with

  20. Penicillin-mediated changes in viable benthic diatom assemblages – insights about the relevance of bacteria across spatial and seasonal scales.

    Digital Repository Service at National Institute of Oceanography (India)

    DeCosta, P.M.; Anil, A.C.

    species composition of the viable, benthic diatom assemblages when treated with penicillin. The probable mechanisms responsible for these penicillin-mediated changes are numerous. Theoretically, penicillin-mediated changes in diatom assemblages... seawater (MBL) (Cavanaugh 1975) enriched with f/2 level of nutrients (Guillard and Ryther 1962) was used as the basal diluent and will henceforth be termed control. Penicillin was incorporated in the control diluent at 0.2 mg ml-1. In the original MPN...

  1. Development of a Rapid Real-Time PCR Method as a Tool To Quantify Viable Photobacterium phosphoreum Bacteria in Salmon (Salmo salar) Steaks

    OpenAIRE

    Macé, Sabrina; Mamlouk, Kelthoum; Chipchakova, Stoyka; Prévost, Hervé; Joffraud, Jean-jacques; Dalgaard, Paw,; Pilet, Marie-France; Dousset, Xavier

    2013-01-01

    A specific real-time PCR quantification method combined with a propidium monoazide sample treatment step was developed to determine quantitatively the viable population of the Photobacterium phosphoreum species group in raw modified-atmosphere-packed salmon. Primers were designed to amplify a 350-bp fragment of the gyrase subunit B gene (gyrB) of P. phosphoreum. The specificity of the two primers was demonstrated by using purified DNA from 81 strains of 52 different bacterial species. When th...

  2. The possible causal relationship between fragmentation of genomic DNA and formation of viable, but non-culturable probiotic bacteria upon storage in dry state.

    Science.gov (United States)

    Hansen, Marie-Louise R W; Ramsussen, Morten Arendt; Skov, Thomas; Clausen, Anders; Risbo, Jens

    2017-10-24

    In this study, the aim was to establish if loss of DNA integrity is a cause of loss of culturability for probiotic bacteria during storage in dry state. The number of colony forming units (CFU), number of metabolically active cells, and DNA integrity during dry storage of probiotic strains, B. animalis subsp. lactis BB-12 and L. acidophilus LA-5, were investigated. The probiotic strains were freeze-dried and stored at 20°C, with and without oxygen present, and at water activity levels 0.22 or 0.32. Dry storage resulted in a decrease in CFU during the entire storage period. The number of metabolically active cells was unchanged during storage of B. animalis subsp. lactis BB-12, but did decrease during the first week of storage of L. acidophilus LA-5. Loss of DNA integrity was evident for both strains during storage and correlated well with the loss of CFU. Both loss of CFU and loss of DNA integrity were significantly greater for both strains when oxygen was present and when aw was increased. Statistical analysis indicates a possible causal relationship between DNA degradation and loss of culturability and this idea is consistent with the function of DNA at cell division. The study contributes with new knowledge of the cause for loss of CFU during dry storage of probiotic bacteria, which possibly can aid in the improvement of preservation techniques. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 2017. © 2017 American Institute of Chemical Engineers.

  3. Predictive models for the effect of storage temperature on Vibrio parahaemolyticus viability and counts of total viable bacteria in Pacific oysters (Crassostrea gigas).

    Science.gov (United States)

    Fernandez-Piquer, Judith; Bowman, John P; Ross, Tom; Tamplin, Mark L

    2011-12-01

    Vibrio parahaemolyticus is an indigenous bacterium of marine environments. It accumulates in oysters and may reach levels that cause human illness when postharvest temperatures are not properly controlled and oysters are consumed raw or undercooked. Predictive models were produced by injecting Pacific oysters (Crassostrea gigas) with a cocktail of V. parahaemolyticus strains, measuring viability rates at storage temperatures from 3.6 to 30.4°C, and fitting the data to a model to obtain parameter estimates. The models were evaluated with Pacific and Sydney Rock oysters (Saccostrea glomerata) containing natural populations of V. parahaemolyticus. V. parahaemolyticus viability was measured by direct plating samples on thiosulfate-citrate-bile salts-sucrose (TCBS) agar for injected oysters and by most probable number (MPN)-PCR for oysters containing natural populations. In parallel, total viable bacterial counts (TVC) were measured by direct plating on marine agar. Growth/inactivation rates for V. parahaemolyticus were -0.006, -0.004, -0.005, -0.003, 0.030, 0.075, 0.095, and 0.282 log₁₀ CFU/h at 3.6, 6.2, 9.6, 12.6, 18.4, 20.0, 25.7, and 30.4°C, respectively. The growth rates for TVC were 0.015, 0.023, 0.016, 0.048, 0.055, 0.071, 0.133, and 0.135 log₁₀ CFU/h at 3.6, 6.2, 9.3, 14.9, 18.4, 20.0, 25.7, and 30.4°C, respectively. Square root and Arrhenius-type secondary models were generated for V. parahaemolyticus growth and inactivation kinetic data, respectively. A square root model was produced for TVC growth. Evaluation studies showed that predictive growth for V. parahaemolyticus and TVC were "fail safe." The models can assist oyster companies and regulators in implementing management strategies to minimize V. parahaemolyticus risk and enhancing product quality in supply chains.

  4. [Survival of Gram-positive spore-forming bacteria including Bacillus cereus after hand washing using alcohol-based handrub].

    Science.gov (United States)

    Ogawa, Midori; Takada, Shinichiro; Takahashi, Masao; Yasuda, Etsuko; Watase, Mariko; Taniguchi, Hatsumi

    2006-12-01

    Hand washing is the most fundamental method for preventing infection. Currently, hand washing with an alcohol-based handrub is the international gold standard method. However, in our study we found many samples of ineffective hand washing using an alcohol-based handrub. The rates of ineffective samples were 10.4% (5/48) in 2004 and 34.3% (12/35) in 2005. We examined the morphology by Gram staining and biochemical properties of the bacteria which remained after hand washing in 2005. Their colonies were divided into 3 groups (round colonies, irregular-shaped and diffusive colonies). The round colonies were considered Staphylococcus spp., and the irregular-shaped colonies or diffusive colonies were considered Gram-positive spore-forming bacteria. In the 12 ineffective hand washing samples (more than the same number of bacteria colonies as before hand washing, or > or = 300), there were 3 samples considered to be the result of the survival of Staphylococcus spp., and 9 samples considered to be the result of the survival of Gram-positive spore-forming bacteria including Bacillus cereus. Based on these results, we should take careful measures, such as wearing sterile gloves if necessary. We should never be overconfident regarding the effect of hand washing.

  5. Diallylthiosulfinate (Allicin, a Volatile Antimicrobial from Garlic (Allium sativum, Kills Human Lung Pathogenic Bacteria, Including MDR Strains, as a Vapor

    Directory of Open Access Journals (Sweden)

    Jana Reiter

    2017-10-01

    Full Text Available Garlic (Allium sativum has potent antimicrobial activity due to allicin (diallylthiosulfinate synthesized by enzyme catalysis in damaged garlic tissues. Allicin gives crushed garlic its characteristic odor and its volatility makes it potentially useful for combating lung infections. Allicin was synthesized (>98% pure by oxidation of diallyl disulfide by H2O2 using formic acid as a catalyst and the growth inhibitory effect of allicin vapor and allicin in solution to clinical isolates of lung pathogenic bacteria from the genera Pseudomonas, Streptococcus, and Staphylococcus, including multi-drug resistant (MDR strains, was demonstrated. Minimal inhibitory (MIC and minimal bactericidal concentrations (MBC were determined and compared to clinical antibiotics using standard European Committee on Antimicrobial Susceptibility Testing (EUCAST procedures. The cytotoxicity of allicin to human lung and colon epithelial and murine fibroblast cells was tested in vitro and shown to be ameliorated by glutathione (GSH. Similarly, the sensitivity of rat precision-cut lung slices (PCLS to allicin was decreased by raising the [GSH] to the approximate blood plasma level of 1 mM. Because allicin inhibited bacterial growth as a vapor, it could be used to combat bacterial lung infections via direct inhalation. Since there are no volatile antibiotics available to treat pulmonary infections, allicin, particularly at sublethal doses in combination with oral antibiotics, could make a valuable addition to currently available treatments.

  6. Diallylthiosulfinate (Allicin), a Volatile Antimicrobial from Garlic (Allium sativum), Kills Human Lung Pathogenic Bacteria, Including MDR Strains, as a Vapor.

    Science.gov (United States)

    Reiter, Jana; Levina, Natalja; van der Linden, Mark; Gruhlke, Martin; Martin, Christian; Slusarenko, Alan J

    2017-10-12

    Garlic ( Allium sativum ) has potent antimicrobial activity due to allicin (diallylthiosulfinate) synthesized by enzyme catalysis in damaged garlic tissues. Allicin gives crushed garlic its characteristic odor and its volatility makes it potentially useful for combating lung infections. Allicin was synthesized (>98% pure) by oxidation of diallyl disulfide by H₂O₂ using formic acid as a catalyst and the growth inhibitory effect of allicin vapor and allicin in solution to clinical isolates of lung pathogenic bacteria from the genera Pseudomonas , Streptococcus , and Staphylococcus , including multi-drug resistant (MDR) strains, was demonstrated. Minimal inhibitory (MIC) and minimal bactericidal concentrations (MBC) were determined and compared to clinical antibiotics using standard European Committee on Antimicrobial Susceptibility Testing (EUCAST) procedures. The cytotoxicity of allicin to human lung and colon epithelial and murine fibroblast cells was tested in vitro and shown to be ameliorated by glutathione (GSH). Similarly, the sensitivity of rat precision-cut lung slices (PCLS) to allicin was decreased by raising the [GSH] to the approximate blood plasma level of 1 mM. Because allicin inhibited bacterial growth as a vapor, it could be used to combat bacterial lung infections via direct inhalation. Since there are no volatile antibiotics available to treat pulmonary infections, allicin, particularly at sublethal doses in combination with oral antibiotics, could make a valuable addition to currently available treatments.

  7. An Antimicrobial Metabolite from Bacillus sp.: Significant activity against pathogenic bacteria including multidrug-resistant clinical strains

    Directory of Open Access Journals (Sweden)

    AJAY GHOSH CHALASANI

    2015-12-01

    Full Text Available In this study, the cell free modified trypticase soya broth (pH 7.4+0.2 of Bacillus subtilis URID 12.1 showed significant antimicrobial activity against multidrug-resistant strains of Staphylococcus aureus, S. epidermidis, Streptococcus pyogenes and Enterococcus faecalis. The partially purified antimicrobial molecule was found to be resistant to extremes of pH and temperatures and also to higher concentrations of trypsin and proteinase K. The antimicrobial molecule was purified by a three-step method that included reverse-phased high performance liquid chromatography (RP-HPLC. The minimum inhibitory concentration (MIC values were determined for 11 species of bacteria using a microbroth dilution technique. The HPLC-purified fraction showed the MICs ranging from 0.5 to 1 µg/ml for methicillin and vancomycin resistant Staphylococcus aureus (MVRSA and methicillin-resistant Staphylococcus epidermidis (MRSE strains. The molecular mass of the antimicrobial compound was determined to be 842.37 Da. The same antimicrobial fraction showed negligible haemolytic activity against human red blood cells even at a concentration as high as 100µg/ml. Because of its significant antimicrobial activity at low MIC values coupled with its non-haemolytic property, it may prove to be a novel antimicrobial lead molecule.

  8. Managing Viable Knowledge

    NARCIS (Netherlands)

    Achterbergh, J.M.I.M.; Vriens, D.J.

    2002-01-01

    In this paper, Beer's Viable System Model (VSM) is applied to knowledge management. Based on the VSM, domains of knowledge are identified that an organization should possess to maintain its viability. The logic of the VSM is also used to support the diagnosis, design and implementation of the

  9. Isolation and identification of microorganisms including lactic acid bacteria and their use in microbial deacidification of wines from domestic vineyards.

    Science.gov (United States)

    Drozdz, Iwona; Makarewicz, Malgorzata; Tuszyński, Tadeusz

    2013-01-01

    The aim of this study was to identify various bacteria isolated from grapes and their wines. Additionally we investigated the capacity of lactic acid bacteria for microbiological deacidification of wines produced in Poland. We have identified Oenococcus oeni, Lactobacillus acidophilus and Lactobacillus delbrueckii. During the microbial deacidification process, we observed decreases of total acidity and increases of volatile acidity, with statistically significant changes noted for O. oeni in Marechal Foch and Seyval Blanc, and for Lb. acidophilus in Frontenac. On the other hand, a statistically significant increase in pH was observed in Marechal Foch and Seyval Blanc following deacidification by O. oeni.

  10. Individual Patterns of Complexity in Cystic Fibrosis Lung Microbiota, Including Predator Bacteria, over a 1-Year Period

    Science.gov (United States)

    de Dios Caballero, Juan; Vida, Rafael; Cobo, Marta; Máiz, Luis; Suárez, Lucrecia; Galeano, Javier; Baquero, Fernando; Cantón, Rafael

    2017-01-01

    ABSTRACT Cystic fibrosis (CF) lung microbiota composition has recently been redefined by the application of next-generation sequencing (NGS) tools, identifying, among others, previously undescribed anaerobic and uncultivable bacteria. In the present study, we monitored the fluctuations of this ecosystem in 15 CF patients during a 1-year follow-up period, describing for the first time, as far as we know, the presence of predator bacteria in the CF lung microbiome. In addition, a new computational model was developed to ascertain the hypothetical ecological repercussions of a prey-predator interaction in CF lung microbial communities. Fifteen adult CF patients, stratified according to their pulmonary function into mild (n = 5), moderate (n = 9), and severe (n = 1) disease, were recruited at the CF unit of the Ramón y Cajal University Hospital (Madrid, Spain). Each patient contributed three or four induced sputum samples during a 1-year follow-up period. Lung microbiota composition was determined by both cultivation and NGS techniques and was compared with the patients’ clinical variables. Results revealed a particular microbiota composition for each patient that was maintained during the study period, although some fluctuations were detected without any clinical correlation. For the first time, Bdellovibrio and Vampirovibrio predator bacteria were shown in CF lung microbiota and reduced-genome bacterial parasites of the phylum Parcubacteria were also consistently detected. The newly designed computational model allows us to hypothesize that inoculation of predators into the pulmonary microbiome might contribute to the control of chronic colonization by CF pathogens in early colonization stages. PMID:28951476

  11. Necrotizing Enterocolitis in Preterm Pigs Is Associated with Increased Density of Intestinal Mucosa-Associated Bacteria Including Clostridium perfringens

    DEFF Research Database (Denmark)

    Støy, Ann Cathrine Findal; Mølbak, Lars; Delègue, Camilla Lindholm

    2015-01-01

    correlates with NEC severity in preterm pigs and that in vitro infection with increasing densities of Clostridium perfringens, which has been associated with NEC in preterm infants, would lead to a transcriptional response related to the inflammatory conditions of NEC. Methods: First, we determined...... the density of total bacteria and C. perfringens in the distal small intestinal mucosa of 58 NEC and healthy preterm pigs using quantitative PCR. Next, we analyzed in IPEC-J2 cells the effect of different infection densities of C. perfringens type A on the expression of genes related to intestinal function...... and immune response. Results: Total bacterial and C. perfringens densities were higher in NEC versus healthy pigs and correlated positively with NEC severity. In IPEC-J2 cells expression levels of inflammation-related genes (CCL5, NFKBIA, IL8, IL1RN, and TNFAIP3) increased, while the expression of the sodium...

  12. In vitro characterization of aggregation and adhesion properties of viable and heat-killed forms of two probiotic Lactobacillus strains and interaction with foodborne zoonotic bacteria, especially Campylobacter jejuni.

    Science.gov (United States)

    Tareb, Raouf; Bernardeau, Marion; Gueguen, Marielle; Vernoux, Jean-Paul

    2013-04-01

    Bacterial aggregation and/or adhesion are key factors for colonization of the digestive ecosystem and the ability of probiotic strains to exclude pathogens. In the present study, two probiotic strains, Lactobacillus rhamnosus CNCM-I-3698 and Lactobacillus farciminis CNCM-I-3699, were evaluated as viable or heat-killed forms and compared with probiotic reference Lactobacillus strains (Lb. rhamnosus GG and Lb. farciminis CIP 103136). The autoaggregation potential of both forms was higher than that of reference strains and twice that of pathogenic strains. The coaggregation potential of these two beneficial micro-organisms was evaluated against several pathogenic agents that threaten the global safety of the feed/food chain: Escherichia coli, Salmonella spp., Campylobacter spp. and Listeria monocytogenes. The strongest coaggregative interactions were demonstrated with Campylobacter spp. by a coaggregation test, confirmed by electron microscopic examination for the two forms. Viable forms were investigated for the nature of the bacterial cell-surface molecules involved, by sugar reversal tests and chemical and enzymic pretreatments. The results suggest that the coaggregation between both probiotic strains and C. jejuni CIP 70.2(T) is mediated by a carbohydrate-lectin interaction. The autoaggregation potential of the two probiotics decreased upon exposure to proteinase, SDS or LiCl, showing that proteinaceous components on the surface of the two lactobacilli play an important role in this interaction. Adhesion abilities of both Lactobacillus strains were also demonstrated at significant levels on Caco-2 cells, mucin and extracellular matrix material. Both viable and heat-killed forms of the two probiotic lactobacilli inhibited the attachment of C. jejuni CIP 70.2(T) to mucin. In conclusion, in vitro assays showed that Lb. rhamnosus CNCM-I-3698 and Lb. farciminis CNCM-I-3699, as viable or heat-killed forms, are adherent to different intestinal matrix models and are

  13. In vitro antibacterial and chemical properties of essential oils including native plants from Brazil against pathogenic and resistant bacteria.

    Science.gov (United States)

    Barbosa, Lidiane Nunes; Probst, Isabella da Silva; Andrade, Bruna Fernanda Murbach Teles; Alves, Fernanda Cristina Bérgamo; Albano, Mariana; da Cunha, Maria de Lourdes Ribeiro de Souza; Doyama, Julio Toshimi; Rall, Vera Lúcia Mores; Fernandes Júnior, Ary

    2015-01-01

    The antimicrobials products from plants have increased in importance due to the therapeutic potential in the treatment of infectious diseases. Therefore, we aimed to examine the chemical characterisation (GC-MS) of essential oils (EO) from seven plants and measure antibacterial activities against bacterial strains isolated from clinical human specimens (methicillin-resistant Staphylococcus aureus (MRSA) and sensitive (MSSA), Escherichia coli, Pseudomonas aeruginosa, Salmonella Typhimurium) and foods (Salmonella Enteritidis). Assays were performed using the minimal inhibitory concentration (MIC and MIC90%) (mg/mL) by agar dilution and time kill curve methods (log CFU/mL) to aiming synergism between EO. EO chemical analysis showed a predominance of terpenes and its derivatives. The highest antibacterial activities were with Cinnamomun zeylanicum (0.25 mg/mL on almost bacteria tested) and Caryophyllus aromaticus EO (2.40 mg/mL on Salmonella Enteritidis), and the lowest activity was with Eugenia uniflora (from 50.80 mg/mL against MSSA to 92.40 mg/mL against both Salmonella sources and P. aeruginosa) EO. The time kill curve assays revealed the occurrence of bactericide synergism in combinations of C. aromaticus and C. zeylanicum with Rosmarinus. officinalis. Thus, the antibacterial activities of the EO were large and this can also be explained by complex chemical composition of the oils tested in this study and the synergistic effect of these EO, yet requires further investigation because these interactions between the various chemical compounds can increase or reduce (antagonism effect) the inhibitory effect of essential oils against bacterial strains.

  14. Viable Syntax: Rethinking Minimalist Architecture

    Directory of Open Access Journals (Sweden)

    Ken Safir

    2010-03-01

    Full Text Available Hauser et al. (2002 suggest that the human language faculty emerged as a genetic innovation in the form of what is called here a ‘keystone factor’—a single, simple, formal mental capability that, interacting with the pre-existing faculties of hominid ancestors, caused a cascade of effects resulting in the language faculty in modern humans. They take Merge to be the keystone factor, but instead it is posited here that Merge is the pre-existing mechanism of thought made viable by a principle that permits relations interpretable at the interfaces to be mapped onto c-command. The simplified minimalist architecture proposed here respects the keystone factor as closely as possible, but is justified on the basis of linguistic analyses it makes available, including a relativized intervention theory applicable across Case, scope, agreement, selection and linearization, a derivation of the A/A’-distinction from Case theory, and predictions such as why in situ wh-interpretation is island-insensitive, but susceptible to intervention effects.

  15. Enumeration of viable and non-viable larvated Ascaris eggs with quantitative PCR.

    Science.gov (United States)

    Raynal, Maria; Villegas, Eric N; Nelson, Kara L

    2012-12-01

    The goal of this study was to further develop an incubation-quantitative polymerase chain reaction (qPCR) method for quantifying viable Ascaris eggs by characterizing the detection limit and number of template copies per egg, determining the specificity of the method, and testing the method with viable and inactivated larvated eggs. The number of template copies per cell was determined by amplifying DNA from known numbers of eggs at different development stages; the value was estimated to be 32 copies. The specificity of the method was tested against a panel of bacteria, fungi, protozoa and helminths, and no amplification was found with non-target DNA. Finally, fully larvated eggs were inactivated by four different treatments: 254 nm ultraviolet light, 2,000 ppm NH(3)-N at pH 9, moderate heat (48 °C) and high heat (70 °C). Concentrations of treated eggs were measured by direct microscopy and incubation-qPCR. The qPCR signal decreased following all four treatments, and was in general agreement with the decrease in viable eggs determined by microscopy. The incubation-qPCR method for enumerating viable Ascaris eggs is a promising approach that can produce results faster than direct microscopy, and may have benefits for applications such as assessing biosolids.

  16. Methylotrophic bacteria in sustainable agriculture.

    Science.gov (United States)

    Kumar, Manish; Tomar, Rajesh Singh; Lade, Harshad; Paul, Diby

    2016-07-01

    Excessive use of chemical fertilizers to increase production from available land has resulted in deterioration of soil quality. To prevent further soil deterioration, the use of methylotrophic bacteria that have the ability to colonize different habitats, including soil, sediment, water, and both epiphytes and endophytes as host plants, has been suggested for sustainable agriculture. Methylotrophic bacteria are known to play a significant role in the biogeochemical cycle in soil ecosystems, ultimately fortifying plants and sustaining agriculture. Methylotrophs also improve air quality by using volatile organic compounds such as dichloromethane, formaldehyde, methanol, and formic acid. Additionally, methylotrophs are involved in phosphorous, nitrogen, and carbon cycling and can help reduce global warming. In this review, different aspects of the interaction between methylotrophs and host plants are discussed, including the role of methylotrophs in phosphorus acquisition, nitrogen fixation, phytohormone production, iron chelation, and plant growth promotion, and co-inoculation of these bacteria as biofertilizers for viable agriculture practices.

  17. Antimicrobial activity of Thai traditional medicinal plants extract incorporated alginate-tapioca starch based edible films against food related bacteria including foodborne pathogens

    OpenAIRE

    Tepsorn, Racha

    2009-01-01

    In Thai traditional medicine, different plant extracts are known to have a bactericidal or at least a bacteriostatic effect on bacteria and/or fungi. In Thailand, medicinal plants have been used safely since ancient times as herbal medicines and also as food colouring and flavouring agents. The application of selected plant extracts to foods could prevent foodborne diseases and food spoilage. In this study the antimicrobial activities of Andrographis paniculata (Burm.f.) Nees, Curcuma zedoari...

  18. Distribution and species composition of planktonic luminous bacteria in the Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Ramaiah, N.; Chandramohan, D.

    Distribution of the total viable heterotrophic bacteria and the luminous bacteria in the neretic and oceanic waters of the west coast of India was studied. Counts of viable heterotrophs fluctuated widely, generally with a decrease in their number...

  19. Aerobiological Stabilities of Different Species of Gram-Negative Bacteria, Including Well-Known Biothreat Simulants, in Single-Cell Particles and Cell Clusters of Different Compositions.

    Science.gov (United States)

    Dybwad, Marius; Skogan, Gunnar

    2017-09-15

    The ability to perform controlled experiments with bioaerosols is a fundamental enabler of many bioaerosol research disciplines. A practical alternative to using hazardous biothreat agents, e.g., for detection equipment development and testing, involves using appropriate model organisms (simulants). Several species of Gram-negative bacteria have been used or proposed as biothreat simulants. However, the appropriateness of different bacterial genera, species, and strains as simulants is still debated. Here, we report aerobiological stability characteristics of four species of Gram-negative bacteria (Pantoea agglomerans, Serratia marcescens, Escherichia coli, and Xanthomonas arboricola) in single-cell particles and cell clusters produced using four spray liquids (H2O, phosphate-buffered saline[PBS], spent culture medium[SCM], and a SCM-PBS mixture). E. coli showed higher stability in cell clusters from all spray liquids than the other species, but it showed similar or lower stability in single-cell particles. The overall stability was higher in cell clusters than in single-cell particles. The highest overall stability was observed for bioaerosols produced using SCM-containing spray liquids. A key finding was the observation that stability differences caused by particle size or compositional changes frequently followed species-specific patterns. The results highlight how even moderate changes to one experimental parameter, e.g., bacterial species, spray liquid, or particle size, can strongly affect the aerobiological stability of Gram-negative bacteria. Taken together, the results highlight the importance of careful and informed selection of Gram-negative bacterial biothreat simulants and also the accompanying particle size and composition. The outcome of this work contributes to improved selection of simulants, spray liquids, and particle size for use in bioaerosol research.IMPORTANCE The outcome of this work contributes to improved selection of simulants, spray

  20. Deep stromal mycobacterial keratitis: viable bacteria after six months of treatment: case report and literature review Ceratite estromal profunda por micobactéria: bactéria viável após seis meses de tratamento: relato de caso e revisão da literatura

    Directory of Open Access Journals (Sweden)

    Filipe Accioly de Gusmão

    2005-08-01

    Full Text Available To report the presence of viable mycobacteria in a patient with keratitis treated for 6 months. Species identification was performed using the PRA method (polymerase chain reaction followed by restriction endonuclease analysis. Clonality was evaluated with RAPD (randomly amplified polymorphic DNA and ERIC-PCR (enterobacterial repetitive intergenic consensus - polymerase chain reaction methods. The patient reported trauma due to a metallic foreign body 3 weeks prior to presentation. Initial corneal scraping cultures revealed Mycobacterium abscessus. After 6 months of topical and systemic treatment the patient presented with no active inflammation and was considered clinically cured. An optic penetrating keratoplasty was performed. Culture of the excised cornea revealed Mycobacterium abscessus. Both isolates had the same clonal origin. The most interesting finding of this case report was the positive culture of the excised cornea after 6 months of intensive specific topical therapy. To our knowledge, this is the first report in the literature showing this possibility in the treatment of Mycobacterial keratitis. Thus, Mycobacterium abscessus may present viable bacteria after long-term treatment and should be followed carefully for a long period of time after tapering the medication.O objetivo do caso é descrever a presença de micobactérias viáveis em pacientes com ceratite, 6 meses após tratamento intensivo. A identificação de espécies, foi efetuada usando método PRA (polymerase chain reaction seguida pela restriction endonuclease analysis. Clonalidade foi avaliada pelos métodos RAPD (randomly amplified polymorphic DNA e ERIC-PCR (enterobacterial repetitive intergenic consensus - polymerase chain reaction. Paciente refere trauma com corpo estranho metálico há 3 semanas. A cultura da córnea revelou Mycobacterium abscessus. Após 6 meses de tratamento tópico e sistêmico, paciente apresentava-se sem inflamação, sendo considerado

  1. Ethanolic Echinacea purpurea Extracts Contain a Mixture of Cytokine-Suppressive and Cytokine-Inducing Compounds, Including Some That Originate from Endophytic Bacteria.

    Directory of Open Access Journals (Sweden)

    Daniel A Todd

    originate from endophytic bacteria. Together, our findings indicate that ethanolic E. purpurea extracts contain multiple constituents that differentially regulate cytokine production by macrophages.

  2. Ethanolic Echinacea purpurea Extracts Contain a Mixture of Cytokine-Suppressive and Cytokine-Inducing Compounds, Including Some That Originate from Endophytic Bacteria

    Science.gov (United States)

    Britton, Emily R.; Oberhofer, Martina; Leyte-Lugo, Martha; Moody, Ashley N.; Shymanovich, Tatsiana; Grubbs, Laura F.; Juzumaite, Monika; Graf, Tyler N.; Oberlies, Nicholas H.; Faeth, Stanley H.; Laster, Scott M.; Cech, Nadja B.

    2015-01-01

    bacteria. Together, our findings indicate that ethanolic E. purpurea extracts contain multiple constituents that differentially regulate cytokine production by macrophages. PMID:25933416

  3. Pure Quantum Interpretations Are not Viable

    Science.gov (United States)

    Schmelzer, I.

    2011-02-01

    Pure interpretations of quantum theory, which throw away the classical part of the Copenhagen interpretation without adding new structure to its quantum part, are not viable. This is a consequence of a non-uniqueness result for the canonical operators.

  4. Fluconazole-Pyridoxine Bis-Triazolium Compounds with Potent Activity against Pathogenic Bacteria and Fungi Including Their Biofilm-Embedded Forms

    Directory of Open Access Journals (Sweden)

    Marsel R. Garipov

    2017-01-01

    Full Text Available Two novel quaternary ammonium salts, bis-triazolium derivatives of fluconazole and pyridoxine, were synthesized by reaction of fluconazole with pyridoxine-based synthetic intermediates. The leading compound demonstrated pronounced antimycotic and antibacterial in vitro activity, comparable to or exceeding that of the reference antifungal (fluconazole, terbinafine and antibacterial/antiseptic (miramistin, benzalkonium chloride agents. In contrast to many antimicrobials, the leading compound was also active against biofilm-embedded staphylococci and Escherichia coli. While no biofilm structure destruction occurred, all compounds were able to diffuse into the matrix and reduce the number of colony-forming units by three orders of magnitude at 16 × MBC. The leading compound was significantly less toxic than miramistin and benzalkonium chloride and more toxic than the reference antifungal drugs. The obtained results make the described chemotype a promising starting point for the development of new broad-spectrum antimicrobial therapies with powerful effect on fungal and bacterial pathogens including their biofilm-embedded forms.

  5. Bleach vs. Bacteria

    Science.gov (United States)

    ... Articles | Inside Life Science Home Page Bleach vs. Bacteria By Sharon Reynolds Posted April 2, 2014 Your ... hypochlorous acid to help kill invading microbes, including bacteria. Researchers funded by the National Institutes of Health ...

  6. Deletion of ultraconserved elements yields viable mice

    Energy Technology Data Exchange (ETDEWEB)

    Ahituv, Nadav; Zhu, Yiwen; Visel, Axel; Holt, Amy; Afzal, Veena; Pennacchio, Len A.; Rubin, Edward M.

    2007-07-15

    Ultraconserved elements have been suggested to retainextended perfect sequence identity between the human, mouse, and ratgenomes due to essential functional properties. To investigate thenecessities of these elements in vivo, we removed four non-codingultraconserved elements (ranging in length from 222 to 731 base pairs)from the mouse genome. To maximize the likelihood of observing aphenotype, we chose to delete elements that function as enhancers in amouse transgenic assay and that are near genes that exhibit markedphenotypes both when completely inactivated in the mouse as well as whentheir expression is altered due to other genomic modifications.Remarkably, all four resulting lines of mice lacking these ultraconservedelements were viable and fertile, and failed to reveal any criticalabnormalities when assayed for a variety of phenotypes including growth,longevity, pathology and metabolism. In addition more targeted screens,informed by the abnormalities observed in mice where genes in proximityto the investigated elements had been altered, also failed to revealnotable abnormalities. These results, while not inclusive of all thepossible phenotypic impact of the deleted sequences, indicate thatextreme sequence constraint does not necessarily reflect crucialfunctions required for viability.

  7. Is Greenberg's "Macro-Carib" viable?

    Directory of Open Access Journals (Sweden)

    Spike Gildea

    Full Text Available In his landmark work Language in the Americas, Greenberg (1987 proposed that Macro-Carib was one of the major low-level stocks of South America, which together with Macro-Panoan and Macro-Ge-Bororo were claimed to comprise the putative Ge-Pano-Carib Phylum. His Macro-Carib includes the isolates Andoke and Kukura, and the Witotoan, Peba-Yaguan, and Cariban families. Greenberg's primary evidence came from person-marking paradigms in individual languages, plus scattered words from individual languages collected into 79 Macro-Carib 'etymologies' and another 64 Amerind 'etymologies'. The goal of this paper is to re-evaluate Greenberg's Macro-Carib claim in the light of the much more extensive and reliable language data that has become available largely since 1987. Based on full person-marking paradigms for Proto-Cariban, Yagua, Bora and Andoke, we conclude that Greenberg's morphological claims are unfounded. For our lexical comparison, we created lexical lists for Proto-Cariban, Proto-Witotoan, Yagua and Andoke, for both Greenberg's 143 putative etymologies and for the Swadesh 100 list. From both lists, a total of 23 potential cognates were found, but no consonantal correspondences were repeated even once. We conclude that our greatly expanded and improved database does not provide sufficient evidence to convince the skeptic that the Macro-Carib hypothesis is viable

  8. Living bacteria in silica gels

    Science.gov (United States)

    Nassif, Nadine; Bouvet, Odile; Noelle Rager, Marie; Roux, Cécile; Coradin, Thibaud; Livage, Jacques

    2002-09-01

    The encapsulation of enzymes within silica gels has been extensively studied during the past decade for the design of biosensors and bioreactors. Yeast spores and bacteria have also been recently immobilized within silica gels where they retain their enzymatic activity, but the problem of the long-term viability of whole cells in an inorganic matrix has never been fully addressed. It is a real challenge for the development of sol-gel processes. Generic tests have been performed to check the viability of Escherichia coli bacteria in silica gels. Surprisingly, more bacteria remain culturable in the gel than in an aqueous suspension. The metabolic activity of the bacteria towards glycolysis decreases slowly, but half of the bacteria are still viable after one month. When confined within a mineral environment, bacteria do not form colonies. The exchange of chemical signals between isolated bacteria rather than aggregates can then be studied, a point that could be very important for 'quorum sensing'.

  9. A multicenter study of viable PCR using propidium monoazide to detect Legionella in water samples.

    Science.gov (United States)

    Scaturro, Maria; Fontana, Stefano; Dell'eva, Italo; Helfer, Fabrizia; Marchio, Michele; Stefanetti, Maria Vittoria; Cavallaro, Mario; Miglietta, Marilena; Montagna, Maria Teresa; De Giglio, Osvalda; Cuna, Teresa; Chetti, Leonarda; Sabattini, Maria Antonietta Bucci; Carlotti, Michela; Viggiani, Mariagabriella; Stenico, Alberta; Romanin, Elisa; Bonanni, Emma; Ottaviano, Claudio; Franzin, Laura; Avanzini, Claudio; Demarie, Valerio; Corbella, Marta; Cambieri, Patrizia; Marone, Piero; Rota, Maria Cristina; Bella, Antonino; Ricci, Maria Luisa

    2016-07-01

    Legionella quantification in environmental samples is overestimated by qPCR. Combination with a viable dye, such as Propidium monoazide (PMA), could make qPCR (named then vPCR) very reliable. In this multicentre study 717 artificial water samples, spiked with fixed concentrations of Legionella and interfering bacterial flora, were analysed by qPCR, vPCR and culture and data were compared by statistical analysis. A heat-treatment at 55 °C for 10 minutes was also performed to obtain viable and not-viable bacteria. When data of vPCR were compared with those of culture and qPCR, statistical analysis showed significant differences (P 0.05). Overall this study provided a good experimental reproducibility of vPCR but also highlighted limits of PMA in the discriminating capability of dead and live bacteria, making vPCR not completely reliable. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Significance of Viable but Nonculturable Escherichia coli: Induction, Detection, and Control.

    Science.gov (United States)

    Ding, Tian; Suo, Yuanjie; Xiang, Qisen; Zhao, Xihong; Chen, Shiguo; Ye, Xingqian; Liu, Donghong

    2017-03-28

    Diseases caused by foodborne or waterborne pathogens are emerging. Many pathogens can enter into the viable but nonculturable (VBNC) state, which is a survival strategy when exposed to harsh environmental stresses. Pathogens in the VBNC state have the ability to evade conventional microbiological detection methods, posing a significant and potential health risk. Therefore, controlling VBNC bacteria in food processing and the environment is of great importance. As the typical one of the gram-negatives, Escherichia coli (E. coli) is a widespread foodborne and waterborne pathogenic bacterium and is able to enter into a VBNC state in extreme conditions (similar to the other gram-negative bacteria), including inducing factors and resuscitation stimulus. VBNC E. coli has the ability to recover both culturability and pathogenicity, which may bring potential health risk. This review describes the concrete factors (nonthermal treatment, chemical agents, and environmental factors) that induce E. coli into the VBNC state, the condition or stimulus required for resuscitation of VBNC E. coli, and the methods for detecting VBNC E. coli. Furthermore, the mechanism of genes and proteins involved in the VBNC E. coli is also discussed in this review.

  11. Using Generic Examples to Make Viable Arguments

    Science.gov (United States)

    Adams, Anne E.; Ely, Rob; Yopp, David

    2017-01-01

    The twenty-first century has seen an increased call to train students to craft mathematical arguments. The third of the Common Core's (CCSS) Standards for Mathematical Practice (SMP 3) (CCSSI 2010) calls for all mathematically proficient students to "construct viable arguments" to support the truth of their ideas and to "critique…

  12. Aeroallergens and viable microbes in sandstorm dust. Potential triggers of allergic and nonallergic respiratory ailments.

    Science.gov (United States)

    Kwaasi, A A; Parhar, R S; al-Mohanna, F A; Harfi, H A; Collison, K S; al-Sedairy, S T

    1998-03-01

    Aeroallergens and antigens in sandstorm dust, extracts of which were skin prick test (SPT) positive in allergic patients, were detected by rocket immunoelectrophoresis and ELISA. Fungi and bacteria isolated by agar settle plates and soil dilution and soil washing methods were enumerated and identified. Cat dander, Acacia, Alternaria, Aspergillus, Chenopodium, Cladosporium, Bermuda grass, Pithecellobium, Prosopis, Rumex, cultivated rye, and Washingtonia palm allergens were detected by both methods. Viable microbes including 1892 +/- 325 colony-forming units (cfu) of bacteria, and 869 +/- 75 cfu of fungi were isolated per gram of dust by the soil dilution method. Randomly selected microbial colonies on streaking and subculture were found to consist of between two and seven mixed colonies. Fungi including Alternaria, Aspergillus, Botrytis, Cladosporium, Mortierella, Mucor, Mycelia sterilia, Penicillium, Pythium, Ulocladium, Verticillium, and some yeasts were isolated. Actinomyces, Bacillus, Pseudomonas, and mostly coagulase-negative Staphylococcus species were identified, but the bulk of unidentified bacterial isolates were mainly mixed colonies of rods, cocci, coccobacilli, and some filamentous types. Six-hour agar settle-plate counts during sandstorms were 100 and 40% higher for bacteria and fungi, respectively, than without sandstorms. The most abundant aeroallergens were those of Acacia, Alternaria, Aspergillus, Bermuda grass, Cladosporium, cultivated rye, Prosopis, and cat dander. Pithecellobium dulce, Rumex crispus, and Washingtonia palm allergens were detectable for the first time in Riyadh. IgE reactivities of the dust in man were demonstrated by ELISA using sera from atopic, exposed, and normal subjects. These results indicate that sandstorm dust is a prolific source of potential triggers of allergic and nonallergic respiratory ailments, and the methods mentioned here should be routinely used for quick sampling of the environment.

  13. Detection and quantification of viable Bacillus cereus group species in milk by propidium monoazide quantitative real-time PCR.

    Science.gov (United States)

    Cattani, Fernanda; Barth, Valdir C; Nasário, Jéssica S R; Ferreira, Carlos A S; Oliveira, Sílvia D

    2016-04-01

    The Bacillus cereus group includes important spore-forming bacteria that present spoilage capability and may cause foodborne diseases. These microorganisms are traditionally evaluated in food using culturing methods, which can be laborious and time-consuming, and may also fail to detect bacteria in a viable but nonculturable state. The purpose of this study was to develop a quantitative real-time PCR (qPCR) combined with a propidium monoazide (PMA) treatment to analyze the contamination of UHT milk by B. cereus group species viable cells. Thirty micrograms per milliliter of PMA was shown to be the most effective concentration for reducing the PCR amplification of extracellular DNA and DNA from dead cells. The quantification limit of the PMA-qPCR assay was 7.5 × 10(2) cfu/mL of milk. One hundred thirty-five UHT milk samples were analyzed to evaluate the association of PMA to qPCR to selectively detect viable cells. The PMA-qPCR was able to detect B. cereus group species in 44 samples (32.6%), whereas qPCR without PMA detected 78 positive samples (57.8%). Therefore, the PMA probably inhibited the amplification of DNA from cells that were killed during UHT processing, which avoided an overestimation of bacterial cells when using qPCR and, thus, did not overvalue potential health risks. A culture-based method was also used to detect and quantify B. cereus sensu stricto in the same samples and showed positive results in 15 (11.1%) samples. The culture method and PMA-qPCR allowed the detection of B. cereus sensu stricto in quantities compatible with the infective dose required to cause foodborne disease in 3 samples, indicating that, depending on the storage conditions, even after UHT treatment, infective doses may be reached in ready-to-consume products. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  14. Monotone viable trajectories for functional differential inclusions

    Science.gov (United States)

    Haddad, Georges

    This paper is a study on functional differential inclusions with memory which represent the multivalued version of retarded functional differential equations. The main result gives a necessary and sufficient equations. The main result gives a necessary and sufficient condition ensuring the existence of viable trajectories; that means trajectories remaining in a given nonempty closed convex set defined by given constraints the system must satisfy to be viable. Some motivations for this paper can be found in control theory where F( t, φ) = { f( t, φ, u)} uɛU is the set of possible velocities of the system at time t, depending on the past history represented by the function φ and on a control u ranging over a set U of controls. Other motivations can be found in planning procedures in microeconomics and in biological evolutions where problems with memory do effectively appear in a multivalued version. All these models require viability constraints represented by a closed convex set.

  15. Protein design algorithms predict viable resistance to an experimental antifolate.

    Science.gov (United States)

    Reeve, Stephanie M; Gainza, Pablo; Frey, Kathleen M; Georgiev, Ivelin; Donald, Bruce R; Anderson, Amy C

    2015-01-20

    Methods to accurately predict potential drug target mutations in response to early-stage leads could drive the design of more resilient first generation drug candidates. In this study, a structure-based protein design algorithm (K* in the OSPREY suite) was used to prospectively identify single-nucleotide polymorphisms that confer resistance to an experimental inhibitor effective against dihydrofolate reductase (DHFR) from Staphylococcus aureus. Four of the top-ranked mutations in DHFR were found to be catalytically competent and resistant to the inhibitor. Selection of resistant bacteria in vitro reveals that two of the predicted mutations arise in the background of a compensatory mutation. Using enzyme kinetics, microbiology, and crystal structures of the complexes, we determined the fitness of the mutant enzymes and strains, the structural basis of resistance, and the compensatory relationship of the mutations. To our knowledge, this work illustrates the first application of protein design algorithms to prospectively predict viable resistance mutations that arise in bacteria under antibiotic pressure.

  16. Platelet Activation by Streptococcus pyogenes Leads to Entrapment in Platelet Aggregates, from Which Bacteria Subsequently Escape

    Science.gov (United States)

    Svensson, Lisbeth; Baumgarten, Maria; Mörgelin, Matthias

    2014-01-01

    Platelet activation and aggregation have been reported to occur in response to a number of Gram-positive pathogens. Here, we show that platelet aggregates induced by Streptococcus pyogenes were unstable and that viable bacteria escaped from the aggregates over time. This was not due to differential activation in response to the bacteria compared with physiological activators. All the bacterial isolates induced significant platelet activation, including integrin activation and alpha and dense-granule release, at levels equivalent to those induced by potent physiological platelet activators that induced stable aggregates. The ability to escape the aggregates and to resist the antibacterial effects of platelets was dependent on active protein synthesis by the bacteria within the aggregate. We conclude that S. pyogenes bacteria can temporarily cover themselves with activated platelets, and we propose that this may facilitate survival of the bacteria in the presence of platelets. PMID:25069984

  17. Quantification and qualification of bacteria trapped in chewed gum.

    Directory of Open Access Journals (Sweden)

    Stefan W Wessel

    Full Text Available Chewing of gum contributes to the maintenance of oral health. Many oral diseases, including caries and periodontal disease, are caused by bacteria. However, it is unknown whether chewing of gum can remove bacteria from the oral cavity. Here, we hypothesize that chewing of gum can trap bacteria and remove them from the oral cavity. To test this hypothesis, we developed two methods to quantify numbers of bacteria trapped in chewed gum. In the first method, known numbers of bacteria were finger-chewed into gum and chewed gums were molded to standard dimensions, sonicated and plated to determine numbers of colony-forming-units incorporated, yielding calibration curves of colony-forming-units retrieved versus finger-chewed in. In a second method, calibration curves were created by finger-chewing known numbers of bacteria into gum and subsequently dissolving the gum in a mixture of chloroform and tris-ethylenediaminetetraacetic-acid (TE-buffer. The TE-buffer was analyzed using quantitative Polymerase-Chain-Reaction (qPCR, yielding calibration curves of total numbers of bacteria versus finger-chewed in. Next, five volunteers were requested to chew gum up to 10 min after which numbers of colony-forming-units and total numbers of bacteria trapped in chewed gum were determined using the above methods. The qPCR method, involving both dead and live bacteria yielded higher numbers of retrieved bacteria than plating, involving only viable bacteria. Numbers of trapped bacteria were maximal during initial chewing after which a slow decrease over time up to 10 min was observed. Around 10(8 bacteria were detected per gum piece depending on the method and gum considered. The number of species trapped in chewed gum increased with chewing time. Trapped bacteria were clearly visualized in chewed gum using scanning-electron-microscopy. Summarizing, using novel methods to quantify and qualify oral bacteria trapped in chewed gum, the hypothesis is confirmed that chewing

  18. Air-spore in Cartagena, Spain: viable and non-viable sampling methods.

    Science.gov (United States)

    Elvira-Rendueles, Belen; Moreno, Jose; Garcia-Sanchez, Antonio; Vergara, Nuria; Martinez-Garcia, Maria Jose; Moreno-Grau, Stella

    2013-01-01

    In the presented study the airborne fungal spores of the semiarid city of Cartagena, Spain, are identified and quantified by means of viable or non-viable sampling methods. Airborne fungal samples were collected simultaneously using a filtration method and a pollen and particle sampler based on the Hirst methodology. This information is very useful for elucidating geographical patterns of hay fever and asthma. The qualitative results showed that when the non-viable methodology was employed, Cladosporium, Ustilago, and Alternaria were the most abundant spores identified in the atmosphere of Cartagena, while the viable methodology showed that the most abundant taxa were: Cladosporium, Penicillium, Aspergillus and Alternaria. The quantitative results of airborne fungal spores identified by the Hirst-type air sampler (non-viable method), showed that Deuteromycetes represented 74% of total annual spore counts, Cladosporium being the major component of the fungal spectrum (62.2%), followed by Alternaria (5.3%), and Stemphylium (1.3%). The Basidiomycetes group represented 18.9% of total annual spore counts, Ustilago (7.1%) being the most representative taxon of this group and the second most abundant spore type. Ascomycetes accounted for 6.9%, Nectria (2.3%) being the principal taxon. Oomycetes (0.2%) and Zygomycestes and Myxomycestes (0.06%) were scarce. The prevailing species define our bioaerosol as typical of dry air. The viable methodology was better at identifying small hyaline spores and allowed for the discrimination of the genus of some spore types. However, non-viable methods revealed the richness of fungal types present in the bioaerosol. Thus, the use of both methodologies provides a more comprehensive characterization of the spore profile.

  19. Parejas viables que perduran en el tiempo

    OpenAIRE

    Juan José Cuervo Rodríguez

    2013-01-01

    El presente artículo científico presenta resultados del proceso llevado a cabo en el proyecto de investigación docente "Mecanismos de autorregulación en parejas viables que perduran en el tiempo". Se soporta en una mirada compleja de la psicología basada en una epistemología de la construcción. En el ámbito metodológico, se inscribe en los estudios de terapia familiar desde una perspectiva de la comunicación humana como un todo integrado. Participaron nueve parejas. Los criterios de inclusión...

  20. Non-viable Borrelia burgdorferi induce inflammatory mediators and apoptosis in human oligodendrocytes.

    Science.gov (United States)

    Parthasarathy, Geetha; Fevrier, Helene B; Philipp, Mario T

    2013-11-27

    In previous studies, exposure to live Borrelia burgdorferi was shown to induce inflammation and apoptosis of human oligodendrocytes. In this study we assessed the ability of non-viable bacteria (heat killed or sonicated) to induce inflammatory mediators and cell death. Both heat-killed and sonicated bacteria induced release of CCL2, IL-6, and CXCL8 from oligodendrocytes in a dose dependent manner. In addition, non-viable B. burgdorferi also induced cell death as evaluated by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and another cell viability assay. These results suggest that spirochetal residues left after bacterial demise, due to treatment or otherwise, may continue to be pathogenic to the central nervous system. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  1. Enzymatic isolation of viable human odontoblasts.

    Science.gov (United States)

    Cuffaro, H M; Pääkkönen, V; Tjäderhane, L

    2016-05-01

    To improve an enzymatic method previously used for isolation of rat odontoblasts to isolate viable mature human odontoblasts. Collagenase I, collagenase I/hyaluronidase mixture and hyaluronidase were used to extract mature human odontoblasts from the pulp chamber. Detachment of odontoblasts from dentine was determined with field emission scanning electron microscopy (FESEM) and to analyse the significance of differences in tubular diameter, and the t-test was used. MTT-reaction was used to analyse cell viability, and nonparametric Kruskal-Wallis and Mann-Whitney post hoc tests were used to analyse the data. Immunofluorescent staining of dentine sialoprotein (DSP), aquaporin-4 (AQP4) and matrix metalloproteinase-20 (MMP-20) and quantitative PCR (qPCR) of dentine sialophosphoprotein (DSPP) were used to confirm the odontoblastic nature of the cells. MTT-reaction and FESEM demonstrated collagenase I/hyaluronidase resulted in more effective detachment and higher viability than collagenase I alone. Hyaluronidase alone was not able to detach odontoblasts. Immunofluorescence revealed the typical odontoblastic-morphology with one process, and DSP, AQP4 and MMP-20 were detected. Quantitative PCR of DSPP confirmed that the isolated cells expressed this odontoblast-specific gene. The isolation of viable human odontoblasts was successful. The cells demonstrated morphology typical for odontoblasts and expressed characteristic odontoblast-type genes and proteins. This method will enable new approaches, such as apoptosis analysis, for studies using fully differentiated odontoblasts. © 2015 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  2. Manufacture of Probiotic Bacteria

    Science.gov (United States)

    Muller, J. A.; Ross, R. P.; Fitzgerald, G. F.; Stanton, C.

    Lactic acid bacteria (LAB) have been used for many years as natural biopreservatives in fermented foods. A small group of LAB are also believed to have beneficial health effects on the host, so called probiotic bacteria. Probiotics have emerged from the niche industry from Asia into European and American markets. Functional foods are one of the fastest growing markets today, with estimated growth to 20 billion dollars worldwide by 2010 (GIA, 2008). The increasing demand for probiotics and the new food markets where probiotics are introduced, challenges the industry to produce high quantities of probiotic cultures in a viable and stable form. Dried concentrated probiotic cultures are the most convenient form for incorporation into functional foods, given the ease of storage, handling and transport, especially for shelf-stable functional products. This chapter will discuss various aspects of the challenges associated with the manufacturing of probiotic cultures.

  3. A Rapid Method for Quantifying Viable Mycobacterium avium subsp. paratuberculosis in Cellular Infection Assays

    Science.gov (United States)

    Pooley, Hannah B.; de Silva, Kumudika; Purdie, Auriol C.; Begg, Douglas J.; Whittington, Richard J.

    2016-01-01

    ABSTRACT Determining the viability of bacteria is a key outcome of in vitro cellular infection assays. Currently, this is done by culture, which is problematic for fastidious slow-growing bacteria such as Mycobacterium avium subsp. paratuberculosis, where it can take up to 4 months to confirm growth. This study aimed to identify an assay that can rapidly quantify the number of viable M. avium subsp. paratuberculosis cells in a cellular sample. Three commercially available bacterial viability assays along with a modified liquid culture method coupled with high-throughput quantitative PCR growth detection were assessed. Criteria for assessment included the ability of each assay to differentiate live and dead M. avium subsp. paratuberculosis organisms and their accuracy at low bacterial concentrations. Using the culture-based method, M. avium subsp. paratuberculosis growth was reliably detected and quantified within 2 weeks. There was a strong linear association between the 2-week growth rate and the initial inoculum concentration. The number of viable M. avium subsp. paratuberculosis cells in an unknown sample was quantified based on the growth rate, by using growth standards. In contrast, none of the commercially available viability assays were suitable for use with samples from in vitro cellular infection assays. IMPORTANCE Rapid quantification of the viability of Mycobacterium avium subsp. paratuberculosis in samples from in vitro cellular infection assays is important, as it allows these assays to be carried out on a large scale. In vitro cellular infection assays can function as a preliminary screening tool, for vaccine development or antimicrobial screening, and also to extend findings derived from experimental animal trials. Currently, by using culture, it takes up to 4 months to obtain quantifiable results regarding M. avium subsp. paratuberculosis viability after an in vitro infection assay; however, with the quantitative PCR and liquid culture method

  4. Roots of success: cultivating viable community forestry

    Energy Technology Data Exchange (ETDEWEB)

    MacQueen, Duncan

    2009-05-15

    Is community forestry emerging from the shadows? The evidence shows that locally controlled enterprises can be economically viable, and often build on stronger social and environmental foundations than the big private-sector players. Certainly this is an industry in need of a shakeup. Many forests have become flashpoints where agro-industry, large-scale logging concerns and conservation interests clash, while forest-dependent communities are left out in the cold. Meanwhile, governments – driven by concerns over the climate impacts of deforestation – are having to gear up for legal, sustainable forestry production. Community forestry could be crucial to solving many of these challenges. By building on local core capabilities and developing strategic partnerships, they are forging key new business models that could transform the sector.

  5. Polymerase chain reaction-based discrimination of viable from non-viable Mycoplasma gallisepticum

    Directory of Open Access Journals (Sweden)

    Ching Giap Tan

    2014-02-01

    Full Text Available The present study was based on the reverse transcription polymerase chain reaction (RT-PCR of the 16S ribosomal nucleic acid (rRNA of Mycoplasma for detection of viable Mycoplasma gallisepticum. To determine the stability of M. gallisepticum 16S rRNA in vitro, three inactivation methods were used and the suspensions were stored at different temperatures. The 16S rRNA of M. gallisepticum was detected up to approximately 20–25 h at 37 °C, 22–25 h at 16 °C, and 23–27 h at 4 °C. The test, therefore, could detect viable or recently dead M. gallisepticum (< 20 h. The RT-PCR method was applied during an in vivo study of drug efficacy under experimental conditions, where commercial broiler-breeder eggs were inoculated with M. gallisepticum into the yolk. Hatched chicks that had been inoculated in ovo were treated with Macrolide 1. The method was then applied in a flock of day 0 chicks with naturally acquired vertical transmission of M. gallisepticum, treated with Macrolide 2. Swabs of the respiratory tract were obtained for PCR and RT-PCR evaluations to determine the viability of M. gallisepticum. This study proved that the combination of both PCR and RT-PCR enables detection and differentiation of viable from non-viable M. gallisepticum.

  6. Reclassification of rhizosphere bacteria including strains causing corky root of lettuce and proposal of Rhizorhapis suberifaciens gen. nov., comb. nov., Sphingobium mellinum sp. nov., Sphingobium xanthum sp. nov. and Rhizorhabdus argentea gen. nov., sp. nov.

    Science.gov (United States)

    Francis, Isolde M; Jochimsen, Kenneth N; De Vos, Paul; van Bruggen, Ariena H C

    2014-04-01

    The genus Rhizorhapis gen. nov. (to replace the illegitimate genus name Rhizomonas) is proposed for strains of Gram-negative bacteria causing corky root of lettuce, a widespread and important lettuce disease worldwide. Only one species of the genus Rhizomonas was described, Rhizomonas suberifaciens, which was subsequently reclassified as Sphingomonas suberifaciens based on 16S rRNA gene sequences and the presence of sphingoglycolipid in the cell envelope. However, the genus Sphingomonas is so diverse that further reclassification was deemed necessary. Twenty new Rhizorhapis gen. nov.- and Sphingomonas-like isolates were obtained from lettuce or sow thistle roots, or from soil using lettuce seedlings as bait. These and previously reported isolates were characterized in a polyphasic study including 16S rRNA gene sequencing, DNA-DNA hybridization, DNA G+C content, whole-cell fatty acid composition, morphology, substrate oxidation, temperature and pH sensitivity, and pathogenicity to lettuce. The isolates causing lettuce corky root belonged to the genera Rhizorhapis gen. nov., Sphingobium, Sphingopyxis and Rhizorhabdus gen. nov. More specifically, we propose to reclassify Rhizomonas suberifaciens as Rhizorhapis suberifaciens gen. nov., comb. nov. (type strain, CA1(T) = LMG 17323(T) = ATCC 49355(T)), and also propose the novel species Sphingobium xanthum sp. nov., Sphingobium mellinum sp. nov. and Rhizorhabdus argentea gen. nov., sp. nov. with the type strains NL9(T) ( = LMG 12560(T) = ATCC 51296(T)), WI4(T) ( = LMG 11032(T) = ATCC 51292(T)) and SP1(T) ( = LMG 12581(T) = ATCC 51289(T)), respectively. Several strains isolated from lettuce roots belonged to the genus Sphingomonas, but none of them were pathogenic.

  7. ATP bioluminescence rapid detection of total viable count in soy sauce.

    Science.gov (United States)

    Yan, Shou-Lei; Miao, Su-Na; Deng, Shao-Ya; Zou, Min-Juan; Zhong, Fo-Sheng; Huang, Wen-Biao; Pan, Si-Yi; Wang, Qing-Zhang

    2012-01-01

    The adenosine triphosphate (ATP) bioluminescence rapid determination method may be useful for enumerating the total viable count (TVC) in soy sauce, as it has been previously used in food and beverages for sanitation with good precision. However, many factors interfere with the correlation between total aerobic plate counts and ATP bioluminescence. This study investigated these interfering factors, including ingredients of soy sauce and bacteria at different physiological stages. Using the ATP bioluminescence method, TVC was obtained within 4 h, compared to 48 h required for the conventional aerobic plate count (APC) method. Our results also indicated a high correlation coefficient (r = 0.90) between total aerobic plate counts and ATP bioluminescence after filtration and resuscitation with special medium. The limit of quantification of the novel detection method is 100 CFU/mL; there is a good linear correlation between the bioluminescence intensity and TVC in soy sauce in the range 1 × 10(2) -3 × 10(4) CFU/mL and even wider. The method employed a luminescence recorder (Tristar LB-941) and 96-well plates and could analyse 50-100 samples simultaneously at low cost. In this study, we evaluated and eliminated the interfering factors and made the ATP bioluminescence rapid method available for enumerating TVC in soy sauce. Copyright © 2011 John Wiley & Sons, Ltd.

  8. Preliminary stochastic model for managing Vibrio parahaemolyticus and total viable bacterial counts in a Pacific oyster (Crassostrea gigas) supply chain.

    Science.gov (United States)

    Fernandez-Piquer, Judith; Bowman, John P; Ross, Tom; Estrada-Flores, Silvia; Tamplin, Mark L

    2013-07-01

    Vibrio parahaemolyticus can accumulate and grow in oysters stored without refrigeration, representing a potential food safety risk. High temperatures during oyster storage can lead to an increase in total viable bacteria counts, decreasing product shelf life. Therefore, a predictive tool that allows the estimation of both V. parahaemolyticus populations and total viable bacteria counts in parallel is needed. A stochastic model was developed to quantitatively assess the populations of V. parahaemolyticus and total viable bacteria in Pacific oysters for six different supply chain scenarios. The stochastic model encompassed operations from oyster farms through consumers and was built using risk analysis software. Probabilistic distributions and predictions for the percentage of Pacific oysters containing V. parahaemolyticus and high levels of viable bacteria at the point of consumption were generated for each simulated scenario. This tool can provide valuable information about V. parahaemolyticus exposure and potential control measures and can help oyster companies and regulatory agencies evaluate the impact of product quality and safety during cold chain management. If coupled with suitable monitoring systems, such models could enable preemptive action to be taken to counteract unfavorable supply chain conditions.

  9. Molecular approaches for viable bacterial population and transcriptional analyses in a rodent model of dental caries.

    Science.gov (United States)

    Klein, M I; Scott-Anne, K M; Gregoire, S; Rosalen, P L; Koo, H

    2012-10-01

    Culturing methods are the primary approach for microbiological analysis of plaque biofilms in rodent models of dental caries. In this study, we developed strategies for the isolation of DNA and RNA from plaque biofilms formed in vivo to analyse the viable bacterial population and gene expression. Plaque biofilm samples from rats were treated with propidium monoazide to isolate DNA from viable cells, and the purified DNA was used to quantify total bacteria and the Streptococcus mutans population via quantitative polymerase chain reaction (qPCR) and specific primers; the same samples were also analysed by counting colony-forming units (CFU). In parallel, RNA was isolated from plaque-biofilm samples (from the same animals) and used for transcriptional analyses via reverse transcription-qPCR. The viable populations of both S. mutans and total bacteria assessed by qPCR were positively correlated with the CFU data (P  0.8). However, the qPCR data showed higher bacterial cell counts, particularly for total bacteria (vs. CFU). Moreover, S. mutans proportion in the plaque biofilm determined by qPCR analysis showed strong correlation with incidence of smooth-surface caries (P = 0.0022, r = 0.71). The purified RNAs presented high RNA integrity numbers (> 7), which allowed measurement of the expression of genes that are critical for S. mutans virulence (e.g. gtfB and gtfC). Our data show that the viable microbial population and the gene expression can be analysed simultaneously, providing a global assessment of the infectious aspect of dental caries. Our approach could enhance the value of the current rodent model in further understanding the pathophysiology of this disease and facilitating the exploration of novel anti-caries therapies. © 2012 John Wiley & Sons A/S.

  10. The Conceptual Mechanism for Viable Organizational Learning Based on Complex System Theory and the Viable System Model

    Science.gov (United States)

    Sung, Dia; You, Yeongmahn; Song, Ji Hoon

    2008-01-01

    The purpose of this research is to explore the possibility of viable learning organizations based on identifying viable organizational learning mechanisms. Two theoretical foundations, complex system theory and viable system theory, have been integrated to provide the rationale for building the sustainable organizational learning mechanism. The…

  11. Economically viable large-scale hydrogen liquefaction

    Science.gov (United States)

    Cardella, U.; Decker, L.; Klein, H.

    2017-02-01

    The liquid hydrogen demand, particularly driven by clean energy applications, will rise in the near future. As industrial large scale liquefiers will play a major role within the hydrogen supply chain, production capacity will have to increase by a multiple of today’s typical sizes. The main goal is to reduce the total cost of ownership for these plants by increasing energy efficiency with innovative and simple process designs, optimized in capital expenditure. New concepts must ensure a manageable plant complexity and flexible operability. In the phase of process development and selection, a dimensioning of key equipment for large scale liquefiers, such as turbines and compressors as well as heat exchangers, must be performed iteratively to ensure technological feasibility and maturity. Further critical aspects related to hydrogen liquefaction, e.g. fluid properties, ortho-para hydrogen conversion, and coldbox configuration, must be analysed in detail. This paper provides an overview on the approach, challenges and preliminary results in the development of efficient as well as economically viable concepts for large-scale hydrogen liquefaction.

  12. Beer spoilage bacteria and hop resistance

    NARCIS (Netherlands)

    Sakamoto, K; Konings, WN

    2003-01-01

    For brewing industry, beer spoilage bacteria have been problematic for centuries. They include some lactic acid bacteria such as Lactobacillus brevis, Lactobacillus lindneri and Pediococcus damnosus, and some Gram-negative bacteria such as Pectinatus cerevisiiphilus, Pectinatus frisingensis and

  13. Sorption and precipitation of Mn2+ by viable and autoclaved Shewanella putrefaciens: Effect of contact time

    KAUST Repository

    Chubar, Natalia

    2013-01-01

    The sorption of Mn(II) by viable and inactivated cells of Shewanella putrefaciens, a non-pathogenic, facultative anaerobic, gram-negative bacterium characterised as a Mn(IV) and Fe(III) reducer, was studied under aerobic conditions, as a function of pH, bacterial density and metal loading. During a short contact time (3-24h), the adsorptive behaviour of live and dead bacteria toward Mn(II) was sufficiently similar, an observation that was reflected in the studies on adsorption kinetics at various metal loadings, effects of pH, bacteria density, isotherms and drifting of pH during adsorption. Continuing the experiment for an additional 2-30days demonstrated that the Mn(II) sorption by suspensions of viable and autoclaved cells differed significantly from one another. The sorption to dead cells was characterised by a rapid equilibration and was described by an isotherm. In contrast, the sorption (uptake) to live bacteria exhibited a complex time-dependent uptake. This uptake began as adsorption and ion exchange processes followed by bioprecipitation, and it was accompanied by the formation of polymeric sugars (EPS) and the release of dissolved organic substances. FTIR, EXAFS/XANES and XPS demonstrated that manganese(II) phosphate was the main precipitate formed in 125ml batches, which is the first evidence of the ability of microbes to synthesise manganese phosphates. XPS and XANES spectra did not detect Mn(II) oxidation. Although the release of protein-like compounds by the viable bacteria increased in the presence of Mn2+ (and, by contrast, the release of carbohydrates did not change), electrochemical analyses did not indicate any aqueous complexation of Mn(II) by the organic ligands. © 2012 Elsevier Ltd.

  14. Isolation and characterization of bacteria capable of tolerating the extreme conditions of clean room environments.

    Science.gov (United States)

    La Duc, Myron T; Dekas, Anne; Osman, Shariff; Moissl, Christine; Newcombe, David; Venkateswaran, Kasthuri

    2007-04-01

    In assessing the bacterial populations present in spacecraft assembly, spacecraft test, and launch preparation facilities, extremophilic bacteria (requiring severe conditions for growth) and extremotolerant bacteria (tolerant to extreme conditions) were isolated. Several cultivation approaches were employed to select for and identify bacteria that not only survive the nutrient-limiting conditions of clean room environments but can also withstand even more inhospitable environmental stresses. Due to their proximity to spacefaring objects, these bacteria pose a considerable risk for forward contamination of extraterrestrial sites. Samples collected from four geographically distinct National Aeronautics and Space Administration clean rooms were challenged with UV-C irradiation, 5% hydrogen peroxide, heat shock, pH extremes (pH 3.0 and 11.0), temperature extremes (4 degrees C to 65 degrees C), and hypersalinity (25% NaCl) prior to and/or during cultivation as a means of selecting for extremotolerant bacteria. Culture-independent approaches were employed to measure viable microbial (ATP-based) and total bacterial (quantitative PCR-based) burdens. Intracellular ATP concentrations suggested a viable microbial presence ranging from below detection limits to 10(6) cells/m(2). However, only 0.1 to 55% of these viable cells were able to grow on defined culture medium. Isolated members of the Bacillaceae family were more physiologically diverse than those reported in previous studies, including thermophiles (Geobacillus), obligate anaerobes (Paenibacillus), and halotolerant, alkalophilic species (Oceanobacillus and Exiguobacterium). Non-spore-forming microbes (alpha- and beta-proteobacteria and actinobacteria) exhibiting tolerance to the selected stresses were also encountered. The multiassay cultivation approach employed herein enhances the current understanding of the physiological diversity of bacteria housed in these clean rooms and leads us to ponder the origin and means

  15. Parejas viables que perduran en el tiempo

    Directory of Open Access Journals (Sweden)

    Juan José Cuervo Rodríguez

    2013-01-01

    Full Text Available El presente artículo científico presenta resultados del proceso llevado a cabo en el proyecto de investigación docente "Mecanismos de autorregulación en parejas viables que perduran en el tiempo". Se soporta en una mirada compleja de la psicología basada en una epistemología de la construcción. En el ámbito metodológico, se inscribe en los estudios de terapia familiar desde una perspectiva de la comunicación humana como un todo integrado. Participaron nueve parejas. Los criterios de inclusión fueron: cinco o más años de convivencia, participación voluntaria, no presentar (ni haber presentado problemáticas especiales que ameriten intervención psicoterapéutica y la obtención de un porcentaje significativo en el uso de estrategias de comunicación asertiva en la resolución de conflictos. El método general utilizado fue el análisis de la comunicación en tarea de conversación. Los principales hallazgos señalan una estrecha relación entre el contexto de desarrollo de las parejas, la emergencia de códigos comunicacionales propios y la posibilidad de perdurar en el tiempo; también, se resalta el tipo de comunicación asertiva o constructiva, la construcción de valores como el respeto y la aceptación de las diferencias, y el deseo por vivir y construir bienestar común, como elementos constitutivos de su identidad como pareja.

  16. Acquisition of a High Diversity of Bacteria during the Hajj Pilgrimage, Including Acinetobacter baumannii with blaOXA-72 and Escherichia coli with blaNDM-5 Carbapenemase Genes

    Science.gov (United States)

    Leangapichart, Thongpan; Gautret, Philippe; Belhouchat, Khadidja; Memish, Ziad; Raoult, Didier

    2016-01-01

    Pilgrims returning from the Hajj (pilgrimage to Mecca) can be carriers of multidrug-resistant bacteria (MDR). Pharyngeal and rectal swab samples were collected from 98 pilgrims before and after they traveled to the Hajj in 2014 to investigate the acquisition of MDR bacteria. The bacterial diversity in pharyngeal swab samples was assessed by culture with selective media. There was a significantly higher diversity of bacteria in samples collected after the return from the Hajj than in those collected before (P = 0.0008). Surprisingly, Acinetobacter baumannii strains were isolated from 16 pharyngeal swab samples (1 sample taken during the Hajj and 15 samples taken upon return) and 26 post-Hajj rectal swab samples, while none were isolated from samples taken before the Hajj. Testing of all samples by real-time PCR targeting blaOXA-51 gave positive results for only 1% of samples taken during the Hajj, 21/90 (23.3%) pharyngeal swab samples taken post-Hajj, and 35/90 (38.9%) rectal swab samples taken post-Hajj. One strain of A. baumannii isolated from the pharynx was resistant to imipenem and harbored a blaOXA-72 carbapenemase gene. Multilocus sequence typing analysis of 43 A. baumannii isolates revealed a huge diversity of 35 sequence types (STs), among which 18 were novel STs reported for the first time in this study. Moreover, we also found one Escherichia coli isolate, collected from a rectal swab sample from a pilgrim taken after the Hajj, which harbored blaNDM-5, blaCTX-M-15, blaTEM-1, and aadA2 (ST2659 and ST181). In conclusion, pilgrims are at a potential risk of acquiring and transmitting MDR Acinetobacter spp. and carbapenemase-producing Gram-negative bacteria during the Hajj season. PMID:27458222

  17. Acquisition of a High Diversity of Bacteria during the Hajj Pilgrimage, Including Acinetobacter baumannii with blaOXA-72 and Escherichia coli with blaNDM-5 Carbapenemase Genes.

    Science.gov (United States)

    Leangapichart, Thongpan; Gautret, Philippe; Griffiths, Karolina; Belhouchat, Khadidja; Memish, Ziad; Raoult, Didier; Rolain, Jean-Marc

    2016-10-01

    Pilgrims returning from the Hajj (pilgrimage to Mecca) can be carriers of multidrug-resistant bacteria (MDR). Pharyngeal and rectal swab samples were collected from 98 pilgrims before and after they traveled to the Hajj in 2014 to investigate the acquisition of MDR bacteria. The bacterial diversity in pharyngeal swab samples was assessed by culture with selective media. There was a significantly higher diversity of bacteria in samples collected after the return from the Hajj than in those collected before (P = 0.0008). Surprisingly, Acinetobacter baumannii strains were isolated from 16 pharyngeal swab samples (1 sample taken during the Hajj and 15 samples taken upon return) and 26 post-Hajj rectal swab samples, while none were isolated from samples taken before the Hajj. Testing of all samples by real-time PCR targeting blaOXA-51 gave positive results for only 1% of samples taken during the Hajj, 21/90 (23.3%) pharyngeal swab samples taken post-Hajj, and 35/90 (38.9%) rectal swab samples taken post-Hajj. One strain of A. baumannii isolated from the pharynx was resistant to imipenem and harbored a blaOXA-72 carbapenemase gene. Multilocus sequence typing analysis of 43 A. baumannii isolates revealed a huge diversity of 35 sequence types (STs), among which 18 were novel STs reported for the first time in this study. Moreover, we also found one Escherichia coli isolate, collected from a rectal swab sample from a pilgrim taken after the Hajj, which harbored blaNDM-5, blaCTX-M-15, blaTEM-1, and aadA2 (ST2659 and ST181). In conclusion, pilgrims are at a potential risk of acquiring and transmitting MDR Acinetobacter spp. and carbapenemase-producing Gram-negative bacteria during the Hajj season. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  18. Antibacterial activity of silver-killed bacteria: the "zombies" effect

    Science.gov (United States)

    Wakshlak, Racheli Ben-Knaz; Pedahzur, Rami; Avnir, David

    2015-04-01

    We report a previously unrecognized mechanism for the prolonged action of biocidal agents, which we denote as the zombies effect: biocidally-killed bacteria are capable of killing living bacteria. The concept is demonstrated by first killing Pseudomonas aeruginosa PAO1 with silver nitrate and then challenging, with the dead bacteria, a viable culture of the same bacterium: Efficient antibacterial activity of the killed bacteria is observed. A mechanism is suggested in terms of the action of the dead bacteria as a reservoir of silver, which, due to Le-Chatelier's principle, is re-targeted to the living bacteria. Langmuirian behavior, as well as deviations from it, support the proposed mechanism.

  19. Presence of biofilm containing viable multiresistant organisms despite terminal cleaning on clinical surfaces in an intensive care unit.

    Science.gov (United States)

    Vickery, K; Deva, A; Jacombs, A; Allan, J; Valente, P; Gosbell, I B

    2012-01-01

    Despite recent attention to surface cleaning and hand hygiene programmes, multiresistant organisms (MROs) continue to be isolated from the hospital environment. Biofilms, consisting of bacteria embedded in exopolymeric substances (EPS) are difficult to remove due to their increased resistance to detergents and disinfectants, and periodically release free-swimming planktonic bacteria back into the environment which may may act as an infection source. To establish whether reservoirs of MROs exist in the environment as biofilms. Following terminal cleaning, equipment and furnishings were removed aseptically from an intensive care unit (ICU) and subjected to culture and scanning electron microscopy (SEM). Samples were placed in 5 mL of tryptone soya broth, sonicated for 5 min before plate culture on horse blood agar, Brillance MRSA and Brilliance VRE agar plates. Samples for SEM were fixed in 3% glutaraldehyde and hexamethyldisilizane (HMDS) prior to sputter-coating with gold and examination in an electron microscope. Biofilm was demonstrated visually on the sterile supply bucket, the opaque plastic door, the venetian blind cord, and the sink rubber, whereas EPS alone was seen on the curtain. Viable bacteria were grown from three samples, including MRSA from the venetian blind cord and the curtain. Biofilm containing MROs persist on clinical surfaces from an ICU despite terminal cleaning, suggesting that current cleaning practices are inadequate to control biofilm development. The presence of MROs being protected within these biofilms may be the mechanism by which MROs persist within the hospital environment. Copyright © 2011 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

  20. Viable group A streptococci in macrophages during acute soft tissue infection.

    Directory of Open Access Journals (Sweden)

    Pontus Thulin

    2006-03-01

    Full Text Available Group A streptococcal severe soft tissue infections, such as necrotizing fasciitis, are rapidly progressive infections associated with high mortality. Group A streptococcus is typically considered an extracellular pathogen, but has been shown to reside intracellularly in host cells.We characterized in vivo interactions between group A streptococci (GAS and cells involved in innate immune responses, using human biopsies (n = 70 collected from 17 patients with soft tissue infections. Immunostaining and in situ image analysis revealed high amounts of bacteria in the biopsies, even in those collected after prolonged antibiotic therapy. Viability of the streptococci was assessed by use of a bacterial viability stain, which demonstrated viable bacteria in 74% of the biopsies. GAS were present both extracellularly and intracellularly within phagocytic cells, primarily within macrophages. Intracellular GAS were predominantly noted in biopsies from newly involved tissue characterized by lower inflammation and bacterial load, whereas purely extracellular GAS or a combination of intra- and extracellular GAS dominated in severely inflamed tissue. The latter tissue was also associated with a significantly increased amount of the cysteine protease streptococcal pyrogenic exotoxin SpeB. In vitro studies confirmed that macrophages serve as reservoirs for viable GAS, and infection with a speB-deletion mutant produced significantly lower frequencies of cells with viable GAS following infection as compared to the wild-type bacteria.This is the first study to demonstrate that GAS survive intracellularly in macrophages during acute invasive infections. This intracellular presence may have evolved as a mechanism to avoid antibiotic eradication, which may explain our finding that high bacterial load is present even in tissue collected after prolonged intravenous antibiotic therapy. This new insight into the pathogenesis of streptococcal soft tissue infections

  1. Viable Group A Streptococci in Macrophages during Acute Soft Tissue Infection.

    Directory of Open Access Journals (Sweden)

    2006-01-01

    Full Text Available BACKGROUND: Group A streptococcal severe soft tissue infections, such as necrotizing fasciitis, are rapidly progressive infections associated with high mortality. Group A streptococcus is typically considered an extracellular pathogen, but has been shown to reside intracellularly in host cells. METHODS AND FINDINGS: We characterized in vivo interactions between group A streptococci (GAS and cells involved in innate immune responses, using human biopsies (n = 70 collected from 17 patients with soft tissue infections. Immunostaining and in situ image analysis revealed high amounts of bacteria in the biopsies, even in those collected after prolonged antibiotic therapy. Viability of the streptococci was assessed by use of a bacterial viability stain, which demonstrated viable bacteria in 74% of the biopsies. GAS were present both extracellularly and intracellularly within phagocytic cells, primarily within macrophages. Intracellular GAS were predominantly noted in biopsies from newly involved tissue characterized by lower inflammation and bacterial load, whereas purely extracellular GAS or a combination of intra- and extracellular GAS dominated in severely inflamed tissue. The latter tissue was also associated with a significantly increased amount of the cysteine protease streptococcal pyrogenic exotoxin SpeB. In vitro studies confirmed that macrophages serve as reservoirs for viable GAS, and infection with a speB-deletion mutant produced significantly lower frequencies of cells with viable GAS following infection as compared to the wild-type bacteria. CONCLUSIONS: This is the first study to demonstrate that GAS survive intracellularly in macrophages during acute invasive infections. This intracellular presence may have evolved as a mechanism to avoid antibiotic eradication, which may explain our finding that high bacterial load is present even in tissue collected after prolonged intravenous antibiotic therapy. This new insight into the pathogenesis

  2. Correlations between cyanobacterial density and bacterial transformation to the viable but nonculturable (VBNC) state in four freshwater water bodies.

    Science.gov (United States)

    Chen, Huirong; Shen, Ju; Pan, Gaoshan; Liu, Jing; Li, Jiancheng; Hu, Zhangli

    2015-10-01

    Nutrient concentrations, phytoplankton density and community composition, and the viable but nonculturable (VBNC) state of heterotrophic bacteria were investigated in three connected reservoirs and a small isolated lake in South China to study the relationship between biotic and abiotic factors and the VBNC state in bacteria. Nutrient concentrations in the reservoirs increased in the direction of water flow, whereas Wenshan Lake was more eutrophic. Cyanobacterial blooms occurred in all four water bodies, with differing seasonal trends and dominant species. In Xili and Tiegang Reservoirs, the VBNC ratio (percent of VBNC state bacteria over total viable bacteria) was high for most of the year and negatively correlated with cyanobacterial density. Laboratory co-culture experiments were performed with four heterotrophic bacterial species isolated from Wenshan Lake (Escherichia coli, Klebsiella peneumoniae, Bacillus megaterium and Bacillus cereus) and the dominant cyanobacterial species (Microcystis aeruginosa). For the first three bacterial species, the presence of M. aeruginosa induced the VBNC state and the VBNC ratio was positively correlated with M. aeruginosa density. However, B. cereus inhibited M. aeruginosa growth. These results demonstrate that cyanobacteria could potentially regulate the transformation to the VBNC state of waterborne bacteria, and suggest a role for bacteria in cyanobacterial bloom initiation and termination.

  3. Asouzu's Complementary Ontology as a Foundation for a Viable ...

    African Journals Online (AJOL)

    This paper on “Asouzu's Complementary Ontology as a foundation for a viable Ethic of the Environment”, posits that an ethic of the environment can be seen as viable if it considers the whole of reality as ontologically relevant. This point of view would free environmental ethics of anthropocentric bias and its attendant ...

  4. Grazing of particle-associated bacteria - An elimination of the non-viable fraction

    Digital Repository Service at National Institute of Oceanography (India)

    Gonsalves, M.J.B.D.; Fernandes, S.O.; LakshmiPriya, M.; LokaBharathi, P.A.

    multiply and release their progeny. © 2016 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/ licenses/by-nc-nd/4.0/). ion e capable....) and meroplank- tonic organisms (larval stages of benthic invertebrates: i.org/10.1016/j.bjm.2016.10.009 2016 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. This is an open access article under the CC icense (http...

  5. Big bacteria

    DEFF Research Database (Denmark)

    Schulz, HN; Jørgensen, BB

    2001-01-01

    and by actively creating an advective flow through the entire population. Diffusion limitation generally restricts the maximal size of prokaryotic cells and provides a selective advantage for mum-sized cells at the normally low substrate concentrations in the environment. The largest heterotrophic bacteria......, the 80 x 600 mum large Epulopiscium sp. from the gut of tropical fish, are presumably living in a very nutrient-rich medium. Many large bacteria contain numerous inclusions in the cells that reduce the volume of active cytoplasm. The most striking examples of competitive advantage from large cell size....... By their ability to store vast quantities of both nitrate and elemental sulfur in the cells, these bacteria have become independent of the coexistence of their substrates. In fact, a close relative, T. namibiensis, can probably respire in the sulfidic mud for several months before again filling up their large...

  6. Separation of viable and non-viable tomato (Solanum lycopersicum L.) seeds using single seed near-infrared spectroscopy

    DEFF Research Database (Denmark)

    Shrestha, Santosh; Deleuran, Lise Christina; Gislum, René

    2017-01-01

    -viable tomato seeds of two cultivars using chemometrics. The data exploration were performed by principal component analysis (PCA). Subsequently, viable and non-viable seeds were classified by partial least squares-discriminant analysis (PLS-DA) and interval PLS-DA (iPLS-DA). The indication of clustering...... of viable and non-viable seeds were observed in the PCA of each cultivar and the pooled samples. However, the PCA did not exhibit a pattern of separation among the early, normal and late germinated tomato seeds. The NIR spectral regions of 1160–1170, 1383–1397, 1647–1666, 1860–1884 and 1915–1940 nm were...... identified as important for classification of viable and non-viable tomato seeds by iPLS-DA. The sensitivity i.e. ability to correctly identify the positive samples and specificity i.e. ability to reject the negative samples of the (iPLS-DA) model on identified spectral regions for prediction of viable...

  7. Is telomerase a viable target in cancer?

    Science.gov (United States)

    Buseman, C.M.; Wright, W.E.; Shay, J.W.

    2012-01-01

    The ideal cancer treatment would specifically target cancer cells yet have minimal or no adverse effects on normal somatic cells. Telomerase, the ribonucleoprotein reverse transcriptase that maintains the ends of human chromosome, is an attractive cancer therapeutic target for exactly this reason [1]. Telomerase is expressed in more than 85% of cancer cells, making it a nearly universal cancer marker, while the majority of normal somatic cells are telomerase negative. Telomerase activity confers limitless replicative potential to cancer cells, a hallmark of cancer which must be attained for the continued growth that characterizes almost all advanced neoplasms [2]. In this review we will summarize the role of telomeres and telomerase in cancer cells, and how properties of telomerase are being exploited to create targeted cancer therapies including telomerase inhibitors, telomerase-targeted immunotherapies and telomerase-driven virotherapies. A frank and balanced assessment of the current state of telomerase inhibitors with caveats and potential limitations will be included. PMID:21802433

  8. Cooperativism, a viable option in Mexico

    Directory of Open Access Journals (Sweden)

    Martha E. Izquierdo Muciño

    2013-12-01

    Full Text Available There are a big number of successful cooperative societies that have survived to the worst ravages of economic politics that the country is currently living, including companies that originally were commercial enterprises. Therefore this becomes a living proof that thought this system, is possible to achieve an alternative economy, fairer and more inclusive where is possible to get out of the crisis that the county is facing.Received: 08.07.2013Accepted: 30.07.2013

  9. Real-time detection of viable microorganisms by intracellular phototautomerism

    Directory of Open Access Journals (Sweden)

    Schuren Frank

    2010-06-01

    Full Text Available Abstract Background To date, the detection of live microorganisms present in the environment or involved in infections is carried out by enumeration of colony forming units on agar plates, which is time consuming, laborious and limited to readily cultivable microorganisms. Although cultivation-independent methods are available, they involve multiple incubation steps and do mostly not discriminate between dead or live microorganisms. We present a novel generic method that is able to specifically monitor living microorganisms in a real-time manner. Results The developed method includes exposure of cells to a weak acid probe at low pH. The neutral probe rapidly permeates the membrane and enters the cytosol. In dead cells no signal is obtained, as the cytosolic pH reflects that of the acidic extracellular environment. In live cells with a neutral internal pH, the probe dissociates into a fluorescent phototautomeric anion. After reaching peak fluorescence, the population of live cells decays. This decay can be followed real-time as cell death coincides with intracellular acidification and return of the probe to its uncharged non-fluorescent state. The rise and decay of the fluorescence signal depends on the probe structure and appears discriminative for bacteria, fungi, and spores. We identified 13 unique probes, which can be applied in the real-time viability method described here. Under the experimental conditions used in a microplate reader, the reported method shows a detection limit of 106 bacteria ml-1, while the frequently used LIVE/DEAD BacLight™ Syto9 and propidium iodide stains show detection down to 106 and 107 bacteria ml-1, respectively. Conclusions We present a novel fluorescence-based method for viability assessment, which is applicable to all bacteria and eukaryotic cell types tested so far. The RTV method will have a significant impact in many areas of applied microbiology including research on biocidal activity, improvement of

  10. Removal of viable bioaerosol particles with a low-efficiency HVAC filter enhanced by continuous emission of unipolar air ions.

    Science.gov (United States)

    Huang, R; Agranovski, I; Pyankov, O; Grinshpun, S

    2008-04-01

    Continuous emission of unipolar ions has been shown to improve the performance of respirators and stationary filters challenged with non-biological particles. In this study, we investigated the ion-induced enhancement effect while challenging a low-efficiency heating, ventilation and air-conditioning (HVAC) filter with viable bacterial cells, bacterial and fungal spores, and viruses. The aerosol concentration was measured in real time. Samples were also collected with a bioaerosol sampler for viable microbial analysis. The removal efficiency of the filter was determined, respectively, with and without an ion emitter. The ionization was found to significantly enhance the filter efficiency in removing viable biological particles from the airflow. For example, when challenged with viable bacteria, the filter efficiency increased as much as four- to fivefold. For viable fungal spores, the ion-induced enhancement improved the efficiency by a factor of approximately 2. When testing with virus-carrying liquid droplets, the original removal efficiency provided by the filter was rather low: 9.09 +/- 4.84%. While the ion emission increased collection about fourfold, the efficiency did not reach 75-100% observed with bacteria and fungi. These findings, together with our previously published results for non-biological particles, demonstrate the feasibility of a new approach for reducing aerosol particles in HVAC systems used for indoor air quality control. Recirculated air in HVAC systems used for indoor air quality control in buildings often contains considerable number of viable bioaerosol particles because of limited efficiency of the filters installed in these systems. In the present study, we investigated - using aerosolized bacterial cells, bacterial and fungal spores, and virus-carrying particles - a novel idea of enhancing the performance of a low-efficiency HVAC filter utilizing continuous emission of unipolar ions in the filter vicinity. The findings described in

  11. Survival Strategy of Erwinia amylovora against Copper: Induction of the Viable-but-Nonculturable State

    Science.gov (United States)

    Ordax, Mónica; Marco-Noales, Ester; López, María M.; Biosca, Elena G.

    2006-01-01

    Copper compounds, widely used to control plant-pathogenic bacteria, have traditionally been employed against fire blight, caused by Erwinia amylovora. However, recent studies have shown that some phytopathogenic bacteria enter into the viable-but-nonculturable (VBNC) state in the presence of copper. To determine whether copper kills E. amylovora or induces the VBNC state, a mineral medium without copper or supplemented with 0.005, 0.01, or 0.05 mM Cu2+ was inoculated with 107 CFU/ml of this bacterium and monitored over 9 months. Total and viable cell counts were determined by epifluorescence microscopy using the LIVE/DEAD kit and by flow cytometry with 5-cyano-2,3-ditolyl tetrazolium chloride and SYTO 13. Culturable cells were counted on King's B nonselective solid medium. Changes in the bacterial morphology in the presence of copper were observed by scanning electron microscopy. E. amylovora entered into the VBNC state at all three copper concentrations assayed, much faster when the copper concentration increased. The addition of different agents which complex copper allowed the resuscitation (restoration of culturability) of copper-induced VBNC cells. Finally, copper-induced VBNC cells were virulent only for the first 5 days, while resuscitated cells always regained their pathogenicity on immature fruits over 9 months. These results have shown, for the first time, the induction of the VBNC state in E. amylovora as a survival strategy against copper. PMID:16672494

  12. Ammonia production by human faecal bacteria, and the enumeration, isolation and characterization of bacteria capable of growth on peptides and amino acids

    Directory of Open Access Journals (Sweden)

    Richardson Anthony J

    2013-01-01

    Full Text Available Abstract Background The products of protein breakdown in the human colon are considered to be detrimental to gut health. Amino acid catabolism leads to the formation of sulfides, phenolic compounds and amines, which are inflammatory and/or precursors to the formation of carcinogens, including N-nitroso compounds. The aim of this study was to investigate the kinetics of protein breakdown and the bacterial species involved. Results Casein, pancreatic casein hydrolysate (mainly short-chain peptides or amino acids were incubated in vitro with suspensions of faecal bacteria from 3 omnivorous and 3 vegetarian human donors. Results from the two donor groups were similar. Ammonia production was highest from peptides, followed by casein and amino acids, which were similar. The amino acids metabolized most extensively were Asp, Ser, Lys and Glu. Monensin inhibited the rate of ammonia production from amino acids by 60% (P = 0.001, indicating the involvement of Gram-positive bacteria. Enrichment cultures were carried out to investigate if, by analogy with the rumen, there was a significant population of asaccharolytic, obligately amino acid-fermenting bacteria (‘hyper-ammonia-producing’ bacteria; HAP in the colon. Numbers of bacteria capable of growth on peptides or amino acids alone averaged 3.5% of the total viable count, somewhat higher than the rumen. None of these were HAP, however. The species enriched included Clostridium spp., one of which was C. perfringens, Enterococcus, Shigella and Escherichia coli. Conclusions Protein fermentation by human faecal bacteria in the absence of sugars not only leads to the formation of hazardous metabolic products, but also to the possible proliferation of harmful bacteria. The kinetics of protein metabolism were similar to the rumen, but HAP bacteria were not found.

  13. Ammonia production by human faecal bacteria, and the enumeration, isolation and characterization of bacteria capable of growth on peptides and amino acids

    Science.gov (United States)

    2013-01-01

    Background The products of protein breakdown in the human colon are considered to be detrimental to gut health. Amino acid catabolism leads to the formation of sulfides, phenolic compounds and amines, which are inflammatory and/or precursors to the formation of carcinogens, including N-nitroso compounds. The aim of this study was to investigate the kinetics of protein breakdown and the bacterial species involved. Results Casein, pancreatic casein hydrolysate (mainly short-chain peptides) or amino acids were incubated in vitro with suspensions of faecal bacteria from 3 omnivorous and 3 vegetarian human donors. Results from the two donor groups were similar. Ammonia production was highest from peptides, followed by casein and amino acids, which were similar. The amino acids metabolized most extensively were Asp, Ser, Lys and Glu. Monensin inhibited the rate of ammonia production from amino acids by 60% (P = 0.001), indicating the involvement of Gram-positive bacteria. Enrichment cultures were carried out to investigate if, by analogy with the rumen, there was a significant population of asaccharolytic, obligately amino acid-fermenting bacteria (‘hyper-ammonia-producing’ bacteria; HAP) in the colon. Numbers of bacteria capable of growth on peptides or amino acids alone averaged 3.5% of the total viable count, somewhat higher than the rumen. None of these were HAP, however. The species enriched included Clostridium spp., one of which was C. perfringens, Enterococcus, Shigella and Escherichia coli. Conclusions Protein fermentation by human faecal bacteria in the absence of sugars not only leads to the formation of hazardous metabolic products, but also to the possible proliferation of harmful bacteria. The kinetics of protein metabolism were similar to the rumen, but HAP bacteria were not found. PMID:23312016

  14. Viable Cell Culture Banking for Biodiversity Characterization and Conservation.

    Science.gov (United States)

    Ryder, Oliver A; Onuma, Manabu

    2018-02-15

    Because living cells can be saved for indefinite periods, unprecedented opportunities for characterizing, cataloging, and conserving biological diversity have emerged as advanced cellular and genetic technologies portend new options for preventing species extinction. Crucial to realizing the potential impacts of stem cells and assisted reproductive technologies on biodiversity conservation is the cryobanking of viable cell cultures from diverse species, especially those identified as vulnerable to extinction in the near future. The advent of in vitro cell culture and cryobanking is reviewed here in the context of biodiversity collections of viable cell cultures that represent the progress and limitations of current efforts. The prospects for incorporating collections of frozen viable cell cultures into efforts to characterize the genetic changes that have produced the diversity of species on Earth and contribute to new initiatives in conservation argue strongly for a global network of facilities for establishing and cryobanking collections of viable cells.

  15. Issues of organizational cybernetics and viability beyond Beer's viable systems model

    Science.gov (United States)

    Nechansky, Helmut

    2013-11-01

    The paper starts summarizing the claims of Beer's viable systems model to identify five issues any viable organizations has to deal with in an unequivocal hierarchical structure of five interrelated systems. Then the evidence is introduced for additional issues and related viable structures of organizations, which deviate from Beer's model. These issues are: (1) the establishment and (2) evolution of an organization; (3) systems for independent top-down control (like "Six Sigma"); (4) systems for independent bottom-up correction of performance problems (like "Kaizen"), both working outside a hierarchical structure; (5) pull production systems ("Just in Time") and (6) systems for checks and balances of top-level power (like boards and shareholder meetings). Based on that an evolutionary approach to organizational cybernetics is outlined, addressing the establishment of organizations and possible courses of developments, including recent developments in quality and production engineering, as well as problems of setting and changing goal values determining organizational policies.

  16. Characterization of the Viable but Nonculturable (VBNC State in Saccharomyces cerevisiae.

    Directory of Open Access Journals (Sweden)

    Mohammad Salma

    Full Text Available The Viable But Non Culturable (VBNC state has been thoroughly studied in bacteria. In contrast, it has received much less attention in other microorganisms. However, it has been suggested that various yeast species occurring in wine may enter in VBNC following sulfite stress.In order to provide conclusive evidences for the existence of a VBNC state in yeast, the ability of Saccharomyces cerevisiae to enter into a VBNC state by applying sulfite stress was investigated. Viable populations were monitored by flow cytometry while culturable populations were followed by plating on culture medium. Twenty-four hours after the application of the stress, the comparison between the culturable population and the viable population demonstrated the presence of viable cells that were non culturable. In addition, removal of the stress by increasing the pH of the medium at different time intervals into the VBNC state allowed the VBNC S. cerevisiae cells to "resuscitate". The similarity between the cell cycle profiles of VBNC cells and cells exiting the VBNC state together with the generation rate of cells exiting VBNC state demonstrated the absence of cellular multiplication during the exit from the VBNC state. This provides evidence of a true VBNC state. To get further insight into the molecular mechanism pertaining to the VBNC state, we studied the involvement of the SSU1 gene, encoding a sulfite pump in S. cerevisiae. The physiological behavior of wild-type S. cerevisiae was compared to those of a recombinant strain overexpressing SSU1 and null Δssu1 mutant. Our results demonstrated that the SSU1 gene is only implicated in the first stages of sulfite resistance but not per se in the VBNC phenotype. Our study clearly demonstrated the existence of an SO2-induced VBNC state in S. cerevisiae and that the stress removal allows the "resuscitation" of VBNC cells during the VBNC state.

  17. High-Throughput Sequencing of Viable Microbial Communities in Raw Pork Subjected to a Fast Cooling Process.

    Science.gov (United States)

    Yang, Chao; Che, You; Qi, Yan; Liang, Peixin; Song, Cunjiang

    2017-01-01

    This study aimed to investigate the effect of the fast cooling process on the microbiological community in chilled fresh pork during storage. We established a culture-independent method to study viable microbes in raw pork. Tray-packaged fresh pork and chilled fresh pork were completely spoiled after 18 and 49 d in aseptic bags at 4 °C, respectively. 16S/18S ribosomal RNAs were reverse transcribed to cDNA to characterize the activity of viable bacteria/fungi in the 2 types of pork. Both cDNA and total DNA were analyzed by high-throughput sequencing, which revealed that viable Bacteroides sp. were the most active genus in rotten pork, although viable Myroides sp. and Pseudomonas sp. were also active. Moreover, viable fungi were only detected in chilled fresh pork. The sequencing results revealed that the fast cooling process could suppress the growth of microbes present initially in the raw meat to extend its shelf life. Our results also suggested that fungi associated with pork spoilage could not grow well in aseptic tray-packaged conditions. © 2016 Institute of Food Technologists®.

  18. The elusive minimum viable population size for white sturgeon

    Energy Technology Data Exchange (ETDEWEB)

    Jager, Yetta [ORNL; Lepla, Ken B. [Idaho Power Company; Van Winkle, Webb [Van Windle Environmental Consulting; James, Mr Brad [Washington Department of Fish and Wildlife; McAdam, Dr Steve [University of British Columbia, Vancouver

    2010-01-01

    Biological conservation of sturgeon populations is a concern for many species. Those responsible for managing the white sturgeon (Acipenser transmontanus) and similar species are interested in identifying extinction thresholds to avoid. Two thresholds that exist in theory are the minimum viable population size (MVP) and minimum amount of suitable habitat. In this paper, we present both model and empirical estimates of these thresholds. We modified a population viability analysis (PVA) model for white sturgeon to include two new Allee mechanisms. Despite this, PVA-based MVP estimates were unrealistically low compared with empirical estimates unless opportunities for spawning were assumed to be less frequent. PVA results revealed a trade-off between MVP and habitat thresholds; smaller populations persisted in longer river segments and vice versa. Our empirical analyses suggested (1) a MVP range based on population trends from 1,194 to 27,700 individuals, and (2) a MVP estimate of 4,000 individuals based on recruitment. Long-term historical population surveys are needed for more populations to pinpoint an MVP based on trends, whereas the available data were sufficient to estimate MVP based on recruitment. Beyond the MVP, we developed a hierarchical model for population status based on empirical data. Metapopulation support was the most important predictor of population health, followed by the length of free-flowing habitat, with habitat thresholds at 26 and 150 km. Together, these results suggest that habitat and connectivity are important determinants of population status that likely influence the site-specific MVP thresholds.

  19. Is Greenberg’s “Macro-Carib” viable?

    Directory of Open Access Journals (Sweden)

    Spike Gildea

    2007-08-01

    Full Text Available In his landmark work Language in the Americas, Greenberg (1987 proposed that Macro-Carib was one of the major low-level stocks of South America, which together with Macro-Panoan and Macro-Ge-Bororo were claimed to comprise the putative Ge-Pano-Carib Phylum. His Macro-Carib includes the isolates Andoke and Kukura, and the Witotoan, Peba-Yaguan, and Cariban families. Greenberg’s primary evidence came from person-marking paradigms in individual languages, plus scattered words from individual languages collected into 79 Macro-Carib ‘etymologies’ and another 64 Amerind ‘etymologies’. The goal of this paper is to re-evaluate Greenberg’s Macro-Carib claim in the light of the much more extensive and reliable language data that has become available largely since 1987. Based on full person-marking paradigms for Proto-Cariban, Yagua, Bora and Andoke, we conclude that Greenberg’s morphological claims are unfounded. For our lexical comparison, we created lexical lists for Proto-Cariban, Proto-Witotoan, Yagua and Andoke, for both Greenberg’s 143 putative etymologies and for the Swadesh 100 list. From both lists, a total of 23 potential cognates were found, but no consonantal correspondences were repeated even once. We conclude that our greatly expanded and improved database does not provide sufficient evidence to convince the skeptic that the Macro-Carib hypothesis is viable.

  20. SMA actuators: a viable practical technology (Presentation Video)

    Science.gov (United States)

    Browne, Alan L.; Brown, Jeffrey; Hodgson, Darel E.

    2015-04-01

    Diverse products either based solely on or incorporating Shape Memory Alloys (SMA) have and are being made in a wide range of industries, and IP is being captured. Why then compared to SE (superelastic) Nitinol, and especially conventional technology, do so few ideas reach production? This presentation delves deeply into this topic in reaching the final assessment that SMA actuators are indeed now a viable practical technology. The presentation begins with an introduction to and description of the fundamental basis of SMA actuator technology. Examples of multiple commercially available geometric forms of SMA actuators are given and the functionalities that they provide are described. This is followed by examples of multiple commercial products incorporating such SMA actuators. Given that there are literally millions of commercial products incorporating conventional actuator technologies, indications are given as to why there are their less than 1000 that utilize SMA. Experience based challenges to the commercial use of SMA actuators are described. Besides having to compete with existing non-SMA technology which is quite mature additional challenges that are unique to SM actuators are indicated these including a wider than expected set of technical engineering problems and challenges and that a broader scope of dynamics is required.

  1. The viable but non-culturable state in pathogenic Escherichia coli: A general review

    Directory of Open Access Journals (Sweden)

    Jennifer A. Pienaar

    2016-02-01

    Full Text Available Background: The persistence and pathogenicity of pathogenic bacteria are dependent on the ability of the species to survive in adverse conditions. During the infectious process, the organism may need to pass through certain hostile anatomical sites, such as the stomach. Under various environmental stresses, many bacteria enter into the viable but non-culturable (VBNC state, where they are ‘alive’ or metabolically active, but will not grow on conventional media. Escherichia coli bacteria encounter several diverse stress factors during their growth, survival and infection and thus may enter into the VBNC state.Objectives: This review discusses various general aspects of the VBNC state, the mechanisms and possible public health impact of indicator and pathogenic E. coli entering into the VBNC state.Method: A literature review was conducted to ascertain the possibleimpact of E. coli entering into the VBNC state.Results: Escherichia coli enter into the VBNC state by means of several induction mechanisms. Various authors have found that E. coli can be resuscitated post-VBNC. Certain strains of pathogenic E. coli are still able to produce toxins in the VBNC state, whilst others are avirulent during the VBNC state but are able to regain virulence after resuscitation.Conclusion: Pathogenic and indicator E. coli entering into the VBNC state could have an adverse effect on public health if conventional detection methods are used, where the number of viable cells could be underestimated and the VBNC cells still produce toxins or could, at anytime, be resuscitated and become virulent again.

  2. Texture analysis of cardiac cine magnetic resonance imaging to detect non-viable segments in patients with chronic myocardial infarction.

    Science.gov (United States)

    Larroza, Andrés; López-Lereu, María P; Monmeneu, José V; Gavara, Jose; Chorro, Francisco J; Bodí, Vicente; Moratal, David

    2018-02-01

    To investigate the ability of texture analysis to differentiate between infarcted non-viable, viable, and remote segments on cardiac cine magnetic resonance imaging (MRI). This retrospective study included 50 patients suffering chronic myocardial infarction. The data was randomly split into training (30 patients) and testing (20 patients) sets. The left ventricular myocardium was segmented according to the 17-segment model in both cine and late gadolinium enhancement (LGE) MRI. Infarcted myocardium regions were identified on LGE in short-axis views. Non-viable segments were identified as those showing LGE ≥ 50%, and viable segments those showing 0 cine images. A support vector machine (SVM) classifier was trained with different combination of texture features to obtain a model that provided optimal classification performance. The best classification on testing set was achieved with local binary patterns features using a 2D + t approach, in which the features are computed by including information of the time dimension available in cine sequences. The best overall area under the receiver operating characteristic curve (AUC) were: 0.849, sensitivity of 92% to detect non-viable segments, 72% to detect viable segments, and 85% to detect remote segments. Non-viable segments can be detected on cine MRI using texture analysis and this may be used as hypothesis for future research aiming to detect the infarcted myocardium by means of a gadolinium-free approach. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  3. Bacteriophage treatment significantly reduces viable Clostridium difficile and prevents toxin production in an in vitro model system.

    Science.gov (United States)

    Meader, Emma; Mayer, Melinda J; Gasson, Michael J; Steverding, Dietmar; Carding, Simon R; Narbad, Arjan

    2010-12-01

    Clostridium difficile is primarily a nosocomial pathogen, causing thousands of cases of antibiotic-associated diarrhoea in the UK each year. In this study, we used a batch fermentation model of a C. difficile colonised system to evaluate the potential of a prophylactic and a remedial bacteriophage treatment regime to control the pathogen. It is shown that the prophylaxis regime was effective at preventing the growth of C. difficile (p = <0.001) and precluded the production of detectable levels of toxins A and B. The remedial treatment regime caused a less profound and somewhat transient decrease in the number of viable C. difficile cells (p = <0.0001), but still resulted in a lower level of toxin production relative to the control. The numbers of commensal bacteria including total aerobes and anaerobes, Bifidobacterium sp., Bacteroides sp., Lactobacillus sp., total Clostridium sp., and Enterobacteriaceae were not significantly decreased by this therapy, whereas significant detrimental effects were observed with metronidazole treatment. Our study indicates that phage therapy has potential to be used for the control of C. difficile; it highlights the main benefits of this approach, and some future challenges. Copyright © 2010 Elsevier Ltd. All rights reserved.

  4. Formation of manganese phosphate and manganese carbonate during long-term sorption of Mn2+ by viable Shewanella putrefaciens: effects of contact time and temperature

    NARCIS (Netherlands)

    Chubar, N.; Avramut, C.; Visser, T.

    The influence of temperature (5, 10, 22 and 30 C) on the long-term (30 days) sorption of Mn2+ by viable Shewanella putrefaciens was studied by FTIR and EXAFS. The additional Mn-removal capacity of these bacteria was found to result from the surface precipitation of Mn-containing inorganic phases.

  5. Viable adhered Staphylococcus aureus highly reduced on novel antimicrobial sutures using chlorhexidine and octenidine to avoid surgical site infection (SSI)

    Science.gov (United States)

    Schneider, Jochen; Harrasser, Norbert; Tübel, Jutta; Mühlhofer, Heinrich; Pförringer, Dominik; von Deimling, Constantin; Foehr, Peter; Kiefel, Barbara; Krämer, Christina; Stemberger, Axel; Schieker, Matthias

    2018-01-01

    Background Surgical sutures can promote migration of bacteria and thus start infections. Antiseptic coating of sutures may inhibit proliferation of adhered bacteria and avoid such complications. Objectives This study investigated the inhibition of viable adhering bacteria on novel antimicrobially coated surgical sutures using chlorhexidine or octenidine, a critical factor for proliferation at the onset of local infections. The medical need, a rapid eradication of bacteria in wounds, can be fulfilled by a high antimicrobial efficacy during the first days after wound closure. Methods As a pretesting on antibacterial efficacy against relevant bacterial pathogens a zone of inhibition assay was conducted with middle ranged concentrated suture coatings (22 μg/cm). For further investigation of adhering bacteria in detail the most clinically relevant Staphylococcus aureus (ATCC®49230™) was used. Absorbable braided sutures were coated with chlorhexidine-laurate, chlorhexidine-palmitate, octenidine-laurate, and octenidine-palmitate. Each coating type resulted in 11, 22, or 33 μg/cm drug content on sutures. Scanning electron microscopy (SEM) was performed once to inspect the coating quality and twice to investigate if bacteria have colonized on sutures. Adhesion experiments were assessed by exposing coated sutures to S. aureus suspensions for 3 h at 37°C. Subsequently, sutures were sonicated and the number of viable bacteria released from the suture surface was determined. Furthermore, the number of viable planktonic bacteria was measured in suspensions containing antimicrobial sutures. Commercially available sutures without drugs (Vicryl®, PGA Resorba®, and Gunze PGA), as well as triclosan-containing Vicryl® Plus were used as control groups. Results Zone of inhibition assay documented a multispecies efficacy of novel coated sutures against tested bacterial strains, comparable to most relevant S. aureus over 48 hours. SEM pictures demonstrated uniform layers on

  6. Viable adhered Staphylococcus aureus highly reduced on novel antimicrobial sutures using chlorhexidine and octenidine to avoid surgical site infection (SSI).

    Science.gov (United States)

    Obermeier, Andreas; Schneider, Jochen; Harrasser, Norbert; Tübel, Jutta; Mühlhofer, Heinrich; Pförringer, Dominik; Deimling, Constantin von; Foehr, Peter; Kiefel, Barbara; Krämer, Christina; Stemberger, Axel; Schieker, Matthias; Burgkart, Rainer; von Eisenhart-Rothe, Rüdiger

    2018-01-01

    Surgical sutures can promote migration of bacteria and thus start infections. Antiseptic coating of sutures may inhibit proliferation of adhered bacteria and avoid such complications. This study investigated the inhibition of viable adhering bacteria on novel antimicrobially coated surgical sutures using chlorhexidine or octenidine, a critical factor for proliferation at the onset of local infections. The medical need, a rapid eradication of bacteria in wounds, can be fulfilled by a high antimicrobial efficacy during the first days after wound closure. As a pretesting on antibacterial efficacy against relevant bacterial pathogens a zone of inhibition assay was conducted with middle ranged concentrated suture coatings (22 μg/cm). For further investigation of adhering bacteria in detail the most clinically relevant Staphylococcus aureus (ATCC®49230™) was used. Absorbable braided sutures were coated with chlorhexidine-laurate, chlorhexidine-palmitate, octenidine-laurate, and octenidine-palmitate. Each coating type resulted in 11, 22, or 33 μg/cm drug content on sutures. Scanning electron microscopy (SEM) was performed once to inspect the coating quality and twice to investigate if bacteria have colonized on sutures. Adhesion experiments were assessed by exposing coated sutures to S. aureus suspensions for 3 h at 37°C. Subsequently, sutures were sonicated and the number of viable bacteria released from the suture surface was determined. Furthermore, the number of viable planktonic bacteria was measured in suspensions containing antimicrobial sutures. Commercially available sutures without drugs (Vicryl®, PGA Resorba®, and Gunze PGA), as well as triclosan-containing Vicryl® Plus were used as control groups. Zone of inhibition assay documented a multispecies efficacy of novel coated sutures against tested bacterial strains, comparable to most relevant S. aureus over 48 hours. SEM pictures demonstrated uniform layers on coated sutures with higher roughness for

  7. Drinking Water Fact Sheet: Coliform Bacteria

    OpenAIRE

    Mesner, Nancy; Daniels, Barbara

    2010-01-01

    This fact sheet provides information about coliform bacteria. Including sections about what coliform bacteria is, how it enters drinking water, health concerns from exposure, drinking water standards, and how to treat drinking water that contains coliforms.

  8. Concentrations of viable oil-degrading microorganisms are increased in feces from Calanus finmarchicus feeding in petroleum oil dispersions.

    Science.gov (United States)

    Størdal, Ingvild Fladvad; Olsen, Anders Johny; Jenssen, Bjørn Munro; Netzer, Roman; Hansen, Bjørn Henrik; Altin, Dag; Brakstad, Odd Gunnar

    2015-09-15

    Zooplankton are suggested to be biotic contributors to the transport and weathering of oil in marine environments due to their ingestion of oil. In the present experiment, feeding activity and microbial communities in feces from Calanus finmarchicus feeding in oil dispersions were characterized. Feeding activity was significantly reduced in oil dispersions. The microbial communities in clean and oil-containing copepod feces were dominated by Rhodobacteraceae family bacteria (Lesingera, Phaeobacter, Rugeria, and Sulfitobacter), which were suggested to be indigenous to copepod feces. The results also indicated that these bacteria were metabolizing oil compounds, as a significant increase in the concentrations of viable oil degrading microorganisms was observed in oil-containing feces. This study shows that bacteria in feces from copepods feeding in dilute oil dispersions have capacity for degradation of oil. Zooplankton may therefore contribute to weathering of oil by excreting feces with microbial communities already adapted to degradation of oil. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Optimization of protein production by Micrococcus luteus for exploring pollutant-degrading uncultured bacteria

    National Research Council Canada - National Science Library

    Su, Xiaomei; Liu, Yindong; Hu, Jinxing; Ding, Linxian; Shen, Chaofeng

    2014-01-01

    .... For the purpose of resuscitating and stimulating “viable but non-culturable” (VBNC) or uncultured bacteria, Micrococcus luteus proteins are more convenient and cost-effective than purified resuscitation-promoting factor (Rpf) protein...

  10. Wanted Alive: Finding Bacteria in Your Food.

    Science.gov (United States)

    Kawamura, Akira

    2017-08-17

    In this issue of Cell Chemical Biology, Pezacki and co-workers (Sherratt et al., 2017) report a simple method to metabolically label viable bacteria, which can be used to detect and capture foodborne pathogens. The method may also find many other applications because it can be used to recover live cells, pathogens and non-pathogens, from various biomedical and environmental samples. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Membrane vesicle protein PagC as a novel biomarker for detecting pathogenic Salmonella in the viable but not culturable state.

    Science.gov (United States)

    Xu, Jun; Suita, Kazuasa; Okuno, Katsuya; Takaya, Akiko; Yamamoto, Tomoko; Isogai, Emiko

    2017-12-04

    The viable but non-culturable (VBNC) state is a remarkable survival mechanism in which cells exist in a physiologically inactive state. Bacteria in the VBNC state do not form colonies, and thus, are difficult to detect using colony-based methods. As a result, VBNC bacteria are potentially virulent and can cause widespread contamination during food production. In the present study, we reported a novel biomarker, the membrane vesicle protein PagC, for the detection of VBNC Salmonella. Salmonella cells were chemically induced into the VBNC state by H2O2 treatment. The bacterial cells retained their shapes but were observed to release numerous membrane vesicles, which were accompanied by a transient PagC overexpression. Immunoblotting was performed to detect PagC in pathogenic strains, including Salmonella Enteritidis and S. Typhimurium, which are harmful and known to cause food-borne gastroenteritis in humans and other animals. Therefore, our findings demonstrated the potential use of PagC as a biomarker for the detection of VBNC Salmonella in food production.

  12. The search for viable local government system in Nigeria: an ...

    African Journals Online (AJOL)

    The history of the Nigerian local government system has been one long episode of trails and errors aimed at achieving viable local government institution without much success. Local government in the country began its long series of reforms from the colonial period when the colonial government attempted to ...

  13. Detection of viable toxigenic Vibrio cholerae and virulent Shigella ...

    African Journals Online (AJOL)

    A rapid and sensitive assay was developed for the detection of low numbers of viable Vibrio cholerae and Shigella spp. cells in environmental and drinking water samples. Water samples were filtered, and the filters were enriched in a non-selective medium. The enrichment cultures were prepared for polymerase chain ...

  14. Comment: Towards a Viable Local Government Structure in Nigeria ...

    African Journals Online (AJOL)

    Local governments are principally established for development at the grassroots and they must be structured in a manner that makes them viable and capable of achieving this purpose. The objective of this comment is to appraise the current local government structure under the Nigerian constitutional framework with a view ...

  15. Cultivation and multiplication of viable axenic Trypanosoma vivax in ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-09-01

    Sep 1, 2009 ... Cultivation and multiplication of viable axenic. Trypanosoma vivax in vitro and in vivo. O. A. Idowu, A. B. Idowu, C. F. Mafiana and S. O. Sam-Wobo*. Parasitology Laboratory, Department of Biological Sciences, University of Agriculture, Abeokuta, Nigeria. Accepted 13 April, 2006. Trypanosoma vivax was ...

  16. Detection of viable toxigenic Vibrio cholerae and virulent Shigella ...

    African Journals Online (AJOL)

    DRINIE

    2003-04-02

    Apr 2, 2003 ... A rapid and sensitive assay was developed for the detection of low numbers of viable Vibrio cholerae and Shigella spp. cells in environmental and drinking water samples. Water samples were filtered, and the filters were enriched in a non-selective medium. The enrichment cultures were prepared for ...

  17. High speed flow cytometric separation of viable cells

    Science.gov (United States)

    Sasaki, Dennis T.; Van den Engh, Gerrit J.; Buckie, Anne-Marie

    1995-01-01

    Hematopoietic cell populations are separated to provide cell sets and subsets as viable cells with high purity and high yields, based on the number of original cells present in the mixture. High-speed flow cytometry is employed using light characteristics of the cells to separate the cells, where high flow speeds are used to reduce the sorting time.

  18. Microfiltration of enzyme treated egg whites for accelerated detection of viable Salmonella.

    Science.gov (United States)

    Ku, Seockmo; Ximenes, Eduardo; Kreke, Thomas; Foster, Kirk; Deering, Amanda J; Ladisch, Michael R

    2016-11-01

    We report detection of egg white within 7 h by concentrating the bacteria using microfiltration through 0.2-μm cutoff polyethersulfone hollow fiber membranes. A combination of enzyme treatment, controlled cross-flow on both sides of the hollow fibers, and media selection were key to controlling membrane fouling so that rapid concentration and the subsequent detection of low numbers of microbial cells were achieved. We leveraged the protective effect of egg white proteins and peptone so that the proteolytic enzymes did not attack the living cells while hydrolyzing the egg white proteins responsible for fouling. The molecular weight of egg white proteins was reduced from about 70 kDa to 15 kDa during hydrolysis. This enabled a 50-fold concentration of the cells when a volume of 525 mL of peptone and egg white, containing 13 CFU of Salmonella, was decreased to a 10 mL volume in 50 min. A 10-min microcentrifugation step further concentrated the viable Salmonella cells by 10×. The final cell recovery exceeded 100%, indicating that microbial growth occurred during the 3-h processing time. The experiments leading to rapid concentration, recovery, and detection provided further insights on the nature of membrane fouling enabling fouling effects to be mitigated. Unlike most membrane processes where protein recovery is the goal, recovery of viable microorganisms for pathogen detection is the key measure of success, with modification of cell-free proteins being both acceptable and required to achieve rapid microfiltration of viable microorganisms. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:1464-1471, 2016. © 2016 American Institute of Chemical Engineers.

  19. Detection of viable Salmonella in lettuce by propidium monoazide real-time PCR.

    Science.gov (United States)

    Liang, Ningjian; Dong, Jin; Luo, Laixin; Li, Yong

    2011-05-01

    Contamination of lettuce by Salmonella has caused serious public health problems. Polymerase chain reaction (PCR) allows rapid detection of pathogenic bacteria in food, but it is inaccurate as it might amplify DNA from dead target cells as well. This study aimed to investigate the stability of DNA of dead Salmonella cells in lettuce and to develop an approach to detecting viable Salmonella in lettuce. Salmonella-free lettuce was inoculated with heat-killed Salmonella Typhimurium cells and stored at 4 °C. Bacterial DNA extracted from the sample was amplified by real-time PCR targeting the invA gene. Our results indicate that DNA from the dead cells remained stable in lettuce for at least 8 d. To overcome this limitation, propidium monoazide (PMA), a dye that can selectively penetrate dead bacterial cells and cross-link their DNA upon light exposure, was combined with real-time PCR. Lettuce samples inoculated with different levels of dead or viable S. Typhimurium cells were treated or untreated with PMA before DNA extraction. Real-time PCR suggests that PMA treatment effectively prevented PCR amplification from as high as 10(8) CFU/g dead S. Typhimurium cells in lettuce. The PMA real-time PCR assay could detect viable Salmonella at as low as 10(2) CFU/mL in pure culture and 10(3) CFU/g in lettuce. With 12-h enrichment, S. Typhimurium of 10(1) CFU/g in lettuce was detectable. In conclusion, the PMA real-time PCR assay provides an alternative to real-time PCR assay for accurate detection of Salmonella in food. © 2011 Institute of Food Technologists®

  20. Selective detection of viable seed-borne Acidovorax citrulli by real-time PCR with propidium monoazide

    Science.gov (United States)

    Tian, Qian; Feng, Jian-jun; Hu, Jie; Zhao, Wen-jun

    2016-01-01

    In recent years, use of the DNA-intercalating dye propidium monoazide (PMA) in real-time PCR has been reported as a novel method to detect viable bacteria in different types of samples, such as food, environmental, and microbiological samples. In this study, viable cells of Acidovorax citrulli, the causal agent of bacterial seedling blight and fruit blotch, were selectively detected and differentiated from dead cells by real-time fluorescent polymerase chain reaction amplification after the bacterial solution was treated with the DNA-binding dye PMA. The primers and TaqMan probe were based on the A. citrulli genome (Aave_1909, Gene ID: 4669443) and were highly specific for A. citrulli. The detection threshold of this assay was 103 colony-forming units per mL (CFU/mL) in pure cell suspensions containing viable and dead cells and infected watermelon seeds. Application of this assay enables the selective detection of viable cells of A. citrulli and facilitates monitoring of the pathogen in watermelon and melon seeds. PMID:27739469

  1. Abundance and Distribution of Enteric Bacteria and Viruses in Coastal and Estuarine Sediments—a Review

    Science.gov (United States)

    Hassard, Francis; Gwyther, Ceri L.; Farkas, Kata; Andrews, Anthony; Jones, Vera; Cox, Brian; Brett, Howard; Jones, Davey L.; McDonald, James E.; Malham, Shelagh K.

    2016-01-01

    The long term survival of fecal indicator organisms (FIOs) and human pathogenic microorganisms in sediments is important from a water quality, human health and ecological perspective. Typically, both bacteria and viruses strongly associate with particulate matter present in freshwater, estuarine and marine environments. This association tends to be stronger in finer textured sediments and is strongly influenced by the type and quantity of clay minerals and organic matter present. Binding to particle surfaces promotes the persistence of bacteria in the environment by offering physical and chemical protection from biotic and abiotic stresses. How bacterial and viral viability and pathogenicity is influenced by surface attachment requires further study. Typically, long-term association with surfaces including sediments induces bacteria to enter a viable-but-non-culturable (VBNC) state. Inherent methodological challenges of quantifying VBNC bacteria may lead to the frequent under-reporting of their abundance in sediments. The implications of this in a quantitative risk assessment context remain unclear. Similarly, sediments can harbor significant amounts of enteric viruses, however, the factors regulating their persistence remains poorly understood. Quantification of viruses in sediment remains problematic due to our poor ability to recover intact viral particles from sediment surfaces (typically bacteria and viruses into the water column during sediment resuspension also represents a risk to water quality. In conclusion, our poor process level understanding of viral/bacterial-sediment interactions combined with methodological challenges is limiting the accurate source apportionment and quantitative microbial risk assessment for pathogenic organisms associated with sediments in aquatic environments. PMID:27847499

  2. FTIR spectroscopy offers hints towards widespread molecular changes in cobalt-acclimated freshwater bacteria.

    Science.gov (United States)

    Kardas, Mehmet; Gozen, Ayse Gul; Severcan, Feride

    2014-10-01

    High concentrations of heavy metals can be toxic for bacteria. However, after prolonged exposure, bacteria can become acclimated and begin to be able to grow in the presence of heavy metals. Acclimation can involve alterations of metabolism and molecular structures. Our aim was to examine these alterations in cobalt-acclimated bacteria via attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy on viable samples. Bacillus sp. and Pseudomonas sp. isolated from a temperate shallow lake and a well-established strain of E. coli were investigated. Our results revealed consistent, wide-spread changes in cell membrane and cell wall dynamics of Bacillus sp. and E. coli, including a decrease in peptidoglycan content of Bacillus sp. and increased lipid ordering of the membrane in both bacteria. Furthermore, a decrease in RNA and protein concentrations of Bacillus sp. was measured. All three bacteria studied showed a decrease in conformational freedom of proteins following cobalt acclimation. Interestingly, both Bacillus sp. and E. coli showed slight but significant alterations in their DNA conformations which might imply a methylation-mediated memory formation leading to epigenetic modulation for cobalt adaptation. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Bacteria associated with cultures of psathyrella atroumbonata ...

    African Journals Online (AJOL)

    These bacteria include Bacillus licheniformis, Bacillus subtilis, Leuconostoc mesenteroides, Pseudomonas aeruginosa, Bacillus cereus and Staphylococcus aureus. The average bacteria count was 1.0 x 106 cfu/ml and these bacteria grew within pH range of 5.0 and 9.0. the optimum temperature range of growth lied ...

  4. Coscheduling in Clusters: Is It a Viable Alternative?

    Energy Technology Data Exchange (ETDEWEB)

    Choi, G S; Kim, J H; Ersoz, D; Yoo, A B; Das, C R

    2003-11-10

    As clusters are widely accepted as cost-effective infrastructures for many scientific and commercial applications, improving the deliverable performance and reducing the energy consumption of such systems has become a pressing issue. In this paper, we exploit the feasibility of achieving these objectives through efficiently scheduling the communicating processes of parallel applications. In this context, we conduct an in-depth evaluation of a broad spectrum of scheduling alternatives for clusters. These include the widely used batch scheduling, local scheduling, gang scheduling, all prior communication-driven coscheduling algorithms, and a newly proposed HYBRID coscheduling algorithm. In order to provide ease of implementation and portability across many cluster platforms, we propose a generic framework for deploying any coscheduling algorithm. We have implemented four prior coscheduling algorithms (Dynamic Coscheduling (DCS), Spin Block (SB), Periodic Boost (PB), and Co-ordinated Coscheduling (CC)) and the HYBRID coscheduling using this framework on a 16-node, Myrinet connected Linux cluster that uses GM as the communication layer. In addition, we use PBS as the batch scheduler and a previously proposed gang scheduler (SCore) to analyze all classes of scheduling techniques. Performance and energy measurements using several NAS and LLNL benchmarks on the Linux cluster provide several interesting conclusions. First, although batch scheduling is currently used in most clusters, all blocking-based coscheduling techniques such as SB, CC and HYBRID and the gang scheduling can provide much better performance even in a dedicated cluster platform. Under high system load, these coscheduling schemes can provide orders of magnitude reduction in average response time and much better performance-energy behavior compared to the PBS scheme. Second, in contrast to some of the prior studies, we observe that blocking-based schemes like SB and HYBRID can provide better performance

  5. Acupuntura un tratamiento viable para las adicciones en Colombia

    Directory of Open Access Journals (Sweden)

    Hernán López Seuscún

    2013-07-01

    Los tratamientos con auriculoterapia, como el protocolo NADA (National Acupuncture Detoxification Association, son los métodos más usados para las adicciones en el mundo, y aunque no se ha logrado evidenciar su efectividad, por su costo, facilidad y el poco riesgo de efectos adversos se hace viable en un país con pocos recursos económicos como Colombia.

  6. Academic Pediatric Dentistry is a Rewarding, Financially Viable Career Path.

    Science.gov (United States)

    Townsend, Janice A; Chi, Donald L

    2017-09-15

    Newly graduated pediatric dentists have unprecedented levels of debt. High levels of student debt may be perceived as an obstacle to pursue an academic career. However, opportunities exist through faculty compensation models and loan repayment programs that make an academic career financially viable. The purpose of this paper is to outline the benefits of a career in academic dentistry and provide examples of young pediatric dentistry faculty members who have been able to manage student debt while pursuing meaningful and rewarding careers.

  7. How Can We Prevent Violence Becoming a Viable Political Strategy?

    OpenAIRE

    Patricia Justino

    2009-01-01

    A basic issue that conflict analysis investigates is how non-peaceful ways of living and governing become viable political strategies. Macro-level studies provide some important insights but micro-level analysis is vital to understand the mechanisms that make violence possible. This briefing outlines some preliminary findings in this respect from MICROCON, a major research programme analysing violent conflict at the micro level. It also discusses their implications for policies aimed at preve...

  8. A PCR-Based Method for Monitoring Legionella pneumophila in Water Samples Detects Viable but Noncultivable Legionellae That Can Recover Their Cultivability▿

    Science.gov (United States)

    Dusserre, Eric; Ginevra, Christophe; Hallier-Soulier, Sylvie; Vandenesch, François; Festoc, Gabriel; Etienne, Jerome; Jarraud, Sophie; Molmeret, Maëlle

    2008-01-01

    Legionella pneumophila is the causative agent of Legionnaires' disease. This bacterium is ubiquitous in aqueous environments and uses amoebae as an intracellular replicative niche. Real-time PCR has been developed for rapid detection of Legionella DNA in water samples. In addition to culturable bacteria, this method may also detect dead and viable but noncultivable (VBNC) legionellae. In order to understand the significance of positive PCR results in this setting, we prepared water samples containing known concentrations of L. pneumophila and analyzed them comparatively by means of conventional culture, real-time PCR, viability labeling, and immunodetection (solid-phase cytometry). We also examined the influence of chlorination on the results of the four methods. The different techniques yielded similar results for nonchlorinated water samples but not for chlorinated samples. After treatment for 24 h with 0.5 and 1 ppm chlorine, all cultures were negative, PCR and immunodetection showed about 106 genome units and bacteria/ml, and total-viable-count (TVC) labeling detected 105 and 102 metabolically active bacteria/ml, respectively. Thus, PCR also detected bacteria that were VBNC. The recoverability of VBNC forms was confirmed by 5 days of coculture with Acanthamoeba polyphaga. Therefore, some TVC-positive bacteria were potentially infective. These data show that L. pneumophila PCR detects not only culturable bacteria but also VBNC forms and dead bacterial DNA at low chlorine concentrations. PMID:18515476

  9. Review on SERS of Bacteria

    Directory of Open Access Journals (Sweden)

    Pamela A. Mosier-Boss

    2017-11-01

    Full Text Available Surface enhanced Raman spectroscopy (SERS has been widely used for chemical detection. Moreover, the inherent richness of the spectral data has made SERS attractive for use in detecting biological materials, including bacteria. This review discusses methods that have been used to obtain SERS spectra of bacteria. The kinds of SERS substrates employed to obtain SERS spectra are discussed as well as how bacteria interact with silver and gold nanoparticles. The roll of capping agents on Ag/Au NPs in obtaining SERS spectra is examined as well as the interpretation of the spectral data.

  10. Isolation of viable Neospora caninum from brains of wild gray wolves (Canis lupus).

    Science.gov (United States)

    Dubey, J P; Jenkins, M C; Ferreira, L R; Choudhary, S; Verma, S K; Kwok, O C H; Fetterer, R; Butler, E; Carstensen, M

    2014-03-17

    Neospora caninum is a common cause of abortion in cattle worldwide. Canids, including the dog and the dingo (Canis familiaris), the coyote (Canis latrans), and the gray wolf (Canis lupus) are its definitive hosts that can excrete environmentally resistant oocysts in the environment, but also can act as intermediate hosts, harboring tissue stages of the parasite. In an attempt to isolate viable N. caninum from tissues of naturally infected wolves, brain and heart tissue from 109 wolves from Minnesota were bioassayed in mice. Viable N. caninum (NcWolfMn1, NcWolfMn2) was isolated from the brains of two wolves by bioassays in interferon gamma gene knockout mice. DNA obtained from culture-derived N. caninum tachyzoites of the two isolates were analyzed by N. caninum-specific Nc5 polymerase chain reaction and confirmed diagnosis. This is the first report of isolation of N. caninum from tissues of any wild canid host. Published by Elsevier B.V.

  11. Exopolysaccharides from marine bacteria

    Science.gov (United States)

    Chi, Zhenming; Fang, Yan

    2005-01-01

    Microbial polysaccharides represent a class of important products of growing interest for many sectors of industry. In recent years, there has been a growing interest in isolating new exopolysaccharides (EPSs)-producing bacteria from marine environments, particularly from various extreme marine environments. Many new marine microbial EPSs with novel chemical compositions, properties and structures have been found to have potential applications in fields such as adhesives, textiles, Pharmaceuticals and medicine for anti-cancer, food additives, oil recovery and metal removal in mining and industrial waste treatments, etc This paper gives a brief summary of the information about the EPSs produced by marine bacteria, including their chemical compositions, properties and structures, together with their potential applications in industry.

  12. Incidence of spore-forming bacteria in unsweetened evaporated ...

    African Journals Online (AJOL)

    All the samples had high numbers of spore-forming bacteria of the genera Bacillus spp and Clostridium spp. with mean total aerobic viable counts of ... the three brands were identified as Bacillus cereus, Bacillus licheniformis, Bacillus coagulans, Bacillus stearothermophilus, Bacillus subtilis and Clostridium perfringens, with ...

  13. Processing ruminal ingesta to release bacteria attached to feed ...

    African Journals Online (AJOL)

    Resultate van latere eksperimente wat in die ana6robe kabinet gedoen is, het getoon dat swak ana6robiose verant- woordelik was vir ten minste sommige van die nadelige uitwerking van die 'Ultra-Turrax' en die 'Stomacher'. Keywords: Ruminal bacteria, ciliate protozoa, processing ruminal ingesta, viable counts.

  14. A rapid biosensor for viable B. anthracis spores.

    Science.gov (United States)

    Baeumner, Antje J; Leonard, Barbara; McElwee, John; Montagna, Richard A

    2004-09-01

    A simple membrane-strip-based biosensor assay has been combined with a nucleic acid sequence-based amplification (NASBA) reaction for rapid (4 h) detection of a small number (ten) of viable B. anthracis spores. The biosensor is based on identification of a unique mRNA sequence from one of the anthrax toxin genes, the protective antigen ( pag), encoded on the toxin plasmid, pXO1, and thus provides high specificity toward B. anthracis. Previously, the anthrax toxins activator ( atxA) mRNA had been used in our laboratory for the development of a biosensor for the detection of a single B. anthracis spore within 12 h. Changing the target sequence to the pag mRNA provided the ability to shorten the overall assay time significantly. The vaccine strain of B. anthracis (Sterne strain) was used in all experiments. A 500-microL sample containing as few as ten spores was mixed with 500 microL growth medium and incubated for 30 min for spore germination and mRNA production. Thus, only spores that are viable were detected. Subsequently, RNA was extracted from lysed cells, selectively amplified using NASBA, and rapidly identified by the biosensor. While the biosensor assay requires only 15 min assay time, the overall process takes 4 h for detection of ten viable B. anthracis spores, and is shortened significantly if more spores are present. The biosensor is based on an oligonucleotide sandwich-hybridization assay format. It uses a membrane flow-through system with an immobilized DNA probe that hybridizes with the target sequence. Signal amplification is provided when the target sequence hybridizes to a second DNA probe that has been coupled to liposomes encapsulating the dye sulforhodamine B. The amount of liposomes captured in the detection zone can be read visually or quantified with a hand-held reflectometer. The biosensor can detect as little as 1 fmol target mRNA (1 nmol L(-1)). Specificity analysis revealed no cross-reactivity with 11 organisms tested, among them closely

  15. Molecular diversity of RelA enzyme in marine bacteria- A bioinformatics analysis

    Digital Repository Service at National Institute of Oceanography (India)

    Nath, A.I.V; Tresa, R.A; Alornekar, A; Varghese, N.S.

    The RelA (relaxed) protein is a crucial protein related to unculturability in bacteria. In response to nutrient scarcity, most of the marine bacteria are known to enter a viable but non-culturable (VBNC) state, but remain intact and retain viability...

  16. Truce with oxygen - A naerobiosis outcompete aerobiosis in the Antarctic lacustrine bacteria

    Digital Repository Service at National Institute of Oceanography (India)

    LokaBharathi, P.A.; Nair, S.; DeSouza, M.J.B.D.; Chandramohan, D.

    The total number of bacteria counted directly by epifluorescent microscopy showed that they ranged from 10 sup(8)-10 sup(-1) in Antarctic lake water samples. The percentages of retrievable viable counts (RVC) of anaerobic bacteria (AnB) was greater...

  17. EFFECT OF AEROSOLIZATION ON CULTURABILITY AND VIABILITY OF GRAM-NEGATIVE BACTERIA

    Science.gov (United States)

    Estimations of the bacterial content of air can be more easily made now than a decade ago, with colony formation the method of choice for enumeration of airborne bacteria.However, plate counts are subject to error because bacteria exposed to the air may remain viable yet lose the...

  18. Phytopathogenic Bacteria

    NARCIS (Netherlands)

    Wolf, van der J.M.; Boer, de S.H.

    2015-01-01

    A few hundred bacterial species, belonging to the Proteobacteria, Mollecutes and Actinomycetes cause a large number of different plant diseases, some of which are devastating for agricultural crops. Symptoms of bacterial plant diseases are diverse and include necrosis, tissue maceration, wilting,

  19. Modulation of the endocannabinoid system in viable and non-viable first trimester pregnancies by pregnancy-related hormones

    Directory of Open Access Journals (Sweden)

    Taylor Anthony H

    2011-11-01

    Full Text Available Abstract Background In early pregnancy, increased plasma levels of the endocannabinoid anandamide (AEA are associated with miscarriage through mechanisms that might affect the developing placenta or maternal decidua. Methods In this study, we compare AEA levels in failed and viable pregnancies with the levels of the trophoblastic hormones (beta-human chorionic gonadotrophin (beta-hCG, progesterone (P4 and (pregnancy-associated placental protein-A (PAPP-A essential for early pregnancy success and relate that to the expression of the cannabinoid receptors and enzymes that modulate AEA levels. Results The median plasma AEA level in non-viable pregnancies (1.48 nM; n = 20 was higher than in viable pregnancies (1.21 nM; n = 25; P = 0.013, as were progesterone and beta-hCG levels (41.0 vs 51.5 ng/mL; P = 0.052 for P4 and 28,650 vs 6,560 mIU/L; P = 0.144 for beta-hCG, respectively, but were not statistically significant. Serum PAPP-A levels in the viable group were approximately 6.8 times lower than those in the non-viable group (1.82 vs 12.25 mg/L; P = 0.071, but again these differences were statistically insignificant. In the spontaneous miscarriage group, significant correlations between P4 and beta-hCG, P4 and PAPP-A and AEA and PAPP-A levels were observed. Simultaneously, immunohistochemical distributions of the two main cannabinoid receptors and the AEA-modifying enzymes, fatty acid amide hydrolase (FAAH and N-acylphosphatidylethanolamine-phospholipase D (NAPE-PLD, changed within both the decidua and trophoblast. Conclusions The association of higher AEA levels with early pregnancy failure and with beta-hCG and PAPP-A, but not with progesterone concentrations suggest that plasma AEA levels and pregnancy failure are linked via a mechanism that may involve trophoblastic beta-hCG, and PAPP-A, but not, progesterone production. Although the trophoblast, decidua and embryo contain receptors for AEA, the main AEA target in early pregnancy failure

  20. Science ... bacteria ... art ...

    OpenAIRE

    Dimech, Anne Marie; Zammit, Gabrielle

    2015-01-01

    Bacteria are everywhere, from the top of the windswept cliffs of Dwejra, Gozo, right to the core of the ancient catacombs in Rabat, Malta. Anne Marie Dimech met Dr Gabrielle Zammit to learn about the unique bacteria discovered growing on artworks in ancient Maltese temples and how these bacteria could be useful to medicine. http://www.um.edu.mt/think/science-bacteria-art/

  1. Growing unculturable bacteria.

    Science.gov (United States)

    Stewart, Eric J

    2012-08-01

    The bacteria that can be grown in the laboratory are only a small fraction of the total diversity that exists in nature. At all levels of bacterial phylogeny, uncultured clades that do not grow on standard media are playing critical roles in cycling carbon, nitrogen, and other elements, synthesizing novel natural products, and impacting the surrounding organisms and environment. While molecular techniques, such as metagenomic sequencing, can provide some information independent of our ability to culture these organisms, it is essentially impossible to learn new gene and pathway functions from pure sequence data. A true understanding of the physiology of these bacteria and their roles in ecology, host health, and natural product production requires their cultivation in the laboratory. Recent advances in growing these species include coculture with other bacteria, recreating the environment in the laboratory, and combining these approaches with microcultivation technology to increase throughput and access rare species. These studies are unraveling the molecular mechanisms of unculturability and are identifying growth factors that promote the growth of previously unculturable organisms. This minireview summarizes the recent discoveries in this area and discusses the potential future of the field.

  2. Fate of viable but non-culturable Listeria monocytogenes in pig manure microcosms

    Directory of Open Access Journals (Sweden)

    Jeremy eDesneux

    2016-03-01

    Full Text Available The fate of two strains of L. monocytogenes and their ability to become viable but non-culturable (VBNC was investigated in microcosms containing piggery effluents (two raw manures and two biologically treated manures stored for two months at 8°C and 20°C. Levels of L. monocytogenes were estimated using the culture method, qPCR, and propidium monoazide treatment combined with qPCR (qPCRPMA. The chemical composition and the microbial community structure of the manures were also analysed. The strains showed similar decline rates and persisted up to 63 days. At day zero, the percentage of VBNC cells among viable cells was higher in raw manures (81.5-94.8% than in treated manures (67.8-79.2%. The changes in their proportion over time depended on the temperature and on the type of effluent: the biggest increase was observed in treated manures at 20°C and the smallest increase in raw manures at 8°C. The chemical parameters had no influence on the behaviour of the strains, but decrease of the persistence of viable cells was associated with an increase in the microbial richness of the manures. This study demonstrated that storing manure altered the culturability of L. monocytogenes, which rapidly entered the VBNC state, and underlines the importance of including VBNC cells when estimating the persistence of the pathogens in farm effluents.

  3. Desiccation induces viable but Non-Culturable cells in Sinorhizobium meliloti 1021.

    Science.gov (United States)

    Vriezen, Jan Ac; de Bruijn, Frans J; Nüsslein, Klaus R

    2012-01-20

    Sinorhizobium meliloti is a microorganism commercially used in the production of e.g. Medicago sativa seed inocula. Many inocula are powder-based and production includes a drying step. Although S. meliloti survives drying well, the quality of the inocula is reduced during this process. In this study we determined survival during desiccation of the commercial strains 102F84 and 102F85 as well as the model strain USDA1021.The survival of S. meliloti 1021 was estimated during nine weeks at 22% relative humidity. We found that after an initial rapid decline of colony forming units, the decline slowed to a steady 10-fold reduction in colony forming units every 22 days. In spite of the reduction in colony forming units, the fraction of the population identified as viable (42-54%) based on the Baclight live/dead stain did not change significantly over time. This change in the ability of viable cells to form colonies shows (i) an underestimation of the survival of rhizobial cells using plating methods, and that (ii) in a part of the population desiccation induces a Viable But Non Culturable (VBNC)-like state, which has not been reported before. Resuscitation attempts did not lead to a higher recovery of colony forming units indicating the VBNC state is stable under the conditions tested. This observation has important consequences for the use of rhizobia. Finding methods to resuscitate this fraction may increase the quality of powder-based seed inocula.

  4. Inkjet printing of viable human dental follicle stem cells

    Directory of Open Access Journals (Sweden)

    Mau Robert

    2015-09-01

    Full Text Available Inkjet printing technology has the potential to be used for seeding of viable cells for tissue engineering approaches. For this reason, a piezoelectrically actuated, drop-on-demand inkjet printing system was applied to deliver viable human dental follicle stem cells (hDFSC of sizes of about 15 μm up to 20 μm in diameter. The purpose of these investigations was to verify the stability of the printing process and to evaluate cell viability post printing. Using a Nanoplotter 2.1 (Gesim, Germany equipped with the piezoelectric printhead NanoTip HV (Gesim, Germany, a concentration of 6.6 ×106 cells ml−1 in DMEM with 10% fetal calf serum (FCS could be dispensed. The piezoelectric printhead has a nominal droplet volume of ~ 400 pl and was set to a voltage of 75 V and a pulse of 50 μs while dosing 50 000 droplets over a time of 100 seconds. The volume and trajectory of the droplet were checked by a stroboscope test right before and after the printing process. It was found that the droplet volume decreases significantly by 35% during printing process, while the trajectory of the droplets remains stable with only an insignificant number of degrees deviation from the vertical line. It is highly probable that some cell sedimentations or agglomerations affect the printing performance. The cell viability post printing was assessed by using the Trypan Blue dye exclusion test. The printing process was found to have no significant influence on cell survival. In conclusion, drop-on-demand inkjet printing can be a potent tool for the seeding of viable cells.

  5. Molar Pregnancy with a Co-Existing Viable Fetus

    Directory of Open Access Journals (Sweden)

    Ruya Deveer

    2014-03-01

    Full Text Available     The aim of this study was to report the clinical features, management, and outcome of a case of molar pregnancy with a coexisting viable fetus and to review the literature. In this article, we report a case of pregnancy with diffuse placental molar change and a normal fetus which presented with hyperemesis gravidarum and hyperthyroidism. Genetic amniocentesis showed normal fetal karyotype. A healthy full-term live male infant was delivered by cesarean section. In molar pregnancies with a normal karyotype fetus, with intensive maternal follow-up, continuation of pregnancy can be suggested.

  6. Proposal to consistently apply the International Code of Nomenclature of Prokaryotes (ICNP) to names of the oxygenic photosynthetic bacteria (cyanobacteria), including those validly published under the International Code of Botanical Nomenclature (ICBN)/International Code of Nomenclature for algae, fungi and plants (ICN), and proposal to change Principle 2 of the ICNP.

    Science.gov (United States)

    Pinevich, Alexander V

    2015-03-01

    This taxonomic note was motivated by the recent proposal [Oren & Garrity (2014) Int J Syst Evol Microbiol 64, 309-310] to exclude the oxygenic photosynthetic bacteria (cyanobacteria) from the wording of General Consideration 5 of the International Code of Nomenclature of Prokaryotes (ICNP), which entails unilateral coverage of these prokaryotes by the International Code of Nomenclature for algae, fungi, and plants (ICN; formerly the International Code of Botanical Nomenclature, ICBN). On the basis of key viewpoints, approaches and rules in the systematics, taxonomy and nomenclature of prokaryotes it is reciprocally proposed to apply the ICNP to names of cyanobacteria including those validly published under the ICBN/ICN. For this purpose, a change to Principle 2 of the ICNP is proposed to enable validation of cyanobacterial names published under the ICBN/ICN rules. © 2015 IUMS.

  7. PMA-PhyloChip DNA Microarray to Elucidate Viable Microbial Community Structure

    Science.gov (United States)

    Venkateswaran, Kasthuri J.; Stam, Christina N.; Andersen, Gary L.; DeSantis, Todd

    2011-01-01

    in the dark. Thereafter, the sample is exposed to visible light for five minutes, so that the DNA from dead cells will be cross-linked. Following this PMA treatment step, the sample is concentrated by centrifugation and washed (to remove excessive PMA) before DNA is extracted. The 16S rRNA gene fragments will be amplified by PCR to screen the total microbial community using PhyloChip DNA microarray analysis. This approach will detect only the viable microbial community since the PMA intercalated DNA from dead cells would be unavailable for PCR amplification. The total detection time including PCR reaction for low biomass samples will be a few hours. Numerous markets may use this technology. The food industry uses spore detection to validate new alternative food processing technologies, sterility, and quality. Pharmaceutical and medical equipment companies also detect spores as a marker for sterility. This system can be used for validating sterilization processes, water treatment systems, and in various public health and homeland security applications.

  8. Transformation of gram positive bacteria by sonoporation

    Science.gov (United States)

    Yang, Yunfeng; Li, Yongchao

    2014-03-11

    The present invention provides a sonoporation-based method that can be universally applied for delivery of compounds into Gram positive bacteria. Gram positive bacteria which can be transformed by sonoporation include, for example, Bacillus, Streptococcus, Acetobacterium, and Clostridium. Compounds which can be delivered into Gram positive bacteria via sonoporation include nucleic acids (DNA or RNA), proteins, lipids, carbohydrates, viruses, small organic and inorganic molecules, and nano-particles.

  9. Building Viable and Sustainable Regional Netchains: Case Studies of Regional Pork Netchains in Spain, Germany, and The Netherlands

    Directory of Open Access Journals (Sweden)

    Rannia Nijhoff‐Savvaki

    2012-06-01

    Full Text Available The present paper aims to give insight into critical issues contributing to the successful building of viable and sustainable regional netchains, focussing on chain governance mechanisms (coordination mechanisms, quality management systems, information systems and social embedding. It uses three representative case studies from the regional pork sector in Spain, Germany, and The Netherlands, illustrating different trajectories to commercially viable and sustainable regional netchains. By analysing the cases on each critical aspect, the present paper describes important issues and proposes specific elements of further research, including on the roles for(nongovernmental organisations.

  10. Social Networking and Smart Technology: Viable Environmental Communication Tools…?

    Science.gov (United States)

    Montain, J.; Byrne, J. M.

    2010-12-01

    To what extent do popular social networking channels represent a viable means for disseminating information regarding environmental change to the general public? Are new forms of communication such as YouTube™, Facebook™, MySpace™ and Twitter™ and smart devices such as iPhone™ and BlackBerry™ useful and effective in terms motivating people into social action and behavioural modification; or do they simply pay ‘lip service’ to these pressing environmental issues? This project will explore the background connections between social networking and environmental communication and education; and outline why such tools might be an appropriate way to connect to a broad audience in an efficient and unconventional manner. Further, research will survey the current prevalence of reliable environmental change information on social networking Internet-based media; and finally, suggestions for improved strategies and new directions will be provided.

  11. Dissolvable tattoo sensors: from science fiction to a viable technology

    Science.gov (United States)

    Cheng, Huanyu; Yi, Ning

    2017-01-01

    Early surrealistic painting and science fiction movies have envisioned dissolvable tattoo electronic devices. In this paper, we will review the recent advances that transform that vision into a viable technology, with extended capabilities even beyond the early vision. Specifically, we focus on the discussion of a stretchable design for tattoo sensors and degradable materials for dissolvable sensors, in the form of inorganic devices with a performance comparable to modern electronics. Integration of these two technologies as well as the future developments of bio-integrated devices is also discussed. Many of the appealing ideas behind developments of these devices are drawn from nature and especially biological systems. Thus, bio-inspiration is believed to continue playing a key role in future devices for bio-integration and beyond.

  12. A viable logarithmic f(R) model for inflation

    Energy Technology Data Exchange (ETDEWEB)

    Amin, M.; Khalil, S. [Center for Fundamental Physics, Zewail City of Science and Technology,6 October City, Giza (Egypt); Salah, M. [Center for Fundamental Physics, Zewail City of Science and Technology,6 October City, Giza (Egypt); Department of Mathematics, Faculty of Science, Cairo University,Giza (Egypt)

    2016-08-18

    Inflation in the framework of f(R) modified gravity is revisited. We study the conditions that f(R) should satisfy in order to lead to a viable inflationary model in the original form and in the Einstein frame. Based on these criteria we propose a new logarithmic model as a potential candidate for f(R) theories aiming to describe inflation consistent with observations from Planck satellite (2015). The model predicts scalar spectral index 0.9615

  13. Simultaneous pyometra and viable puppies’ gestation in a bitch

    Directory of Open Access Journals (Sweden)

    A. Risso

    2014-08-01

    Full Text Available Here we describe a case of pyometra coexisting with gestation in a 4.5 year-old miniature short-haired Dachshund. The dog exhibited depression, vaginal discharge, polydipsia and dehydration. Ultrasound examination revealed the presence of low to moderate anechoic fluid collection in the left uterine horn. Blood analysis revealed mild neutrophilia with a left shift. Based on these findings a presumptive diagnosis of pyometra was made and the bitch was treated using amoxicillin-clavulanate with dopaminergic agonist (cabergoline. A second ultrasound scan revealed the presence of two gestational vesicles in the right uterine horn that were successfully carried to term. Unusually, while pyometra persisted in the left uterine horn, two viable puppies were delivered by caesarean section from the right uterine horn.

  14. Inactivation of Airborne Bacteria and Viruses Using Extremely Low Concentrations of Chlorine Dioxide Gas.

    Science.gov (United States)

    Ogata, Norio; Sakasegawa, Miyusse; Miura, Takanori; Shibata, Takashi; Takigawa, Yasuhiro; Taura, Kouichi; Taguchi, Kazuhiko; Matsubara, Kazuki; Nakahara, Kouichi; Kato, Daisuke; Sogawa, Koushirou; Oka, Hiroshi

    2016-01-01

    Infectious airborne microbes, including many pathological microbes that cause respiratory infections, are commonly found in medical facilities and constitute a serious threat to human health. Thus, an effective method for reducing the number of microbes floating in the air will aid in the minimization of the incidence of respiratory infectious diseases. Here, we demonstrate that chlorine dioxide (ClO2) gas at extremely low concentrations, which has no detrimental effects on human health, elicits a strong effect to inactivate bacteria and viruses and significantly reduces the number of viable airborne microbes in a hospital operating room. In one set of experiments, a suspension of Staphylococcus aureus, bacteriophage MS2, and bacteriophage ΦX174 were released into an exposure chamber. When ClO2 gas at 0.01 or 0.02 parts per million (ppm, volume/volume) was present in the chamber, the numbers of surviving microbes in the air were markedly reduced after 120 min. The reductions were markedly greater than the natural reductions of the microbes in the chamber. In another experiment, the numbers of viable airborne bacteria in the operating room of a hospital collected over a 24-hour period in the presence or absence of 0.03 ppm ClO2 gas were found to be 10.9 ± 6.7 and 66.8 ± 31.2 colony-forming units/m3 (n = 9, p gas at extremely low concentrations (≤0.03 ppm) can reduce the number of viable microbes floating in the air in a room. These results strongly support the potential use of ClO2 gas at a non-toxic level to reduce infections caused by the inhalation of pathogenic microbes in nursing homes and medical facilities. © 2016 S. Karger AG, Basel.

  15. Viable but nonculturable state of foodborne pathogens in grapefruit juice: a study of laboratory.

    Science.gov (United States)

    Nicolò, Marco Sebastiano; Gioffrè, Angela; Carnazza, Santina; Platania, Giuseppe; Silvestro, Isabella Di; Guglielmino, Salvatore Pietro Paolo

    2011-01-01

    Several foodborne human pathogens, when exposed to harsh conditions, enter viable but nonculturable (VBNC) state; however, still open is the question whether VBNC pathogens could be a risk for public health, because, potentially, they can resuscitate. Moreover, cultural methods for food safety control were not able to detect VBNC forms of foodborne bacteria. Particularly, it has not been established whether food chemophysical characteristics can induce VBNC state in contaminating pathogen bacterial populations, especially in food, such as salads and fresh fruit juices, not subjected to any decontamination treatment. In this preliminary study, we intentionally contaminated grapefruit juice to determine whether pathogen bacteria could enter VNBC state. In fact, grapefruit juice contains natural antimicrobial compounds, has an average pH of about 3 and low content in carbohydrates. Such characteristics make grapefruit juice a harsh environment for microbial survival. For this purpose, Escherichia coli O157:H7, Salmonella enterica serovar Typhimurium ATCC 14028, Listeria monocytogenes ATCC 7644, and Shigella flexneri ATCC 12022, at two different inoculum sizes, have been used. Viability by the LIVE/DEAD BacLight Bacterial Viability kit and culturability by plate counts assay were monitored, whereas "resuscitation" of nonculturable populations was attempted by inoculation in nutrient-rich media. The data showed that L. monocytogenes lost both culturability and viability and did not resuscitate within 24 h independently on inoculum size, whereas E. coli O157:H7 was able to resuscitate after 24 h but did not after 48 h. Salmonella Typhimurium and S. flexneri, depending on inoculum size, lost culturability but maintained viability and were able to resuscitate; moreover, S. flexneri was still able to form colonies after 48 h at high inoculum size. In conclusion, entry into VBNC state differs on the species, depending, in turn, on inoculum size and time of incubation.

  16. Cultivation strategies for growth of uncultivated bacteria.

    Science.gov (United States)

    Vartoukian, Sonia R

    2016-11-01

    The majority of environmental bacteria and around a third of oral bacteria remain uncultivated. Furthermore, several bacterial phyla have no cultivable members and are recognised only by detection of their DNA by molecular methods. Possible explanations for the resistance of certain bacteria to cultivation in purity in vitro include: unmet fastidious growth requirements; inhibition by environmental conditions or chemical factors produced by neighbouring bacteria in mixed cultures; or conversely, dependence on interactions with other bacteria in the natural environment, without which they cannot survive in isolation. Auxotrophic bacteria, with small genomes lacking in the necessary genetic material to encode for essential nutrients, frequently rely on close symbiotic relationships with other bacteria for survival, and may therefore be recalcitrant to cultivation in purity. Since in-vitro culture is essential for the comprehensive characterisation of bacteria, particularly with regard to virulence and antimicrobial resistance, the cultivation of uncultivated organisms has been a primary focus of several research laboratories. Many targeted and open-ended strategies have been devised and successfully used. Examples include: the targeted detection of specific bacteria in mixed plate cultures using colony hybridisation; growth in simulated natural environments or in co-culture with 'helper' strains; and modified media preparation techniques or development of customised media eg. supplementation of media with potential growth-stimulatory factors such as siderophores. Despite significant advances in recent years in methodologies for the cultivation of previously uncultivated bacteria, a substantial proportion remain to be cultured and efforts to devise high-throughput strategies should be a high priority.

  17. Total viable bacterial count using a real time all-fibre spectroscopic system.

    Science.gov (United States)

    Bogomolny, E; Swift, S; Vanholsbeeck, F

    2013-07-21

    Rapid, accurate and sensitive enumeration of bacterial populations in the natural environment is an essential task for many research fields. Widely used standard methods for counting bacteria such as heterotrophic plate count require 1 to 8 days of incubation time for limited accuracy, while more accurate and rapid techniques are often expensive and may require bulky equipment. In the present study, we have developed a computerized optical prototype for bacterial detection. The goal of this research was to estimate the potential of this optical system for Total Viable Bacterial Count in water. For this purpose, we tested water batches with different microbiological content. Bacterial detection was based on fluorescence enhanced by nucleic acid staining. High sensitivity was achieved by a stable diode pumped solid state laser, sensitive CCD spectrometer and in situ excitation and signal collection. The results have shown that the bacterial count from different water origins using our optical setup along with multivariate analysis presents a higher accuracy and a shorter detection time compared to standard methods. For example, in a case where the fluorescence signal is calibrated to the water batch regression line, the relative standard deviation of the optical system enumeration varies between 21 and 36%, while that of the heterotropic plate count counterpart varies between 41 and 59%. In summary, we conclude that the all-fibre optical system may offer the following advantages over conventional methods: near real time examinations, portability, sensitivity, accuracy and ability to detect 10(2) to 10(8) CFU per ml bacterial concentrations.

  18. Sponge-associated bacteria: general overview and special aspects of bacteria associated with Halichondria panicea.

    Science.gov (United States)

    Imhoff, J F; Stöhr, R

    2003-01-01

    Increasing evidence is accumulating that highlights the important role of bacteria in bacteria-sponge associations. It appears to be equally important to analyse the specific association of bacteria with sponges, to realise the biological function of biologically active substances produced by sponge-associated bacteria, and to consider the relationship between bacteria and sponges in the search for new pharmaceutical products. In this chapter the current knowledge on bacteria-sponge associations is briefly reviewed. Results are summarised that were obtained by three major methodological approaches: (1) classical microscope observations, (2) investigations attempting to characterise sponge-associated bacteria by describing pure culture isolates, and (3) the rapidly growing evidence from genetic analyses of sponge-associated bacteria. Special emphasis is given to the evidence of possible symbiotic interactions between bacteria and sponges and to the synthesis of natural products by bacteria isolated from or associated with marine sponges. Case studies including morphological and genetic studies together with results from pure culture studies have been performed with bacteria from the sponges Rhodopaloeides odorabile, Aplysina cavernicola, and Halichondria panicea. In addition, new results on bacteria associated with Halichondria panicea are also presented.

  19. Colpoda secrete viable Listeria monocytogenes within faecal pellets.

    Science.gov (United States)

    Raghu Nadhanan, Rethish; Thomas, Connor J

    2014-02-01

    Transmission electron microscopy was used to demonstrate that co-cultures of the ciliate Colpoda RR (an environmental isolate) and Colpoda MLS-5 (a food processing environment isolate) with the pathogenic Listeria monocytogenes DRDC8 resulted in secretion of faecal pellets containing intact DRDC8 cells. A green fluorescent protein expressing variant of DRDC8 was used in co-cultures to confirm that the pellet-associated bacterial cells were L. monocytogenes. Viability was confirmed by plate counts, and assay of microbial respiratory activity-proved DRDC8 cells present within faecal pellets was metabolically active. Following treatment of faecal pellets secreted by Colpoda RR and MLS-5 with gentamycin and sodium hypochlorite (NaOCl), no loss of viability of the pellet-located DRDC8 cells was observed, indicating that faecal pellet encapsulated DRDC8 cells are resistant to biocidal agents. This work suggests that Colpoda-derived faecal pellets may provide a mechanism for transmission of L. monocytogenes and other pathogenic bacteria. Furthermore, bacteria encapsulated by faecal pellets may be resistant to disinfectants and cleaning agents used in food manufacturing and preparation facilities. © 2013 Society for Applied Microbiology and John Wiley & Sons Ltd.

  20. Synthetic Biology in Streptomyces Bacteria

    NARCIS (Netherlands)

    Medema, Marnix H.; Breitling, Rainer; Takano, Eriko

    2011-01-01

    Actinomycete bacteria of the genus Streptomyces are major producers of bioactive compounds for the biotechnology industry. They are the source of most clinically used antibiotics, as well as of several widely used drugs against common diseases, including cancer . Genome sequencing has revealed that

  1. Experience in using thermal disinfection to remove viable bacteria and endotoxins in centraly distributed reverse osmosis water.

    Science.gov (United States)

    Alayoud, Ahmed; Hamzi, Mohamed Amine; Razkaoui, Abdelaziz; Benyahia, Mohammed

    2014-01-01

    The water used for dilution of hemodialysis concentrates has to meet official quality recommendations regarding microbiology and chemical parameters. To avoid chemical use and to simplify treatments, hot water has been used to control microbial contamination of water distribution systems. In this study we evaluated the efficacy of heat disinfection in maintaining the quality of dialysis water generated by reverse osmosis (RO). During the first part of the study, we consecutively used (1) continuous water circulation, (2) daily heat disinfection and (3) a combination of daily heat disinfection and weekly chemical disinfection while checking bacterial count and endotoxin level every 4-5 weeks. During the second part of the study, we continued using daily heat disinfection while checking bacterial count and endotoxin level on weekly basis. The endotoxin levels at all sampling points of the water treatment system were lower than 0.005/ ml throughout the study. The application of heat disinfection alone reduced bacterial levels but an escape phenomenon occurred. After an interval of 21 days, an exponential increase of bacterial count was noted and cultures from the RO unit revealed growth of Pseudomonas fluorescence. The addition of chemical disinfection was successful in eliminating micro-organisms. Throughout this study, micro-organisms and endotoxins were not detectable in dialysate fluid and substitution fluid in dialysis monitors. The isolation of a thermo-sensitive organism from the RO unit after a period of relying on thermal disinfection suggests the existence of dead space in the RO unit that is not adequately exposed to heat but is accessible to chemical disinfection. .

  2. Towards a viable and just global nursing ethics.

    Science.gov (United States)

    Crigger, Nancy J

    2008-01-01

    Globalization, an outgrowth of technology, while informing us about people throughout the world, also raises our awareness of the extreme economic and social disparities that exist among nations. As part of a global discipline, nurses are vitally interested in reducing and eliminating disparities so that better health is achieved for all people. Recent literature in nursing encourages our discipline to engage more actively with social justice issues. Justice in health care is a major commitment of nursing; thus questions in the larger sphere of globalization, justice and ethics, are our discipline's questions also. Global justice, or fairness, is not an issue for some groups or institutions, but a deeper human rights issue that is a responsibility for everyone. What can we do to help reduce or eliminate the social and economic disparities that are so evident? What kind of ethical milieu is needed to address the threat that globalization imposes on justice and fairness? This article enriches the conceptualization of globalization by investigating recent work by Schweiker and Twiss. In addition, I discuss five qualities or characteristics that will facilitate the development of a viable and just global ethic. A global ethic guides all people in their response to human rights and poverty. Technology and business, two major forces in globalization that are generally considered beneficial, are critiqued as barriers to social justice and the common good.

  3. Keeping checkpoint/restart viable for exascale systems.

    Energy Technology Data Exchange (ETDEWEB)

    Riesen, Rolf E.; Bridges, Patrick G. (IBM Research, Ireland, Mulhuddart, Dublin); Stearley, Jon R.; Laros, James H., III; Oldfield, Ron A.; Arnold, Dorian (University of New Mexico, Albuquerque, NM); Pedretti, Kevin Thomas Tauke; Ferreira, Kurt Brian; Brightwell, Ronald Brian

    2011-09-01

    Next-generation exascale systems, those capable of performing a quintillion (10{sup 18}) operations per second, are expected to be delivered in the next 8-10 years. These systems, which will be 1,000 times faster than current systems, will be of unprecedented scale. As these systems continue to grow in size, faults will become increasingly common, even over the course of small calculations. Therefore, issues such as fault tolerance and reliability will limit application scalability. Current techniques to ensure progress across faults like checkpoint/restart, the dominant fault tolerance mechanism for the last 25 years, are increasingly problematic at the scales of future systems due to their excessive overheads. In this work, we evaluate a number of techniques to decrease the overhead of checkpoint/restart and keep this method viable for future exascale systems. More specifically, this work evaluates state-machine replication to dramatically increase the checkpoint interval (the time between successive checkpoint) and hash-based, probabilistic incremental checkpointing using graphics processing units to decrease the checkpoint commit time (the time to save one checkpoint). Using a combination of empirical analysis, modeling, and simulation, we study the costs and benefits of these approaches on a wide range of parameters. These results, which cover of number of high-performance computing capability workloads, different failure distributions, hardware mean time to failures, and I/O bandwidths, show the potential benefits of these techniques for meeting the reliability demands of future exascale platforms.

  4. Case-based anatomy teaching: a viable alternative?

    Science.gov (United States)

    Eseonu, Onyedikachi; Carachi, Robert; Brindley, Nicola

    2013-08-01

    Over the last two decades, there has been a decline in the amount of time available for anatomy teaching in the medical undergraduate curriculum, and new methods of anatomy teaching have been adopted for pragmatic reasons, with little evidence base to support their proposed educational benefits. This study seeks to establish the effect of a case-based teaching method on students' confidence in anatomy. Forty-three student volunteers in the clinical phase of the Glasgow medical course were given weekly anatomy teaching sessions based on clinical case presentations over 4 weeks. The students were given an anatomy test, and were asked to rate their confidence in their anatomy knowledge before and after the teaching sessions. There was a two-point increase in students' self-rated confidence, and a 10.9 per cent increase in average test score after the case-based anatomy teaching sessions. Both of these increases were statistically significant (p teaching was also highly rated by students, which may make it a viable option for the teaching of anatomy in the modern medical curriculum. © 2013 John Wiley & Sons Ltd.

  5. Towards viable cosmological models of disformal theories of gravity

    Science.gov (United States)

    Sakstein, Jeremy

    2015-01-01

    The late-time cosmological dynamics of disformal gravity are investigated using dynamical systems methods. It is shown that in the general case there are no stable attractors that screen fifth forces locally and simultaneously describe a dark energy dominated universe. Viable scenarios have late-time properties that are independent of the disformal parameters and are identical to the equivalent conformal quintessence model. Our analysis reveals that configurations where the Jordan frame metric becomes singular are only reached in the infinite future, thus explaining the natural pathology resistance observed numerically by several previous works. The viability of models where this can happen is discussed in terms of both the cosmological dynamics and local phenomena. We identify a special parameter tuning such that there is a new fixed point that can match the presently observed dark energy density and equation of state. This model is unviable when the scalar couples to the visible sector but may provide a good candidate model for theories where only dark matter is disformally coupled.

  6. Energy transduction in lactic acid bacteria

    NARCIS (Netherlands)

    Poolman, Bert

    In the discovery of some general principles of energy transduction, lactic acid bacteria have played an important role. In this review, the energy transducing processes of lactic acid bacteria are discussed with the emphasis on the major developments of the past 5 years. This work not only includes

  7. Bacteria and protozoa in soil microhabitats as affected by earthworms

    DEFF Research Database (Denmark)

    Winding, Anne; Rønn, Regin; Hendriksen, Niels B.

    1997-01-01

    , were compared. The total, viable, and culturable number of bacteria, the metabolic potentials of bacterial populations, and the number of protozoa and nematodes were determined in soil size fractions. Significant differences between soil fractions were shown by all assays. The highest number......-cyano-2,3-ditolyl tetrazolim chloride (CTC)-reducing bacteria explained a major part of the variation in the number of protozoa. High protozoan activity and predation thus coincided with high bacterial activity. In soil with elm leaves, fungal growth is assumed to inhibit bacterial and protozoan...... activity. In soil with elm leaves and earthworms, earthworm activity led to increased culturability of bacteria, activity of protozoa, number of nematodes, changed metabolic potentials of the bacteria, and decreased differences in metabolic potentials between bacterial populations in the soil fractions...

  8. 34 CFR 303.15 - Include; including.

    Science.gov (United States)

    2010-07-01

    ... 34 Education 2 2010-07-01 2010-07-01 false Include; including. 303.15 Section 303.15 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF SPECIAL EDUCATION AND REHABILITATIVE SERVICES, DEPARTMENT OF EDUCATION EARLY INTERVENTION PROGRAM FOR INFANTS AND TODDLERS WITH...

  9. Anti-Biofilm Activities from Marine Cold Adapted Bacteria Against Staphylococci and Pseudomonas aeruginosa.

    Science.gov (United States)

    Papa, Rosanna; Selan, Laura; Parrilli, Ermenegilda; Tilotta, Marco; Sannino, Filomena; Feller, Georges; Tutino, Maria L; Artini, Marco

    2015-01-01

    Microbial biofilms have great negative impacts on the world's economy and pose serious problems to industry, public health and medicine. The interest in the development of new approaches for the prevention and treatment of bacterial adhesion and biofilm formation has increased. Since, bacterial pathogens living in biofilm induce persistent chronic infections due to the resistance to antibiotics and host immune system. A viable approach should target adhesive properties without affecting bacterial vitality in order to avoid the appearance of resistant mutants. Many bacteria secrete anti-biofilm molecules that function in regulating biofilm architecture or mediating the release of cells from it during the dispersal stage of biofilm life cycle. Cold-adapted marine bacteria represent an untapped reservoir of biodiversity able to synthesize a broad range of bioactive compounds, including anti-biofilm molecules. The anti-biofilm activity of cell-free supernatants derived from sessile and planktonic cultures of cold-adapted bacteria belonging to Pseudoalteromonas, Psychrobacter, and Psychromonas species were tested against Staphylococcus aureus, Staphylococcus epidermidis, and Pseudomonas aeruginosa strains. Reported results demonstrate that we have selected supernatants, from cold-adapted marine bacteria, containing non-biocidal agents able to destabilize biofilm matrix of all tested pathogens without killing cells. A preliminary physico-chemical characterization of supernatants was also performed, and these analyses highlighted the presence of molecules of different nature that act by inhibiting biofilm formation. Some of them are also able to impair the initial attachment of the bacterial cells to the surface, thus likely containing molecules acting as anti-biofilm surfactant molecules. The described ability of cold-adapted bacteria to produce effective anti-biofilm molecules paves the way to further characterization of the most promising molecules and to test their

  10. Abundance and Distribution of Enteric Bacteria and Viruses in Coastal and Estuarine Sediments-a Review.

    Science.gov (United States)

    Hassard, Francis; Gwyther, Ceri L; Farkas, Kata; Andrews, Anthony; Jones, Vera; Cox, Brian; Brett, Howard; Jones, Davey L; McDonald, James E; Malham, Shelagh K

    2016-01-01

    The long term survival of fecal indicator organisms (FIOs) and human pathogenic microorganisms in sediments is important from a water quality, human health and ecological perspective. Typically, both bacteria and viruses strongly associate with particulate matter present in freshwater, estuarine and marine environments. This association tends to be stronger in finer textured sediments and is strongly influenced by the type and quantity of clay minerals and organic matter present. Binding to particle surfaces promotes the persistence of bacteria in the environment by offering physical and chemical protection from biotic and abiotic stresses. How bacterial and viral viability and pathogenicity is influenced by surface attachment requires further study. Typically, long-term association with surfaces including sediments induces bacteria to enter a viable-but-non-culturable (VBNC) state. Inherent methodological challenges of quantifying VBNC bacteria may lead to the frequent under-reporting of their abundance in sediments. The implications of this in a quantitative risk assessment context remain unclear. Similarly, sediments can harbor significant amounts of enteric viruses, however, the factors regulating their persistence remains poorly understood. Quantification of viruses in sediment remains problematic due to our poor ability to recover intact viral particles from sediment surfaces (typically true viral titre in sediments may be being vastly underestimated. In turn, this is limiting our ability to understand the fate and transport of viruses in sediments. Model systems (e.g., human cell culture) are also lacking for some key viruses, preventing our ability to evaluate the infectivity of viruses recovered from sediments (e.g., norovirus). The release of particle-bound bacteria and viruses into the water column during sediment resuspension also represents a risk to water quality. In conclusion, our poor process level understanding of viral

  11. Anti-biofilm activities from marine cold adapted bacteria against staphylococci and Pseudomonas aeruginosa

    Directory of Open Access Journals (Sweden)

    Rosanna ePapa

    2015-12-01

    Full Text Available Microbial biofilms have great negative impacts on the world’s economy and pose serious problems to industry, public health and medicine. The interest in the development of new approaches for the prevention and treatment of bacterial adhesion and biofilm formation has increased. Since, bacterial pathogens living in biofilm induce persistent chronic infections due to the resistance to antibiotics and host immune system. A viable approach should target adhesive properties without affecting bacterial vitality in order to avoid the appearance of resistant mutants. Many bacteria secrete anti-biofilm molecules that function in regulating biofilm architecture or mediating the release of cells from it during the dispersal stage of biofilm life cycle. Cold-adapted marine bacteria represent an untapped reservoir of biodiversity able to synthesize a broad range of bioactive compounds, including anti-biofilm molecules.The anti-biofilm activity of cell-free supernatants derived from sessile and planktonic cultures of cold-adapted bacteria belonging to Pseudoalteromonas, Psychrobacter and Psychromonas species were tested against Staphylococcus aureus, Staphylococcus epidermidis and Pseudomonas aeruginosa strains. Reported results demonstrate that we have selected supernatants, from cold-adapted marine bacteria, containing non-biocidal agents able to destabilize biofilm matrix of all tested pathogens without killing cells. A preliminary physico-chemical characterization of supernatants was also performed, and these analyses highlighted the presence of molecules of different nature that act by inhibiting biofilm formation. Some of them are also able to impair the initial attachment of the bacterial cells to the surface, thus likely containing molecules acting as anti-biofilm surfactant molecules.The described ability of cold-adapted bacteria to produce effective anti-biofilm molecules paves the way to further characterization of the most promising molecules

  12. Identification of Viable Helicobacter pylori in Drinking Water Supplies by Cultural and Molecular Techniques.

    Science.gov (United States)

    Santiago, Paula; Moreno, Yolanda; Ferrús, M Antonía

    2015-08-01

    Helicobacter pylori is one of the most common causes of chronic bacterial infection in humans, directly related to peptic ulcer and gastric cancer. It has been suggested that H. pylori can be acquired through different transmission routes, including water. In this study, culture and qPCR were used to detect and identify the presence of H. pylori in drinking water. Furthermore, the combined techniques PMA-qPCR and DVC-FISH were applied for detection of viable cells of H. pylori. Among 24 drinking water samples, 16 samples were positive for the presence of H. pylori, but viable cells were only detected in six samples. Characteristic colonies, covered by a mass of bacterial unspecific growth, were observed on selective agar plates from an only sample, after enrichment. The mixed culture was submitted to DVC-FISH and qPCR analysis, followed by sequencing of the amplicons. Molecular techniques confirmed the growth of H. pylori on the agar plate. Our results demonstrate for the first time that H. pylori can survive and be potentially infective in drinking water, showing that water distribution systems could be a potential route for H. pylori transmission. © 2015 John Wiley & Sons Ltd.

  13. Acupuntura un tratamiento viable para las adicciones en Colombia

    Directory of Open Access Journals (Sweden)

    Hernán López-Suescún

    2013-09-01

    Full Text Available Resumen La acupuntura es una antigua técnica terapéutica desarrollada en China, que ha evidenciado ser efectiva en síntomas como las náuseas, vómito y dolor dentario. A pesar del sustento fisiológico que posibilitaría un uso efectivo en otras patologías, incluyendo el campo de las adicciones, los estudios son contradictorios, posiblemente por la diferencias de visión entre la medicina oriental y la occidental. El consumo de psicoactivos es un problema de salud pública en Colombia y en el mundo que genera grandes costos tangibles e intangibles, los cuales, en países desarrollados, puede llegar hasta el 1,6 % del PIB. En contraste, el beneficio económico del tratamiento de las adicciones, según las Naciones Unidas Contra la Droga y el Delito (UNODC, está entre 1:3 a 1:13; por lo tanto, cualquier esfuerzo que se realice en favor de los consumidores es una ganancia. Con base en estos datos, los organismos internacionales han generado políticas que ayudan a aminorar estos efectos. Colombia, como integrante de estos organismos, ha realizado varios compromisos para llevar a cabo dichas metas. Los tratamientos con auriculoterapia, como el protocolo NADA (National Acupuncture Detoxification Association, son los métodos más usados para las adicciones en el mundo, y aunque no se ha logrado evidenciar su efectividad, por su costo, facilidad y el poco riesgo de efectos adversos se hace viable en un país con pocos recursos económicos como Colombia.

  14. Development of a Commercially Viable, Modular Autonomous Robotic Systems for Converting any Vehicle to Autonomous Control

    Science.gov (United States)

    Parish, David W.; Grabbe, Robert D.; Marzwell, Neville I.

    1994-01-01

    A Modular Autonomous Robotic System (MARS), consisting of a modular autonomous vehicle control system that can be retrofit on to any vehicle to convert it to autonomous control and support a modular payload for multiple applications is being developed. The MARS design is scalable, reconfigurable, and cost effective due to the use of modern open system architecture design methodologies, including serial control bus technology to simplify system wiring and enhance scalability. The design is augmented with modular, object oriented (C++) software implementing a hierarchy of five levels of control including teleoperated, continuous guidepath following, periodic guidepath following, absolute position autonomous navigation, and relative position autonomous navigation. The present effort is focused on producing a system that is commercially viable for routine autonomous patrolling of known, semistructured environments, like environmental monitoring of chemical and petroleum refineries, exterior physical security and surveillance, perimeter patrolling, and intrafacility transport applications.

  15. Genomics of Probiotic Bacteria

    Science.gov (United States)

    O'Flaherty, Sarah; Goh, Yong Jun; Klaenhammer, Todd R.

    Probiotic bacteria from the Lactobacillus and Bifidobacterium species belong to the Firmicutes and the Actinobacteria phylum, respectively. Lactobacilli are members of the lactic acid bacteria (LAB) group, a broadly defined family of microorganisms that ferment various hexoses into primarily lactic acid. Lactobacilli are typically low G + C gram-positive species which are phylogenetically diverse, with over 100 species documented to date. Bifidobacteria are heterofermentative, high G + C content bacteria with about 30 species of bifidobacteria described to date.

  16. Relative abundance and distribution of bacteria in the gut of ...

    African Journals Online (AJOL)

    Quantitative analyses of bacterial flora associated with the intestine of Macrobrachium vollenhovenii, sediment and water from Epe lagoon and Badagry Creek were carried out. Total viable counts (TVC) of bacteria in the intestine of the prawn ranged from 5.7 ± 0.3 × 107 to 8.1 ± 0.3 × 107-1 (cfu g) and 2.8 ± 0.6 × 107 to 5.3 ...

  17. Application of Reverse Transcriptase -PCR (RT-PCR) for rapid detection of viable Escherichia coli in drinking water samples.

    Science.gov (United States)

    Molaee, Neda; Abtahi, Hamid; Ghannadzadeh, Mohammad Javad; Karimi, Masoude; Ghaznavi-Rad, Ehsanollah

    2015-01-01

    Polymerase chain reaction (PCR) is preferred to other methods for detecting Escherichia coli (E. coli) in water in terms of speed, accuracy and efficiency. False positive result is considered as the major disadvantages of PCR. For this reason, reverse transcriptase-polymerase chain reaction (RT-PCR) can be used to solve this problem. The aim of present study was to determine the efficiency of RT-PCR for rapid detection of viable Escherichia coli in drinking water samples and enhance its sensitivity through application of different filter membranes. Specific primers were designed for 16S rRNA and elongation Factor II genes. Different concentrations of bacteria were passed through FHLP and HAWP filters. Then, RT-PCR was performed using 16srRNA and EF -Tu primers. Contamination of 10 wells was determined by RT-PCR in Arak city. To evaluate RT-PCR efficiency, the results were compared with most probable number (MPN) method. RT-PCR is able to detect bacteria in different concentrations. Application of EF II primers reduced false positive results compared to 16S rRNA primers. The FHLP hydrophobic filters have higher ability to absorb bacteria compared with HAWB hydrophilic filters. So the use of hydrophobic filters will increase the sensitivity of RT-PCR. RT-PCR shows a higher sensitivity compared to conventional water contamination detection method. Unlike PCR, RT-PCR does not lead to false positive results. The use of EF-Tu primers can reduce the incidence of false positive results. Furthermore, hydrophobic filters have a higher ability to absorb bacteria compared to hydrophilic filters.

  18. Experimental human-like model to assess the part of viable Legionella reaching the thoracic region after nebulization.

    Directory of Open Access Journals (Sweden)

    Jérémie Pourchez

    Full Text Available The incidence of Legionnaires' disease (LD in European countries and the USA has been constantly increasing since 1998. Infection of humans occurs through aerosol inhalation. To bridge the existing gap between the concentration of Legionella in a water network and the deposition of bacteria within the thoracic region (assessment of the number of viable Legionella, we validated a model mimicking realistic exposure through the use of (i recent technology for aerosol generation and (ii a 3D replicate of the human upper respiratory tract. The model's sensitivity was determined by monitoring the deposition of (i aerosolized water and Tc99m radio-aerosol as controls, and (ii bioaerosols generated from both Escherichia coli and Legionella pneumophila sg 1 suspensions. The numbers of viable Legionella prior to and after nebulization were provided by culture, flow cytometry and qPCR. This study was designed to obtain more realistic data on aerosol inhalation (vs. animal experimentation and deposition at the thoracic region in the context of LD. Upon nebulization, 40% and 48% of the initial Legionella inoculum was made of cultivable and non-cultivable cells, respectively; 0.7% of both populations reached the filter holder mimicking the thoracic region in this setup. These results are in agreement with experimental data based on quantitative microbial risk assessment methods and bring new methods that may be useful for preventing LD.

  19. Abundance and Community Structure of Bacteria on Asian Dust Particles Collected in Beijing, China, during the Asian Dust Season.

    Science.gov (United States)

    Yamaguchi, Nobuyasu; Baba, Takashi; Ichijo, Tomoaki; Himezawa, Yuka; Enoki, Kanami; Saraya, Makoto; Li, Pin-Fang; Nasu, Masao

    2016-01-01

    Approximately 180 t/km(2) of Asian dust particles are estimated to fall annually on Beijing, China, and there is significant concern about the influence of microbes transported by Asian dust events on human health and downwind ecosystems. In this study, we collected Asian dust particles in Beijing, and analyzed the bacterial communities on these particles by culture-independent methods. Bacterial cells on Asian dust particles were visualized first by laser scanning microscopy, which demonstrated that Asian dust particles carry bacterial cells to Beijing. Bacterial abundance, as determined by quantitative polymerase chain reaction (PCR), was 10(8) to 10(9) cells/g, a value about 10 times higher than that in Asian dust source soils. Inter-seasonal variability of bacterial community structures among Asian dust samples, as compared by terminal restriction fragment length polymorphism (T-RFLP), was low during the Asian dust season. Several viable bacteria, including intestinal bacteria, were found in Asian dust samples by denaturing gradient gel electrophoresis (DGGE). Clone library analysis targeting 16S ribosomal RNA (rRNA) gene sequences demonstrated that bacterial phylogenetic diversity was high in the dust samples, and most of these were environmental bacteria distributed in soil and air. The dominant species in the clone library was Segetibacter aerophilus (Bacteroidetes), which was first isolated from an Asian dust sample collected in Korea. Our results also indicate the possibility of a change in the bacterial community structure during transportation and increases in desiccation-tolerant bacteria such as Firmicutes.

  20. Effect of myocardial revascularisation on left ventricular systolic function in patients with and without viable myocardium: should non-viable segments be revascularised?

    Science.gov (United States)

    Stipac, Alja Vlahovic; Stankovic, Ivan; Vidakovic, Radosav; Putnikovic, Biljana; Ilic, Ivan; Milicic, Biljana; Neskovic, Aleksandar N

    2013-12-01

    To assess the effect of surgical revascularisation on left ventricular (LV) systolic function in patients with viable and non-viable dysfunctional LV segments determined by low dose dobutamine stress echocardiography (DSE). Prospective observational cohort study. Single tertiary care centre. Consecutive patients referred to surgical revascularisation (n=115). DSE and surgical revascularisation. Functional recovery defined as increase in ejection fraction ≥ 5% 1 year after revascularisation in patients with and without viable myocardium (viability defined as improvement of contractility in ≥ 4 LV segments on DSE). The mean age, ejection fraction and wall motion score index (WMSi) of patients were 59 ± 9 years, 44 ± 9% and 1.82 ± 0.31, respectively. There was no difference between DSE positive and DSE negative patients for any of those parameters at baseline study (p>0.05 for all). After 12 months, the ejection fraction increased 11 ± 1% in patients with viable myocardium vs 7 ± 1% in patients without viable myocardium (p=0.002). Moreover, in patients with viable myocardium, the greatest increase of ejection fraction occurred 1 month after surgery (9 ± 1%), whereas in those patients with negative DSE the ejection fraction increased more gradually (2±1% after 1 month, p=0.002 between groups for 1 month vs preoperative value), but still improved after 12 months follow-up (pmyocardial revascularisation. Functional recovery continuously occurs throughout the first year after surgical treatment.

  1. How honey kills bacteria

    NARCIS (Netherlands)

    Kwakman, Paulus H. S.; te Velde, Anje A.; de Boer, Leonie; Speijer, Dave; Vandenbroucke-Grauls, Christina M. J. E.; Zaat, Sebastian A. J.

    2010-01-01

    With the rise in prevalence of antibiotic-resistant bacteria, honey is increasingly valued for its antibacterial activity. To characterize all bactericidal factors in a medical-grade honey, we used a novel approach of successive neutralization of individual honey bactericidal factors. All bacteria

  2. Entry of Yersinia Pestis into the Viable but Nonculturable State in a Low-Temperature Tap Water Microcosm

    Science.gov (United States)

    2011-03-16

    pestis has been the cause of some the most devastating disease epidemics in human history, including at least three world- wide pandemics [1]. The...non-culturable state. Past studies suggest that the later possibility is the most likely, for example, Oliver et al. showed that E. coli and Salmonella ...Escherichia coli and Salmonella typhimurium into the viable but nonculturable state following chlorination of wastewater. J Water Health 3: 249–257

  3. Identification of intracellular bacteria in adenoid and tonsil tissue specimens: the efficiency of culture versus fluorescent in situ hybridization (FISH).

    Science.gov (United States)

    Stępińska, M; Olszewska-Sosińska, O; Lau-Dworak, M; Zielnik-Jurkiewicz, B; Trafny, E A

    2014-01-01

    Monocyte/macrophage cells from human nasopharyngeal lymphoid tissue can be a source of bacteria responsible for human chronic and recurrent upper respiratory tract infection. Detection and characterization of pathogens surviving intracellularly could be a key element in bacteriological diagnosis of the infections as well as in the study on interactions between bacteria and their host. The present study was undertaken to assess the possibility of isolation of viable bacteria from the cells expressing monocyte/macrophage marker CD14 in nasopharyngeal lymphoid tissue. Overall, 74 adenotonsillectomy specimens (adenoids and tonsils) from 37 children with adenoid hypertrophy and recurrent infections as well as 15 specimens from nine children with adenoid hypertrophy, which do not suffer from upper respiratory tract infections (the control group), were studied. The suitability of immunomagnetic separation for extraction of CD14(+) cells from lymphoid tissue and for further isolation of the intracellular pathogens has been shown. The coexistence of living pathogens including Haemophilus influenzae, Staphylococcus aureus, and Streptococcus pyogenes with the bacteria representing normal nasopharyngeal microbiota inside CD14(+) cells was demonstrated. Twenty-four strains of these pathogens from 32.4 % of the lysates of CD14(+) cells were isolated. Concurrently, the fluorescent in situ hybridization (FISH) with a universal EUB388, and the species-specific probes demonstrated twice more often the persistence of these bacterial species in the lysates of CD14(+) cells than conventional culture. Although the FISH technique appears to be more sensitive than traditional culture in the intracellular bacteria identification, the doubts on whether the bacteria are alive, and therefore, pathogenic would still exist without the strain cultivation.

  4. A technique for determining viable military logistics support alternatives

    Science.gov (United States)

    Hester, Jesse Stuart

    A look at today's US military will see them operating much beyond the scope of protecting and defending the United States. These operations now consist of, but are not limited to humanitarian aid, disaster relief, peace keeping, and conflict resolution. This broad spectrum of operational environments has necessitated a transformation of the individual military services to a hybrid force that is attempting to leverage the inherent and emerging capabilities and strengths of all those under the umbrella of the Department of Defense (DOD), this concept has been coined Joint Operations. Supporting Joint Operations requires a new approach to determining a viable military logistics support system. The logistics architecture for these operations has to accommodate scale, time, varied mission objectives, and imperfect information. Compounding the problem is the human in the loop (HITL) decision maker (DM) who is a necessary component for quickly assessing and planning logistics support activities. Past outcomes are not necessarily good indicators of future results, but they can provide a reasonable starting point for planning and prediction of specific needs for future requirements. Adequately forecasting the necessary logistical support structure and commodities needed for any resource intensive environment has progressed well beyond stable demand assumptions to one in which dynamic and nonlinear environments can be captured with some degree of fidelity and accuracy. While these advances are important, a holistic approach that allows exploration of the operational environment or design space does not exist to guide the military logistician in a methodical way to support military forecasting activities. To bridge this capability gap, a method called Adaptive Technique for Logistics Architecture Solutions (ATLAS) has been developed. This method provides a process that facilitates the use of techniques and tools that filter and provide relevant information to the DM. By doing

  5. Quantification and Qualification of Bacteria Trapped in Chewed Gum

    NARCIS (Netherlands)

    Wessel, Stefan W.; van der Mei, Henny C.; Morando, David; Slomp, Anje M.; van de Belt-Gritter, Betsy; Maitra, Amarnath; Busscher, Henk J.

    2015-01-01

    Chewing of gum contributes to the maintenance of oral health. Many oral diseases, including caries and periodontal disease, are caused by bacteria. However, it is unknown whether chewing of gum can remove bacteria from the oral cavity. Here, we hypothesize that chewing of gum can trap bacteria and

  6. Incidence of pathogenic bacteria in the Asejire Lake, western Nigeria

    African Journals Online (AJOL)

    This was implied as a result of the presence of the bacteria (Escherichia coli) in this freshwater lake; other bacteria isolated include Pseudomonas and Micrococcus species. This water body is therefore considered unsuitable for drinking. KEY WORDS: Feacal contamination, presumptive coliform count, coliform bacteria ...

  7. Liquid biopsy in cancer patients: advances in capturing viable CTCs for functional studies using the EPISPOT assay.

    Science.gov (United States)

    Alix-Panabières, Catherine; Pantel, Klaus

    2015-01-01

    Circulating tumor cells (CTCs) in the blood of cancer patients have received increasing attention as new diagnostic tool enabling 'liquid biopsies'. In contrast to the wealth of descriptive studies demonstrating the clinical relevance of CTCs as biomarkers, the extremely low concentration of CTCs in the peripheral blood of most cancer patients challenges further functional studies. This article discusses the current possibilities to enrich and, in particular, detect viable CTCs with emphasis on the EPithelial ImmunoSPOT technology. This functional assay detects viable CTCs at the single-cell level and has been used on hundreds of patients with different tumor types including epithelial tumors (breast, prostate and colon cancer) and melanomas. Moreover, the article summarizes recent advances in the in vitro and in vivo expansion of CTCs from cancer patients. These functional analyses will contribute to identifying the biological properties of metastatic cells and reveal new therapeutic targets against disseminating cancer cells.

  8. Antibiotics from predatory bacteria

    Directory of Open Access Journals (Sweden)

    Juliane Korp

    2016-03-01

    Full Text Available Bacteria, which prey on other microorganisms, are commonly found in the environment. While some of these organisms act as solitary hunters, others band together in large consortia before they attack their prey. Anecdotal reports suggest that bacteria practicing such a wolfpack strategy utilize antibiotics as predatory weapons. Consistent with this hypothesis, genome sequencing revealed that these micropredators possess impressive capacities for natural product biosynthesis. Here, we will present the results from recent chemical investigations of this bacterial group, compare the biosynthetic potential with that of non-predatory bacteria and discuss the link between predation and secondary metabolism.

  9. Method of Detecting Coliform Bacteria and Escherichia Coli Bacteria from Reflected Light

    Science.gov (United States)

    Vincent, Robert (Inventor)

    2013-01-01

    The present invention relates to a method of detecting coliform bacteria in water from reflected light and a method of detecting Eschericha Coli bacteria in water from reflected light, and also includes devices for the measurement, calculation and transmission of data relating to that method.

  10. Cybernetically sound organizational structures II: Relating de Sitter's design theory to Beer's viable system model

    NARCIS (Netherlands)

    Achterbergh, J.M.I.M.; Vriens, D.J.

    2011-01-01

    - Purpose – The purpose of this paper is to show how the viable system model (VSM) and de Sitter's design theory can complement each other in the context of the diagnosis and design of viable organizations. - Design/methodology/approach – Key concepts from Beer's model and de Sitter's design

  11. Optimization of a Binary Concrete Crack Self-Healing System Containing Bacteria and Oxygen

    Directory of Open Access Journals (Sweden)

    Jinlong Zhang

    2017-01-01

    Full Text Available An optimized strategy for the enhancement of microbially induced calcium precipitation including spore viability ensurance, nutrient selection and O2 supply was developed. Firstly, an optimal yeast extract concentration of 5 g/l in sporulation medium was determined based on viable spore yield and spore viability. Furthermore, the effects of certain influential factors on microbial calcium precipitation process of H4 in the presence of oxygen releasing tablet (ORT were evaluated. The results showed that CaO2 is preferable to other peroxides in improving the calcium precipitation by H4. H4 strain is able to precipitate a highly insoluble calcium at the CaO2 dosage range of 7.5–12.5 g/l, and the most suitable spore concentration is 6 × 108 spores/ml when the spore viability (viable spore ratio is approximately 50%. Lactate is the best carbon source and nitrate is the best nitrogen source for aerobic incubation. This work has laid a foundation of ternary self-healing system containing bacteria, ORT, and nutrients, which will be promising for the self-healing of cracks deep inside the concrete structure.

  12. Probiotic bacteria survive in Cheddar cheese and modify populations of other lactic acid bacteria.

    Science.gov (United States)

    Ganesan, B; Weimer, B C; Pinzon, J; Dao Kong, N; Rompato, G; Brothersen, C; McMahon, D J

    2014-06-01

    Starter lactic acid bacteria in Cheddar cheese face physico-chemical stresses during manufacture and ageing that alter their abilities to survive and to interact with other bacterial populations. Nonstarter bacteria are derived from milk handling, cheese equipment and human contact during manufacture. Probiotic bacteria are added to foods for human health benefits that also encounter physiological stresses and microbial competition that may mitigate their survival during ageing. We added probiotic Lactobacillus acidophilus, Lactobacillus casei, Lactobacillus paracasei and Bifidobacterium animalis subsp. lactis to full-fat, reduced-fat and low-fat Cheddar cheeses, aiming to study their survival over 270 days of ageing and to determine the role of the cheese matrix in their survival. Probiotic and other lactic acid bacterial populations were enumerated by quantitative PCR using primers specifically targeting the different bacterial genera or species of interest. Bifidobacteria were initially added at 10(6) CFU g(-1) cheese and survived variably in the different cheeses over the 270-day ageing process. Probiotic lactobacilli that were added at 10(7) CFU g(-1) cheese and incident nonstarter lactobacilli (initially at 10(8) CFU g(-1) cheese) increased by 10- to 100-fold over 270 days. Viable bacterial populations were differentiated using propidium monoazide followed by species-specific qPCR assays, which demonstrated that the starter and probiotic microbes survived over ageing, independent of cheese type. Addition of probiotic bacteria, at levels 100-fold below that of starter bacteria, modified starter and nonstarter bacterial levels. We demonstrated that starter lactococci, nonstarter lactobacilli and probiotic bacteria are capable of surviving throughout the cheesemaking and ageing process, indicating that delivery via hard cheeses is possible. Probiotic addition at lower levels may also alter starter and nonstarter bacterial survival. We applied qPCR to study

  13. Hymenolepis nana: immunity against oncosphere challenge in mice previously given viable or non-viable oncospheres of H. nana, H. diminuta, H. microstoma and Taenia taeniaeformis.

    Science.gov (United States)

    Ito, A; Onitake, K; Sasaki, J; Takami, T

    1991-04-01

    When mice, previously given oral inoculation with viable oncospheres of the heterologous cestode species (Hymenolepis diminuta, H. microstoma, Taenia taeniaeformis) and the homologous one (H. nana), were challenged with oncospheres of H. nana 4 days after the primary inoculation, they showed strong and complete resistance to H. nana challenge, respectively. However, the resistance was not evoked in mice given either infective eggs of Toxocara canis or non-viable oncospheres of all cestode species examined. Congenitally athymic nude mice given viable oncospheres did not show any resistance to H. nana either. Eosinophil infiltration around cysticercoids of H. nana in the intestinal villi appeared to be more prominent in mice previously given viable oncospheres of H. diminuta than in mice given non-viable oncospheres or PBS only. Some of the eosinophils in the villus harboring cysticercoid(s) of H. nana invaded the epithelia in the former, whereas all eosinophils remained in the lamina propria in the latter. There was almost no eosinophil infiltration in nude mice. Microscopic observations revealed that oncospheres of H. diminuta, which require beetles as the intermediate host like H. microstoma, could invade the mouse intestinal tissue. Therefore, it is strongly suggested that the strong cross resistance to H. nana in mice, induced by oncospheres of all heterologous cestode species, is thymus-dependent and due to oncospheral invasion into the intestinal tissue of mice.

  14. Nondestructive detection of total viable count changes of chilled pork in high oxygen storage condition based on hyperspectral technology

    Science.gov (United States)

    Zheng, Xiaochun; Peng, Yankun; Li, Yongyu; Chao, Kuanglin; Qin, Jianwei

    2017-05-01

    The plate count method is commonly used to detect the total viable count (TVC) of bacteria in pork, which is timeconsuming and destructive. It has also been used to study the changes of the TVC in pork under different storage conditions. In recent years, many scholars have explored the non-destructive methods on detecting TVC by using visible near infrared (VIS/NIR) technology and hyperspectral technology. The TVC in chilled pork was monitored under high oxygen condition in this study by using hyperspectral technology in order to evaluate the changes of total bacterial count during storage, and then evaluate advantages and disadvantages of the storage condition. The VIS/NIR hyperspectral images of samples stored in high oxygen condition was acquired by a hyperspectral system in range of 400 1100nm. The actual reference value of total bacteria was measured by standard plate count method, and the results were obtained in 48 hours. The reflection spectra of the samples are extracted and used for the establishment of prediction model for TVC. The spectral preprocessing methods of standard normal variate transformation (SNV), multiple scatter correction (MSC) and derivation was conducted to the original reflectance spectra of samples. Partial least squares regression (PLSR) of TVC was performed and optimized to be the prediction model. The results show that the near infrared hyperspectral technology based on 400-1100nm combined with PLSR model can describe the growth pattern of the total bacteria count of the chilled pork under the condition of high oxygen very vividly and rapidly. The results obtained in this study demonstrate that the nondestructive method of TVC based on NIR hyperspectral has great potential in monitoring of edible safety in processing and storage of meat.

  15. Extracellular communication in bacteria

    DEFF Research Database (Denmark)

    Chhabra, S.R.; Philipp, B.; Eberl, L.

    2005-01-01

    molecules, in different Gram-positive and Gram-negative bacteria they control pathogenicity, secondary metabolite production, biofilm differentiation, DNA transfer and bioluminescence. The development of biosensors for the detection of these signal molecules has greatly facilitated their subsequent chemical...

  16. [Darwin and bacteria].

    Science.gov (United States)

    Ledermann D, Walter

    2009-02-01

    As in 2009 the scientific world celebrates two hundreds years from the birthday of Charles Darwin and one hundred and fifty from the publication of The Origin of Species, an analysis of his complete work is performed, looking for any mention of bacteria. But it seems that the great naturahst never took knowledge about its existence, something rather improbable in a time when the discovery of bacteria shook the medical world, or he deliberately ignored them, not finding a place for such microscopic beings into his theory of evolution. But the bacteria badly affected his familiar life, killing scarlet fever one of his children and worsening to death the evolution of tuberculosis of his favourite Annie. Darwin himself could suffer the sickness of Chagas, whose etiological agent has a similar level to bacteria in the scale of evolution.

  17. Aggregation Patterns in Stressed Bacteria

    CERN Document Server

    Tsimring, L S; Aranson, I S; Ben-Jacob, E; Cohen, I; Shochet, O; Tsimring, Lev; Levine, Herbert; Aranson, Igor; Ben-Jacob, Eshel; Cohen, Inon; Shochet, Ofer

    1995-01-01

    We study the formation of spot patterns seen in a variety of bacterial species when the bacteria are subjected to oxidative stress due to hazardous byproducts of respiration. Our approach consists of coupling the cell density field to a chemoattractant concentration as well as to nutrient and waste fields. The latter serves as a triggering field for emission of chemoattractant. Important elements in the proposed model include the propagation of a front of motile bacteria radially outward form an initial site, a Turing instability of the uniformly dense state and a reduction of motility for cells sufficiently far behind the front. The wide variety of patterns seen in the experiments is explained as being due the variation of the details of the initiation of the chemoattractant emission as well as the transition to a non-motile phase.

  18. Poverty alleviation in Uganda: the case for a viable optimum ...

    African Journals Online (AJOL)

    Poverty alleviation is a long and painstaking process. It involves knowing what poverty is, its causes and means of alleviating it. Poverty is one of the scourges including disease and ignorance a combination of which deprives humanity of the basic needs for living. Among the strategies to alleviate poverty is effective ...

  19. The Short Saphenous Vein: A Viable Alternative Conduit for ...

    African Journals Online (AJOL)

    A wide variety of vascular conduits including the. Internal Mammary Artery (IMA), Radial Artery. (RA) and the Long Saphenous Vein (LSV), are available to the Cardiac Surgeon performing Coronary. Artery Bypass Graft procedures. These have demonstrated various successes over the years in both long-term patency.

  20. Some Viable Techniques for Assessing and Counselling Cognitive Processing Weakness

    Science.gov (United States)

    Haruna, Abubakar Sadiq

    2016-01-01

    Cognitive Processing weakness (CPW) is a psychological problem that impedes students' ability to learn effectively in a normal school setting. Such weakness may include; auditory, visual, conceptual, sequential, speed and attention processing. This paper therefore examines the basic assessment or diagnostic approaches such as Diagnosis by…

  1. Light activated antimicrobial agents can inactivate oral malodour causing bacteria.

    Science.gov (United States)

    Rai, Marika; Spratt, David; Gomez-Pereira, Paola R; Patel, Jay; Nair, Sean P

    2016-10-18

    Oral malodour is a common condition which affects a large proportion of the population, resulting in social, emotional and psychological stress. Certain oral bacteria form a coating called a biofilm on the tongue dorsum and degrade organic compounds releasing volatile sulfur compounds that are malodourous. Current chemical treatments for oral malodour such as mouthwashes containing chlorhexidine or essential oils, are not sufficiently effective at reducing the bacterial load on the tongue. One potential alternative to current chemical treatments for oral malodour is the use of light activated antimicrobial agents (LAAAs), which display no toxicity or antimicrobial activity in the dark, but when exposed to light of a specific wavelength produce reactive oxygen species which induce damage to target cells in a process known as photodynamic inactivation. This study aimed to determine whether oral malodour causing bacteria were susceptible to lethal photosensitization. Five bacterial species that are causative agents of oral malodour were highly sensitive to lethal photosensitization and were efficiently killed by methylene blue in conjunction with 665 nm laser light. Between 4.5-5 log10 reductions in the number of viable bacteria were achieved with 20 µM methylene blue and 14.53 J cm(-2) laser light for Porphyromonas gingivalis, Prevotella intermedia, Peptostreptococcus anaerobius and Solobacterium moorei. The number of viable cells fell below the limit of detection in the case of Fusobacterium nucleatum. These findings demonstrate that methylene blue in combination with 665 nm laser light is effective at killing bacteria associated with oral malodour, suggesting photodynamic therapy could be a viable treatment option for oral malodour.

  2. Quantitative assessment of viable cells of Lactobacillus plantarum strains in single, dual and multi-strain biofilms.

    Science.gov (United States)

    Fernández Ramírez, Mónica D; Kostopoulos, Ioannis; Smid, Eddy J; Nierop Groot, Masja N; Abee, Tjakko

    2017-03-06

    Biofilms of Lactobacillus plantarum are a potential source for contamination and recontamination of food products. Although biofilms have been mostly studied using single species or even single strains, it is conceivable that in a range of environmental settings including food processing areas, biofilms are composed of multiple species with each species represented by multiple strains. In this study six spoilage related L. plantarum strains FBR1-FBR6 and the model strain L. plantarum WCFS1 were characterised in single, dual and multiple strain competition models. A quantitative PCR approach was used with added propidium monoazide (PMA) enabling quantification of intact cells in the biofilm, representing the viable cell fraction that determines the food spoilage risk. Our results show that the performance of individual strains in multi-strain cultures generally correlates with their performance in pure culture, and relative strain abundance in multi-strain biofilms positively correlated with the relative strain abundance in suspended (planktonic) cultures. Performance of individual strains in dual-strain biofilms was highly influenced by the presence of the secondary strain, and in most cases no correlation between the relative contributions of viable planktonic cells and viable cells in the biofilm was noted. The total biofilm quantified by CV staining of the dual and multi-strain biofilms formed was mainly correlated to CV values of the dominant strain obtained in single strain studies. However, the combination of strain FBR5 and strain WCFS1 showed significantly higher CV values compared to the individual performances of both strains indicating that total biofilm formation was higher in this specific condition. Notably, L. plantarum FBR5 was able to outgrow all other strains and showed the highest relative abundance in dual and multi-strain biofilms. All the dual and multi-strain biofilms contained a considerable number of viable cells, representing a potential

  3. The fecal bacteria

    Science.gov (United States)

    Sadowsky, Michael J.; Whitman, Richard L.

    2011-01-01

    The Fecal Bacteria offers a balanced, integrated discussion of fecal bacteria and their presence and ecology in the intestinal tract of mammals, in the environment, and in the food supply. This volume covers their use in examining and assessing water quality in order to offer protection from illnesses related to swimming in or ingesting contaminated water, in addition to discussing their use in engineering considerations of water quality, modeling, monitoring, and regulations. Fecal bacteria are additionally used as indicators of contamination of ready-to-eat foods and fresh produce. The intestinal environment, the microbial community structure of the gut microbiota, and the physiology and genomics of this broad group of microorganisms are explored in the book. With contributions from an internationally recognized group of experts, the book integrates medicine, public health, environmental, and microbiological topics in order to provide a unique, holistic understanding of fecal bacteria. Moreover, it shows how the latest basic science and applied research findings are helping to solve problems and develop effective management strategies. For example, readers will discover how the latest tools and molecular approaches have led to our current understanding of fecal bacteria and enabled us to improve human health and water quality. The Fecal Bacteria is recommended for microbiologists, clinicians, animal scientists, engineers, environmental scientists, food safety experts, water quality managers, and students. It will help them better understand fecal bacteria and use their knowledge to protect human and environmental health. They can also apply many of the techniques and molecular tools discussed in this book to the study of a broad range of microorganisms in a variety of habitats.

  4. All-printed smart structures: a viable option?

    Science.gov (United States)

    O'Donnell, John; Ahmadkhanlou, Farzad; Yoon, Hwan-Sik; Washington, Gregory

    2014-03-01

    The last two decades have seen evolution of smart materials and structures technologies from theoretical concepts to physical realization in many engineering fields. These include smart sensors and actuators, active damping and vibration control, biomimetics, and structural health monitoring. Recently, additive manufacturing technologies such as 3D printing and printed electronics have received attention as methods to produce 3D objects or electronic components for prototyping or distributed manufacturing purposes. In this paper, the viability of manufacturing all-printed smart structures, with embedded sensors and actuators, will be investigated. To this end, the current 3D printing and printed electronics technologies will be reviewed first. Then, the plausibility of combining these two different additive manufacturing technologies to create all-printed smart structures will be discussed. Potential applications for this type of all-printed smart structures include most of the traditional smart structures where sensors and actuators are embedded or bonded to the structures to measure structural response and cause desired static and dynamic changes in the structure.

  5. Prototype to product—developing a commercially viable neural prosthesis

    Science.gov (United States)

    Seligman, Peter

    2009-12-01

    The Cochlear implant or 'Bionic ear' is a device that enables people who do not get sufficient benefit from a hearing aid to communicate with the hearing world. The Cochlear implant is not an amplifier, but a device that electrically stimulates the auditory nerve in a way that crudely mimics normal hearing, thus providing a hearing percept. Many recipients are able to understand running speech without the help of lipreading. Cochlear implants have reached a stage of maturity where there are now 170 000 recipients implanted worldwide. The commercial development of these devices has occurred over the last 30 years. This development has been multidisciplinary, including audiologists, engineers, both mechanical and electrical, histologists, materials scientists, physiologists, surgeons and speech pathologists. This paper will trace the development of the device we have today, from the engineering perspective. The special challenges of designing an active device that will work in the human body for a lifetime will be outlined. These challenges include biocompatibility, extreme reliability, safety, patient fitting and surgical issues. It is emphasized that the successful development of a neural prosthesis requires the partnership of academia and industry.

  6. Prototype to product-developing a commercially viable neural prosthesis.

    Science.gov (United States)

    Seligman, Peter

    2009-12-01

    The Cochlear implant or 'Bionic ear' is a device that enables people who do not get sufficient benefit from a hearing aid to communicate with the hearing world. The Cochlear implant is not an amplifier, but a device that electrically stimulates the auditory nerve in a way that crudely mimics normal hearing, thus providing a hearing percept. Many recipients are able to understand running speech without the help of lipreading. Cochlear implants have reached a stage of maturity where there are now 170 000 recipients implanted worldwide. The commercial development of these devices has occurred over the last 30 years. This development has been multidisciplinary, including audiologists, engineers, both mechanical and electrical, histologists, materials scientists, physiologists, surgeons and speech pathologists. This paper will trace the development of the device we have today, from the engineering perspective. The special challenges of designing an active device that will work in the human body for a lifetime will be outlined. These challenges include biocompatibility, extreme reliability, safety, patient fitting and surgical issues. It is emphasized that the successful development of a neural prosthesis requires the partnership of academia and industry.

  7. Prediction of subsequent miscarriage risk in women who present with a viable pregnancy at the first early pregnancy scan.

    Science.gov (United States)

    Stamatopoulos, Nicole; Lu, Chuan; Casikar, Ishwari; Reid, Shannon; Mongelli, Max; Hardy, Nigel; Condous, George

    2015-10-01

    To generate and evaluate a new prediction model for miscarriage in women who present with a viable intrauterine pregnancy (IUP) at the primary early pregnancy scan and to compare this new model to a previously published model. Data were collected prospectively from women presenting to the early pregnancy unit with a viable IUP between November 2006 and January 2013. More than 30 historical, clinical and ultrasonographic variables were recorded on a standardised datasheet at the first visit. Women were followed until the final outcome was known at the end of the first trimester: viable IUP or miscarriage. A new multinomial logistic regression model was developed retrospectively on training cases and tested prospectively on test cases. The performance of the new prediction model was evaluated using receiver operating characteristic (ROC) curves and compared to a previously published model. After removing cases with missing values for the model of Oates, the area under the ROC curve (AUC) was also calculated for the new model and the Oates model. A total of 1115 consecutive first-trimester women presented to the early pregnancy unit. Eight hundred and sixty-two women with a viable IUP at the first scan whose outcome was known at the end of the first trimester were included in the final analysis. Five hundred and sixty-six women were included in the training set and 296 in the test set. 92.1% were viable and 7.9% had miscarried at the end of the first trimester. The most significant independent prognostic variables for the logistic regression model were as follows: maternal age, embryonic heart rate (EHR), logarithm [gestational sac (GS) volume/crown-rump length (CRL)], CRL and the presence or absence of clots per vagina (PV) at presentation. The performance of the new model compared with the Oates model gave an AUC of 0.870 vs 0.847 for the training set and 0.783 vs 0.744 for the test set. After removing cases with missing values for the model of Oates 2013, the

  8. “Limits of Control” – Crucial Parameters for a Reliable Quantification of Viable Campylobacter by Real-Time PCR

    Science.gov (United States)

    Krüger, Nora-Johanna; Buhler, Christiane; Iwobi, Azuka N.; Huber, Ingrid; Ellerbroek, Lüppo; Appel, Bernd; Stingl, Kerstin

    2014-01-01

    The unsuitability of the “CFU” parameter and the usefulness of cultivation-independent quantification of Campylobacter on chicken products, reflecting the actual risk for infection, is increasingly becoming obvious. Recently, real-time PCR methods in combination with the use of DNA intercalators, which block DNA amplification from dead bacteria, have seen wide application. However, much confusion exists in the correct interpretation of such assays. Campylobacter is confronted by oxidative and cold stress outside the intestine. Hence, damage caused by oxidative stress probably represents the most frequent natural death of Campylobacter on food products. Treatment of Campylobacter with peroxide led to complete loss of CFU and to significant entry of any tested DNA intercalator, indicating disruption of membrane integrity. When we transiently altered the metabolic state of Campylobacter by abolishing the proton-motive force or by inhibiting active efflux, CFU was constant but enhanced entry of ethidium bromide (EtBr) was observed. Consistently, ethidium monoazide (EMA) also entered viable Campylobacter, in particular when nutrients for bacterial energization were lacking (in PBS) or when the cells were less metabolically active (in stationary phase). In contrast, propidium iodide (PI) and propidium monoazide (PMA) were excluded from viable bacterial cells, irrespective of their metabolic state. As expected for a diffusion-limited process, the extent of signal reduction from dead cells depended on the temperature, incubation time and concentration of the dyes during staining, prior to crosslinking. Consistently, free protein and/or DNA present in varying amounts in the heterogeneous matrix lowered the concentration of the DNA dyes at the bacterial membrane and led to considerable variation of the residual signal from dead cells. In conclusion, we propose an improved approach, taking into account principles of method variability and recommend the implementation of

  9. "Limits of control"--crucial parameters for a reliable quantification of viable campylobacter by real-time PCR.

    Science.gov (United States)

    Krüger, Nora-Johanna; Buhler, Christiane; Iwobi, Azuka N; Huber, Ingrid; Ellerbroek, Lüppo; Appel, Bernd; Stingl, Kerstin

    2014-01-01

    The unsuitability of the "CFU" parameter and the usefulness of cultivation-independent quantification of Campylobacter on chicken products, reflecting the actual risk for infection, is increasingly becoming obvious. Recently, real-time PCR methods in combination with the use of DNA intercalators, which block DNA amplification from dead bacteria, have seen wide application. However, much confusion exists in the correct interpretation of such assays. Campylobacter is confronted by oxidative and cold stress outside the intestine. Hence, damage caused by oxidative stress probably represents the most frequent natural death of Campylobacter on food products. Treatment of Campylobacter with peroxide led to complete loss of CFU and to significant entry of any tested DNA intercalator, indicating disruption of membrane integrity. When we transiently altered the metabolic state of Campylobacter by abolishing the proton-motive force or by inhibiting active efflux, CFU was constant but enhanced entry of ethidium bromide (EtBr) was observed. Consistently, ethidium monoazide (EMA) also entered viable Campylobacter, in particular when nutrients for bacterial energization were lacking (in PBS) or when the cells were less metabolically active (in stationary phase). In contrast, propidium iodide (PI) and propidium monoazide (PMA) were excluded from viable bacterial cells, irrespective of their metabolic state. As expected for a diffusion-limited process, the extent of signal reduction from dead cells depended on the temperature, incubation time and concentration of the dyes during staining, prior to crosslinking. Consistently, free protein and/or DNA present in varying amounts in the heterogeneous matrix lowered the concentration of the DNA dyes at the bacterial membrane and led to considerable variation of the residual signal from dead cells. In conclusion, we propose an improved approach, taking into account principles of method variability and recommend the implementation of

  10. "Limits of control"--crucial parameters for a reliable quantification of viable campylobacter by real-time PCR.

    Directory of Open Access Journals (Sweden)

    Nora-Johanna Krüger

    Full Text Available The unsuitability of the "CFU" parameter and the usefulness of cultivation-independent quantification of Campylobacter on chicken products, reflecting the actual risk for infection, is increasingly becoming obvious. Recently, real-time PCR methods in combination with the use of DNA intercalators, which block DNA amplification from dead bacteria, have seen wide application. However, much confusion exists in the correct interpretation of such assays. Campylobacter is confronted by oxidative and cold stress outside the intestine. Hence, damage caused by oxidative stress probably represents the most frequent natural death of Campylobacter on food products. Treatment of Campylobacter with peroxide led to complete loss of CFU and to significant entry of any tested DNA intercalator, indicating disruption of membrane integrity. When we transiently altered the metabolic state of Campylobacter by abolishing the proton-motive force or by inhibiting active efflux, CFU was constant but enhanced entry of ethidium bromide (EtBr was observed. Consistently, ethidium monoazide (EMA also entered viable Campylobacter, in particular when nutrients for bacterial energization were lacking (in PBS or when the cells were less metabolically active (in stationary phase. In contrast, propidium iodide (PI and propidium monoazide (PMA were excluded from viable bacterial cells, irrespective of their metabolic state. As expected for a diffusion-limited process, the extent of signal reduction from dead cells depended on the temperature, incubation time and concentration of the dyes during staining, prior to crosslinking. Consistently, free protein and/or DNA present in varying amounts in the heterogeneous matrix lowered the concentration of the DNA dyes at the bacterial membrane and led to considerable variation of the residual signal from dead cells. In conclusion, we propose an improved approach, taking into account principles of method variability and recommend the

  11. Development of economically viable, highly integrated, highly modular SEGIS architecture.

    Energy Technology Data Exchange (ETDEWEB)

    Enslin, Johan (Petra Solar, Inc., South Plainfield, NJ); Hamaoui, Ronald (Petra Solar, Inc., South Plainfield, NJ); Gonzalez, Sigifredo; Haddad, Ghaith (Petra Solar, Inc., South Plainfield, NJ); Rustom, Khalid (Petra Solar, Inc., South Plainfield, NJ); Stuby, Rick (Petra Solar, Inc., South Plainfield, NJ); Kuran, Mohammad (Petra Solar, Inc., South Plainfield, NJ); Mark, Evlyn (Petra Solar, Inc., South Plainfield, NJ); Amarin, Ruba (Petra Solar, Inc., South Plainfield, NJ); Alatrash, Hussam (Petra Solar, Inc., South Plainfield, NJ); Bower, Ward Isaac; Kuszmaul, Scott S.; Sena-Henderson, Lisa; David, Carolyn; Akhil, Abbas Ali

    2012-03-01

    Initiated in 2008, the SEGIS initiative is a partnership involving the U.S. DOE, Sandia National Laboratories, private sector companies, electric utilities, and universities. Projects supported under the initiative have focused on the complete-system development of solar technologies, with the dual goal of expanding renewable PV applications and addressing new challenges of connecting large-scale solar installations in higher penetrations to the electric grid. Petra Solar, Inc., a New Jersey-based company, received SEGIS funds to develop solutions to two of these key challenges: integrating increasing quantities of solar resources into the grid without compromising (and likely improving) power quality and reliability, and moving the design from a concept of intelligent system controls to successful commercialization. The resulting state-of-the art technology now includes a distributed photovoltaic (PV) architecture comprising AC modules that not only feed directly into the electrical grid at distribution levels but are equipped with new functions that improve voltage stability and thus enhance overall grid stability. This integrated PV system technology, known as SunWave, has applications for 'Power on a Pole,' and comes with a suite of technical capabilities, including advanced inverter and system controls, micro-inverters (capable of operating at both the 120V and 240V levels), communication system, network management system, and semiconductor integration. Collectively, these components are poised to reduce total system cost, increase the system's overall value and help mitigate the challenges of solar intermittency. Designed to be strategically located near point of load, the new SunWave technology is suitable for integration directly into the electrical grid but is also suitable for emerging microgrid applications. SunWave was showcased as part of a SEGIS Demonstration Conference at Pepco Holdings, Inc., on September 29, 2011, and is presently

  12. Non-viable antagonist cells are associated with reduced biocontrol performance by viable cells of the yeast Papiliotrema flavescens against Fusarium head blight of wheat.

    Science.gov (United States)

    Microbially-based plant disease control products have achieved commercial market success, but the efficacy of such biocontrol products is sometimes deemed inconsistent. Improper processing of harvested microbial biomass or long-term storage can reduce the proportion of viable cells and necessitate t...

  13. Removal of Paralytic Shellfish Toxins by Probiotic Lactic Acid Bacteria

    Directory of Open Access Journals (Sweden)

    Mari Vasama

    2014-07-01

    Full Text Available Paralytic shellfish toxins (PSTs are non-protein neurotoxins produced by saltwater dinoflagellates and freshwater cyanobacteria. The ability of Lactobacillus rhamnosus strains GG and LC-705 (in viable and non-viable forms to remove PSTs (saxitoxin (STX, neosaxitoxin (neoSTX, gonyautoxins 2 and 3 (GTX2/3, C-toxins 1 and 2 (C1/2 from neutral and acidic solution (pH 7.3 and 2 was examined using HPLC. Binding decreased in the order of STX ~ neoSTX > C2 > GTX3 > GTX2 > C1. Removal of STX and neoSTX (77%–97.2% was significantly greater than removal of GTX3 and C2 (33.3%–49.7%. There were no significant differences in toxin removal capacity between viable and non-viable forms of lactobacilli, which suggested that binding rather than metabolism is the mechanism of the removal of toxins. In general, binding was not affected by the presence of other organic molecules in solution. Importantly, this is the first study to demonstrate the ability of specific probiotic lactic bacteria to remove PSTs, particularly the most toxic PST-STX, from solution. Further, these results warrant thorough screening and assessment of safe and beneficial microbes for their usefulness in the seafood and water industries and their effectiveness in vivo.

  14. In search of a viable reaction pathway in the chelation of a metallo-protein

    Science.gov (United States)

    Rose, Frisco; Hodak, Miroslav; Bernholc, Jerry

    2010-03-01

    Misfolded metallo-proteins are potential causal agents in the onset of neuro-degenerative diseases, such as Alzheimer's and Parkinson's Diseases (PD). Experimental results involving metal chelation have shown significant promise in symptom reduction and misfolding reversal. We explore, through atomistic simulations, potential reaction pathways for the chelation of Cu^2+ from the metal binding site in our representation of a partially misfolded α-synuclein, the protein implicated in PD. Our ab initio simulations use Density Functional Theory (DFT) and nudged elastic band to obtain the minimized energy coordinates of this reaction. Our simulations include ab initio water at the interaction site and in its first solvation shells, while the remainder is fully solvated with orbital-free DFT water representation [1]. Our ongoing studies of viable chelation agents include nicotine, caffeine and other potential reagents, we will review the best case agents in this presentation. [4pt] [1] Hodak M, Lu W, Bernholc J. Hybrid ab initio Kohn-Sham density functional theory/frozen-density orbital-free density functional theory simulation method suitable for biological systems. J. Chem. Phys. 2008 Jan;128(1):014101-9.

  15. Antimicrobial activity of polyphenol-rich fractions from Sida alba L. (Malvaceae against co-trimoxazol-resistant bacteria strains

    Directory of Open Access Journals (Sweden)

    Konaté Kiessoun

    2012-02-01

    Full Text Available Abstract Background The increased resistance of microorganisms to the currently used antimicrobials has lead to the evaluation of other agents that might have antimicrobial activity. Medicinal plants are sources of phytochemicals which are able to initiate different biological activities including antimicrobials Materials and methods In vitro antibacterial (MIC, MBC and time-kill studies of polyphenol-rich fractions from Sida alba L. (Malvaceae was assessed using ten bacteria strains (Gram-negative and Gram-positive. Results All test bacteria were susceptible to the polyphenol-rich fractions. Time-kill results showed that after 5 h exposition there was no viable microorganism in the initial inoculum and the effect of polyphenol-rich fractions was faster on Enterococcus faecalis (Gram-positive bacterium comparatively to the other bacteria strains. Conclusion The data analysis indicates that the tested of polyphenol-rich fractions has significant effects when compared with the standard antibiotic. These results therefore justify the traditional use of sida alba L., alone or in combination with other herbs to treat bacterial infections.

  16. Antimicrobial activity of polyphenol-rich fractions from Sida alba L. (Malvaceae) against co-trimoxazol-resistant bacteria strains.

    Science.gov (United States)

    Konaté, Kiessoun; Hilou, Adama; Mavoungou, Jacques François; Lepengué, Alexis Nicaise; Souza, Alain; Barro, Nicolas; Datté, Jacques Y; M'batchi, Bertrand; Nacoulma, Odile Germaine

    2012-02-24

    The increased resistance of microorganisms to the currently used antimicrobials has lead to the evaluation of other agents that might have antimicrobial activity. Medicinal plants are sources of phytochemicals which are able to initiate different biological activities including antimicrobials In vitro antibacterial (MIC, MBC and time-kill studies) of polyphenol-rich fractions from Sida alba L. (Malvaceae) was assessed using ten bacteria strains (Gram-negative and Gram-positive). All test bacteria were susceptible to the polyphenol-rich fractions. Time-kill results showed that after 5 h exposition there was no viable microorganism in the initial inoculum and the effect of polyphenol-rich fractions was faster on Enterococcus faecalis (Gram-positive bacterium) comparatively to the other bacteria strains. The data analysis indicates that the tested of polyphenol-rich fractions has significant effects when compared with the standard antibiotic. These results therefore justify the traditional use of sida alba L., alone or in combination with other herbs to treat bacterial infections.

  17. Mycorrhiza helper bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Deveau, Aurelie [French National Insitute for Agricultural Research (INRA); Labbe, Jessy [ORNL

    2016-10-01

    This chapter focuses on the Mycorrhiza Helper Bacteria (MHB), a generic name given to bacteria which stimulate the formation of mycorrhizal symbiosis. By extension, some bacterial strains that positively impact the functioning of mycorrhizal symbiosis are also called MHB. These bacteria have applicative interests, as they indirectly improve the health and growth of tree seedlings. MHB are not restricted to a specific type of ecosystem, but are rather generalist in the way that they associate with both herbaceous and woody mycorrhizal plants from boreal, temperate, arid and tropical ecosystems. However, understanding the molecular mechanisms and their specificities will help us to know more about the ecology of the MHB. The process of acquisition varies between fungal species; while ectomycorrhizal fungi most probably recurrently acquire them from the environment, the association between bacterial endosymbionts and Glomeromycota probably dates back to very ancient times, and has since been vertically transmitted.

  18. Optical modulator including grapene

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Ming; Yin, Xiaobo; Zhang, Xiang

    2016-06-07

    The present invention provides for a one or more layer graphene optical modulator. In a first exemplary embodiment the optical modulator includes an optical waveguide, a nanoscale oxide spacer adjacent to a working region of the waveguide, and a monolayer graphene sheet adjacent to the spacer. In a second exemplary embodiment, the optical modulator includes at least one pair of active media, where the pair includes an oxide spacer, a first monolayer graphene sheet adjacent to a first side of the spacer, and a second monolayer graphene sheet adjacent to a second side of the spacer, and at least one optical waveguide adjacent to the pair.

  19. Immediate natural tooth pontic: A viable yet temporary prosthetic solution: A patient reported outcome

    Directory of Open Access Journals (Sweden)

    Sudhir Bhandari

    2012-01-01

    Conclusion: The concept of immediate pontic placement is surely a viable treatment option and promises an excellent transient esthetic solution for a lost tooth as well as enables good preparation of the extraction site for future prosthetic replacement.

  20. Improved identification of viable myocardium using second harmonic imaging during dobutamine stress echocardiography

    NARCIS (Netherlands)

    F. Sozzi (Fabiola); D. Poldermans (Don); J.J. Bax (Jeroen); A. Elhendy (Abdou); E.C. Vourvouri (Eleni); R. Valkema (Roelf); J. de Sutter; A.F.L. Schinkel (Arend); A. Borghetti; J.R.T.C. Roelandt (Jos)

    2001-01-01

    textabstractOBJECTIVE: To determine whether, compared with fundamental imaging, second harmonic imaging can improve the accuracy of dobutamine stress echocardiography for identifying viable myocardium, using nuclear imaging as a reference. PATIENTS: 30 patients with chronic left

  1. Bacteria encapsulated electrospun nanofibrous webs for remediation of methylene blue dye in water.

    Science.gov (United States)

    Sarioglu, Omer Faruk; Keskin, Nalan Oya San; Celebioglu, Asli; Tekinay, Turgay; Uyar, Tamer

    2017-04-01

    In this study, preparation and application of novel biocomposite materials that were produced by encapsulation of bacterial cells within electrospun nanofibrous webs are described. A commercial strain of Pseudomonas aeruginosa which has methylene blue (MB) dye remediation capability was selected for encapsulation, and polyvinyl alcohol (PVA) and polyethylene oxide (PEO) were selected as the polymer matrices for the electrospinning of bacteria encapsulated nanofibrous webs. Encapsulation of bacterial cells was monitored by scanning electron microscopy (SEM) and fluorescence microscopy, and the viability of encapsulated bacteria was checked by live/dead staining and viable cell counting assay. Both bacteria/PVA and bacteria/PEO webs have shown a great potential for remediation of MB, yet bacteria/PEO web has shown higher removal performances than bacteria/PVA web, which was probably due to the differences in the initial viable bacterial cells for those two samples. The bacteria encapsulated electrospun nanofibrous webs were stored at 4°C for three months and they were found as potentially storable for keeping encapsulated bacterial cells alive. Overall, the results suggest that electrospun nanofibrous webs are suitable platforms for preservation of living bacterial cells and they can be used directly as a starting inoculum for bioremediation of water systems. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Visual Impairment, Including Blindness

    Science.gov (United States)

    ... Who Knows What? (log-in required) Select Page Visual Impairment, Including Blindness Mar 31, 2017 Links updated, ... doesn’t wear his glasses. Back to top Visual Impairments in Children Vision is one of our ...

  3. Immunization of rodents against Hymenolepis infections using non-viable homologous oncospheres.

    Science.gov (United States)

    Fan, Ping-Chin; Chung, Wen-Cheng; Ito, Akira

    2004-12-01

    Immunity to Taiwan Taenia infection in pigs can be stimulated using homologous or heterologous non-viable Taenia oncospheres. This study was designed to determine whether homologous non-viable oncospheres could stimulate immunity to Hymenolepis infection in rodents. Hatched oncospheres were prepared from eggs of Hymenolepis diminuta, Hymenolepis nana, and Hymenolepis microstoma and kept at -70 degrees C for more than 1 month. A mixture of 500 non-viable oncospheres of each tapeworm and complete Freund's adjuvant was injected subcutaneously in four groups of Sprague-Dawley rats or ICR mice one to four times at an interval of 1 week; controls were not immunized. After immunization, each rodent was orally inoculated with three fresh active cysticercoids of H. diminuta or H. microstoma or 500 fresh eggs of H. nana. The animals were then necropsied for adult tapeworms. No rats or mice immunized with non-viable oncospheres of H. diminuta or H. nana were infected by the challenge inoculation. However, 28 of 34 mice immunized with non-viable H. microstoma oncospheres were infected after inoculation with cysticercoids. This study demonstrated complete protection against infection by homologous parasites in rats or mice immunized with non-viable oncospheres of H. diminuta and H. nana, respectively. Repeated immunization may not be required if resistance is stimulated in rodent hosts.

  4. [Viable myocardium detecting by CARTO voltage mapping in swine model of acute myocardial infarction].

    Science.gov (United States)

    Lin, Tao; Ma, Yi-Tong; Yang, Yi-Ning; Mu, Hu-Yati; He, Peng-Yi; Yang, Yu-Chun; Chou, Ping; Liu, Fen; Zhang, Yan-Yi

    2010-08-01

    To evaluate the accuracy and practicability of detecting viable myocardium by CARTO voltage mapping in swine model of acute myocardial infarction (MI). MI was induced in 13 anesthetized swines via occluding the distal of left anterior descending coronary arteries by angioplasty balloon for 60-90 minutes. The viable myocardium detection by CARTO voltage mapping was made after reconstruction of the left ventricle using CARTO and the results were compared with TTC staining. The standard of CARTO voltage to detect viable myocardium was 0.5 - 1.5 mV while viable myocardium showed pink color by TTC staining. Eleven out of 13 swines survived the operation and 2 swines died of ventricular fibrillation at 45 and 65 minutes post ischemia. Left ventricle was divided into 16 segments and 176 segments from 11 swines were analyzed. Viable myocardium detected by CARTO voltage mapping was identical as identified by TTC staining (Kappa = 0.816, P < 0.001). Taken the TTC result as standard, the sensitivity, specificity and accuracy rate of CARTO voltage mapping are 71.8%, 96.5% and 90.9% respectively. CARTO voltage mapping could be used as a reliable tool to detect viable myocardium in this model.

  5. Mycophagous soil bacteria

    NARCIS (Netherlands)

    Rudnick, M.B.

    2015-01-01

    Abstract

    Soil microorganisms evolved several strategies to compete for limited nutrients in soil. Bacteria of the genus Collimonas developed a way to exploit fungi as a source of organic nutrients. This strategy has been termed

  6. Do Bacteria Age?

    Indian Academy of Sciences (India)

    Aging, a progressive deterioration of the physical functions necessary for survival and fertility, resulting from deleterious changes, is one of the most fundamental features of Eukary- otes. Bacteria are thought to be examples of organisms that do not age. They divide by binary fission, which is assumed to be a symmetrical ...

  7. Antifreeze Proteins of Bacteria

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 12; Issue 12. Antifreeze Proteins of Bacteria. M K Chattopadhyay. General Article Volume 12 Issue 12 December 2007 pp 25-30. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/012/12/0025-0030. Keywords.

  8. Listening to Include

    Science.gov (United States)

    Veck, Wayne

    2009-01-01

    This paper attempts to make important connections between listening and inclusive education and the refusal to listen and exclusion. Two lines of argument are advanced. First, if educators and learners are to include each other within their educational institutions as unique individuals, then they will need to listen attentively to each other.…

  9. A clinically viable capsule endoscopy video analysis platform for automatic bleeding detection

    Science.gov (United States)

    Yi, Steven; Jiao, Heng; Xie, Jean; Mui, Peter; Leighton, Jonathan A.; Pasha, Shabana; Rentz, Lauri; Abedi, Mahmood

    2013-02-01

    In this paper, we present a novel and clinically valuable software platform for automatic bleeding detection on gastrointestinal (GI) tract from Capsule Endoscopy (CE) videos. Typical CE videos for GI tract run about 8 hours and are manually reviewed by physicians to locate diseases such as bleedings and polyps. As a result, the process is time consuming and is prone to disease miss-finding. While researchers have made efforts to automate this process, however, no clinically acceptable software is available on the marketplace today. Working with our collaborators, we have developed a clinically viable software platform called GISentinel for fully automated GI tract bleeding detection and classification. Major functional modules of the SW include: the innovative graph based NCut segmentation algorithm, the unique feature selection and validation method (e.g. illumination invariant features, color independent features, and symmetrical texture features), and the cascade SVM classification for handling various GI tract scenes (e.g. normal tissue, food particles, bubbles, fluid, and specular reflection). Initial evaluation results on the SW have shown zero bleeding instance miss-finding rate and 4.03% false alarm rate. This work is part of our innovative 2D/3D based GI tract disease detection software platform. While the overall SW framework is designed for intelligent finding and classification of major GI tract diseases such as bleeding, ulcer, and polyp from the CE videos, this paper will focus on the automatic bleeding detection functional module.

  10. Is flapless implant surgery a viable option in posterior maxilla? A review.

    Science.gov (United States)

    Doan, N; Du, Z; Crawford, R; Reher, P; Xiao, Y

    2012-09-01

    This article reviews the literature on the outcome of flapless surgery for dental implants in the posterior maxilla. The literature search was carried out in using the keywords: flapless, dental implants and maxilla. A hand search and Medline search were carried out on studies published between 1971 and 2011. The authors included research involving a minimum of 15 dental implants with a follow-up period of 1 year, an outcome measurement of implant survival, but excluded studies involving multiple simultaneous interventions, and studies with missing data. The Cochrane approach for cohort studies and Oxford Centre for Evidence-Based Medicine were applied. Of the 56 published papers selected, 14 papers on the flapless technique showed high overall implant survival rates. The prospective studies yielded 97.01% (95% CI: 90.72-99.0) while retrospective studies or case series illustrated 95.08% (95% CI: 91.0-97.93) survival. The average of intraoperative complications was 6.55% using the flapless procedure. The limited data obtained showed that flapless surgery in posterior maxilla areas could be a viable and predictable treatment method for implant placement. Flapless surgery tends to be more applicable in this area of the mouth. Further long-term clinical controlled studies are needed. Copyright © 2012 International Association of Oral and Maxillofacial Surgeons. All rights reserved.

  11. Remote sensing is a viable tool for mapping soil salinity in agricultural lands

    Directory of Open Access Journals (Sweden)

    Elia Scudiero

    2017-04-01

    Full Text Available Soil salinity negatively impacts the productivity and profitability of western San Joaquin Valley (WSJV farmland. Many factors, including drought, climate change, reduced water allocations, and land-use changes could worsen salinity conditions there, and in other agricultural lands in the state. Mapping soil salinity at regional and state levels is essential for identifying drivers and trends in agricultural soil salinity, and for developing mitigation strategies, but traditional soil sampling for salinity does not allow for accurate large-scale mapping. We tested remote-sensing modeling to map root zone soil salinity for farmland in the WSJV. According to our map, 0.78 million acres are salt affected (i.e., ECe > 4 dS/m, which represents 45% of the mapped farmland; 30% of that acreage is strongly or extremely saline. Independent validations of the remote-sensing estimations indicated acceptable to excellent correspondences, except in areas of low salinity and high soil heterogeneity. Remote sensing is a viable tool for helping landowners make decisions about land use and also for helping water districts and state agencies develop salinity mitigation strategies.

  12. Density-dependent adaptive resistance allows swimming bacteria to colonize an antibiotic gradient.

    Science.gov (United States)

    Hol, Felix J H; Hubert, Bert; Dekker, Cees; Keymer, Juan E

    2016-01-01

    During antibiotic treatment, antibiotic concentration gradients develop. Little is know regarding the effects of antibiotic gradients on populations of nonresistant bacteria. Using a microfluidic device, we show that high-density motile Escherichia coli populations composed of nonresistant bacteria can, unexpectedly, colonize environments where a lethal concentration of the antibiotic kanamycin is present. Colonizing bacteria establish an adaptively resistant population, which remains viable for over 24 h while exposed to the antibiotic. Quantitative analysis of multiple colonization events shows that collectively swimming bacteria need to exceed a critical population density in order to successfully colonize the antibiotic landscape. After colonization, bacteria are not dormant but show both growth and swimming motility under antibiotic stress. Our results highlight the importance of motility and population density in facilitating adaptive resistance, and indicate that adaptive resistance may be a first step to the emergence of genetically encoded resistance in landscapes of antibiotic gradients.

  13. Impact of minocycline ointment for periodontal treatment of oral bacteria.

    Science.gov (United States)

    Nakao, Ryoma; Takigawa, Satoko; Sugano, Naoyuki; Koshi, Ryosuke; Ito, Koichi; Watanabe, Haruo; Senpuku, Hidenobu

    2011-01-01

    Topical tetracyclines, such as minocycline ointment, are frequently used for the treatment of periodontal infection. We investigated the influence of minocycline ointment use on oral bacteria, using supragingival plaque samples from adults who had not taken any antibiotics for 6 months. Initially we investigated the effect of topical minocycline administration on the emergence of tetracycline-resistant oral bacteria in four healthy adults. The isolation frequency of tetracycline-resistant oral bacteria to total viable bacteria increased substantially on day 6 after treatment, although it returned to baseline on day 25. Subsequently we investigated the isolation frequency of tetracycline-resistant oral streptococci (TOS) as a representative oral bacterium, using samples from 41 subjects with periodontal diseases. The percentage of TOS (of the total oral streptococci) increased significantly (from 11.9±15.6% to 34.2±24.0%) after minocycline treatment. Various TOS species were identified; S. mitis, S. salivarius, S. sanguinis, and S. oralis were frequently isolated. PCR and Southern blotting allowed us to identify tetM on the Tn916-like elements as the gene responsible for tetracycline-resistance. These findings suggest that the potential risk of the spread of similar genetic elements through bacteria in the oral cavity should be considered.

  14. Analytic device including nanostructures

    KAUST Repository

    Di Fabrizio, Enzo M.

    2015-07-02

    A device for detecting an analyte in a sample comprising: an array including a plurality of pixels, each pixel including a nanochain comprising: a first nanostructure, a second nanostructure, and a third nanostructure, wherein size of the first nanostructure is larger than that of the second nanostructure, and size of the second nanostructure is larger than that of the third nanostructure, and wherein the first nanostructure, the second nanostructure, and the third nanostructure are positioned on a substrate such that when the nanochain is excited by an energy, an optical field between the second nanostructure and the third nanostructure is stronger than an optical field between the first nanostructure and the second nanostructure, wherein the array is configured to receive a sample; and a detector arranged to collect spectral data from a plurality of pixels of the array.

  15. Hessian fly-associated bacteria: transmission, essentiality, and composition.

    Directory of Open Access Journals (Sweden)

    Raman Bansal

    Full Text Available Plant-feeding insects have been recently found to use microbes to manipulate host plant physiology and morphology. Gall midges are one of the largest groups of insects that manipulate host plants extensively. Hessian fly (HF, Mayetiola destructor is an important pest of wheat and a model system for studying gall midges. To examine the role of bacteria in parasitism, a systematic analysis of bacteria associated with HF was performed for the first time. Diverse bacteria were found in different developmental HF stages. Fluorescent in situ hybridization detected a bacteriocyte-like structure in developing eggs. Bacterial DNA was also detected in eggs by PCR using primers targeted to different bacterial groups. These results indicated that HF hosted different types of bacteria that were maternally transmitted to the next generation. Eliminating bacteria from the insect with antibiotics resulted in high mortality of HF larvae, indicating that symbiotic bacteria are essential for the insect to survive on wheat seedlings. A preliminary survey identified various types of bacteria associated with different HF stages, including the genera Enterobacter, Pantoea, Stenotrophomonas, Pseudomonas, Bacillus, Ochrobactrum, Acinetobacter, Alcaligenes, Nitrosomonas, Arcanobacterium, Microbacterium, Paenibacillus, and Klebsiella. Similar bacteria were also found specifically in HF-infested susceptible wheat, suggesting that HF larvae had either transmitted bacteria into plant tissue or brought secondary infection of bacteria to the wheat host. The bacteria associated with wheat seedlings may play an essential role in the wheat-HF interaction.

  16. A Comprehensive Review of Aliphatic Hydrocarbon Biodegradation by Bacteria.

    Science.gov (United States)

    Abbasian, Firouz; Lockington, Robin; Mallavarapu, Megharaj; Naidu, Ravi

    2015-06-01

    Hydrocarbons are relatively recalcitrant compounds and are classified as high-priority pollutants. However, these compounds are slowly degraded by a large variety of microorganisms. Bacteria are able to degrade aliphatic saturated and unsaturated hydrocarbons via both aerobic and anaerobic pathways. Branched hydrocarbons and cyclic hydrocarbons are also degraded by bacteria. The aerobic bacteria use different types of oxygenases, including monooxygenase, cytochrome-dependent oxygenase and dioxygenase, to insert one or two atoms of oxygen into their targets. Anaerobic bacteria, on the other hand, employ a variety of simple organic and inorganic molecules, including sulphate, nitrate, carbonate and metals, for hydrocarbon oxidation.

  17. The friendly bacteria within us Commensal bacteria of the intestine ...

    Indian Academy of Sciences (India)

    The friendly bacteria within us Commensal bacteria of the intestine: Roles in health and disease B.S. Ramakrishna Professor & Head Gastroenterology & Hepatology Christian Medical College Vellore · Slide 2 · Intestinal bacteria: the hidden organ · Slide 4 · Slide 5 · The normal bacterial flora prevents GI disease · Slide 7.

  18. Acetic acid bacteria in fermented foods and beverages.

    Science.gov (United States)

    De Roos, Jonas; De Vuyst, Luc

    2017-08-29

    Although acetic acid bacteria (AAB) are commonly found in spontaneous or backslopped fermented foods and beverages, rather limited knowledge about their occurrence and functional role in natural food fermentation ecosystems is available. Not only is their cultivation, isolation, and identification difficult, their cells are often present in a viable but not culturable state. Yet, they are promising starter cultures either to better control known food fermentation processes or to produce novel fermented foods and beverages. This review summarizes the most recent findings on the occurrence and functional role of AAB in natural food fermentation processes such as lambic beer, water kefir, kombucha, and cocoa. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Bactericidal efficacy of elevated pH on fish pathogenic and environmental bacteria

    Directory of Open Access Journals (Sweden)

    Clifford E. Starliper

    2013-07-01

    Full Text Available Ship ballast water is a recognized medium for transfer and introductions of nonindigenous species. There is a need for new ballast water treatment methods that effectively and safely eliminate or greatly minimize movements of these species. The present study employed laboratory methods to evaluate the bactericidal efficacy of increased pH (pH 10.0–12.0 for exposure durations of up to 72 h to kill a variety of Gram-negative and Gram-positive bacteria including fish pathogens (Aeromonas spp., Yersinia ruckeri, Edwardsiella ictaluri, Serratia liquefaciens, Carnobacterium sp., other common aquatic-inhabitant bacteria (Serratia marcescens, Pseudomonas fluorescens, Staphylococcus sp., Bacillus sp. and indicators listed in International Maritime Organization D2 Standards; namely, Vibrio cholera (an environmental isolate from fish, Escherichia coli and Enterococcus faecalis. Volumes of 5 N NaOH were added to tryptic soy broth to obtain desired pH adjustments. Viable cells were determined after 0, 4, 12, 24, 48, and 72 h. Initial (0 h cell numbers ranged from 3.40 × 104 cfu/mL for Bacillus sp. to 2.44 × 107 cfu/mL for E. faecalis. The effective endpoints of pH and treatment duration necessary to realize 100% bactericidal effect varied; however, all bacteria tested were killed within 72 h at pH 12.0 or lower. The lowest parameters examined, 4 h at pH 10.0, were bactericidal to V. cholera, E. ictaluri, three of four isolates of E. coli, and (three of four Aeromonas salmonicida subsp. salmonicida. Bactericidal effect was attained at pH 10.0 within 12 h for the other A. salmonicida subsp. salmonicida, and within 24 h for P. fluorescens, and the remaining E. coli.

  20. Bactericidal efficacy of elevated pH on fish pathogenic and environmental bacteria

    Science.gov (United States)

    Starliper, Clifford E.; Watten, Barnaby J.

    2013-01-01

    Ship ballast water is a recognized medium for transfer and introductions of nonindigenous species. There is a need for new ballast water treatment methods that effectively and safely eliminate or greatly minimize movements of these species. The present study employed laboratory methods to evaluate the bactericidal efficacy of increased pH (pH 10.0–12.0) for exposure durations of up to 72 h to kill a variety of Gram-negative and Gram-positive bacteria including fish pathogens (Aeromonas spp., Yersinia ruckeri, Edwardsiella ictaluri, Serratia liquefaciens, Carnobacterium sp.), other common aquatic-inhabitant bacteria (Serratia marcescens, Pseudomonas fluorescens, Staphylococcus sp., Bacillus sp.) and indicators listed in International Maritime Organization D2 Standards; namely, Vibrio cholera (an environmental isolate from fish), Escherichia coli and Enterococcus faecalis. Volumes of 5 N NaOH were added to tryptic soy broth to obtain desired pH adjustments. Viable cells were determined after 0, 4, 12, 24, 48, and 72 h. Initial (0 h) cell numbers ranged from 3.40 × 104 cfu/mL for Bacillus sp. to 2.44 × 107 cfu/mL for E. faecalis. The effective endpoints of pH and treatment duration necessary to realize 100% bactericidal effect varied; however, all bacteria tested were killed within 72 h at pH 12.0 or lower. The lowest parameters examined, 4 h at pH 10.0, were bactericidal to V. cholera, E. ictaluri, three of four isolates of E. coli, and (three of four) Aeromonas salmonicida subsp. salmonicida. Bactericidal effect was attained at pH 10.0 within 12 h for the other A. salmonicida subsp. salmonicida, and within 24 h for P. fluorescens, and the remaining E. coli.

  1. Existence of both culturable and viable but non culturable (VNC) E. coli populations with distinct settling velocities in karst aquifer

    Science.gov (United States)

    Petit, F.; Ratajczak, M.; Massei, N.; Lafite, R.; Clermont, O.; Denamur, E.; Berthe, T.

    2012-12-01

    The karst aquifers are particularly vulnerable to contamination by faecal pathogens mainly during rainfall event. In groundwater, the fate of E. coli is dependent on their ability to overcome environmental stresses and on their association with particles. Moreover, some strains can survive leading to the emergence of a sub-population of E. coli which failed to grow on laboratory media, while they were still alive thus designated as viable but non culturable (VNC). The aim of this study was to investigate (i) the structure of culturable E. coli population based on the survival ability, the distribution in four main phylo-groups (A, B1, B2, D) and the phenotypic characteristics; and, (ii) the fate of culturable and VNC E. coli, according to their settling velocities. This work was carried out on a karstic workshop-site for which the microbial quality of water was impaired related to livestock density and septic tanks overflows. Particles characterisation was performed by estimation of their settling velocities combined with electronic microscopy observation, and solid phase cytometry (ChemScan®RDI) was carried out to quantify the viable E. coli, and thus VNC E. coli. In the karst, different populations of E. coli were coexisting related to their survival, their culturability, and their association to particles. At the sinkhole, during a rainfall event with pasture, E. coli rapidly losing their culturability after 2 days have been more frequently isolated. These isolates are mainly multiresistant to antibiotics and harbor several virulence factors. In the same time, a population of VNC E. coli (79%), associated to the "non settleable particles" (settling velocities ranging between 10-5 to 10-2 mm.s-1), mainly corresponding to colloids and organic or organo-mineral microflocs was injected in the karst system, probably corresponding to the runoff of attached-bacteria originating from cowpats. Once in the karst, the relative contribution of culturable and VNC E. coli

  2. Being Included and Excluded

    DEFF Research Database (Denmark)

    Korzenevica, Marina

    2016-01-01

    Following the civil war of 1996–2006, there was a dramatic increase in the labor mobility of young men and the inclusion of young women in formal education, which led to the transformation of the political landscape of rural Nepal. Mobility and schooling represent a level of prestige that rural...... politics. It analyzes how formal education and mobility either challenge or reinforce traditional gendered norms which dictate a lowly position for young married women in the household and their absence from community politics. The article concludes that women are simultaneously excluded and included from...... people regard as a prerequisite for participating in local community politics. Based on a fieldwork in two villages of Panchthar district in eastern Nepal, this article explores how these changes strengthen or weaken women’s political agency and how this is reflected in their participation in community...

  3. Cassette bacteria detection system. [for monitoring the sterility of regenerated water in spacecraft

    Science.gov (United States)

    1974-01-01

    The design, fabrication, and testing of an automatic bacteria detection system, with a zero-g capability, based on the filter-capable approach, and intended for monitoring the sterility of regenerated water in spacecraft is discussed. The principle of detection is based on measuring the increase in chemiluminescence produced by the action of bacterial porphyrins on a luminol-hydrogen peroxide mixture. Viable organisms are detected by comparing the signal of an incubated water sample with an unincubated control. High signals for the incubated water sample indicate the presence of viable organisms.

  4. Immunization of Rodents Against Hymenolepis Infections using Non-Viable Homologous Oncospheres

    Directory of Open Access Journals (Sweden)

    Ping-Chin Fan

    2004-12-01

    Full Text Available Immunity to Taiwan Taenia infection in pigs can be stimulated using homologous or heterologous nonviable Taenia oncospheres. This study was designed to determine whether homologous non-viable oncospheres could stimulate immunity to Hymenolepis infection in rodents. Hatched oncospheres were prepared from eggs of Hymenolepis diminuta, Hymenolepis nana, and Hymenolepis microstoma and kept at −70°C for more than 1 month. A mixture of 500 non-viable oncospheres of each tapeworm and complete Freund's adjuvant was injected subcutaneously in four groups of Sprague-Dawley rats or ICR mice one to four times at an interval of 1 week; controls were not immunized. After immunization, each rodent was orally inoculated with three fresh active cysticercoids of H. diminuta or H. microstoma or 500 fresh eggs of H. nana. The animals were then necropsied for adult tapeworms. No rats or mice immunized with non-viable oncospheres of H. diminuta or H. nana were infected by the challenge inoculation. However, 28 of 34 mice immunized with non-viable H. microstoma oncospheres were infected after inoculation with cysticercoids. This study demonstrated complete protection against infection by homologous parasites in rats or mice immunized with non-viable oncospheres of H. diminuta and H. nana, respectively. Repeated immunization may not be required if resistance is stimulated in rodent hosts.

  5. PMA-Linked Fluorescence for Rapid Detection of Viable Bacterial Endospores

    Science.gov (United States)

    LaDuc, Myron T.; Venkateswaran, Kasthuri; Mohapatra, Bidyut

    2012-01-01

    The most common approach for assessing the abundance of viable bacterial endospores is the culture-based plating method. However, culture-based approaches are heavily biased and oftentimes incompatible with upstream sample processing strategies, which make viable cells/spores uncultivable. This shortcoming highlights the need for rapid molecular diagnostic tools to assess more accurately the abundance of viable spacecraft-associated microbiota, perhaps most importantly bacterial endospores. Propidium monoazide (PMA) has received a great deal of attention due to its ability to differentiate live, viable bacterial cells from dead ones. PMA gains access to the DNA of dead cells through compromised membranes. Once inside the cell, it intercalates and eventually covalently bonds with the double-helix structures upon photoactivation with visible light. The covalently bound DNA is significantly altered, and unavailable to downstream molecular-based manipulations and analyses. Microbiological samples can be treated with appropriate concentrations of PMA and exposed to visible light prior to undergoing total genomic DNA extraction, resulting in an extract comprised solely of DNA arising from viable cells. This ability to extract DNA selectively from living cells is extremely powerful, and bears great relevance to many microbiological arenas.

  6. Airborne viable fungi in school environments in different climatic regions - A review

    Science.gov (United States)

    Salonen, Heidi; Duchaine, Caroline; Mazaheri, Mandana; Clifford, Sam; Lappalainen, Sanna; Reijula, Kari; Morawska, Lidia

    2015-03-01

    Elevated levels of fungi in indoor environments have been linked with mould/moisture damage in building structures. However, there is a lack of information about "normal" concentrations and flora as well as guidelines of viable fungi in the school environment in different climatic conditions. We have reviewed existing guidelines for indoor fungi and the current knowledge of the concentrations and flora of viable fungi in different climatic areas, the impact of the local factors on concentrations and flora of viable fungi in school environments. Meta-regression was performed to estimate the average behaviour for each analysis of interest, showing wide variation in the mean concentrations in outdoor and indoor school environments (range: 101-103 cfu/m3). These concentrations were significantly higher for both outdoors and indoors in the moderate than in the continental climatic area, showing that the climatic condition was a determinant for the concentrations of airborne viable fungi. The most common fungal species both in the moderate and continental area were Cladosporium spp. and Penicillium spp. The suggested few quantitative guidelines for indoor air viable fungi for school buildings are much lower than for residential areas. This review provides a synthesis, which can be used to guide the interpretation of the fungi measurements results and help to find indications of mould/moisture in school building structures.

  7. Surface layers of bacteria.

    OpenAIRE

    Beveridge, T. J.; Graham, L L

    1991-01-01

    Since bacteria are so small, microscopy has traditionally been used to study them as individual cells. To this end, electron microscopy has been a most powerful tool for studying bacterial surfaces; the viewing of macromolecular arrangements of some surfaces is now possible. This review compares older conventional electron-microscopic methods with new cryotechniques currently available and the results each has produced. Emphasis is not placed on the methodology but, rather, on the importance ...

  8. Motility of electric cable bacteria

    DEFF Research Database (Denmark)

    Bjerg, Jesper Tataru; Damgaard, Lars Riis; Holm, Simon Agner

    2016-01-01

    Cable bacteria are filamentous bacteria that electrically couple sulfide oxidation and oxygen reduction at centimeter distances, and observations in sediment environments have suggested that they are motile. By time-lapse microscopy, we found that cable bacteria used gliding motility on surfaces...

  9. Enteric coated spheres produced by extrusion/spheronization provide effective gastric protection and efficient release of live therapeutic bacteria.

    Science.gov (United States)

    de Barros, João M S; Lechner, Tabea; Charalampopoulos, Dimitrios; Khutoryanskiy, Vitaliy V; Edwards, Alexander D

    2015-09-30

    We present a novel but simple enteric coated sphere formulation containing probiotic bacteria (Lactobacillus casei). Oral delivery of live bacterial cells (LBC) requires live cells to survive firstly manufacturing processes and secondly GI microbicidal defenses including gastric acid. We incorporated live L. casei directly in the granulation liquid, followed by granulation, extrusion, spheronization, drying and spray coating to produce dried live probiotic spheres. A blend of MCC, calcium-crosslinked alginate, and lactose was developed that gave improved live cell survival during manufacturing, and gave excellent protection from gastric acid plus rapid release in intestinal conditions. No significant loss of viability was observed in all steps except drying, which resulted in approximately 1 log loss of viable cells. Eudragit coating was used to protect dried live cells from acid, and microcrystalline cellulose (MCC) was combined with sodium alginate to achieve efficient sphere disintegration leading to rapid and complete bacterial cell release in intestinal conditions. Viability and release of L. casei was evaluated in vitro in simulated GI conditions. Uncoated spheres gave partial acid protection, but enteric coated spheres effectively protected dried probiotic LBC from acid for 2h, and subsequently released all viable cells within 1h of transfer into simulated intestinal fluid. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Pepsin homologues in bacteria

    Directory of Open Access Journals (Sweden)

    Bateman Alex

    2009-09-01

    Full Text Available Abstract Background Peptidase family A1, to which pepsin belongs, had been assumed to be restricted to eukaryotes. The tertiary structure of pepsin shows two lobes with similar folds and it has been suggested that the gene has arisen from an ancient duplication and fusion event. The only sequence similarity between the lobes is restricted to the motif around the active site aspartate and a hydrophobic-hydrophobic-Gly motif. Together, these contribute to an essential structural feature known as a psi-loop. There is one such psi-loop in each lobe, and so each lobe presents an active Asp. The human immunodeficiency virus peptidase, retropepsin, from peptidase family A2 also has a similar fold but consists of one lobe only and has to dimerize to be active. All known members of family A1 show the bilobed structure, but it is unclear if the ancestor of family A1 was similar to an A2 peptidase, or if the ancestral retropepsin was derived from a half-pepsin gene. The presence of a pepsin homologue in a prokaryote might give insights into the evolution of the pepsin family. Results Homologues of the aspartic peptidase pepsin have been found in the completed genomic sequences from seven species of bacteria. The bacterial homologues, unlike those from eukaryotes, do not possess signal peptides, and would therefore be intracellular acting at neutral pH. The bacterial homologues have Thr218 replaced by Asp, a change which in renin has been shown to confer activity at neutral pH. No pepsin homologues could be detected in any archaean genome. Conclusion The peptidase family A1 is found in some species of bacteria as well as eukaryotes. The bacterial homologues fall into two groups, one from oceanic bacteria and one from plant symbionts. The bacterial homologues are all predicted to be intracellular proteins, unlike the eukaryotic enzymes. The bacterial homologues are bilobed like pepsin, implying that if no horizontal gene transfer has occurred the duplication

  11. Combining ethidium monoazide treatment with real-time PCR selectively quantifies viable Batrachochytrium dendrobatidis cells.

    Science.gov (United States)

    Blooi, Mark; Martel, An; Vercammen, Francis; Pasmans, Frank

    2013-02-01

    Detection of the lethal amphibian fungus Batrachochytrium dendrobatidis relies on PCR-based techniques. Although highly accurate and sensitive, these methods fail to distinguish between viable and dead cells. In this study a novel approach combining the DNA intercalating dye ethidium monoazide (EMA) and real-time PCR is presented that allows quantification of viable B. dendrobatidis cells without the need for culturing. The developed method is able to suppress real-time PCR signals of heat-killed B. dendrobatidis zoospores by 99.9 % and is able to discriminate viable from heat-killed B. dendrobatidis zoospores in mixed samples. Furthermore, the novel approach was applied to assess the antifungal activity of the veterinary antiseptic F10(®) Antiseptic Solution. This disinfectant killed B. dendrobatidis zoospores effectively within 1 min at concentrations as low as 1:6400. Copyright © 2013 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.

  12. Abundance and distribution of enteric bacteria and viruses in coastal and estuarine sediments – a review.

    Directory of Open Access Journals (Sweden)

    Francis Hassard

    2016-11-01

    Full Text Available The long term survival of faecal indicator organisms (FIOs and human pathogenic microorganisms in sediments is important from a water quality, human health and ecological perspective. Typically, both bacteria and viruses strongly associate with particulate matter present in freshwater, estuarine and marine environments. This association tends to be stronger in finer textured sediments and is strongly influenced by the type and quantity of clay minerals and organic matter present. Binding to particle surfaces promotes the persistence of bacteria in the environment by offering physical and chemical protection from biotic and abiotic stresses. How bacterial and viral viability and pathogenicity is influenced by surface attachment requires further study. Typically, long-term association with surfaces including sediments induces bacteria to enter a viable-but-non-culturable (VBNC state. Inherent methodological challenges of quantifying VBNC bacteria may lead to the frequent under-reporting of their abundance in sediments. The implications of this in a quantitative risk assessment context remain unclear. Similarly, sediments can harbour significant amounts of enteric viruses, however, the factors regulating their persistence remains poorly understood. Quantification of viruses in sediment remains problematic due to our poor ability to recover intact viral particles from sediment surfaces (typically <10%, our inability to distinguish between infective and damaged (non-infective viral particles, aggregation of viral particles, and inhibition during qPCR. This suggests that the true viral titre in sediments may be being vastly underestimated. In turn, this is limiting our ability to understand the fate and transport of viruses in sediments. Model systems (e.g. human cell culture are also lacking for some key viruses, preventing our ability to evaluate the infectivity of viruses recovered from sediments (e.g. norovirus. The release of particle

  13. El modelo de sistema viable: un instrumento para la organización efectiva

    Directory of Open Access Journals (Sweden)

    Norlando Sánchez Rueda

    2015-05-01

    Full Text Available RESUMEN En este ensayo se presenta una interpretación teórica del denominado Modelo de Sistema Viable (MSV, de Stafford Beer y su Potencial Aplicación en Tareas de Diagnóstico  y diseño empresarial, al igual que para Mejorar las capacidades Organizacionales de Auto- Regulación  y Auto- Organización. Se explica como el Modelo del Sistema Viable permite conocer e interpretar  los mecanismos de estabilidad y adaptabilidad de las organizaciones, pilares para el crecimiento de una verdadera organización Efectiva.

  14. The talking language in some major Gram-negative bacteria.

    Science.gov (United States)

    Banerjee, Goutam; Ray, Arun Kumar

    2016-08-01

    Cell-cell interaction or quorum sensing (QS) is a vital biochemical/physiological process in bacteria that is required for various physiological functions, including nutrient uptake, competence development, biofilm formation, sporulation, as well as for toxin secretion. In natural environment, bacteria live in close association with other bacteria and interaction among them is crucial for survival. The QS-regulated gene expression in bacteria is a cell density-dependent process and the initiation process depends on the threshold level of the signaling molecule, N-acyl-homoserine lactone (AHL). The present review summarizes the QS signal and its respective circuit in Gram-negative bacteria. Most of the human pathogens belong to Gram-negative group, and only a few of them cause disease through QS system. Thus, inhibition of pathogenic bacteria is important. Use of antibiotics creates a selective pressure (antibiotics act as natural selection factor to promote one group of bacteria over another group) for emerging multidrug-resistant bacteria and will not be suitable for long-term use. The alternative process of inhibition of QS in bacteria using different natural and synthetic molecules is called quorum quenching. However, in the long run, QS inhibitors or blockers may also develop resistance, but obviously it will solve some sort of problems. In this review, we also have stated the mode of action of quorum-quenching molecule. The understanding of QS network in pathogenic Gram-negative bacteria will help us to solve many health-related problems in future.

  15. Melanocortin agonism as a viable strategy to control alveolar bone loss induced by oral infection.

    Science.gov (United States)

    Madeira, Mila F M; Queiroz-Junior, Celso M; Montero-Melendez, Trinidad; Werneck, Silvia M C; Corrêa, Jôice D; Soriani, Frederico M; Garlet, Gustavo P; Souza, Daniele G; Teixeira, Mauro M; Silva, Tarcilia A; Perretti, Mauro

    2016-12-01

    Alveolar bone loss is a result of an aggressive form of periodontal disease (PD) associated with Aggregatibacter actinomycetemcomitans (Aa) infection. PD is often observed with other systemic inflammatory conditions, including arthritis. Melanocortin peptides activate specific receptors to exert antiarthritic properties, avoiding excessing inflammation and modulating macrophage function. Recent work has indicated that melanocortin can control osteoclast development and function, but whether such protection takes place in infection-induced alveolar bone loss has not been investigated. The purpose of this study was to evaluate the role of melanocortin in Aa-induced PD. Mice were orally infected with Aa and treated with the melanocortin analog DTrp8-γMSH or vehicle daily for 30 d. Then, periodontal tissue was collected and analyzed. Aa-infected mice treated with DTrp8-γMSH presented decreased alveolar bone loss and a lower degree of neutrophil infiltration in the periodontium than vehicle-treated animals; these actions were associated with reduced periodontal levels of TNF-α, IFN-γ, and IL-17A. In vitro experiments with cells differentiated into osteoclasts showed that osteoclast formation and resorptive activity were attenuated after treatment with DTrp8-γMSH. Thus, melanocortin agonism could represent an innovative way to tame overexuberant inflammation and, at the same time, preserve bone physiology, as seen after Aa infection.-Madeira, M. F. M., Queiroz-Junior, C. M., Montero-Melendez, T., Werneck, S. M. C., Corrêa, J. D., Soriani, F. M., Garlet, G. P., Souza, D. G., Teixeira, M. M., Silva, T. A., Perretti, M. Melanocortin agonism as a viable strategy to control alveolar bone loss induced by oral infection. © FASEB.

  16. Effective and viable mind-body stress reduction in the workplace: a randomized controlled trial.

    Science.gov (United States)

    Wolever, Ruth Q; Bobinet, Kyra J; McCabe, Kelley; Mackenzie, Elizabeth R; Fekete, Erin; Kusnick, Catherine A; Baime, Michael

    2012-04-01

    Highly stressed employees are subject to greater health risks, increased cost, and productivity losses than those with normal stress levels. To address this issue in an evidence-based manner, worksite stress management programs must be able to engage individuals as well as capture data on stress, health indices, work productivity, and health care costs. In this randomized controlled pilot, our primary objective was to evaluate the viability and proof of concept for two mind-body workplace stress reduction programs (one therapeutic yoga-based and the other mindfulness-based), in order to set the stage for larger cost-effectiveness trials. A second objective was to evaluate 2 delivery venues of the mindfulness-based intervention (online vs. in-person). Intention-to-treat principles and 2 (pre and post) × 3 (group) repeated-measures analysis of covariance procedures examined group differences over time on perceived stress and secondary measures to clarify which variables to include in future studies: sleep quality, mood, pain levels, work productivity, mindfulness, blood pressure, breathing rate, and heart rate variability (a measure of autonomic balance). Two hundred and thirty-nine employee volunteers were randomized into a therapeutic yoga worksite stress reduction program, 1 of 2 mindfulness-based programs, or a control group that participated only in assessment. Compared with the control group, the mind-body interventions showed significantly greater improvements on perceived stress, sleep quality, and the heart rhythm coherence ratio of heart rate variability. The two delivery venues for the mindfulness program produced basically equivalent results. Both the mindfulness-based and therapeutic yoga programs may provide viable and effective interventions to target high stress levels, sleep quality, and autonomic balance in employees. PsycINFO Database Record (c) 2012 APA, all rights reserved.

  17. [Characteristics of adhesion of epiphytic bacteria on leaves of the seagrass Zostera marina and on abiotic surfaces].

    Science.gov (United States)

    Kurilenko, V V; Ivanova, E P; Mikhaĭlov, V V

    2007-01-01

    A comparative study of the adhesion of epiphytic bacteria and marine free-living, saprophytic, and pathogenic bacteria on seagrass leaves and abiotic surfaces was performed to prove the occurrence of true epiphytes of Zostera marina and to elucidate the bacterium-plant symbiotrophic relationships. It was shown that in the course of adhesion to the seagrass leaves of two taxonomically different bacteria, Cytophaga sp. KMM 3552 and Pseudoalteromonas citrea KMM 461, isolated from the seagrass surface, the number of viable cells increased 3-7-fold after 60 h of incubation, reaching 1.0-2.0 x 10(5) cells/cm2; however, in the case of adhesion of these bacteria to abiotic surfaces, such as glass or metal, virtually no viable cells were observed after 60 h of incubation. Such selectivity of cell adhesion was not observed in the case of three other bacterial species studied, viz., Vibrio alginolyticus KMM 3551, Bacillus subtilis KMM 430, and Pseudomonas aeruginosa KMM 433. The amount of viable cells of V. alginolyticus KMM 3551 adsorbed on glass and metal surfaces increased twofold after 40 h of incubation. The cells of saprophytic B. subtilis KMM 430 and pathogenic P. aeruginosa KMM 433 adsorbed on three studied substrata remained viable for 36 h and died by the 60th hour of incubation.

  18. Films of bacteria at interfaces.

    Science.gov (United States)

    Vaccari, Liana; Molaei, Mehdi; Niepa, Tagbo H R; Lee, Daeyeon; Leheny, Robert L; Stebe, Kathleen J

    2017-09-01

    Bacteria are often discussed as active colloids, self-propelled organisms whose collective motion can be studied in the context of non-equilibrium statistical mechanics. In such studies, the behavior of bacteria confined to interfaces or in the proximity of an interface plays an important role. For instance, many studies have probed collective behavior of bacteria in quasi two-dimensional systems such as soap films. Since fluid interfaces can adsorb surfactants and other materials, the stress and velocity boundary conditions at interfaces can alter bacteria motion; hydrodynamic studies of interfaces with differing boundary conditions are reviewed. Also, bacteria in bulk can become trapped at or near fluid interfaces, where they colonize and form structures comprising secretions like exopolysaccharides, surfactants, living and dead bacteria, thereby creating Films of Bacteria at Interfaces (FBI). The formation of FBI is discussed at air-water, oil-water, and water-water interfaces, with an emphasis on film mechanics, and with some allusion to genetic functions guiding bacteria to restructure fluid interfaces. At air-water interfaces, bacteria form pellicles or interfacial biofilms. Studies are reviewed that reveal that pellicle material properties differ for different strains of bacteria, and that pellicle physicochemistry can act as a feedback mechanism to regulate film formation. At oil-water interfaces, a range of FBI form, depending on bacteria strain. Some bacteria-laden interfaces age from an initial active film, with dynamics dominated by motile bacteria, through viscoelastic states, to form an elastic film. Others remain active with no evidence of elastic film formation even at significant interface ages. Finally, bacteria can adhere to and colonize ultra-low surface tension interfaces such as aqueous-aqueous systems common in food industries. Relevant literature is reviewed, and areas of interest for potential application are discussed, ranging from health

  19. Vibrio cholerae classical biotype is converted to the viable non-culturable state when cultured with the El Tor biotype.

    Science.gov (United States)

    Pradhan, Subhra; Mallick, Sanjaya K; Chowdhury, Rukhsana

    2013-01-01

    A unique event in bacterial epidemiology was the emergence of the El Tor biotype of Vibrio cholerae O1 and the subsequent rapid displacement of the existing classical biotype as the predominant cause of epidemic cholera. We demonstrate that when the El Tor and classical biotypes were cocultured in standard laboratory medium a precipitous decline in colony forming units (CFU) of the classical biotype occurred in a contact dependent manner. Several lines of evidence including DNA release, microscopy and flow cytometric analysis indicated that the drastic reduction in CFU of the classical biotype in cocultures was not accompanied by lysis, although when the classical biotype was grown individually in monocultures, lysis of the cells occurred concomitant with decrease in CFU starting from late stationary phase. Furthermore, uptake of a membrane potential sensitive dye and protection of genomic DNA from extracellular DNase strongly suggested that the classical biotype cells in cocultures retained viability in spite of loss of culturability. These results suggest that coculturing the classical biotype with the El Tor biotype protects the former from lysis allowing the cells to remain viable in spite of the loss of culturability. The stationary phase sigma factor RpoS may have a role in the loss of culturability of the classical biotype in cocultures. Although competitive exclusion of closely related strains has been reported for several bacterial species, conversion of the target bacterial population to the viable non-culturable state has not been demonstrated previously and may have important implications in the evolution of bacterial strains.

  20. Surface layers of bacteria.

    Science.gov (United States)

    Beveridge, T J; Graham, L L

    1991-12-01

    Since bacteria are so small, microscopy has traditionally been used to study them as individual cells. To this end, electron microscopy has been a most powerful tool for studying bacterial surfaces; the viewing of macromolecular arrangements of some surfaces is now possible. This review compares older conventional electron-microscopic methods with new cryotechniques currently available and the results each has produced. Emphasis is not placed on the methodology but, rather, on the importance of the results in terms of our perception of the makeup and function of bacterial surfaces and their interaction with the surrounding environment.

  1. Learning from bacteria about natural information processing.

    Science.gov (United States)

    Ben-Jacob, Eshel

    2009-10-01

    Under natural growth conditions, bacteria live in complex hierarchical communities. To conduct complex cooperative behaviors, bacteria utilize sophisticated communication to the extent that their chemical language includes semantic and even pragmatic aspects. I describe how complex colony forms (patterns) emerge through the communication-based interplay between individual bacteria and the colony. Individual cells assume newly co-generated traits and abilities that are not prestored in the genetic information of the cells, that is, not all the information required for efficient responses to all environmental conditions is stored. To solve newly encountered problems, they assess the problem via collective sensing, recall stored information of past experience, and then execute distributed information processing of the 10(9)-10(12) bacteria in the colony--transforming the colony into a "super-brain." I show illuminating examples of swarming intelligence of live bacteria in which they solve optimization problems that are beyond what human beings can solve. This will lead to a discussion about the special nature of bacterial computational principles compared to Turing algorithm computational principles, in particular about the role of distributed information processing.

  2. Detection of sulfonamide resistant bacteria and resistance genes in soils

    Science.gov (United States)

    Wu, Nan; Zhang, Weiyu; Liu, Huifen; Wang, Xiaobo; Yang, Fan; Zeng, Ming; Chen, Pinpin; Wang, Xiao

    2017-04-01

    Manure application could accelerate the environmental dissemination of antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) in soils. In this study, the prevalence of sulfonamide resistant bacteria and resistance genes was investigated in agricultural soils to which organic manures had been applied in Tianjin, China. Anti-sulfonamide bacteria were found in the range of 3.29 × 104 to 1.70 × 105 CFU/g dry soil, occupying 1.5% to 2.2% of total viable counts. And sulI and sulII genes were detected in all sampling sites, with relative abundances of 5.69 × 10-5 to 6.95 × 10-4 and 4.28 × 10-4 to 1.25 × 10-3 respectively. No significant correlations between cultivable sulfonamide resistant bacteria and sul genes were found in this study. While sulI showed significant positive correlation with soil organic matter. Overall, the results highlight that soil plays an important role in resistance genes capture as the environmental reservoir.

  3. Sulfate reducing bacteria detection in gas pipelines; Deteccao de bacterias redutoras de sulfato em gasodutos

    Energy Technology Data Exchange (ETDEWEB)

    Lutterbach, Marcia Teresa S.; Oliveira, Ana Lucia C. de; Cavalcanti, Eduardo H. de S. [Instituto Nacional de Tecnologia (INT), Rio de Janeiro, RJ (Brazil). Div. de Corrosao e Degradacao]. E-mails: marciasl@int.gov.br; analucia@int.gov.br; eduardoh@int.gov.br

    2004-07-01

    Microbiology induced corrosion (MIC) process associated with sulfate reducing bacteria (BRS) are one of the most important matter of concern for the oil and gas industry as 77% of failures have been attributed this sort of degradation. Corrosion products found present in gas transportation pipelines, the so-called 'black-powder' problem, are also a nuisance and source of economic losses for the gas industry. According to the literature, the incidence of black-powder can be ascribed to the metabolism of BRS that can be found in the gas environment. Integrity monitoring programs of gas pipelines adopt pigging as an important tool for internal corrosion monitoring. Solid residue such as the black-powder, collected by pigging, as well as the condensed, can be seen as a very valuable samples for microbiological analyses that can be used to detect and quantify bacteria related to the incidence of MIC processes. In the present work results concerning samples collected by pigging and condensed are presented. Small populations of viable BRS have been found in the pipeline. It can be seen that the inclusion of microbiological analyses of solid and liquid residues as a complementary action in the integrity monitoring programs adopted by gas transportation industry can be very helpful on the decision making concerning preventive and corrective actions to be taken in order to maintain the CIM processes under control. (author)

  4. Use of propidium monoazide for selective profiling of viable microbial cells during Gouda cheese ripening

    NARCIS (Netherlands)

    Erkus, O.; Jager, V.C. de; Geene, R.T.; Alen-Boerrigter, I.J. van; Hazelwood, L.; Hijum, S.A.F.T. van; Kleerebezem, M; Smid, E.J.

    2016-01-01

    DNA based microbial community profiling of food samples is confounded by the presence of DNA derived from membrane compromised (dead or injured) cells. Selective amplification of DNA from viable (intact) fraction of the community by propidium monoazide (PMA) treatment could circumvent this problem.

  5. Induction of viable 2n pollen in sterile Oriental × Trumpet Lilium hybrids

    NARCIS (Netherlands)

    Luo, J.R.; Arens, P.; Niu, L.X.; Tuyl, van J.M.

    2016-01-01

    In order to induce viable 2n pollen from highly sterile diploid Oriental × Trumpet (OT) (Lilium), N2O was used to treat flower buds of four sterile diploid OT cultivars (‘Nymph’, ‘Gluhwein’, ‘Yelloween’, and ‘Shocking’) at different stages of meiosis. There was no pollen germination in

  6. Separable Bilayer Microfiltration Device for Viable Label-free Enrichment of Circulating Tumour Cells

    Science.gov (United States)

    Zhou, Ming-Da; Hao, Sijie; Williams, Anthony J.; Harouaka, Ramdane A.; Schrand, Brett; Rawal, Siddarth; Ao, Zheng; Brennaman, Randall; Gilboa, Eli; Lu, Bo; Wang, Shuwen; Zhu, Jiyue; Datar, Ram; Cote, Richard; Tai, Yu-Chong; Zheng, Si-Yang

    2014-12-01

    The analysis of circulating tumour cells (CTCs) in cancer patients could provide important information for therapeutic management. Enrichment of viable CTCs could permit performance of functional analyses on CTCs to broaden understanding of metastatic disease. However, this has not been widely accomplished. Addressing this challenge, we present a separable bilayer (SB) microfilter for viable size-based CTC capture. Unlike other single-layer CTC microfilters, the precise gap between the two layers and the architecture of pore alignment result in drastic reduction in mechanical stress on CTCs, capturing them viably. Using multiple cancer cell lines spiked in healthy donor blood, the SB microfilter demonstrated high capture efficiency (78-83%), high retention of cell viability (71-74%), high tumour cell enrichment against leukocytes (1.7-2 × 103), and widespread ability to establish cultures post-capture (100% of cell lines tested). In a metastatic mouse model, SB microfilters successfully enriched viable mouse CTCs from 0.4-0.6 mL whole mouse blood samples and established in vitro cultures for further genetic and functional analysis. Our preliminary studies reflect the efficacy of the SB microfilter device to efficiently and reliably enrich viable CTCs in animal model studies, constituting an exciting technology for new insights in cancer research.

  7. Viable Techniques, Leontief’s Closed Model, and Sraffa’s Subsistence Economies

    Directory of Open Access Journals (Sweden)

    Alberto Benítez

    2014-11-01

    Full Text Available This paper studies the production techniques employed in economies that reproduce themselves. Special attention is paid to the distinction usually made between those that do not produce a surplus and those that do, which are referred to as first and second class economies, respectively. Based on this, we present a new definition of viable economies and show that every viable economy of the second class can be represented as a viable economy of the first class under two different forms, Leontief‘s closed model and Sraffa’s subsistence economies. This allows us to present some remarks concerning the economic interpretation of the two models. On the one hand, we argue that the participation of each good in the production of every good can be considered as a normal characteristic of the first model and, on the other hand, we provide a justification for the same condition to be considered a characteristic of the second model. Furthermore, we discuss three definitions of viable techniques advanced by other authors and show that they differ from ours because they admit economies that do not reproduce themselves completely.

  8. Modelling the number of viable vegetative cells of Bacillus cereus passing through the stomach

    NARCIS (Netherlands)

    Wijnands, L.M.; Pielaat, A.; Dufrenne, J.B.; Zwietering, M.H.; Leusden, van F.M.

    2009-01-01

    Aims: Model the number of viable vegetative cells of B. cereus surviving the gastric passage after experiments in simulated gastric conditions. Materials and Methods: The inactivation of stationary and exponential phase vegetative cells of twelve different strains of Bacillus cereus, both mesophilic

  9. Determination of viable Salmonellae from potable and source water through PMA assisted qPCR.

    Science.gov (United States)

    Singh, Gulshan; Vajpayee, Poornima; Bhatti, Saurabh; Ronnie, Nirmala; Shah, Nimish; McClure, Peter; Shanker, Rishi

    2013-07-01

    Resource constrained countries identified as endemic zones for pathogenicity of Salmonella bear an economic burden due to recurring expenditure on medical treatment. qPCR used for Salmonella detection could not discriminate between viable and nonviable cells. Propidium monoazide (PMA) that selectively penetrates nonviable cells to cross-link their DNA, was coupled with ttr gene specific qPCR for quantifying viable salmonellae in source/potable waters collected from a north Indian city. Source water (raw water for urban potable water supply) and urban potable water exhibited viable salmonellae in the range of 2.1×10(4)-2.6×10(6) and 2-7160CFU/100mL, respectively. Potable water at water works exhibited DNA from dead cells but no viable cells were detected. PMA assisted qPCR could specifically detect low numbers of live salmonellae in Source and potable waters. This strategy can be used in surveillance of urban potable water distribution networks to map contamination points for better microbial risk management. Copyright © 2013 Elsevier Inc. All rights reserved.

  10. Food web (bio-)manipulation of South African reservoirs – viable ...

    African Journals Online (AJOL)

    2006-10-04

    Oct 4, 2006 ... Food web (bio-)manipulation of South African reservoirs – viable eutrophication ... Microcystis in local eutrophic waters is perceived as a primary major constraint in implementing 'classical' food-web manip- ulation. Intrinsic ... cially in 'shallow' lakes) to dismal failure (often in deep lakes) and a range of ...

  11. Epoxidation of aldrin to exo-dieldrin by soil bacteria.

    Science.gov (United States)

    Ferguson, J A; Korte, F

    1977-01-01

    Twenty-two strains of soil bacteria, including representatives of the genera Bacillus, Micromonospora, Mycobacterium, Nocardia, Streptomyces, Thermoactinomyces, and Pseudomonas and 10 unidentified gram-negative, motile, rod-shaped bacteria, were shown to degrade aldrin to its epoxide dieldrin. In every case, the exo-stereoisomer of dieldrin was produced exclusively. PMID:407844

  12. 'Atypical' bacteria are a common cause of community-acquired ...

    African Journals Online (AJOL)

    Objectives. To assess the proportion of cases of community· acquired pneumonia caused by 'atypical' bacteria, inclUding the recently discovered Chlamydia pneumoniae, and to compare the clinical, radiographic and laboratory features of patients with and without 'atypical' bacteria. Methods. A prospective serological ...

  13. Fecal bacteria source characterization and sensitivity analysis of SWAT 2005

    Science.gov (United States)

    The Soil and Water Assessment Tool (SWAT) version 2005 includes a microbial sub-model to simulate fecal bacteria transport at the watershed scale. The objectives of this study were to demonstrate methods to characterize fecal coliform bacteria (FCB) source loads and to assess the model sensitivity t...

  14. Isolation of pathogenic bacteria from hospital staff apparel in Nigeria

    African Journals Online (AJOL)

    A survey of bacteria contamination of hospital staff apparel in use in Anambra State, Nigeria, was carried out to deter- mine the extent of contamination by clinically important bacteria. ()f a total of 125 swab samples of hospital staff apparel, 72 (58%) showed bacterial contamination including. 32 (70%) of 46 samples from ...

  15. Short Communication Antibacterial Activities of Lactic Acid Bacteria ...

    African Journals Online (AJOL)

    2011-12-20

    Dec 20, 2011 ... beneficial effects of lactic acid bacteria consumption include improving intestinal tract health (Parvez et ..... Gastrointestinal Microflora Exert Antimicrobial. Activity. Gut. 47:646–652. Ljungh A and Wadstrom T (2006). Lactic Acid. Bacteria as Probiotics. Curr. Issues Intest. Microbiol. 7:73–89. Marteau P, de ...

  16. Chemical communication in bacteria

    Science.gov (United States)

    Suravajhala, Srinivasa Sandeep; Saini, Deepak; Nott, Prabhu

    Luminescence in Vibrio fischeri is a model for quorum-sensing-gene-regulation in bacteria. We study luminescence response of V. fischeri to both internal and external cues at the single cell and population level. Experiments with ES114, a wild-type strain, and ainS mutant show that luminescence induction in cultures is not always proportional to cell-density and there is always a basal level of luminescence. At any given concentration of the exogenously added signals, C6-HSL and C8-HSL, luminescence per cell reaches a maximum during the exponential phase and decreases thereafter. We hypothesize that (1) C6-HSL production and LuxR activity are not proportional to cell-density, and (2) there is a shift in equilibrium from C6-HSL to C8-HSL during the later stages of growth of the culture. RT-PCR analysis of luxI and luxR shows that the expression of these genes is maximum corresponding to the highest level of luminescence. The shift in equilibrium is shown by studying competitive binding of C6-HSL and C8-HSL to LuxR. We argue that luminescence is a unicellular behaviour, and an intensive property like per cell luminescence is more important than gross luminescence of the population in understanding response of bacteria to chemical signalling. Funding from the Department of Science and Technology, India is acknowledged.

  17. Beneficial bacteria inhibit cachexia

    Science.gov (United States)

    Varian, Bernard J.; Goureshetti, Sravya; Poutahidis, Theofilos; Lakritz, Jessica R.; Levkovich, Tatiana; Kwok, Caitlin; Teliousis, Konstantinos; Ibrahim, Yassin M.; Mirabal, Sheyla; Erdman, Susan E.

    2016-01-01

    Muscle wasting, known as cachexia, is a debilitating condition associated with chronic inflammation such as during cancer. Beneficial microbes have been shown to optimize systemic inflammatory tone during good health; however, interactions between microbes and host immunity in the context of cachexia are incompletely understood. Here we use mouse models to test roles for bacteria in muscle wasting syndromes. We find that feeding of a human commensal microbe, Lactobacillus reuteri, to mice is sufficient to lower systemic indices of inflammation and inhibit cachexia. Further, the microbial muscle-building phenomenon extends to normal aging as wild type animals exhibited increased growth hormone levels and up-regulation of transcription factor Forkhead Box N1 [FoxN1] associated with thymus gland retention and longevity. Interestingly, mice with a defective FoxN1 gene (athymic nude) fail to inhibit sarcopenia after L. reuteri therapy, indicating a FoxN1-mediated mechanism. In conclusion, symbiotic bacteria may serve to stimulate FoxN1 and thymic functions that regulate inflammation, offering possible alternatives for cachexia prevention and novel insights into roles for microbiota in mammalian ontogeny and phylogeny. PMID:26933816

  18. Intestinal, segmented, filamentous bacteria.

    Science.gov (United States)

    Klaasen, H L; Koopman, J P; Poelma, F G; Beynen, A C

    1992-06-01

    Segmented, filamentous bacteria (SFBs) are autochthonous, apathogenic bacteria, occurring in the ileum of mice and rats. Although the application of formal taxonomic criteria is impossible due to the lack of an in vitro technique to culture SFBs, microbes with a similar morphology, found in the intestine of a wide range of vertebrate and invertebrate host species, are considered to be related. SFBs are firmly attached to the epithelial cells of the distal ileal mucosa, their preferential ecological niche being the epithelium covering the Peyer's patches. Electron microscopic studies have demonstrated a considerable morphological diversity of SFBs, which may relate to different stages of a life cycle. Determinants of SFB colonization in vivo are host species, genotypical and phenotypical characteristics of the host, diet composition, environmental stress and antimicrobial drugs. SFBs can survive in vitro incubation, but do not multiply. On the basis of their apathogenic character and intimate relationship with the host, it is suggested that SFBs contribute to development and/or maintenance of host resistance to enteropathogens.

  19. Functional amyloids in bacteria.

    Science.gov (United States)

    Romero, Diego; Kolter, Roberto

    2014-06-01

    The term amyloidosis is used to refer to a family of pathologies altering the homeostasis of human organs. Despite having a name that alludes to starch content, the amyloid accumulations are made up of proteins that polymerize as long and rigid fibers. Amyloid proteins vary widely with respect to their amino acid sequences but they share similarities in their quaternary structure; the amyloid fibers are enriched in β-sheets arranged perpendicular to the axis of the fiber. This structural feature provides great robustness, remarkable stability, and insolubility. In addition, amyloid proteins specifically stain with certain dyes such as Congo red and thioflavin-T. The aggregation into amyloid fibers, however, it is not restricted to pathogenic processes, rather it seems to be widely distributed among proteins and polypeptides. Amyloid fibers are present in insects, fungi and bacteria, and they are important in maintaining the homeostasis of the organism. Such findings have motivated the use of the term "functional amyloid" to differentiate these amyloid proteins from their toxic siblings. This review focuses on systems that have evolved in bacteria that control the expression and assembly of amyloid proteins on cell surfaces, such that the robustness of amyloid proteins are used towards a beneficial end. Copyright© by the Spanish Society for Microbiology and Institute for Catalan Studies.

  20. Beneficial bacteria inhibit cachexia.

    Science.gov (United States)

    Varian, Bernard J; Goureshetti, Sravya; Poutahidis, Theofilos; Lakritz, Jessica R; Levkovich, Tatiana; Kwok, Caitlin; Teliousis, Konstantinos; Ibrahim, Yassin M; Mirabal, Sheyla; Erdman, Susan E

    2016-03-15

    Muscle wasting, known as cachexia, is a debilitating condition associated with chronic inflammation such as during cancer. Beneficial microbes have been shown to optimize systemic inflammatory tone during good health; however, interactions between microbes and host immunity in the context of cachexia are incompletely understood. Here we use mouse models to test roles for bacteria in muscle wasting syndromes. We find that feeding of a human commensal microbe, Lactobacillus reuteri, to mice is sufficient to lower systemic indices of inflammation and inhibit cachexia. Further, the microbial muscle-building phenomenon extends to normal aging as wild type animals exhibited increased growth hormone levels and up-regulation of transcription factor Forkhead Box N1 [FoxN1] associated with thymus gland retention and longevity. Interestingly, mice with a defective FoxN1 gene (athymic nude) fail to inhibit sarcopenia after L. reuteri therapy, indicating a FoxN1-mediated mechanism. In conclusion, symbiotic bacteria may serve to stimulate FoxN1 and thymic functions that regulate inflammation, offering possible alternatives for cachexia prevention and novel insights into roles for microbiota in mammalian ontogeny and phylogeny.

  1. Heterologous surface display on lactic acid bacteria: non-GMO alternative?

    Science.gov (United States)

    Zadravec, Petra; Štrukelj, Borut; Berlec, Aleš

    2015-01-01

    Lactic acid bacteria (LAB) are food-grade hosts for surface display with potential applications in food and therapy. Alternative approaches to surface display on LAB would avoid the use of recombinant DNA technology and genetically-modified organism (GMO)-related regulatory requirements. Non-covalent surface display of proteins can be achieved by fusing them to various cell-wall binding domains, of which the Lysine motif domain (LysM) is particularly well studied. Fusion proteins have been isolated from recombinant bacteria or from their growth medium and displayed on unmodified bacteria, enabling heterologous surface display. This was demonstrated on non-viable cells devoid of protein content, termed bacteria-like particles, and on various species of genus Lactobacillus. Of the latter, Lactobacillus salivarius ATCC 11741 was recently shown to be particularly amenable for LysM-mediated display. Possible regulatory implications of heterologous surface display are discussed, particularly those relevant for the European Union.

  2. The Interaction between Plants and Bacteria in the Remediation of Petroleum Hydrocarbons: An Environmental Perspective

    Directory of Open Access Journals (Sweden)

    Panagiotis Gkorezis

    2016-11-01

    Full Text Available Widespread pollution of terrestrial ecosystems with petroleum hydrocarbons (PHCs has generated a need for remediation and, given that many PHCs are biodegradable, bio- and phyto-remediation are often viable approaches for active and passive remediation. This review focuses on phytoremediation with particular interest on the interactions between and use of plant – associated bacteria to restore PHC polluted sites. Plant-associated bacteria include endophytic, phyllospheric and rhizospheric bacteria, and cooperation between these bacteria and their host plants allows for greater plant survivability and treatment outcomes in contaminated sites. Bacterially-driven PHC bioremediation is attributed to the presence of diverse suites of metabolic genes for aliphatic and aromatic hydrocarbons, along with a broader suite of physiological properties including biosurfactant production, biofilm formation, chemotaxis to hydrocarbons, and flexibility in cell-surface hydrophobicity. In soils impacted by PHC contamination, microbial bioremediation generally relies on the addition of high-energy electron acceptors (e.g. oxygen and fertilization to supply limiting nutrients (e.g. nitrogen, phosphorous, potassium in the face of excess PHC carbon. As an alternative, the addition of plants can greatly improve bioremediation rates and outcomes as plants provide microbial habitats, improve soil porosity (thereby increasing mass transfer of substrates and electron acceptors, and exchange limiting nutrients with their microbial counterparts. In return, plant-associated microorganisms improve plant growth by reducing soil toxicity through contaminant removal, producing plant growth promoting metabolites, liberating sequestered plant nutrients from soil, fixing nitrogen, and more generally establishing the foundations of soil nutrient cycling. In a practical and applied sense, the collective action of plants and their associated microorganisms is advantageous for

  3. The Interaction between Plants and Bacteria in the Remediation of Petroleum Hydrocarbons: An Environmental Perspective

    Science.gov (United States)

    Gkorezis, Panagiotis; Daghio, Matteo; Franzetti, Andrea; Van Hamme, Jonathan D.; Sillen, Wouter; Vangronsveld, Jaco

    2016-01-01

    Widespread pollution of terrestrial ecosystems with petroleum hydrocarbons (PHCs) has generated a need for remediation and, given that many PHCs are biodegradable, bio- and phyto-remediation are often viable approaches for active and passive remediation. This review focuses on phytoremediation with particular interest on the interactions between and use of plant-associated bacteria to restore PHC polluted sites. Plant-associated bacteria include endophytic, phyllospheric, and rhizospheric bacteria, and cooperation between these bacteria and their host plants allows for greater plant survivability and treatment outcomes in contaminated sites. Bacterially driven PHC bioremediation is attributed to the presence of diverse suites of metabolic genes for aliphatic and aromatic hydrocarbons, along with a broader suite of physiological properties including biosurfactant production, biofilm formation, chemotaxis to hydrocarbons, and flexibility in cell-surface hydrophobicity. In soils impacted by PHC contamination, microbial bioremediation generally relies on the addition of high-energy electron acceptors (e.g., oxygen) and fertilization to supply limiting nutrients (e.g., nitrogen, phosphorous, potassium) in the face of excess PHC carbon. As an alternative, the addition of plants can greatly improve bioremediation rates and outcomes as plants provide microbial habitats, improve soil porosity (thereby increasing mass transfer of substrates and electron acceptors), and exchange limiting nutrients with their microbial counterparts. In return, plant-associated microorganisms improve plant growth by reducing soil toxicity through contaminant removal, producing plant growth promoting metabolites, liberating sequestered plant nutrients from soil, fixing nitrogen, and more generally establishing the foundations of soil nutrient cycling. In a practical and applied sense, the collective action of plants and their associated microorganisms is advantageous for remediation of PHC

  4. The Interaction between Plants and Bacteria in the Remediation of Petroleum Hydrocarbons: An Environmental Perspective.

    Science.gov (United States)

    Gkorezis, Panagiotis; Daghio, Matteo; Franzetti, Andrea; Van Hamme, Jonathan D; Sillen, Wouter; Vangronsveld, Jaco

    2016-01-01

    Widespread pollution of terrestrial ecosystems with petroleum hydrocarbons (PHCs) has generated a need for remediation and, given that many PHCs are biodegradable, bio- and phyto-remediation are often viable approaches for active and passive remediation. This review focuses on phytoremediation with particular interest on the interactions between and use of plant-associated bacteria to restore PHC polluted sites. Plant-associated bacteria include endophytic, phyllospheric, and rhizospheric bacteria, and cooperation between these bacteria and their host plants allows for greater plant survivability and treatment outcomes in contaminated sites. Bacterially driven PHC bioremediation is attributed to the presence of diverse suites of metabolic genes for aliphatic and aromatic hydrocarbons, along with a broader suite of physiological properties including biosurfactant production, biofilm formation, chemotaxis to hydrocarbons, and flexibility in cell-surface hydrophobicity. In soils impacted by PHC contamination, microbial bioremediation generally relies on the addition of high-energy electron acceptors (e.g., oxygen) and fertilization to supply limiting nutrients (e.g., nitrogen, phosphorous, potassium) in the face of excess PHC carbon. As an alternative, the addition of plants can greatly improve bioremediation rates and outcomes as plants provide microbial habitats, improve soil porosity (thereby increasing mass transfer of substrates and electron acceptors), and exchange limiting nutrients with their microbial counterparts. In return, plant-associated microorganisms improve plant growth by reducing soil toxicity through contaminant removal, producing plant growth promoting metabolites, liberating sequestered plant nutrients from soil, fixing nitrogen, and more generally establishing the foundations of soil nutrient cycling. In a practical and applied sense, the collective action of plants and their associated microorganisms is advantageous for remediation of PHC

  5. Effects of the oral administration of viable and heat-killed Streptococcus bovis HC5 cells to pre-sensitized BALB/c mice.

    Directory of Open Access Journals (Sweden)

    Aline D Paiva

    Full Text Available Antimicrobial peptides have been suggested as an alternative to classical antibiotics in livestock production and bacteriocin-producing bacteria could be added to animal feeds to deliver bacteriocins in the gastrointestinal (GI tract of ruminant and monogastric animals. In this study, viable (V and heat-killed (HK Streptococcus bovis HC5 cells were orally administered to pre-sensitized mice in order to assess the effects of a bacteriocin-producing bacteria on histological parameters and the immune response of the GI tract of monogastric animals. The administration of V and HK S. bovis HC5 cells during 58 days to BALB/c mice did not affect weight gain, but an increase in gut permeability was detected in animals receiving the HK cells. Viable and heat killed cells caused similar morphological alterations in the GI tract of the animals, but the most prominent effects were detected in the small intestine. The oral administration of S. bovis HC5 also influenced cytokine production in the small intestine, and the immune-mediated activity differed between V and HK cells. The relative expression of IL-12 and INF-γ was significantly higher in the small intestine of mice treated with V cells, while an increase in IL-5, IL-13 and TNF-α expression was only detected in mice treated with HK cells. Considering that even under a condition of severe challenge (pre-sensitization followed by daily exposure to the same bacterial immunogen the general health of the animals was maintained, it appears that oral administration of S. bovis HC5 cells could be a useful route to deliver bacteriocin in the GI tract of livestock animals.

  6. Advantageous direct quantification of viable closely related probiotics in petit-suisse cheeses under in vitro gastrointestinal conditions by Propidium Monoazide--qPCR.

    Directory of Open Access Journals (Sweden)

    Martha Lissete Morales Villarreal

    Full Text Available Species-specific Quantitative Real Time PCR (qPCR alone and combined with the use of propidium monoazide (PMA were used along with the plate count method to evaluate the survival of the probiotic strains Lactobacillus acidophilus La-5 and Bifidobacterium animalis subsp. lactis Bb-12, and the bacteriocinogenic and potentially probiotic strain Lactobacillus sakei subsp. sakei 2a in synbiotic (F1 and probiotic (F2 petit-suisse cheeses exposed throughout shelf-life to in vitro simulated gastrointestinal tract conditions. The three strains studied showed a reduction in their viability after the 6 h assay. Bb-12 displayed the highest survival capacity, above 72.6 and 74.6% of the initial populations, respectively, by plate count and PMA-qPCR, maintaining population levels in the range or above 6 log CFU/g. The prebiotic mix of inulin and FOS did not offer any additional protection for the strains against the simulated gastrointestinal environment. The microorganisms' populations were comparable among the three methods at the initial time of the assay, confirming the presence of mainly viable and culturable cells. However, with the intensification of the stress induced throughout the various stages of the in vitro test, the differences among the methods increased. The qPCR was not a reliable enumeration method for the quantification of intact bacterial populations, mixed with large numbers of injured and dead bacteria, as confirmed by the scanning electron microscopy results. Furthermore, bacteria plate counts were much lower (P<0.05 than with the PMA-qPCR method, suggesting the accumulation of stressed or dead microorganisms unable to form colonies. The use of PMA overcame the qPCR inability to differentiate between dead and alive cells. The combination of PMA and species-specific qPCR in this study allowed a quick and unequivocal way of enumeration of viable closely related species incorporated into probiotic and synbiotic petit-suisse cheeses and

  7. Immunomodulatory effect of non-viable components of probiotic culture stimulated with heat-inactivated Escherichia coli and Bacillus cereus on holoxenic mice

    Directory of Open Access Journals (Sweden)

    L. M. Ditu

    2014-09-01

    Full Text Available Background: Competition of probiotic bacteria with other species from the intestinal microbiota involves different mechanisms that occur regardless of probiotics’ viability. The objective of this paper was to assess the cytokine serum levels in holoxenic mice after oral administration of non-viable components (NVC of Enterococcus faecium probiotic culture stimulated with heat-inactivated Escherichia coli and Bacillus cereus in comparison to NVC of unstimulated E. faecium probiotic culture. Methods: Probiotic E. faecium CMGb 16 culture, grown in the presence of heat-inactivated cultures of E. coli and B. cereus CMGB 102, was subsequently separated into supernatant (SN and heat-inactivated cellular sediment (CS fractions by centrifugation. Each NVC was orally administered to holoxenic mice (balb C mouse strain, in three doses, given at 24 hours. Blood samples were collected from the retinal artery, at 7, 14, and 21 days after the first administration of the NVC. The serum concentrations of IL-12 and tumor necrosis factor-alpha (TNF-α interleukins were assessed by ELISA method. Results: After the oral administration of SN component obtained from the probiotic culture stimulated with heat-inactivated cultures of B. cereus CMGB 102 and E. coli O28, the serum concentrations of IL-12 were maintained higher in the samples collected at 7 and 14 days post-administration. No specific TNF-α profile could be established, depending on stimulated or non-stimulated probiotic culture, NVC fraction, or harvesting time. Conclusion: The obtained results demonstrate that non-viable fractions of probiotic bacteria, stimulated by other bacterial species, could induce immunostimulatory effects mediated by cytokines and act, therefore, as immunological adjuvants.

  8. The antimicrobial spectra of selected Penicillia against some pathogenic bacteria and yeasts

    Directory of Open Access Journals (Sweden)

    Shashi Chauhan

    2014-08-01

    Full Text Available The antagonista activity of eight isolaies of penicillia bas been studied against 13 pathogenic organisms, which included 6 Gram-positive bacteria, 4 Gram-negative bacteria and 3 yeasts.

  9. Cable Bacteria in Freshwater Sediments

    DEFF Research Database (Denmark)

    Risgaard-Petersen, Nils; Kristiansen, Michael; Frederiksen, Rasmus

    2015-01-01

    In marine sediments cathodic oxygen reduction at the sediment surface can be coupled to anodic sulfide oxidation in deeper anoxic layers through electrical currents mediated by filamentous, multicellular bacteria of the Desulfobulbaceae family, the so-called cable bacteria. Until now, cable...... bacteria have only been reported from marine environments. In this study, we demonstrate that cable bacteria also occur in freshwater sediments. In a first step, homogenized sediment collected from the freshwater stream Giber Å, Denmark, was incubated in the laboratory. After 2 weeks, pH signatures...... marine cable bacteria, with the genus Desulfobulbus as the closest cultured lineage. The results of the present study indicate that electric currents mediated by cable bacteria could be important for the biogeochemistry in many more environments than anticipated thus far and suggest a common evolutionary...

  10. Immunomodulatory properties of probiotic bacteria

    DEFF Research Database (Denmark)

    Fink, Lisbeth Nielsen

    2007-01-01

    Certain lactic acid bacteria (LAB) are part of the commensal intestinal flora and considered beneficial for health, as they compete with pathogens for adhesion sites in the intestine and ferment otherwise indigestible compounds. Another important property of these so-called probiotic bacteria...... with bacteria, and the cytokine pattern induced by specific bacteria resembled the pattern induced in MoDC, except for TNF-alpha and IL-6, which were induced in response to different bacteria in blood DC/monocytes and monocyte-derived DC. Autologous NK cells produced IFN-gamma when cultured with blood DC......, monocytes and monocyte-derived DC and IL-12-inducing bacteria, whereas only DC induced IFN-gamma production in allogeneic T cells. In vitro-generated DC is a commonly used model of tissue DC, but they differ in certain aspects from intestinal DC, which are in direct contact with the intestinal microbiota...

  11. Biotechnology of Anoxygenic Phototrophic Bacteria.

    Science.gov (United States)

    Frigaard, Niels-Ulrik

    Anoxygenic phototrophic bacteria are a diverse collection of organisms that are defined by their ability to grow using energy from light without evolving oxygen. The dominant groups are purple sulfur bacteria, purple nonsulfur bacteria, green sulfur bacteria, and green and red filamentous anoxygenic phototrophic bacteria. They represent several bacterial phyla but they all have bacteriochlorophylls and carotenoids and photochemical reaction centers which generate ATP and cellular reductants used for CO2 fixation. They typically have an anaerobic lifestyle in the light, although some grow aerobically in the dark. Some of them oxidize inorganic sulfur compounds for light-dependent CO2 fixation; this ability can be exploited for photobiological removal of hydrogen sulfide from wastewater and biogas. The anoxygenic phototrophic bacteria also perform bioremediation of recalcitrant dyes, pesticides, and heavy metals under anaerobic conditions. Finally, these organisms may be useful for overexpression of membrane proteins and photobiological production of H2 and other valuable compounds.

  12. Comparison of solid-phase cytometry and the plate count method for the evaluation of the survival of bacteria in pharmaceutical oils.

    Science.gov (United States)

    De Prijck, K; Peeters, E; Nelis, H J

    2008-12-01

    To compare the survival of four bacterial strains (Escherichia coli, Proteus mirabilis, Staphylococcus aureus, Pseudomonas aeruginosa) in pharmaceutical oils, including jojoba oil/tea tree oil, carbol oil, jojoba oil and sesame oil. Oils were spiked with the test bacteria in a concentration of 10(4) CFU ml(-1). Bacteria were extracted from oils with phosphate-buffered saline containing 0.5% Tween 20. Aliquots of the pooled water layers were analysed by solid-phase cytometry and plate counting. Plate counts dropped to zero for all test strains exposed for 24 h to three of the four oils. In contrast, significant numbers of viable cells were still detected by SPC, except in the jojoba oil/tea tree oil mixture and partly in sesame oil. Exposure of bacteria for 24 h to the two oils containing an antimicrobial led to a loss of their culturability but not necessarily of their viability. The antibacterial activity of the jojoba oil/tea tree oil mixture supersedes that of carbol oil. These in vitro data suggest that the jojoba oil/tea tree oil mixture more than carbol oil inhibits bacterial proliferation when used for intermittent self-catherization.

  13. Project MERCCURI: Bacteria in Space

    OpenAIRE

    Lee, Ruth; Coil, David; Lang, Jenna Morgan; Neches, Russell; Eisen, Jonathan

    2014-01-01

    Some bacteria grown in microgravity have previously been shown to exhibit different morphological and metabolic capabilities than when grown on Earth. As part of Project MERCCURI’s aim to increase microbiological outreach, we sampled at various high-population sporting venues and sites of historical interest nationwide for 48 strains of BSL 1 bacteria. After we grew these bacteria in culture, the 48 strains will be flown to the International Space Station to be “raced” against parallel plates...

  14. Bacteria as natural enemies of plant-parasitic nematodes

    Science.gov (United States)

    Sustainable farming seeks to prevent soil erosion and contamination of groundwater and air. In order for sustainable production systems to become viable, control of economically important pests must be accomplished with minimal or no applications of pesticides. Management of nematodes may include ...

  15. Bacteria, phages and septicemia.

    Directory of Open Access Journals (Sweden)

    Ausra Gaidelyte

    Full Text Available The use of phages is an attractive option to battle antibiotic resistant bacteria in certain bacterial infections, but the role of phage ecology in bacterial infections is obscure. Here we surveyed the phage ecology in septicemia, the most severe type of bacterial infection. We observed that the majority of the bacterial isolates from septicemia patients spontaneously secreted phages active against other isolates of the same bacterial strain, but not to the strain causing the disease. Such phages were also detected in the initial blood cultures, indicating that phages are circulating in the blood at the onset of sepsis. The fact that most of the septicemic bacterial isolates carry functional prophages suggests an active role of phages in bacterial infections. Apparently, prophages present in sepsis-causing bacterial clones play a role in clonal selection during bacterial invasion.

  16. Acoustofluidic bacteria separation

    Science.gov (United States)

    Li, Sixing; Ma, Fen; Bachman, Hunter; Cameron, Craig E.; Zeng, Xiangqun; Huang, Tony Jun

    2017-01-01

    Bacterial separation from human blood samples can help with the identification of pathogenic bacteria for sepsis diagnosis. In this work, we report an acoustofluidic device for label-free bacterial separation from human blood samples. In particular, we exploit the acoustic radiation force generated from a tilted-angle standing surface acoustic wave (taSSAW) field to separate Escherichia coli from human blood cells based on their size difference. Flow cytometry analysis of the E. coli separated from red blood cells shows a purity of more than 96%. Moreover, the label-free electrochemical detection of the separated E. coli displays reduced non-specific signals due to the removal of blood cells. Our acoustofluidic bacterial separation platform has advantages such as label-free separation, high biocompatibility, flexibility, low cost, miniaturization, automation, and ease of in-line integration. The platform can be incorporated with an on-chip sensor to realize a point-of-care sepsis diagnostic device.

  17. Cellulolytic and proteolytic ability of bacteria isolated from gastrointestinal tract and composting of a hippopotamus

    OpenAIRE

    da Cruz Ramos, Geom?rcia Feitosa; Ramos, Patricia Locosque; Passarini, Michel Rodrigo Zambrano; Vieira Silveira, Marghuel A.; Okamoto, D?bora Noma; de Oliveira, Lilian Caroline Gon?alves; Zezzo, Larissa Vieira; Marem, Alyne; Santos Rocha, Rafael Costa; da Cruz, Jo?o Batista; Juliano, Luiz; Vasconcellos, Suzan Pantaroto de [UNIFESP

    2016-01-01

    The bioprospection for cellulase and protease producers is a promise strategy for the discovery of potential biocatalysts for use in hydrolysis of lignocellulosic materials as well as proteic residues. These enzymes can increment and turn viable the production of second generation ethanol from different and alternative sources. In this context, the goal of this study was the investigation of cellulolytic and proteolytic abilities of bacteria isolated from the gastrointestinal tract of a hippo...

  18. Effects of orally administered viable Lactobacillus rhamnosus GG and Propionibacterium freudenreichii subsp. shermanii JS on mouse lymphocyte proliferation.

    Science.gov (United States)

    Kirjavainen, P V; ElNezami, H S; Salminen, S J; Ahokas, J T; Wright, P F

    1999-11-01

    Immunomodulation by probiotics is a subject of growing interest, but the knowledge of dose response and time profile relationships is minimal. In this study we examined the effects of Lactobacillus rhamnosus GG (LGG) and Propionibacterium freudenreichii subsp. shermanii JS (PJS) on the proliferative activity of murine lymphocytes ex vivo. Dose dependency was assessed by treating animals perorally with a low or a high dose (i.e., 10(9) or 10(12) viable bacteria/kg of body weight) for 7 days. The lower dose levels of each strain appeared to enhance T-cell proliferation at the optimal concanavalin A (ConA) concentration (by 69 to 84%) and B-cell proliferation at the optimal and supraoptimal concentrations of lipopolysaccharide (by 57 to 82%). B-cell proliferation was also enhanced by the high LGG dose (by 32 to 39%) but was accompanied by a marginal decrease in T-cell proliferation (by 8%) at the optimal ConA concentration. The time profiles of the immune responses were assessed after daily treatment with the higher dose for 3, 7, and 14 days. A significant decrease in basal lymphoproliferation (by 32 to 42%) was observed with PJS treatment after the 3- and 7-day periods; however, this activity returned to control levels after 14 days of treatment, which also resulted in significantly enhanced T-cell proliferation at optimal and supraoptimal ConA concentrations (by 24 to 80%). The 14-day LGG treatment also enhanced the latter activity (by 119%). In conclusion, LGG and PJS have specific dose- and duration-dependent immunomodulatory effects on the proliferative activity of B and T lymphocytes and may also reduce lymphocyte sensitivity to the cytotoxic effects of lectin mitogens.

  19. Survival of lichens and bacteria exposed to outer space conditions - Results of the Lithopanspermia experiments

    Science.gov (United States)

    de la Torre, Rosa; Sancho, Leopoldo G.; Horneck, Gerda; Ríos, Asunción de los; Wierzchos, Jacek; Olsson-Francis, Karen; Cockell, Charles S.; Rettberg, Petra; Berger, Thomas; de Vera, Jean-Pierre P.; Ott, Sieglinde; Frías, Jesus Martinez; Melendi, Pablo Gonzalez; Lucas, Maria Mercedes; Reina, Manuel; Pintado, Ana; Demets, René

    2010-08-01

    In the space experiments Lithopanspermia, experimental support was provided to the likelihood of the lithopanspermia concept that considers a viable transport of microorganisms between the terrestrial planets by means of meteorites. The rock colonising lichens Rhizocarpon geographicum and Xanthoria elegans, the vagrant lichen Aspicilia fruticulosa, and endolithic and endoevaporitic communities of cyanobacteria and bacteria with their natural rock substrate were exposed to space for 10 days onboard the Biopan facility of the European Space Agency (ESA). Biopan was closed during launch and re-entry. In addition, in the Stone facility, one sample of R. geographicum on its natural granitic substrate was attached at the outer surface of the re-entry capsule close to the stagnation point, only protected by a thin cover of glass textolite. Post-flight analysis, which included determination of the photosynthetic activity, LIVE/DEAD staining, and germination capacity of the ascospores, demonstrated that all three lichen were quite resistant to outer space conditions, which include the full spectrum of solar extraterrestrial electromagnetic radiation or selected wavelength ranges. This high resistance of the lichens to space appears to be due to their symbiotic nature and protection by their upper pigmented layer, the cortex. In contrast, the rock- or halite-inhabiting bacteria were severely damaged by the same exposure. After atmospheric re-entry, the granite of the Stone sample was transformed into a glassy, nearly homogenous material, with several friction striae. None of the lichen cells survived this re-entry process. The data suggest that lichens are suitable candidates for testing the concept of lithopanspermia, because they are extremely resistant to the harsh environment of outer space. The more critical event is the atmospheric re-entry after being captured by a planet. Experiments simulating the re-entry process of a microbe-carrying meteoroid did not show any

  20. Entry of Vibrio harveyi and Vibrio fischeri into the viable but nonculturable state

    Digital Repository Service at National Institute of Oceanography (India)

    Ramaiah; Ravel, J.; Straube, W.L.; Hill, R.T.; Colwell, R.R.

    Physical responses of marine luminous bacteria, Vibrio harveyi (ATCC 14216) and V. fischeri (UM1373) to nutrient-limited normal strength (35 ppt iso-osmolarity) and low (10 ppt hypo-osmolarity) salinity conditions were determined. Plate counts...

  1. Cellular bone matrices: viable stem cell-containing bone graft substitutes.

    Science.gov (United States)

    Skovrlj, Branko; Guzman, Javier Z; Al Maaieh, Motasem; Cho, Samuel K; Iatridis, James C; Qureshi, Sheeraz A

    2014-11-01

    Advances in the field of stem cell technology have stimulated the development and increased use of allogenic bone grafts containing live mesenchymal stem cells (MSCs), also known as cellular bone matrices (CBMs). It is estimated that CBMs comprise greater than 17% of all bone grafts and bone graft substitutes used. To critically evaluate CBMs, specifically their technical specifications, existing published data supporting their use, US Food and Drug Administration (FDA) regulation, cost, potential pitfalls, and other aspects pertaining to their use. Areview of literature. A series of Ovid, Medline, and Pubmed-National Library of Medicine/National Institutes of Health (www.ncbi.nlm.nih.gov) searches were performed. Only articles in English journals or published with English language translations were included. Level of evidence of the selected articles was assessed. Specific technical information on each CBM was obtained by direct communication from the companies marketing the individual products. Five different CBMs are currently available for use in spinal fusion surgery. There is a wide variation between the products with regard to the average donor age at harvest, total cellular concentration, percentage of MSCs, shelf life, and cell viability after defrosting. Three retrospective studies evaluating CBMs and fusion have shown fusion rates ranging from 90.2% to 92.3%, and multiple industry-sponsored trials are underway. No independent studies evaluating spinal fusion rates with the use of CBMs exist. All the commercially available CBMs claim to meet the FDA criteria under Section 361, 21 CFR Part 1271, and are not undergoing FDA premarket review. The CBMs claim to provide viable MSCs and are offered at a premium cost. Numerous challenges exist in regard to MSCs' survival, function, osteoblastic potential, and cytokine production once implanted into the intended host. Cellular bone matrices may be a promising bone augmentation technology in spinal fusion surgery

  2. ¡VAMOS! (Viable Alternative Mine Operating System) - a 'Horizon 2020' project

    Science.gov (United States)

    Sword, Cameron; Bodo, Balazs; Kapusniak, Stef; Bosman, Frank; Rainbird, Jenny; Silva, Eduardo

    2017-04-01

    The 42-month ¡VAMOS! project (Viable Alternative Mine Operating System, Grant Agreement 642477, www.vamos-project.eu), funded by the EC H2020 Programme, will enable access to high-grade EU reserves of mineral ore-bodies by developing an innovative clean and low visibility mining technique. The project will demonstrate the technological and economic viability of the underwater extraction of metallic mineral deposits which are currently technologically, economically, and environmentally unobtainable. In doing so, ¡VAMOS! hopes to encourage investment in abandoned open-pit mines and prospective mines, helping to put the EU back on a level playing field with the rest of the world in terms of access to strategically important minerals. The ¡VAMOS! concept is defined by a remotely-operated underwater mining vehicle, adapted and improved from existing subsea mining technology. Operating in tandem with an HROV, the mining vehicle will connect to a flexible riser through which slurried mined material will be pumped from the mudline to onshore dewatering facilities via a floating mobile deployment-module, on which will be fitted a bypass system linked to an LIBS, allowing real-time grade-control. Analysis of European and national regulation and stakeholder assessments found there is significant support for developing the technology among local communities and governments. An initial environmental assessment of the potential impact of the innovative mining operation concluded the project has a smaller environmental footprint than conventional mining operations: this is due to factors including the quieter operation and absence of blasting, zero water-table flux, and the higher stripping ratio enabled by higher fluid pressure acting on the sidewalls of the mine. The prototypes are currently in their construction phase following a final design freeze in October 2016. Work is now underway on the foresight visioning, economic evaluation and policy guidelines for the

  3. Blogging as a viable research methodology for young people with arthritis: a qualitative study.

    Science.gov (United States)

    Prescott, Julie; Gray, Nicola J; Smith, Felicity J; McDonagh, Janet E

    2015-03-05

    The development of services that are responsive to the needs of users is a health policy priority. Finding ways of engaging young people in research to gain insights into their particular experiences, perspectives, and needs is vital but challenging. These data are critical to improving services in ways that meet the needs of young people. Our aim was to evaluate Web-based blogging as a viable method for understanding the daily experiences and condition management strategies of young people with juvenile arthritis. To meet the objectives of the study, a qualitative approach was required to gather information on the experiences and perspectives of young people regarding the management of their condition and its daily impact. In collaboration with a group of young people with arthritis, a custom website was developed. This website provided the opportunity for young people (aged 11-19) with arthritis from a United Kingdom pediatric hospital to contribute blogs. It was designed so that young people were free to write about whatever was important to them, but the site also included some structure and prompts to facilitate the writing of blogs. Qualitative analytical procedures were employed, supported by NVivo software. Engagement in the study by young people was variable in terms of their participation rates, frequency of website visits, and the length of their blogs. Young people used the site in different ways, some responding to the website categories and prompts that the team created, while others used it as a diary to record their experiences and thoughts. In line with principles of qualitative inquiry, the data collection was participant-led. Young people were in control of what, how much, and how often they wrote. However, some young people expressed difficulty regarding knowing what they should blog about. For a number of reasons, discussed here, the blogs may also not be fully reflective of experiences and perspectives of the participants. However, the data

  4. Isolation of viable Toxoplasma gondii, molecular characterization, and seroprevalence in elk (Cervus canadensis) in Pennsylvania, USA.

    Science.gov (United States)

    Dubey, J P; Brown, J; Verma, S K; Cerqueira-Cézar, C K; Banfield, J; Kwok, O C H; Ying, Y; Murata, F H A; Pradhan, A K; Su, C

    2017-08-30

    Toxoplasmosis is a worldwide zoonosis. The ingestion of uncooked/undercooked meat and consumption of water contaminated with Toxoplasma gondii oocysts excreted by felids are the main modes of transmission of this parasite. T. gondii has been reported in multiple cervid species; however, little is known of the parasite in North American elk (Cervus canadensis). In the present study, antibodies to T. gondii were detected in serum of wild elk from Pennsylvania collected during 2013-2016 by the modified agglutination test (MAT, cut-off 1:25); 221 of 317 (69.7%) had MAT titers of 1:25 in 19, 1:50 in 28, 1:100 in 34, and 1:200 or higher in 140. Thus most (44.1%) elk had relatively high titers. Seroprevalence was slightly higher in males (76.9%) than females (67.5%, not statistically significant, Chi-square tests, P<0.0001) and was higher in adults (76.5%) than yearlings (46.4%, Odds ratio 3.82; 95% CL 1.72-8.47; P=0.001) or calves (21.7%, Odds ratio 12.58; 95% CL 4.51-35.10; P<0.0001). Annual seroprevalence was relatively stable throughout the period tested and ranged from 66.6% to 72.2%. Of the 101 elk harvested in 2016, hearts were bioassayed from 20 elk and tongues were bioassayed from 56; all tongue samples were negative. Viable T. gondii was isolated from hearts of two female elk, one of these was a seronegative adult and the other was a calf with no serum available for testing. Both T. gondii isolates were cultivated in cell culture and DNA derived from tachyzoites was characterized using the PCR-RFLP markers including SAG1, SAG2 (5'- 3'SAG2 and altSAG2), SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico. One isolate belongs to ToxoDB PCR-RFLP genotype #2 and the other is genotype #5. Both genotypes are frequently identified in animals in North America. Copyright © 2017. Published by Elsevier B.V.

  5. Viable Intrauterine Pregnancy and Coexisting Molar Pregnancy in a Bicornuate Uterus: A Rare Presentation

    Directory of Open Access Journals (Sweden)

    Kavitha Krishnamoorthy

    2016-01-01

    Full Text Available A complete hydatidiform mole with a viable coexisting fetus (CMCF is a rare occurrence. Similarly, Mullerian anomalies such as a bicornuate uterus are uncommon variants of normal anatomy. We report a case of a 40-year-old female with a known bicornuate uterus presenting at 13 weeks gestation with vaginal bleeding. Ultrasound findings showed a healthy viable pregnancy in the right horn with complete molar pregnancy in the left horn. After extensive counseling, the patient desired conservative management, however, was unable to continue due to profuse vaginal bleeding. The patient underwent suction dilation and curettage under general anesthesia and evacuation of the uterine horns. Postoperatively, the patient was followed until serum beta-human chorionic gonadotropin (β-hCG level dropped to <5 mU. This is the first case of a CMCF reported in a bicornuate uterus, diagnosed with the use of ultrasound imaging.

  6. A simple way to identify non-viable cells within living plant tissue using confocal microscopy

    Directory of Open Access Journals (Sweden)

    Truernit Elisabeth

    2008-06-01

    Full Text Available Abstract Background Plant cell death is a normal process during plant development. Mutant plants may exhibit misregulation of this process, which can lead to severe growth defects. Simple ways of visualising cell death in living plant tissues can aid the study of plant development and physiology. Results Spectral variants of the fluorescent SYTOX dyes were tested for their usefulness for the detection of non-viable cells within plant embryos and roots using confocal laser-scanning microscopy. The dyes were selective for non-viable cells and showed very little background staining in living cells. Simultaneous detection of SYTOX dye and fluorescent protein (e.g. GFP fluorescence was possible. Conclusion The fluorescent SYTOX dyes are useful for an easy and quick first assay of plant cell viability in living plant samples using fluorescence and confocal laser-scanning microscopy.

  7. Improved identification of viable myocardium using second harmonic imaging during dobutamine stress echocardiography

    OpenAIRE

    Sozzi, Fabiola; Poldermans, Don; Bax, Jeroen; Elhendy, Abdou; Vourvouri, Eleni; Valkema, Roelf; Sutter, J.; Schinkel, Arend; Borghetti, A; Roelandt, Jos

    2001-01-01

    OBJECTIVE—To determine whether, compared with fundamental imaging, second harmonic imaging can improve the accuracy of dobutamine stress echocardiography for identifying viable myocardium, using nuclear imaging as a reference.
PATIENTS—30 patients with chronic left ventricular dysfunction (mean (SD) age, 60 (8) years; 22 men).
METHODS—Dobutamine stress echocardiography was carried out in all patients using both fundamental and second harmonic imaging. All patients underwent dual isotope simul...

  8. Mitochondrial respiration in human viable platelets-Methodology and influence of gender, age and storage

    DEFF Research Database (Denmark)

    Sjövall, Fredrik; Ehinger, Johannes K H; Marelsson, Sigurður E

    2013-01-01

    Studying whole cell preparations with intact mitochondria and respiratory complexes has a clear benefit compared to isolated or disrupted mitochondria due to the dynamic interplay between mitochondria and other cellular compartments. Platelet mitochondria have a potential to serve as a source...... of human viable mitochondria when studying mitochondrial physiology and pathogenic mechanisms, as well as for the diagnostics of mitochondrial diseases. The objective of the present study was to perform a detailed evaluation of platelet mitochondrial respiration using high-resolution respirometry. Further...

  9. Concurrent detection of other respiratory viruses in children shedding viable human respiratory syncytial virus.

    Science.gov (United States)

    Gagliardi, T B; Paula, F E; Iwamoto, M A; Proença-Modena, J L; Santos, A E; Camara, A A; Cervi, M C; Cintra, O A L; Arruda, E

    2013-10-01

    Human respiratory syncytial virus (HRSV) is an important cause of respiratory disease. The majority of studies addressing the importance of virus co-infections to the HRSV-disease have been based on the detection of HRSV by RT-PCR, which may not distinguish current replication from prolonged shedding of remnant RNA from previous HRSV infections. To assess whether co-detections of other common respiratory viruses are associated with increased severity of HRSV illnesses from patients who were shedding viable-HRSV, nasopharyngeal aspirates from children younger than 5 years who sought medical care for respiratory infections in Ribeirão Preto (Brazil) were tested for HRSV by immunofluorescence, RT-PCR and virus isolation in cell culture. All samples with viable-HRSV were tested further by PCR for other respiratory viruses. HRSV-disease severity was assessed by a clinical score scale. A total of 266 samples from 247 children were collected and 111 (42%) were HRSV-positive. HRSV was isolated from 70 (63%), and 52 (74%) of them were positive for at least one additional virus. HRSV-positive diseases were more severe than HRSV-negative ones, but there was no difference in disease severity between patients with viable-HRSV and those HRSV-positives by RT-PCR. Co-detection of other viruses did not correlate with increased disease severity. HRSV isolation in cell culture does not seem to be superior to RT-PCR to distinguish infections associated with HRSV replication in studies of clinical impact of HRSV. A high rate of co-detection of other respiratory viruses was found in samples with viable-HRSV, but this was not associated with more severe HRSV infection. Copyright © 2013 Wiley Periodicals, Inc.

  10. Cosmic constraint on massive neutrinos in viable f( R) gravity with producing Λ CDM background expansion

    Science.gov (United States)

    Lu, Jianbo; Liu, Molin; Wu, Yabo; Wang, Yan; Yang, Weiqiang

    2016-12-01

    Tensions between several cosmic observations were found recently, such as the inconsistent values of H0 (or σ 8) were indicated by the different cosmic observations. Introducing the massive neutrinos in Λ CDM could potentially solve the tensions. Viable f( R) gravity producing Λ CDM background expansion with massive neutrinos is investigated in this paper. We fit the current observational data: Planck-2015 CMB, RSD, BAO, and SNIa to constrain the mass of neutrinos in viable f( R) theory. The constraint results at 95% confidence level are: Σ m_ν case, m_{ν , sterile}^effcase. For the effects due to the mass of the neutrinos, the constraint results on model parameter at 95% confidence level become f_{R0}× 10^{-6}> -1.89 and f_{R0}× 10^{-6}> -2.02 for two cases, respectively. It is also shown that the fitting values of several parameters much depend on the neutrino properties, such as the cold dark matter density, the cosmological quantities at matter-radiation equality, the neutrino density and the fraction of baryonic mass in helium. Finally, the constraint result shows that the tension between direct and CMB measurements of H_0 gets slightly weaker in the viable f( R) model than that in the base Λ CDM model.

  11. Improved identification of viable myocardium using second harmonic imaging during dobutamine stress echocardiography.

    Science.gov (United States)

    Sozzi, F B; Poldermans, D; Bax, J J; Elhendy, A; Vourvouri, E C; Valkema, R; De Sutter, J; Schinkel, A F; Borghetti, A; Roelandt, J R

    2001-12-01

    To determine whether, compared with fundamental imaging, second harmonic imaging can improve the accuracy of dobutamine stress echocardiography for identifying viable myocardium, using nuclear imaging as a reference. 30 patients with chronic left ventricular dysfunction (mean (SD) age, 60 (8) years; 22 men). Dobutamine stress echocardiography was carried out in all patients using both fundamental and second harmonic imaging. All patients underwent dual isotope simultaneous acquisition single photon emission computed tomography (DISA-SPECT) with (99m)technetium-tetrofosmin/(18)F-fluorodeoxyglucose on a separate day. Myocardial viability was considered present by dobutamine stress echocardiography when segments with severe dysfunction showed a biphasic sustained improvement or an ischaemic response. Viability criteria on DISA-SPECT were normal or mildly reduced perfusion and metabolism, or perfusion/metabolism mismatch. Using fundamental imaging, 330 segments showed severe dysfunction at baseline; 144 (44%) were considered viable. The agreement between dobutamine stress echocardiography by fundamental imaging and DISA-SPECT was 78%, kappa = 0.56. Using second harmonic imaging, 288 segments showed severe dysfunction; 138 (48%) were viable. The agreement between dobutamine stress echocardiography and DISA-SPECT was significantly better when second harmonic imaging was used (89%, kappa = 0.77, p = 0.001 v fundamental imaging). Second harmonic imaging applied during dobutamine stress echocardiography increases the agreement with DISA-SPECT for detecting myocardial viability.

  12. Mice carrying a complete deletion of the talin2 coding sequence are viable and fertile

    Energy Technology Data Exchange (ETDEWEB)

    Debrand, Emmanuel; Conti, Francesco J.; Bate, Neil; Spence, Lorraine; Mazzeo, Daniela; Pritchard, Catrin A.; Monkley, Susan J. [Department of Biochemistry, University of Leicester, Lancaster Road, Leicester LE1 9HN (United Kingdom); Critchley, David R., E-mail: drc@le.ac.uk [Department of Biochemistry, University of Leicester, Lancaster Road, Leicester LE1 9HN (United Kingdom)

    2012-09-21

    Highlights: Black-Right-Pointing-Pointer Mice lacking talin2 are viable and fertile with only a mildly dystrophic phenotype. Black-Right-Pointing-Pointer Talin2 null fibroblasts show no major defects in proliferation, adhesion or migration. Black-Right-Pointing-Pointer Maintaining a colony of talin2 null mice is difficult indicating an underlying defect. -- Abstract: Mice homozygous for several Tln2 gene targeted alleles are viable and fertile. Here we show that although the expression of talin2 protein is drastically reduced in muscle from these mice, other tissues continue to express talin2 albeit at reduced levels. We therefore generated a Tln2 allele lacking the entire coding sequence (Tln2{sup cd}). Tln2{sup cd/cd} mice were viable and fertile, and the genotypes of Tln2{sup cd/+} intercrosses were at the expected Mendelian ratio. Tln2{sup cd/cd} mice showed no major difference in body mass or the weight of the major organs compared to wild-type, although they displayed a mildly dystrophic phenotype. Moreover, Tln2{sup cd/cd} mouse embryo fibroblasts showed no obvious defects in cell adhesion, migration or proliferation. However, the number of Tln2{sup cd/cd} pups surviving to adulthood was variable suggesting that such mice have an underlying defect.

  13. Glioma Surgical Aspirate: A Viable Source of Tumor Tissue for Experimental Research

    Directory of Open Access Journals (Sweden)

    Perry F. Bartlett

    2013-04-01

    Full Text Available Brain cancer research has been hampered by a paucity of viable clinical tissue of sufficient quality and quantity for experimental research. This has driven researchers to rely heavily on long term cultured cells which no longer represent the cancers from which they were derived. Resection of brain tumors, particularly at the interface between normal and tumorigenic tissue, can be carried out using an ultrasonic surgical aspirator (CUSA that deposits liquid (blood and irrigation fluid and resected tissue into a sterile bottle for disposal. To determine the utility of CUSA-derived glioma tissue for experimental research, we collected 48 CUSA specimen bottles from glioma patients and analyzed both the solid tissue fragments and dissociated tumor cells suspended in the liquid waste fraction. We investigated if these fractions would be useful for analyzing tumor heterogeneity, using IHC and multi-parameter flow cytometry; we also assessed culture generation and orthotopic xenograft potential. Both cell sources proved to be an abundant, highly viable source of live tumor cells for cytometric analysis, animal studies and in-vitro studies. Our findings demonstrate that CUSA tissue represents an abundant viable source to conduct experimental research and to carry out diagnostic analyses by flow cytometry or other molecular diagnostic procedures.

  14. Characterization of Lactic Acid Bacteria as Poultry Probiotic Candidates with Aflatoxin B1 Binding Activities

    Science.gov (United States)

    Damayanti, E.; Istiqomah, L.; Saragih, J. E.; Purwoko, T.; Sardjono

    2017-12-01

    Our previous studies have selected lactic acid bacteria (LAB) with antifungal activities from traditional fermented foods made from cassava (G7) and silage feed palm leaf (PDS5 and PDS3). In this study we evaluated their ability to bind aflatoxin B1 (AFB1) and probiotic characteristic. The probiotic characteristic assays of LAB consisted of resistance to acidic conditions (pH 3), gastric juice and bile salts 0.3%. We also carried out an in vitro evaluation of LAB aflatoxin binding ability in viable and non-viable cell for 24 and 48 hours of incubation. The measurement of aflatoxin content was performed by ELISA method using AgraQuant Total Aflatoxin Assay kit. The results showed that all isolates were potential as probiotics and the G7 isolate had the highest viability among other isolates in pH 3 (92.61 %) and the bile salts assay (97.71 %). The percentage of aflatoxin reduction between viable and non-viable cell from each LAB isolate were different. The highest aflatoxin reduction in viable cell assay was performed by G7 isolate (69.11 %) whereas in non-viable cell assay was performed by PDS3 isolate (73.75 %) during incubation time 48 hours. In this study, G7 isolate performed the best probiotic characteristics with the highest viability in acid pH assay, bile salt 0.3% assay and percentage of aflatoxin B1 reduction in viable cell condition. Molecular identification using 16S rRNA sequence analysis showed that G7 isolate had homology with Lactobacillus plantarum (99.9%). It was concluded that Lactobacillus plantarum G7 was potential as probiotic with aflatoxin binding activities.

  15. Method of Detecting Coliform Bacteria from Reflected Light

    Science.gov (United States)

    Vincent, Robert K. (Inventor)

    2014-01-01

    The present invention relates to a method of detecting coliform bacteria in water from reflected light, and also includes devices for the measurement, calculation and transmission of data relating to that method.

  16. Bioremediation of toxic substances by mercury resistant marine bacteria

    Digital Repository Service at National Institute of Oceanography (India)

    De, J.; Sarkar, A.; Ramaiah, N.

    Bioremediation of toxic substances includes microbe-mediated enzymatic transformation of toxicants to non-toxic, often assimilable, forms. Mercury-resistant marine bacteria are found to be very promising in dealing with mercury, and a host of other...

  17. Volatile metabolites from some gram-negative bacteria

    DEFF Research Database (Denmark)

    Schöller, Charlotte; Molin, Søren; Wilkins, Ken

    1997-01-01

    A survey of volatile organic compounds (VOCs) excreted from various Gram-negative bacteria (Pseudomonas spp., Serratia spp. and Enterobacter spp.) was carried out. Compounds were identified by gas chromatography-mass spectrometry. VOCs identified included dimethyl disulphide, dimethyl trisulphide...

  18. [Pseudomonas genus bacteria on weeds].

    Science.gov (United States)

    Gvozdiak, R I; Iakovleva, L M; Pasichnik, L A; Shcherbina, T N; Ogorodnik, L E

    2005-01-01

    It has been shown in the work that the weeds (couch-grass and ryegrass) may be affected by bacterial diseases in natural conditions, Pseudomonas genus bacteria being their agents. The isolated bacteria are highly-aggressive in respect of the host-plant and a wide range of cultivated plants: wheat, rye, oats, barley, apple-tree and pear-tree. In contrast to highly aggressive bacteria isolated from the affected weeds, bacteria-epi phytes isolated from formally healthy plants (common amaranth, orache, flat-leaved spurge, field sow thistle, matricary, common coltsfoot, narrow-leaved vetch) and identified as P. syringae pv. coronafaciens, were characterized by weak aggression. A wide range of ecological niches of bacteria evidently promote their revival and distribution everywhere in nature.

  19. Motility of electric cable bacteria

    DEFF Research Database (Denmark)

    Bjerg, Jesper Tataru; Damgaard, Lars Riis; Holm, Simon Agner

    2016-01-01

    Cable bacteria are filamentous bacteria that electrically couple sulfide oxidation and oxygen reduction at centimeter distances, and observations in sediment environments have suggested that they are motile. By time-lapse microscopy, we found that cable bacteria used gliding motility on surfaces...... with a highly variable speed of 0.50.3 ms1 (meanstandard deviation) and time between reversals of 155108 s. They frequently moved forward in loops, and formation of twisted loops revealed helical rotation of the filaments. Cable bacteria responded to chemical gradients in their environment, and around the oxic......-anoxic interface, they curled and piled up, with straight parts connecting back to the source of sulfide. Thus, it appears that motility serves the cable bacteria in establishing and keeping optimal connections between their distant electron donor and acceptors in a dynamic sediment environment....

  20. Polyelectrolyte Complex Beads by Novel Two-Step Process for Improved Performance of Viable Whole-Cell Baeyer-Villiger Monoxygenase by Immobilization

    Directory of Open Access Journals (Sweden)

    Tomáš Krajčovič

    2017-11-01

    Full Text Available A novel immobilization matrix for the entrapment of viable whole-cell Baeyer–Villiger monooxygenase was developed. Viable recombinant Escherichia coli cells overexpressing cyclohexanone monooxygenase were entrapped in polyelectrolyte complex beads prepared by a two-step reaction of oppositely-charged polymers including highly defined cellulose sulphate. Immobilized cells exhibited higher operational stability than free cells during 10 repeated cycles of Baeyer–Villiger biooxidations of rac-bicyclo[3.2.0]hept-2-en-6-one to the corresponding lactones (1R,5S-3-oxabicyclo-[3.3.0]oct-6-en-3-one and (1S,5R-2-oxabicyclo-[3.3.0]oct-6-en-3-one. The morphology of polyelectrolyte complex beads was characterised by environmental scanning electron microscopy; the spatial distribution of polymers in the beads and cell viability were examined using confocal laser scanning microscopy, and the texture was characterised by the mechanical resistance measurements.

  1. How Close We Are to Achieving Commercially Viable Large-Scale Photobiological Hydrogen Production by Cyanobacteria: A Review of the Biological Aspects

    Science.gov (United States)

    Sakurai, Hidehiro; Masukawa, Hajime; Kitashima, Masaharu; Inoue, Kazuhito

    2015-01-01

    Photobiological production of H2 by cyanobacteria is considered to be an ideal source of renewable energy because the inputs, water and sunlight, are abundant. The products of photobiological systems are H2 and O2; the H2 can be used as the energy source of fuel cells, etc., which generate electricity at high efficiencies and minimal pollution, as the waste product is H2O. Overall, production of commercially viable algal fuels in any form, including biomass and biodiesel, is challenging, and the very few systems that are operational have yet to be evaluated. In this paper we will: briefly review some of the necessary conditions for economical production, summarize the reports of photobiological H2 production by cyanobacteria, present our schemes for future production, and discuss the necessity for further progress in the research needed to achieve commercially viable large-scale H2 production. PMID:25793279

  2. Freeze-drying of lactic acid bacteria.

    Science.gov (United States)

    Fonseca, Fernanda; Cenard, Stéphanie; Passot, Stéphanie

    2015-01-01

    Lactic acid bacteria are of great importance for the food and biotechnology industry. They are widely used as starters for manufacturing food (e.g., yogurt, cheese, fermented meats, and vegetables) and probiotic products, as well as for green chemistry applications. Freeze-drying or lyophilization is a convenient method for preservation of bacteria. By reducing water activity to values below 0.2, it allows long-term storage and low-cost distribution at suprazero temperatures, while minimizing losses in viability and functionality. Stabilization of bacteria via freeze-drying starts with the addition of a protectant solution to the bacterial suspension. Freeze-drying includes three steps, namely, (1) freezing of the concentrated and protected cell suspension, (2) primary drying to remove ice by sublimation, and (3) secondary drying to remove unfrozen water by desorption. In this chapter we describe a method for freeze-drying of lactic acid bacteria at a pilot scale, thus allowing control of the process parameters for maximal survival and functionality recovery.

  3. The targeting of phospholipid liposomes to bacteria.

    Science.gov (United States)

    Jones, M N; Kaszuba, M; Reboiras, M D; Lyle, I G; Hill, K J; Song, Y H; Wilmot, S W; Creeth, J E

    1994-11-23

    Phospholipid liposomes have been prepared from phospholipid mixtures including dipalmitoylphosphatidylcholine/phosphatidylinositol (DPPC/PI) and DPPC/dipalmitoylphosphatidylglycerol (DPPC/DPPG) mixtures and targeted to adsorbed biofilms of the skin-associated bacteria Staphylococcus epidermidis and Proteus vulgaris and the oral bacterium Streptococcus sanguis. The effects of time, liposome concentration and density of bacteria in the biofilm have been studied in detail for Staphylococcus epidermidis. The targeting (as assessed by the apparent monolayer coverage of the biofilms by liposomes) to the biofilms was found to be sensitive to the mol% of PI and DPPG in the liposomes and optimum levels of PI were found for targeting to each bacterium. The use of PI and DPPG-containing liposomes for the delivery of the bactericide, Triclosan, to biofilms of Staphylococcus epidermidis was studied as a function of the amount of Triclosan carried by the liposomes. All the liposome systems tested inhibited the growth of bacteria from the biofilms after brief (2 min) exposure to Triclosan-carrying liposomes. At low Triclosan levels bacterial growth inhibition by Triclosan-carrying liposomes exceeded that by an equivalent level of free Triclosan. After short periods (min) of exposure of biofilms to Triclosan-carrying liposomes the bactericide was shown to preferentially concentrate in the biofilms relative to its liposomal lipid carrier. The results suggest that phospholipid liposomes with appropriately chosen lipid composition have potential for the targeting and delivery of bactericide to bacteria.

  4. Metabolic plasticity for isoprenoid biosynthesis in bacteria.

    Science.gov (United States)

    Pérez-Gil, Jordi; Rodríguez-Concepción, Manuel

    2013-05-15

    Isoprenoids are a large family of compounds synthesized by all free-living organisms. In most bacteria, the common precursors of all isoprenoids are produced by the MEP (methylerythritol 4-phosphate) pathway. The MEP pathway is absent from archaea, fungi and animals (including humans), which synthesize their isoprenoid precursors using the completely unrelated MVA (mevalonate) pathway. Because the MEP pathway is essential in most bacterial pathogens (as well as in the malaria parasites), it has been proposed as a promising new target for the development of novel anti-infective agents. However, bacteria show a remarkable plasticity for isoprenoid biosynthesis that should be taken into account when targeting this metabolic pathway for the development of new antibiotics. For example, a few bacteria use the MVA pathway instead of the MEP pathway, whereas others possess the two full pathways, and some parasitic strains lack both the MVA and the MEP pathways (probably because they obtain their isoprenoids from host cells). Moreover, alternative enzymes and metabolic intermediates to those of the canonical MVA or MEP pathways exist in some organisms. Recent work has also shown that resistance to a block of the first steps of the MEP pathway can easily be developed because several enzymes unrelated to isoprenoid biosynthesis can produce pathway intermediates upon spontaneous mutations. In the present review, we discuss the major advances in our knowledge of the biochemical toolbox exploited by bacteria to synthesize the universal precursors for their essential isoprenoids.

  5. Thermophile bacteria in permafrost: model for astrobiology

    Science.gov (United States)

    Gilichinsky, D.; Rivkina, E.; Shcherbakova, V.; Laurinavichius, K.; Kholodov, A.; Abramov, A.

    2003-04-01

    87^oC and acetogenic, growing up to 92^oC with the optimum at 80^oC. Both isolated bacteria were non-halophiles. Using these data, one can conclude that isolated thermophiles are associated with volcano. The next step of this study was carried out on volcano Tolbachik, south border of permafrost zone, Kamchatka peninsula (Russia). During the volcano eruption in 1975-76 the thick (12 to 16 m) layer of interstratify volcano ash, sand and scoria was accumulated on the elevation 1100 m and to the moment this horizon is complete freeze, t=(-1)-(-2)^oC. The analyses showed that frozen samples extracted from the borehole, crossing these young volcano deposits, contain viable microorganisms and among them, thermophilic anaerobic bacteria. Moreover, biogenic methane (up to 1100-1900 μlCH_4/kg soil) was also found in these samples. Thermophiles were never found before in permafrost thickness and this is why this study demonstrate that there are only one way for thermophilic bacteria to appear within frozen volcanic horizon - during the eruption, from volcano or surrounding associated subsurface geological strata. The most important conclusion is that thermophilic bacteria might survive in permafrost and even produce the biogenic gases. This is why the terrestrial volcano microbial community might serve as an exobiological model for hypothesis of existing ancient microbiocenoses, i. e. extraterrestrial habitats that probably might be found around Martian or other planet volcano in the absence of oxygen.

  6. Seed-vectored endophytic bacteria modulate development of rice seedlings.

    Science.gov (United States)

    Verma, S K; Kingsley, K; Irizarry, I; Bergen, M; Kharwar, R N; White, J F

    2017-06-01

    The aim of the present study was to evaluate the effects of the removal of indigenous bacteria from rice seeds on seedling growth and development. Here we report the presence of three indigenous endophytic bacteria in rice seeds that play important roles in modulating seedling development (shoot and root lengths, and formation of root hairs and secondary roots) and defence against pathogens. Seed-associated bacteria were removed using surface sterilization with NaOCl (bleach) followed by antibiotic treatment. When bacteria were absent, growth of seedlings in terms of root hair development and overall seedling size was less than that of seedlings that contained bacteria. Reactive oxygen staining of seedlings showed that endophytic bacteria became intracellular in root parenchyma cells and root hairs. Roots containing endophytic bacteria were seen to stain densely for reactive oxygen, while roots free of bacteria stained lightly for reactive oxygen. Bacteria were isolated and identified as Enterobacter asburiae (VWB1), Pantoea dispersa (VWB2) and Pseudomonas putida (VWB3) by 16S rDNA sequencing. Bacteria were found to produce indole acetic acid (auxins), inhibited the pathogen Fusarium oxysporum and solubilized phosphate. Reinoculation of bacteria onto seedlings derived from surface-disinfected rice and Bermuda grass seeds significantly restored seedling growth and development. Rice seeds harbour indigenous bacterial endophytes that greatly influence seedling growth and development, including root and shoot lengths, root hair formation and disease susceptibility of rice seedlings. This study shows that seeds of rice naturally harbour bacterial endophytes that play key roles in modulation of seedling development. © 2017 The Society for Applied Microbiology.

  7. Reverse transcriptase real-time PCR for detection and quantification of viable Campylobacter jejuni directly from poultry faecal samples

    DEFF Research Database (Denmark)

    Bui, Thanh Xuan; Wolff, Anders; Madsen, Mogens

    2012-01-01

    and quantification of viable Campylobacter jejuni directly from chicken faecal samples. The results of this method anda DNA-based quantitative real-time PCR (qPCR) method were compared with those of a bacterial culture method. Using bacterial culture andRT-qPCR methods, viable C. jejuni cells could be detected...

  8. Elucidation of gibberellin biosynthesis in bacteria reveals convergent evolution

    OpenAIRE

    Nett, Ryan S.; Montanares, Mariana; Marcassa, Ariana; Lu, Xuan; Nagel, Raimund; Charles, Trevor C.; Hedden, Peter; Rojas, Maria Cecilia; Peters, Reuben J.

    2016-01-01

    Gibberellins (GAs) are crucial phytohormones involved in many aspects of plant growth and development, including plant-microbe interactions, which has led to GA production by plant-associated fungi and bacteria as well. While the GA biosynthetic pathways in plants and fungi have been elucidated and found to have independently arisen through convergent evolution, little has been uncovered about GA biosynthesis in bacteria. Some nitrogen-fixing/symbiotic, legume-associated rhizobia, including B...

  9. Natural soil reservoirs for human pathogenic and fecal indicator bacteria

    Science.gov (United States)

    Boschiroli, Maria L; Falkinham, Joseph; Favre-Bonte, Sabine; Nazaret, Sylvie; Piveteau, Pascal; Sadowsky, Michael J.; Byappanahalli, Muruleedhara; Delaquis, Pascal; Hartmann, Alain

    2016-01-01

    Soils receive inputs of human pathogenic and indicator bacteria through land application of animal manures or sewage sludge, and inputs by wildlife. Soil is an extremely heterogeneous substrate and contains meso- and macrofauna that may be reservoirs for bacteria of human health concern. The ability to detect and quantify bacteria of human health concern is important in risk assessments and in evaluating the efficacy of agricultural soil management practices that are protective of crop quality and protective of adjacent water resources. The present chapter describes the distribution of selected Gram-positive and Gram-negative bacteria in soils. Methods for detecting and quantifying soilborne bacteria including extraction, enrichment using immunomagnetic capture, culturing, molecular detection and deep sequencing of metagenomic DNA to detect pathogens are overviewed. Methods for strain phenotypic and genotypic characterization are presented, as well as how comparison with clinical isolates can inform the potential for human health risk.

  10. Presence of Pathogenic Bacteria and Viruses in the Daycare Environment

    DEFF Research Database (Denmark)

    Ibfelt, Tobias; Engelund, Eva Hoy; Permin, Anders

    2015-01-01

    The number of children in daycare centers (DCCs) is rising. This increases exposure to microorganisms and infectious diseases. Little is known about which bacteria and viruses are present in the DCC environment and where they are located. In the study described in this article, the authors set out...... to determine the prevalence of pathogenic bacteria and viruses and to find the most contaminated fomites in DCCs. Fifteen locations in each DCC were sampled for bacteria, respiratory viruses, and gastrointestinal viruses. The locations were in the toilet, kitchen, and playroom areas and included nursery...... pillows, toys, and tables, among other things. Coliform bacteria were primarily found in the toilet and kitchen areas whereas nasopharyngeal bacteria were found mostly on toys and fabric surfaces in the playroom. Respiratory viruses were omnipresent in the DCC environment, especially on the toys....

  11. Gram-negative bacteria can also form pellicles.

    Science.gov (United States)

    Armitano, Joshua; Méjean, Vincent; Jourlin-Castelli, Cécile

    2014-12-01

    There is a growing interest in the bacterial pellicle, a biofilm floating at the air-liquid interface. Pellicles have been well studied in the Gram-positive bacterium Bacillus subtilis, but far less in Gram-negative bacteria, where pellicle studies have mostly focused on matrix components rather than on the regulatory cascades involved. Several Gram-negative bacteria, including pathogenic bacteria, have been shown to be able to form a pellicle under static conditions. Here, we summarize the growing body of knowledge about pellicle formation in Gram-negative bacteria, especially about the components of the pellicle matrix. We also propose that the pellicle is a specific biofilm, and that its formation involves particular processes. Since this lifestyle concerns a growing number of bacteria, its properties undoubtedly deserve further investigation.

  12. Screening lactic acid bacteria from swine origins for multistrain probiotics based on in vitro functional properties.

    Science.gov (United States)

    Guo, Xiao-Hua; Kim, Jong-Man; Nam, Hyang-Mi; Park, Shin-Young; Kim, Jae-Myung

    2010-08-01

    Lactic acid bacteria originated from swine feces and intestines were selected for potential probiotics based on their bile-salt resistance, low pH tolerance, potential adhesion to epithelial cells and especially functional properties, including production of antimicrobial substances, bile-salt hydrolase (BSH) and amylolytic activity. Results showed 7 isolates with antimicrobial activity, 5 with BSH activity and 3 with amylolytic activity were preliminarily selected from 485 lactic acid bacteria based on their highest potential with functional properties in vitro. The 15 isolates were further assayed on the essential characteristics as potential probiotics. All isolates were fully tolerant to 0.3% bile salts and 11 of them were able to resist pH 3 for 3 h without loss of viable cells. The eleven isolates were then evaluated on their adhesion capability. Wide variation in the hydrophobic character and specific adhesion efficiency was observed and three isolates G1-1, G22-2 and G8-5, with respective antimicrobial, BSH and amylolytic activities were finally selected. In addition, the three isolates were compatible in the coexistence assay. Isolate G1-1 was identified as Lactobacillus salivarius by API system and a 16S rRNA gene sequence analysis. Both G8-5 and G22-2 showed the closest homology to Lactobacillus reuteri according to their 16S rRNA gene sequences (99%). From the study, the three Lactobacilli strains were shown to share the functional properties necessary for probiotics use in animal additives. Their compatibility with respective in vitro activities was expected to show enhanced in vivo efficacy after combination for multistrain probiotics use. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  13. Small-molecule-hosting nanocomposite films with multiple bacteria-triggered responses

    NARCIS (Netherlands)

    Pavlukhina, Svetlana; Zhuk, Iryna; Mentbayeva, Almagul; Rautenberg, Emily; Chang, Wei; Yu, Xiaojun; van de Belt-Gritter, Betsy; Busscher, Henk J.; van der Mei, Henny C.; Sukhishvili, Svetlana A.

    We report pH/bacteria-responsive nanocomposite coatings with multiple mechanisms of antibacterial protection that include the permanent retention of antimicrobials, bacteria-triggered release of antibiotics and bacteria-induced film swelling. A novel small-molecule-hosting film was constructed using

  14. Distribution of bacteria and fungi in the earthworm Libyodrillus violaceous (Annelida: Oligochaeta, a native earthworm from Nigeria

    Directory of Open Access Journals (Sweden)

    A. B Idowu

    2006-03-01

    Full Text Available Earthworms are soil invertebrates that play a key role in recycling organic matter in soils.In Nigeria, earthworms include Libyodrillus violaceous. Aerobic and anaerobic bacterial counts, as well as fungal counts of viable microorganisms in soils and gut sections, were made on twenty L. violaceous collected from different sites on the campus of the University of Agriculture, Abeokuta, Nigeria. The samples were collected between April and November, 2002. Numbers of microorganisms were higher in castings and gut sections than in uningested soil samples. The guts and their contents also had higher moisture and total nitrogen contents than the uningested soils. Bacteria and fungi isolated from the samples were identified by standard microbiological procedures on the bases of their morphological and biochemical characteristics. Isolated bacteria were identified as Staphylococcus, Bacillus spp., Pseudomonas aeruginosa, Streptococcus mutans, Clostridium, Spirocheata spp., Azotobacter spp., Micrococcus lylae, Acinetobacter spp., Halobacterium for bacteria. Yeast isolates were identified as Candida spp., Zygosaccharomyces spp., Pichia spp., and Saccharomyces spp while molds were identified as, Aspergillus spp., Pytium spp., Penicillium spp., Fusarium spp and Rhizopus spp. Of the five locations examined, the refuse dump area had the highest numbers of both aerobic and anaerobic organisms, followed by the arboretum while the cultivated land area recorded the lowest counts. The higher numbers of microorganisms observed in the gut sections and casts of the earthworms examined in this work reinforce the general concept that the gut and casts of earthworms show higher microbial diversity and activity than the surrounding soil. Rev. Biol. Trop. 54 (1: 49-58. Epub 2006 Mar 31.

  15. Exploitation of sweet cherry (Prunus avium L.) puree added of stem infusion through fermentation by selected autochthonous lactic acid bacteria.

    Science.gov (United States)

    Di Cagno, Raffaella; Surico, Rosalinda Fortunata; Minervini, Giovanna; Rizzello, Carlo Giuseppe; Lovino, Raffaella; Servili, Maurizio; Taticchi, Agnese; Urbani, Sefania; Gobbetti, Marco

    2011-08-01

    Strains of Lactobacillus plantarum, Pediococcus acidilactici, Pediococcus pentosaceus and Leuconostoc mesenteroides subsp. mesenteroides were identified from 8 cultivars of sweet cherry by partial 16S rRNA gene sequence and subjected to typing by Random Amplified Polymorphic DNA-Polymerase Chain Reaction (RAPD-PCR) analysis. Representative isolates from each species and each cultivar were screened based on the kinetics of growth on cherry puree added of (10%, v/v) stem infusion (CP-SI). A protocol for processing and storage of CP-SI, which included fermentation by selected autochthonous P. pentosaceus SWE5 and L. plantarum FP3 (started CP-SI) or spontaneous fermentation (unstarted CP-SI), was set up. Starters grew and remained viable at elevated cell numbers (ca. 9.0 log cfu g(-1)) during 60 days of storage at 4 °C. The number of presumptive lactic acid bacteria of the unstarted CP-SI did not exceed the value of ca. 3.0 log cfu g(-1). Consumption of carbohydrates (e.g., glucose and fructose) by starter lactic acid bacteria was limited as well as it was the lactic acid fermentation. Consumption of organic acids (e.g., malic acid) and free amino acids was evident, especially, throughout storage. Compared to CP-SI before processing, the concentrations of total phenolic compounds and anthocyanins did not vary in the started CP-SI. The concentration of anthocyanins slightly decreased in the unstarted CP-SI. The antioxidant activity, expressed as the scavenging activity toward DPPH radical, was found at highest level in the started CP-SI which approached that found in CP-SI before processing. During storage, viscosity and, especially, color indexes of started CP-SI were higher than those found in the unstarted CP-SI. Fermentation by autochthonous lactic acid bacteria seemed to also positively interfere with the sensory attributes of CP-SI. Copyright © 2011 Elsevier Ltd. All rights reserved.

  16. Interactions between Diatoms and Bacteria

    Science.gov (United States)

    Amin, Shady A.; Parker, Micaela S.

    2012-01-01

    Summary: Diatoms and bacteria have cooccurred in common habitats for hundreds of millions of years, thus fostering specific associations and interactions with global biogeochemical consequences. Diatoms are responsible for one-fifth of the photosynthesis on Earth, while bacteria remineralize a large portion of this fixed carbon in the oceans. Through their coexistence, diatoms and bacteria cycle nutrients between oxidized and reduced states, impacting bioavailability and ultimately feeding higher trophic levels. Here we present an overview of how diatoms and bacteria interact and the implications of these interactions. We emphasize that heterotrophic bacteria in the oceans that are consistently associated with diatoms are confined to two phyla. These consistent bacterial associations result from encounter mechanisms that occur within a microscale environment surrounding a diatom cell. We review signaling mechanisms that occur in this microenvironment to pave the way for specific interactions. Finally, we discuss known interactions between diatoms and bacteria and exciting new directions and research opportunities in this field. Throughout the review, we emphasize new technological advances that will help in the discovery of new interactions. Deciphering the languages of diatoms and bacteria and how they interact will inform our understanding of the role these organisms have in shaping the ocean and how these interactions may change in future oceans. PMID:22933565

  17. Interactions between diatoms and bacteria.

    Science.gov (United States)

    Amin, Shady A; Parker, Micaela S; Armbrust, E Virginia

    2012-09-01

    Diatoms and bacteria have cooccurred in common habitats for hundreds of millions of years, thus fostering specific associations and interactions with global biogeochemical consequences. Diatoms are responsible for one-fifth of the photosynthesis on Earth, while bacteria remineralize a large portion of this fixed carbon in the oceans. Through their coexistence, diatoms and bacteria cycle nutrients between oxidized and reduced states, impacting bioavailability and ultimately feeding higher trophic levels. Here we present an overview of how diatoms and bacteria interact and the implications of these interactions. We emphasize that heterotrophic bacteria in the oceans that are consistently associated with diatoms are confined to two phyla. These consistent bacterial associations result from encounter mechanisms that occur within a microscale environment surrounding a diatom cell. We review signaling mechanisms that occur in this microenvironment to pave the way for specific interactions. Finally, we discuss known interactions between diatoms and bacteria and exciting new directions and research opportunities in this field. Throughout the review, we emphasize new technological advances that will help in the discovery of new interactions. Deciphering the languages of diatoms and bacteria and how they interact will inform our understanding of the role these organisms have in shaping the ocean and how these interactions may change in future oceans.

  18. Characterization of mercury bioremediation by transgenic bacteria expressing metallothionein and polyphosphate kinase

    Directory of Open Access Journals (Sweden)

    Gonzalez-Ruiz Gloriene

    2011-08-01

    Full Text Available Abstract Background The use of transgenic bacteria has been proposed as a suitable alternative for mercury remediation. Ideally, mercury would be sequestered by metal-scavenging agents inside transgenic bacteria for subsequent retrieval. So far, this approach has produced limited protection and accumulation. We report here the development of a transgenic system that effectively expresses metallothionein (mt-1 and polyphosphate kinase (ppk genes in bacteria in order to provide high mercury resistance and accumulation. Results In this study, bacterial transformation with transcriptional and translational enhanced vectors designed for the expression of metallothionein and polyphosphate kinase provided high transgene transcript levels independent of the gene being expressed. Expression of polyphosphate kinase and metallothionein in transgenic bacteria provided high resistance to mercury, up to 80 μM and 120 μM, respectively. Here we show for the first time that metallothionein can be efficiently expressed in bacteria without being fused to a carrier protein to enhance mercury bioremediation. Cold vapor atomic absorption spectrometry analyzes revealed that the mt-1 transgenic bacteria accumulated up to 100.2 ± 17.6 μM of mercury from media containing 120 μM Hg. The extent of mercury remediation was such that the contaminated media remediated by the mt-1 transgenic bacteria supported the growth of untransformed bacteria. Cell aggregation, precipitation and color changes were visually observed in mt-1 and ppk transgenic bacteria when these cells were grown in high mercury concentrations. Conclusion The transgenic bacterial system described in this study presents a viable technology for mercury bioremediation from liquid matrices because it provides high mercury resistance and accumulation while inhibiting elemental mercury volatilization. This is the first report that shows that metallothionein expression provides mercury resistance and

  19. Use of autochthonous lactic acid bacteria starters to ferment mango juice for promoting its probiotic roles.

    Science.gov (United States)

    Liao, Xue-Yi; Guo, Li-Qiong; Ye, Zhi-Wei; Qiu, Ling-Yan; Gu, Feng-Wei; Lin, Jun-Fang

    2016-05-18

    Strains of Leuconostoc mesenteroides, Pediococcus pentosaceus, and Lactobacillus brevis were identified from mango fruits by partial 16S rDNA gene sequence. Based on the ability of producing mannitol and diacetyl, Leuconostoc mesenteroides MPL18 and MPL39 were selected within the lactic acid bacteria isolates, and used as mixed starters to ferment mango juice (MJ). Both the autochthonous strains grew well in fermented mango juice (FMJ) and remained viable at 9.81 log cfu mL(-1) during 30 days of storage at 4°C. The content of total sugar of FMJ was lower than that of MJ, while the concentration of mannitol was higher than that of MJ, and the concentration of diacetyl was 3.29 ± 0.12 mg L(-1). Among detected organic acids including citric acid, gallic acid, lactic acid, and acetic acid, only citric acid and gallic acid were found in MJ, while all detected organic acids were found in FMJ. The concentration of lactic acid of FMJ was the highest (78.62 ± 13.66 mM) among all detected organic acids. The DPPH radical scavenging capacity of FMJ was higher than that of MJ. Total phenolic compounds were better preserved in FMJ. The acidity and sweetness had a noticeable impact on the overall acceptance of the treated sample.

  20. Development of an Immunomagnetic Separation Method for Viable Salmonella Typhimurium Detected by Flow Cytometry

    DEFF Research Database (Denmark)

    Ahmed, Shakil; Rubahn, Horst-Günter; Erdmann, Helmut

    2016-01-01

    for detection of food-related bacteria. In this study, a flow cytometry based immunomagnetic separation (IMS) method for the isolation and enrichment of Salmonella Typhimurium from liquid samples was developed and optimized. Both polyclonal and monoclonal antibodies have been used to couple with 1 micron sized...... paramagnetic particles for the preparation of immunomagnetic beads (IMBs). The most suitable antibody was chosen by applying an enzyme linked immunosorbent assay (ELISA), whereas living bacteria were detected by flow cytometry. The parameters for both IMS and flow cytometry e.g., concentration of bead...

  1. Electron transport chains of lactic acid bacteria

    NARCIS (Netherlands)

    Brooijmans, R.J.W.

    2008-01-01

    Lactic acid bacteria are generally considered facultative anaerobic obligate fermentative bacteria. They are unable to synthesize heme. Some lactic acid bacteria are unable to form menaquinone as well. Both these components are cofactors of respiratory (electron transport) chains of prokaryotic

  2. Development of a Rapid Real-Time PCR Method as a Tool To Quantify Viable Photobacterium phosphoreum Bacteria in Salmon (Salmo salar) Steaks

    DEFF Research Database (Denmark)

    Macé, Sabrina; Mamlouk, Kelthoum; Chipchakova, Stoyka

    2013-01-01

    -bp fragment of the gyrase subunit B gene (gyrB) of P. phosphoreum. The specificity of the two primers was demonstrated by using purified DNA from 81 strains of 52 different bacterial species. When these primers were used for real-time PCR in pure culture, a good correlation (R2 of 0.99) was obtained...

  3. Culturable bacteria in subglacial sediments and ice from two Southern Hemisphere glaciers.

    Science.gov (United States)

    Foght, J; Aislabie, J; Turner, S; Brown, C E; Ryburn, J; Saul, D J; Lawson, W

    2004-05-01

    Viable prokaryotes have been detected in basal sediments beneath the few Northern Hemisphere glaciers that have been sampled for microbial communities. However, parallel studies have not previously been conducted in the Southern Hemisphere, and subglacial environments in general are a new and underexplored niche for microbes. Unfrozen subglacial sediments and overlying glacier ice samples collected aseptically from the Fox Glacier and Franz Josef Glacier in the Southern Alps of New Zealand now have been shown to harbor viable microbial populations. Total direct counts of 2-7 x 10(6) cells g(-1) dry weight sediment were observed, whereas culturable aerobic heterotrophs ranged from 6-9 x 10(5) colony-forming units g(-1) dry weight. Viable counts in the glacier ice typically were 3-4 orders of magnitude smaller than in sediment. Nitrate-reducing and ferric iron-reducing bacteria were detected in sediment samples from both glaciers, but were few or below detection limits in the ice samples. Nitrogen-fixing bacteria were detected only in the Fox Glacier sediment. Restriction fragment analysis of 16S rDNA amplified from 37 pure cultures of aerobic heterotrophs capable of growth at 4 degrees C yielded 23 distinct groups, of which 11 were identified as beta-Proteobacteria. 16S rDNA sequences from representatives of these 11 groups were analyzed phylogenetically and shown to cluster with bacteria such as Polaromonas vacuolata and Rhodoferax antarcticus, or with clones obtained from permanently cold environments. Chemical analysis of sediment and ice samples revealed a dilute environment for microbial life. Nevertheless, both the sediment samples and one ice sample demonstrated substantial aerobic mineralization of 14C-acetate at 8 degrees C, indicating that sufficient nutrients and viable psychrotolerant microbes were present to support metabolism. Unfrozen subglacial sediments may represent a significant global reservoir of biological activity with the potential to

  4. Identifying viable regulatory and innovation pathways for regenerative medicine: a case study of cultured red blood cells.

    Science.gov (United States)

    Mittra, J; Tait, J; Mastroeni, M; Turner, M L; Mountford, J C; Bruce, K

    2015-01-25

    The creation of red blood cells for the blood transfusion markets represents a highly innovative application of regenerative medicine with a medium term (5-10 year) prospect for first clinical studies. This article describes a case study analysis of a project to derive red blood cells from human embryonic stem cells, including the systemic challenges arising from (i) the selection of appropriate and viable regulatory protocols and (ii) technological constraints related to stem cell manufacture and scale up to clinical Good Manufacturing Practice (GMP) standard. The method used for case study analysis (Analysis of Life Science Innovation Systems (ALSIS)) is also innovative, demonstrating a new approach to social and natural science collaboration to foresight product development pathways. Issues arising along the development pathway include cell manufacture and scale-up challenges, affected by regulatory demands emerging from the innovation ecosystem (preclinical testing and clinical trials). Our discussion reflects on the efforts being made by regulators to adapt the current pharmaceuticals-based regulatory model to an allogeneic regenerative medicine product and the broader lessons from this case study for successful innovation and translation of regenerative medicine therapies, including the role of methodological and regulatory innovation in future development in the field. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

  5. An Extension of the Hawkins and Simon Condition Characterizing Viable Techniques

    Directory of Open Access Journals (Sweden)

    Alberto Benítez Sánchez

    2015-01-01

    Full Text Available This paper discusses an extended version of the Hawkins and Simon condition which constitutes a synthetic formulation of the mathematical properties that viable economies must satisfy in single production models. The new version is implicit in the economic interpretations offered by them of the Hawkins and Simon condition, once a correction is introduced in one of those interpretations. Moreover, the paper details the meaning of the extended version following the interpretation of the original version proposed by Dorfman, Samuelson, and Solow. It also introduces a characteristic property of indecomposable matrices that has not previously been published.

  6. THE CIVILIZATIONAL PROJECT AND lTS DISCONTENTS: TOWARD A VIABLE GLOBAL MARKET SOCIETY?

    Directory of Open Access Journals (Sweden)

    Volker Bornschier

    2015-08-01

    Full Text Available I agree with the point of an anonymous reviewer arguing that a pro-found discussion on the prerequisites of a viable global market society has too many facets to be contained within the bounds of a single journal article. Yet, in order to enter the debate now we should not wait until book length treatments become available-often only after years. This is, therfore, an essay attempting to overview various conflicts and contradictions within the global social system. It sythesizes arguments developed in more detail else-where.

  7. Fake Journals: Their Features and Some Viable Ways to Distinguishing Them

    DEFF Research Database (Denmark)

    Hemmat Esfe, Mohammad; Wongwises, Somchai; Asadi, Amin

    2015-01-01

    In this paper, we aim to discuss the fake journals and their advertisement and publication techniques. These types of journals mostly start and continue their activities by using the name of some indexed journals and establishing fake websites. The fake journals and publishers, while asking...... the authors for a significant amount of money for publishing their papers, have no peer-review process, publish the papers without any revision on the fake sites, and put the scientific reputation and prestige of the researchers in jeopardy. In the rest of the paper, we present some viable techniques in order...

  8. Information Warfare: using the viable system model as a framework to attack organisations

    Directory of Open Access Journals (Sweden)

    Bill Hutchinson

    2002-05-01

    Full Text Available Information is the glue in any organization. It is needed for policy, decision-making, control, and co-ordination. If an organisation's information systems are disrupted or destroyed, then damage to the whole inevitably follows. This paper uses a proven systemic, analytic framework the Viable System Model (VSM - in a functionalist mode, to analyse the vulnerabilities of an organisation's information resources to this form of aggression. It examines the tactics available, and where they can be used to effectively attack an organisation.

  9. Current progress and challenges in engineering viable artificial leaf for solar water splitting

    Directory of Open Access Journals (Sweden)

    Phuc D. Nguyen

    2017-12-01

    Full Text Available Large scale production of H2, a clean fuel, can be realized with just water and solar light energy by employing a viable energy conversion device called artificial leaf. In this tutorial review, we discuss on advances achieved recently and technical challenges remained toward the creation of such a leaf. Development of key components like catalysts for water electrolysis process and light harvester for harvesting solar energy as well as strategies being developed for assembling these components to create a complete artificial leaf will be highlighted.

  10. Emergency total thyroidectomy for bleeding anaplastic thyroid carcinoma: A viable option for palliation

    Directory of Open Access Journals (Sweden)

    Sunil Kumar

    2011-01-01

    Full Text Available Anaplastic thyroid carcinoma (ATC is a rare and highly aggressive thyroid neoplasm. Bleeding from tumor is an uncommon, but potentially life-threatening complication requiring sophisticated intervention facilities which are not usually available at odd hours in emergency. We report the case of a 45-year-old woman who presented with exsanguinating hemorrhage from ATC and was treated by emergency total thyroidectomy. The patient is well three months postoperatively. Emergency total thyroidectomy is a viable option for palliation in ATC presenting with bleeding.

  11. Interactions between arbuscular mycorrhizal fungi and soil bacteria.

    Science.gov (United States)

    Miransari, Mohammad

    2011-02-01

    The soil environment is interesting and complicated. There are so many interactions taking place in the soil, which determine the properties of soil as a medium for the growth and activities of plants and soil microorganisms. The soil fungi, arbuscular mycorrhiza (AM), are in mutual and beneficial symbiosis with most of the terrestrial plants. AM fungi are continuously interactive with a wide range of soil microorganisms including nonbacterial soil microorganisms, plant growth promoting rhizobacteria, mycorrhiza helper bacteria and deleterious bacteria. Their interactions can have important implications in agriculture. There are some interesting interactions between the AM fungi and soil bacteria including the binding of soil bacteria to the fungal spore, the injection of molecules by bacteria into the fungal spore, the production of volatiles by bacteria and the degradation of fungal cellular wall. Such mechanisms can affect the expression of genes in AM fungi and hence their performance and ecosystem productivity. Hence, consideration of such interactive behavior is of significance. In this review, some of the most important findings regarding the interactions between AM fungi and soil bacteria with some new insights for future research are presented.

  12. Gut Bacteria Affect Immunotherapy Response

    Science.gov (United States)

    Three new studies have identified intestinal bacteria that appear to influence the response to checkpoint inhibitors. This Cancer Currents blog post explains how the researchers think their findings could be used to improve patients’ responses to these immunotherapy drugs.

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

    Science.gov (United States)

    Ipe, Deepak S; Ulett, Glen C

    2016-08-01

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

  14. A manual on methods for measuring primary production in aquatic environments: including a chapter on bacteria

    National Research Council Canada - National Science Library

    Vollenweider, Richard A; Talling, J. F; Westlake, D. F

    1969-01-01

    The present manual starts from methods used to assess standing crops of phytoplankton, periphyton and higher aquatic, and proceeds to techniques of rate measurement currently available for these three...

  15. Thymidine kinase diversity in bacteria

    DEFF Research Database (Denmark)

    Sandrini, Michael; Clausen, A.R.; Munch-Petersen, B.

    2006-01-01

    Thymidine kinases (TKs) appear to be almost ubiquitous and are found in nearly all prokaryotes, eukaryotes, and several viruses. They are the key enzymes in thymidine salvage and activation of several anti-cancer and antiviral drugs. We show that bacterial TKs can be subdivided into 2 groups. The....... The TKs from Gram-positive bacteria are more closely related to the eukaryotic TK1 enzymes than are TKs from Gram-negative bacteria....

  16. NC10 bacteria in marine oxygen minimum zones

    DEFF Research Database (Denmark)

    Padilla, Cory C; Bristow, Laura A; Sarode, Neha

    2016-01-01

    Bacteria of the NC10 phylum link anaerobic methane oxidation to nitrite denitrification through a unique O2-producing intra-aerobic methanotrophy pathway. A niche for NC10 in the pelagic ocean has not been confirmed. We show that NC10 bacteria are present and transcriptionally active in oceanic....... rRNA and mRNA transcripts assignable to NC10 peaked within the OMZ and included genes of the putative nitrite-dependent intra-aerobic pathway, with high representation of transcripts containing the unique motif structure of the nitric oxide (NO) reductase of NC10 bacteria, hypothesized...

  17. Insight in the biology of Chlamydia-related bacteria.

    Science.gov (United States)

    Bayramova, Firuza; Jacquier, Nicolas; Greub, Gilbert

    2017-12-18

    The Chlamydiales order is composed of obligate intracellular bacteria and includes the Chlamydiaceae family and several family-level lineages called Chlamydia-related bacteria. In this review we will highlight the conserved and distinct biological features between these two groups. We will show how a better characterization of Chlamydia-related bacteria may increase our understanding on the Chlamydiales order evolution, and may help identifying new therapeutic targets to treat chlamydial infections. Copyright © 2017 The Author(s). Published by Elsevier Masson SAS.. All rights reserved.

  18. Microfiltration of enzyme treated egg whites for accelerated detection of viable Salmonella

    Science.gov (United States)

    We report detection of Salmonella per 25 g egg white within 7 h by concentrating the bacteria using microfiltration through 0.2-lm cutoff polyethersulfone hollow fiber membranes. A combination of enzyme treatment, controlled cross-flow on both sides of the hollow fibers, and media selecti...

  19. Bioreporter bacteria for landmine detection

    Energy Technology Data Exchange (ETDEWEB)

    Burlage, R.S. [Oak Ridge National Lab., TN (United States); Youngblood, T. [Frisby Technologies, Aiken, SC (United States); Lamothe, D. [American Technologies, Inc., Huntsville, AL (United States). Ordnance/Explosives Environmental Services Div.

    1998-04-01

    Landmines (and other UXO) gradually leak explosive chemicals into the soil at significant concentrations. Bacteria, which have adapted to scavenge low concentrations of nutrients, can detect these explosive chemicals. Uptake of these chemicals results in the triggering of specific bacterial genes. The authors have created genetically recombinant bioreporter bacteria that detect small concentrations of energetic chemicals. These bacteria are genetically engineered to produce a bioluminescent signal when they contact specific explosives. A gene for a brightly fluorescent compound can be substituted for increased sensitivity. By finding the fluorescent bacteria, you find the landmine. Detection might be accomplished using stand-off illumination of the minefield and GPS technology, which would result in greatly reduced risk to the deminers. Bioreporter technology has been proven at the laboratory scale, and will be tested under field conditions in the near future. They have created a bacterial strain that detects sub-micromolar concentrations of o- and p-nitrotoluene. Related bacterial strains were produced using standard laboratory protocols, and bioreporters of dinitrotoluene and trinitrotoluene were produced, screening for activity with the explosive compounds. Response time is dependent on the growth rate of the bacteria. Although frill signal production may require several hours, the bacteria can be applied over vast areas and scanned quickly, producing an equivalent detection speed that is very fast. This technology may be applicable to other needs, such as locating buried explosives at military and ordnance/explosive manufacturing facilities.

  20. Modelling the fate and transport of faecal bacteria in estuarine and coastal waters.

    Science.gov (United States)

    Gao, Guanghai; Falconer, Roger A; Lin, Binliang

    2015-11-15

    This paper details a numerical model developed to predict the fate and transport of faecal bacteria in receiving surface waters. The model was first validated by comparing model predicted faecal bacteria concentrations with available field measurements. The model simulations agreed well with the observation data. After calibration, the model was applied to investigate the effects of different parameters, including: tidal processes, river discharges from the upstream boundaries and bacteria inputs from the upstream boundaries, wastewater treatment works (WwTWs), rivers and combined sewer overflows (CSO), on the concentrations of faecal bacteria in the Ribble Estuary. The results revealed that the tide and upstream boundary bacteria inputs were the primary factors controlling the distribution of faecal bacteria. The bacteria inputs from the WwTWs in the model domain were generally found not to have a significant impact on distribution of faecal bacteria in the estuary. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  1. Bacteria and endothelial cells: a toxic relationship.

    Science.gov (United States)

    Lubkin, Ashira; Torres, Victor J

    2017-02-01

    Pathogenic bacteria use the bloodstream as a highway for getting around the body, and thus have to find ways to enter and exit through the endothelium. Many bacteria approach this problem by producing toxins that can breach the endothelial barrier through diverse creative mechanisms, including directly killing endothelial cells (ECs), weakening the cytoskeleton within ECs, and breaking the junctions between ECs. Toxins can also modulate the immune response by influencing endothelial biology, and can modulate endothelial function by influencing the response of leukocytes. Understanding these interactions, in both the in vitro and in vivo contexts, is of critical importance for designing new therapies for sepsis and other severe bacterial diseases. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. DNA Mismatch Repair in Eukaryotes and Bacteria

    Directory of Open Access Journals (Sweden)

    Kenji Fukui

    2010-01-01

    Full Text Available DNA mismatch repair (MMR corrects mismatched base pairs mainly caused by DNA replication errors. The fundamental mechanisms and proteins involved in the early reactions of MMR are highly conserved in almost all organisms ranging from bacteria to human. The significance of this repair system is also indicated by the fact that defects in MMR cause human hereditary nonpolyposis colon cancers as well as sporadic tumors. To date, 2 types of MMRs are known: the human type and Escherichia coli type. The basic features of the former system are expected to be universal among the vast majority of organisms including most bacteria. Here, I review the molecular mechanisms of eukaryotic and bacterial MMR, emphasizing on the similarities between them.

  3. Treatment of dyeing wastewater including reactive dyes (Reactive ...

    African Journals Online (AJOL)

    2013-08-15

    Aug 15, 2013 ... Treatment of dyeing wastewater including reactive dyes. (Reactive Red RB, Reactive Black B, ... Keywords: Rhizopus arrhizus, wastewater treatment, decolourisation, textile dye. INTRODUCTION. Dyeing effluents ... as bacteria, yeasts, algae and fungi, are able to remove differ- ent classes of dyes (Fu and ...

  4. Inactivation of the gene katA or sodA affects the transient entry into the viable but non-culturable response of Staphylococcus aureus in natural seawater at low temperature.

    Science.gov (United States)

    Masmoudi, Salma; Denis, Michel; Maalej, Sami

    2010-12-01

    We have investigated the fate of Staphylococcus aureus by starving the cells and maintaining them in natural seawater at 22 and 4 °C. At 22 °C, cells developed a long-term survival state where about 0.037% of the initial population remained culturable over more than 7 months, whereas at 4 °C, bacteria lost culturability and transiently entered into the viable but non-culturable state (VBNC). However, after 22 days of entry into the VBNC state, the number of viable cells detected via the direct viable count method decreased significantly. We show here that mutational inactivation of catalase (KatA) or superoxide dismutase (SodA) rendered strains hypersensitive to seawater stress at 4 °C and consequently, part of the seawater lethality on S. aureus at low temperature is mediated by reactive oxygen species (ROS) during microcosm-survival process. Shifting the temperature from 4 to 22 °C of totally non-culturable wild-type cells induced a partial recovery of the population. However, deficiencies in catalase or superoxide dismutase prevent resuscitation ability. Copyright © 2010 Elsevier Ltd. All rights reserved.

  5. Phylogenetic analysis on the soil bacteria distributed in karst forest

    Directory of Open Access Journals (Sweden)

    JunPei Zhou

    2009-12-01

    Full Text Available Phylogenetic composition of bacterial community in soil of a karst forest was analyzed by culture-independent molecular approach. The bacterial 16S rRNA gene was amplified directly from soil DNA and cloned to generate a library. After screening the clone library by RFLP, 16S rRNA genes of representative clones were sequenced and the bacterial community was analyzed phylogenetically. The 16S rRNA gene inserts of 190 clones randomly selected were analyzed by RFLP and generated 126 different RFLP types. After sequencing, 126 non-chimeric sequences were obtained, generating 113 phylotypes. Phylogenetic analysis revealed that the bacteria distributed in soil of the karst forest included the members assigning into Proteobacteria, Acidobacteria, Planctomycetes, Chloroflexi (Green nonsulfur bacteria, Bacteroidetes, Verrucomicrobia, Nitrospirae, Actinobacteria (High G+C Gram-positive bacteria, Firmicutes (Low G+C Gram-positive bacteria and candidate divisions (including the SPAM and GN08.

  6. Magnetotactic Bacteria from Extreme Environments

    Directory of Open Access Journals (Sweden)

    Christopher T. Lefèvre

    2013-03-01

    Full Text Available Magnetotactic bacteria (MTB represent a diverse collection of motile prokaryotes that biomineralize intracellular, membrane-bounded, tens-of-nanometer-sized crystals of a magnetic mineral called magnetosomes. Magnetosome minerals consist of either magnetite (Fe3O4 or greigite (Fe3S4 and cause cells to align along the Earth’s geomagnetic field lines as they swim, a trait called magnetotaxis. MTB are known to mainly inhabit the oxic–anoxic interface (OAI in water columns or sediments of aquatic habitats and it is currently thought that magnetosomes function as a means of making chemotaxis more efficient in locating and maintaining an optimal position for growth and survival at the OAI. Known cultured and uncultured MTB are phylogenetically associated with the Alpha-, Gamma- and Deltaproteobacteria classes of the phylum Proteobacteria, the Nitrospirae phylum and the candidate division OP3, part of the Planctomycetes-Verrucomicrobia-Chlamydiae (PVC bacterial superphylum. MTB are generally thought to be ubiquitous in aquatic environments as they are cosmopolitan in distribution and have been found in every continent although for years MTB were thought to be restricted to habitats with pH values near neutral and at ambient temperature. Recently, however, moderate thermophilic and alkaliphilic MTB have been described including: an uncultured, moderately thermophilic magnetotactic bacterium present in hot springs in northern Nevada with a probable upper growth limit of about 63 °C; and several strains of obligately alkaliphilic MTB isolated in pure culture from different aquatic habitats in California, including the hypersaline, extremely alkaline Mono Lake, with an optimal growth pH of >9.0.

  7. Heterotrophic bacteria in soils of Larsemann Oasis of East Antarctica

    Science.gov (United States)

    Churilin, Nikita; Soina, Vera

    2015-04-01

    The study of diversity and functional state of microorganisms in subsurface rocks layers, their participation in the biochemical weathering and formation of organic horizons of soils is important for understanding ecology and microorganisms in Antarctic soils. The study of cultured forms of microorganisms and their potential viability is still relevant to characterize the physiological state, biological activity and resilience of microorganisms involved in the initial soil formation. Improvement of isolation techniques of viable bacteria from the extreme habitats has a particular importance for rising the efficiency of environmental monitoring. The aim of the study was to investigate the viable heterotrophic bacteria involved in the formation of soils from wet valleys Larsemann Oasis, which is one of the warmest ice-free space of East Antarctica. Soil samples were taken from the intermountain humid valleys, where silt-gravelly substrates formed moss, algae, lichen cover. We used nutrient solutions (trypticase soy, R2A and glucose-peptone) to isolate cultured bacteria and study their morphological types in the light microscope. The total number of microorganisms was determined by fluorescent microscopy with acridine orange. SEM was used for morphological studies of bacterial communities in situ. To activate the growth processes we added into nutrient solutions various regulatory metabolites that have dose-dependence and operate at the community level. Physiological and functional conditions were determined by the duration of the lag phase and specific growth rate of bacterial communities in nutrient solutions containing various organic substrates. Soils form under protection of «stone pavement» and organisms leave the surface, so the forming organo-mineral horizon occurs inside of rock, thus the microprofile can form on both sides of the organic horizons. UV radiation, lack of moisture and strong wind are main limiting factors for microorganisms' growth in

  8. Symbiosis in Marine Luminous Bacteria

    Science.gov (United States)

    1993-01-01

    1992) Detection of the light organ symbiont Vibrio fischeri in Hawaiian seawater using lux gene probes. Appl. Environ. Microbiol. 58:942-947. 3. Lee, K...H., and E.G. Ruby (1993) Evidence of viable but non-culturable symbiotic Vibrio fischeri in Hawaiian seawater. Abstr. Gen. Meet. Amer. Soc...Microbiol. 93:258. 4. Lee, K.-H., and E.G. Ruby. Competition between Vibrio fischeri strains during initiation and maintenance of a light organ symbiosis. (in

  9. Viable Reserve Networks Arise From Individual Landholder Responses To Conservation Incentives

    Directory of Open Access Journals (Sweden)

    Kenneth M. Chomitz

    2006-12-01

    Full Text Available Conservation in densely settled biodiversity hotspots often requires setting up reserve networks that maintain sufficient contiguous habitat to support viable species populations. Because it is difficult to secure landholder compliance with a tightly constrained reserve network design, attention has shifted to voluntary incentive mechanisms, such as purchase of conservation easements by reverse auction or through a fixed-price offer. These mechanisms carry potential advantages of transparency, simplicity, and low cost. However, uncoordinated individual response to these incentives has been assumed incompatible with the conservation goal of viability, which depends on contiguous habitat and biodiversity representation. We model such incentives for southern Bahia in the Brazilian Atlantic Forest, one of the biologically richest and most threatened global biodiversity hotspots. Here, forest cover is spatially autocorrelated and associated with depressed land values, a situation that may be characteristic of long-settled areas with forests fragmented by agriculture. We find that in this situation, a voluntary incentive system can yield a reserve network characterized by large, viable patches of contiguous forest, and representation of subregions with distinct vegetation types and biotic assemblages, without explicit planning for those outcomes.

  10. Generation of viable progeny from dead brooders of endangered catfish Clarias magur (Hamilton, 1822

    Directory of Open Access Journals (Sweden)

    Sullip Kumar Majhi

    2017-10-01

    Full Text Available The obligatory air-breathing catfish Clarias magur is a prime candidate for aquaculture owing to its unique taste, high growth rate, and hardy nature. However, recently the IUCN has listed the species under the endangered category because the population has critically declined in the wild. The sexually mature C. magur brooders are often collected from their natural habitats for seed production in captivity. In many cases, the brooder dies due to handling injuries or confinement stress. In this study, we demonstrated that viable progeny could be generated from freshly dead sexually mature C. magur. Three hours after death, the gonads were excised, macroscopically examined and gamete viability was evaluated. Artificial fertilization was performed by mixing the sperm suspension with the eggs. Water was added after 1 min of mixing to activate the fertilization process. We observed 85%-93% fertilization success from gametes derived from dead donors as opposed to 90%-95% from those derived from live control donors. The embryos showed normal development and resulted in the generation of 88%-92% viable progeny, which was similar to the progeny derived from control donors (92%-93%. The results obtained in this study will have profound implications in enhancing the seed production of endangered C. magur and could potentially be applied to other key commercially or endangered fish species. Keywords: Biological sciences, Developmental biology, Zoology

  11. Economically Viable Components from Jerusalem Artichoke (Helianthus tuberosus L. in a Biorefinery Concept

    Directory of Open Access Journals (Sweden)

    Eva Johansson

    2015-04-01

    Full Text Available Biorefinery applications are receiving growing interest due to climatic and waste disposal issues and lack of petroleum resources. Jerusalem artichoke (Helianthus tuberosus L. is suitable for biorefinery applications due to high biomass production and limited cultivation requirements. This paper focuses on the potential of Jerusalem artichoke as a biorefinery crop and the most viable products in such a case. The carbohydrates in the tubers were found to have potential for production of platform chemicals, e.g., succinic acid. However, economic analysis showed that production of platform chemicals as a single product was too expensive to be competitive with petrochemically produced sugars. Therefore, production of several products from the same crop is a must. Additional products are protein based ones from tubers and leaves and biogas from residues, although both are of low value and amount. High bioactive activity was found in the young leaves of the crop, and the sesquiterpene lactones are of specific interest, as other compounds from this group have shown inhibitory effects on several human diseases. Thus, future focus should be on understanding the usefulness of small molecules, to develop methods for their extraction and purification and to further develop sustainable and viable methods for the production of platform chemicals.

  12. In vitro and in vivo bioluminescent quantification of viable stem cells in engineered constructs.

    Science.gov (United States)

    Logeart-Avramoglou, Delphine; Oudina, Karim; Bourguignon, Marianne; Delpierre, Laetitia; Nicola, Marie-Anne; Bensidhoum, Morad; Arnaud, Eric; Petite, Herve

    2010-06-01

    Bioluminescent quantification of viable cells inside three-dimensional porous scaffolds was performed in vitro and in vivo. The assay quantified the bioluminescence of murine stem (C3H10T1/2) cells tagged with the luciferase gene reporter and distributed inside scaffolds of either soft, translucent, AN69 polymeric hydrogel or hard, opaque, coral ceramic materials. Quantitative evaluation of bioluminescence emitted from tagged cells adhering to these scaffolds was performed in situ using either cell lysates and a luminometer or intact cells and a bioluminescence imaging system. Despite attenuation of the signal when compared to cells alone, the bioluminescence correlated with the number of cells (up to 1.5 x 10(5)) present on each material scaffold tested, both in vitro and noninvasively in vivo (subcutaneous implants in the mouse model). The noninvasive bioluminescence measurement technique proved to be comparable to the cell-destructive bioluminescence measurement technique. Monitoring the kinetics of luciferase expression via bioluminescence enabled real-time assessment of cell survival and proliferation on the scaffolds tested over prolonged (up to 59 days) periods of time. This novel, sensitive, easy, fast-to-implement, quantitative bioluminescence assay has great, though untapped, potential for screening and determining noninvasively the presence of viable cells on biomaterial constructs in the tissue engineering and tissue regeneration fields.

  13. Mobilization of Viable Tumor Cells Into the Circulation During Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Olga A. [Division of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, East Melbourne, VIC (Australia); Molecular Radiation Biology Laboratory, Peter MacCallum Cancer Centre, East Melbourne, VIC (Australia); The Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, VIC (Australia); Anderson, Robin L. [The Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, VIC (Australia); Metastasis Research Laboratory, Peter MacCallum Cancer Centre, East Melbourne, VIC (Australia); Russell, Prudence A. [Department of Anatomical Pathology, St. Vincent Hospital, Fitzroy, VIC (Australia); Ashley Cox, R. [Division of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, East Melbourne, VIC (Australia); Ivashkevich, Alesia [Molecular Radiation Biology Laboratory, Peter MacCallum Cancer Centre, East Melbourne, VIC (Australia); Laboratory of DNA Repair and Genomics, Centre for Innate Immunity and Infectious Disease, Monash Institute for Medical Research, Monash University, Clayton, VIC (Australia); Swierczak, Agnieszka; Doherty, Judy P. [Metastasis Research Laboratory, Peter MacCallum Cancer Centre, East Melbourne, VIC (Australia); Jacobs, Daphne H.M. [Division of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, East Melbourne, VIC (Australia); Smith, Jai [Molecular Radiation Biology Laboratory, Peter MacCallum Cancer Centre, East Melbourne, VIC (Australia); Siva, Shankar; Daly, Patricia E. [Division of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, East Melbourne, VIC (Australia); Ball, David L. [Division of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, East Melbourne, VIC (Australia); The Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, VIC (Australia); and others

    2014-02-01

    Purpose: To determine whether radiation therapy (RT) could mobilize viable tumor cells into the circulation of non-small cell lung cancer (NSCLC) patients. Methods and Materials: We enumerated circulating tumor cells (CTCs) by fluorescence microscopy of blood samples immunostained with conventional CTC markers. We measured their DNA damage levels using γ-H2AX, a biomarker for radiation-induced DNA double-strand breaks, either by fluorescence-activated cell sorting or by immunofluorescence microscopy. Results: Twenty-seven RT-treated NSCLC patients had blood samples analyzed by 1 or more methods. We identified increased CTC numbers after commencement of RT in 7 of 9 patients treated with palliative RT, and in 4 of 8 patients treated with curative-intent RT. Circulating tumor cells were also identified, singly and in clumps in large numbers, during RT by cytopathologic examination (in all 5 cases studied). Elevated γ-H2AX signal in post-RT blood samples signified the presence of CTCs derived from irradiated tumors. Blood taken after the commencement of RT contained tumor cells that proliferated extensively in vitro (in all 6 cases studied). Circulating tumor cells formed γ-H2AX foci in response to ex vivo irradiation, providing further evidence of their viability. Conclusions: Our findings provide a rationale for the development of strategies to reduce the concentration of viable CTCs by modulating RT fractionation or by coadministering systemic therapies.

  14. Determination of viable wine yeast using DNA binding dyes and quantitative PCR.

    Science.gov (United States)

    Andorrà, Imma; Esteve-Zarzoso, Braulio; Guillamón, José M; Mas, Albert

    2010-12-15

    The detection and quantification of wine yeast can be misleading due to under or overestimation of these microorganisms. Underestimation may be caused by variable growing rates of different microorganisms in culture media or the presence of viable but non-cultivable microorganisms. Overestimation may be caused by the lack of discrimination between live and dead microorganisms if quantitative PCR is used to quantify with DNA as the template. However, culture-independent methods that use dyes have been described to remove the DNA from dead cells and then quantify the live microorganisms. Two dyes have been studied in this paper: ethidium monoazide bromide (EMA) and propidium monoazide bromide (PMA). The technique was applied to grape must fermentation and ageing wines. Both dyes presented similar results on yeast monitoring. Membrane cell recovery was necessary when yeasts were originated from ethanol-containing media. When applied to grape must fermentation, differences of up to 1 log unit were seen between the QPCR estimation with or without the dye during the stationary phase. In ageing wines, good agreement was found between plating techniques and QPCR. Most of the viable cells were also culturable and no differences were observed with the methods, except for Zygosaccharomyces bailii and Dekkera bruxellensis where much higher counts were occasionally detected by QPCR. The presence of excess dead cells did not interfere with the quantification of live cells with either of the dyes. Copyright © 2010 Elsevier B.V. All rights reserved.

  15. Economically viable components from Jerusalem artichoke (Helianthus tuberosus L.) in a biorefinery concept.

    Science.gov (United States)

    Johansson, Eva; Prade, Thomas; Angelidaki, Irini; Svensson, Sven-Erik; Newson, William R; Gunnarsson, Ingólfur Bragi; Hovmalm, Helena Persson

    2015-04-22

    Biorefinery applications are receiving growing interest due to climatic and waste disposal issues and lack of petroleum resources. Jerusalem artichoke (Helianthus tuberosus L.) is suitable for biorefinery applications due to high biomass production and limited cultivation requirements. This paper focuses on the potential of Jerusalem artichoke as a biorefinery crop and the most viable products in such a case. The carbohydrates in the tubers were found to have potential for production of platform chemicals, e.g., succinic acid. However, economic analysis showed that production of platform chemicals as a single product was too expensive to be competitive with petrochemically produced sugars. Therefore, production of several products from the same crop is a must. Additional products are protein based ones from tubers and leaves and biogas from residues, although both are of low value and amount. High bioactive activity was found in the young leaves of the crop, and the sesquiterpene lactones are of specific interest, as other compounds from this group have shown inhibitory effects on several human diseases. Thus, future focus should be on understanding the usefulness of small molecules, to develop methods for their extraction and purification and to further develop sustainable and viable methods for the production of platform chemicals.

  16. Tumour targeting with systemically administered bacteria.

    LENUS (Irish Health Repository)

    Morrissey, David

    2012-01-31

    Challenges for oncology practitioners and researchers include specific treatment and detection of tumours. The ideal anti-cancer therapy would selectively eradicate tumour cells, whilst minimising side effects to normal tissue. Bacteria have emerged as biological gene vectors with natural tumour specificity, capable of homing to tumours and replicating locally to high levels when systemically administered. This property enables targeting of both the primary tumour and secondary metastases. In the case of invasive pathogenic species, this targeting strategy can be used to deliver genes intracellularly for tumour cell expression, while non-invasive species transformed with plasmids suitable for bacterial expression of heterologous genes can secrete therapeutic proteins locally within the tumour environment (cell therapy approach). Many bacterial genera have been demonstrated to localise to and replicate to high levels within tumour tissue when intravenously (IV) administered in rodent models and reporter gene tagging of bacteria has permitted real-time visualisation of this phenomenon. Live imaging of tumour colonising bacteria also presents diagnostic potential for this approach. The nature of tumour selective bacterial colonisation appears to be tumour origin- and bacterial species- independent. While originally a correlation was drawn between anaerobic bacterial colonisation and the hypoxic nature of solid tumours, it is recently becoming apparent that other elements of the unique microenvironment within solid tumours, including aberrant neovasculature and local immune suppression, may be responsible. Here, we consider the pre-clinical data supporting the use of bacteria as a tumour-targeting tool, recent advances in the area, and future work required to develop it into a beneficial clinical tool.

  17. Assessment of airborne bacteria of milk processing unit complex associated environment

    Directory of Open Access Journals (Sweden)

    Apurva K Pathak

    2013-01-01

    Full Text Available Aims: The aim of this study was to identify the sources of airborne contaminants in milk processing units. Materials and Methods: The aero-bacteriological investigation has been done fortnightly for a period of 1 year extramurally within the premises of milk processing unit complex with the help of modified two-stage Andersen Sampler. The raw milk samples were analyzed for total plate count and total coliform count. Results: The mean ± standard deviation of bioload of total coliform/mL, total plate count in million/mL, total airborne viable cultivable bacteria, Gram-negative bacteria, and the members of the family Enterobacteriaceae recorded were 3193.6 ± 220, 1673.33 ± 229.8, 3117.96 ± 1678.1, 46.33 ± 28.874, and 47.92 ± 33.5, respectively. Seasonal variations in airborne bacterial population were reported for this environment, high humidity and moderate temperature were the major factors for dissemination and distribution of Gram-negative bacilli. The temperature was positively and humidity was negatively significantly correlated with total airborne viable cultivable bacteria of this environment. There was no correlation established between bioload of milk and bioload of airborne bacteria. Conclusion: The airborne bacterial bioload in milk processing unit complex environment areas were higher than the acceptable limit, with temporal and spatial variations. Mechanical activities were supposed to be the key factor governing aerosolization of potentially harmful bacteria which could contaminate the products. These results could be useful to establish a standard to the small-scale dairy processing units where monitoring of airborne bacteria were rarely adopted by dairy manufacturers in their routine quality control.

  18. Sustained delivery of commensal bacteria from pod-intravaginal rings.

    Science.gov (United States)

    Gunawardana, Manjula; Mullen, Madeline; Yoo, Jennifer; Webster, Paul; Moss, John A; Baum, Marc M

    2014-01-01

    Topical administration of live commensal bacteria to the vaginal tract holds significant potential as a cost-effective strategy for the treatment of sexually transmitted infections and the delivery of mucosal vaccines. Probiotic-releasing intravaginal rings (IVRs) embody significant theoretical advantages over traditional daily-dosage forms, such as sustained and controlled delivery leading to improved adherence to therapy compared to that of frequent dosing. The conventional IVR designs, however, are not amenable to the delivery of live bacteria. We have developed a novel pod-IVR technology where polymer-coated tablets ("pods") of Lactobacillus gasseri strain ATCC 33323, a commensal microorganism of human origin, are embedded in silicone IVRs. The release rate of bacterial cells is controlled by the diameter of a delivery channel that exposes a portion of the pod to external fluids. In vitro studies demonstrated that the prototype devices released between 1.1×10(7) and 14×10(7) cells per day for up to 21 days in a controlled sustained fashion with stable burst-free release kinetics. The daily release rates were correlated with the cross-sectional area of the delivery channel. Bacteria in the IVR pods remained viable throughout the in vitro studies and formed biofilms on the surfaces of the devices. This proof-of-principle study represents the first demonstration of a prolonged, sustained release of bacteria from an intravaginal device and warrants further investigation of this device as a nonchemotherapeutic agent for the restoration and maintenance of normal urogenital flora.

  19. Effect of Antarctic solar radiation on sewage bacteria viability.

    Science.gov (United States)

    Hughes, Kevin A

    2005-06-01

    The majority of coastal Antarctic research stations discard untreated sewage waste into the near-shore marine environment. However, Antarctic solar conditions are unique, with ozone depletion increasing the proportion of potentially damaging ultraviolet-B (UV-B) radiation reaching the marine environment. This study assessed the influence of Antarctic solar radiation on the viability of Escherichia coli and sewage microorganisms at Rothera Research Station, Adelaide Island, Antarctic Peninsula. Cell viability decreased with increased exposure time and with exposure to shorter wavelengths of solar radiation. Cell survival also declined with decreasing cloud cover, solar zenith angle and ozone column depth. However, particulates in sewage increased the persistence of viable bacteria. Ultraviolet radiation doses over Rothera Point were highest during the austral summer. During this time, solar radiation may act to partially reduce the number of viable sewage-derived microorganisms in the surface seawater around Antarctic outfalls. Nevertheless, this effect is not reliable and every effort should be made to fully treat sewage before release into the Antarctic marine environment.

  20. Contribution of midgut bacteria to blood digestion and egg production in aedes aegypti (diptera: culicidae) (L.)

    Science.gov (United States)

    2011-01-01

    Background The insect gut harbors a variety of microorganisms that probably exceed the number of cells in insects themselves. These microorganisms can live and multiply in the insect, contributing to digestion, nutrition, and development of their host. Recent studies have shown that midgut bacteria appear to strengthen the mosquito's immune system and indirectly enhance protection from invading pathogens. Nevertheless, the physiological significance of these bacteria for mosquitoes has not been established to date. In this study, oral administration of antibiotics was employed in order to examine the contribution of gut bacteria to blood digestion and fecundity in Aedes aegypti. Results The antibiotics carbenicillin, tetracycline, spectinomycin, gentamycin and kanamycin, were individually offered to female mosquitoes. Treatment of female mosquitoes with antibiotics affected the lysis of red blood cells (RBCs), retarded the digestion of blood proteins and reduced egg production. In addition, antibiotics did not affect the survival of mosquitoes. Mosquito fertility was restored in the second gonotrophic cycle after suspension of the antibiotic treatment, showing that the negative effects of antibiotics in blood digestion and egg production in the first gonotrophic cycle were reversible. Conclusions The reduction of bacteria affected RBC lysis, subsequently retarded protein digestion, deprived mosquito from essential nutrients and, finally, oocyte maturation was affected, resulting in the production of fewer viable eggs. These results indicate that Ae. aegypti and its midgut bacteria work in synergism to digest a blood meal. Our findings open new possibilities to investigate Ae. aegypti-associated bacteria as targets for mosquito control strategies. PMID:21672186

  1. Microalgae-bacteria biofilms: a sustainable synergistic approach in remediation of acid mine drainage.

    Science.gov (United States)

    Abinandan, Sudharsanam; Subashchandrabose, Suresh R; Venkateswarlu, Kadiyala; Megharaj, Mallavarapu

    2018-02-01

    Microalgae and bacteria offer a huge potential in delving interest to study and explore various mechanisms under extreme environments. Acid mine drainage (AMD) is one such environment which is extremely acidic containing copious amounts of heavy metals and poses a major threat to the ecosystem. Despite its extreme conditions, AMD is the habitat for several microbes and their activities. The use of various chemicals in prevention of AMD formation and conventional treatment in a larger scale is not feasible under different geological conditions. It implies that microbe-mediated approach is a viable and sustainable alternative technology for AMD remediation. Microalgae in biofilms play a pivotal role in such bioremediation as they maintain mutualism with heterotrophic bacteria. Synergistic approach of using microalgae-bacteria biofilms provides supportive metabolites from algal biomass for growth of bacteria and mediates remediation of AMD. However, by virtue of their physiology and capabilities of metal removal, non-acidophilic microalgae can be acclimated for use in AMD remediation. A combination of selective acidophilic and non-acidophilic microalgae together with bacteria, all in the form of biofilms, may be very effective for bioremediation of metal-contaminated waters. The present review critically examines the nature of mutualistic interactions established between microalgae and bacteria in biofilms and their role in removal of metals from AMDs, and consequent biomass production for the yield of biofuel. Integration of microalgal-bacterial consortia in fuel cells would be an attractive emerging approach of microbial biotechnology for AMD remediation.

  2. Influence of adhesion to activated carbon particles on the viability of waterborne pathogenic bacteria under flow.

    Science.gov (United States)

    van der Mei, Henny C; Atema-Smit, Jelly; Jager, Debbie; Langworthy, Don E; Collias, Dimitris I; Mitchell, Michael D; Busscher, Henk J

    2008-07-01

    In rural areas around the world, people often rely on water filtration plants using activated carbon particles for safe water supply. Depending on the carbon surface, adhering microorganisms die or grow to form a biofilm. Assays to assess the efficacy of activated carbons in bacterial removal do not allow direct observation of bacterial adhesion and the determination of viability. Here we propose to use a parallel plate flow chamber with carbon particles attached to the bottom plate to study bacterial adhesion to individual carbon particles and determine the viability of adhering bacteria. Observation and enumeration is done after live/dead staining in a confocal laser scanning microscope. Escherichiae coli adhered in higher numbers than Raoultella terrigena, except to a coconut-based carbon, which showed low bacterial adhesion compared to other wood-based carbon types. After adhesion, 83-96% of the bacteria adhering to an acidic carbon were dead, while on a basic carbon 54-56% were dead. A positively charged, basic carbon yielded 76-78% bacteria dead, while on a negatively charged coconut-based carbon only 32-37% were killed upon adhesion. The possibility to determine both adhesion as well as the viability of adhering bacteria upon adhesion to carbon particles is most relevant, because if bacteria adhere but remain viable, this still puts the water treatment system at risk, as live bacteria can grow and form a biofilm that can then be shedded to cause contamination. (c) 2008 Wiley Periodicals, Inc.

  3. Multifork chromosome replication in slow-growing bacteria

    OpenAIRE

    Damian Trojanowski; Joanna Hołówka; Katarzyna Ginda; Dagmara Jakimowicz; Jolanta Zakrzewska-Czerwińska

    2017-01-01

    The growth rates of bacteria must be coordinated with major cell cycle events, including chromosome replication. When the doubling time (Td) is shorter than the duration of chromosome replication (C period), a new round of replication begins before the previous round terminates. Thus, newborn cells inherit partially duplicated chromosomes. This phenomenon, which is termed multifork replication, occurs among fast-growing bacteria such as Escherichia coli and Bacillus subtilis. In contrast, it ...

  4. Material and method for promoting the growth of anaerobic bacteria

    Science.gov (United States)

    Adler, H.I.

    1984-10-09

    A material and method is disclosed for promoting the growth of anaerobic bacteria which includes a nutrient media containing a hydrogen donor and sterile membrane fragments of bacteria having an electron transfer system which reduces oxygen to water. Dissolved oxygen in the medium is removed by adding the sterile membrane fragments to the nutrient medium and holding the medium at a temperature of about 10 to about 60 C until the dissolved oxygen is removed. No Drawings

  5. Incorporation of therapeutically modified bacteria into gut microbiota inhibits obesity.

    Science.gov (United States)

    Chen, Zhongyi; Guo, Lilu; Zhang, Yongqin; Walzem, Rosemary L; Pendergast, Julie S; Printz, Richard L; Morris, Lindsey C; Matafonova, Elena; Stien, Xavier; Kang, Li; Coulon, Denis; McGuinness, Owen P; Niswender, Kevin D; Davies, Sean S

    2014-08-01

    Metabolic disorders, including obesity, diabetes, and cardiovascular disease, are widespread in Westernized nations. Gut microbiota composition is a contributing factor to the susceptibility of an individual to the development of these disorders; therefore, altering a person's microbiota may ameliorate disease. One potential microbiome-altering strategy is the incorporation of modified bacteria that express therapeutic factors into the gut microbiota. For example, N-acylphosphatidylethanolamines (NAPEs) are precursors to the N-acylethanolamide (NAE) family of lipids, which are synthesized in the small intestine in response to feeding and reduce food intake and obesity. Here, we demonstrated that administration of engineered NAPE-expressing E. coli Nissle 1917 bacteria in drinking water for 8 weeks reduced the levels of obesity in mice fed a high-fat diet. Mice that received modified bacteria had dramatically lower food intake, adiposity, insulin resistance, and hepatosteatosis compared with mice receiving standard water or control bacteria. The protective effects conferred by NAPE-expressing bacteria persisted for at least 4 weeks after their removal from the drinking water. Moreover, administration of NAPE-expressing bacteria to TallyHo mice, a polygenic mouse model of obesity, inhibited weight gain. Our results demonstrate that incorporation of appropriately modified bacteria into the gut microbiota has potential as an effective strategy to inhibit the development of metabolic disorders.

  6. Teaching general problem-solving skills is not a substitute for, or a viable addition to, teaching mathematics

    NARCIS (Netherlands)

    Sweller, John; Clark, Richard; Kirschner, Paul A.

    2010-01-01

    Sweller, J., Clark, R., & Kirschner, P. A. (2010). Teaching general problem-solving skills is not a substitute for, or a viable addition to, teaching mathematics. Notices of the American Mathematical Society, 57, 1303-1304.

  7. The Belem Framework for Action: Harnessing the Power and Potential of Adult Learning and Education for a Viable Future

    Science.gov (United States)

    Adult Learning, 2012

    2012-01-01

    This article presents the Belem Framework for Action. This framework focuses on harnessing the power and potential of adult learning and education for a viable future. This framework begins with a preamble on adult education and towards lifelong learning.

  8. Collection of Viable Aerosolized Influenza Virus and Other Respiratory Viruses in a Student Health Care Center through Water-Based Condensation Growth.

    Science.gov (United States)

    Pan, Maohua; Bonny, Tania S; Loeb, Julia; Jiang, Xiao; Lednicky, John A; Eiguren-Fernandez, Arantzazu; Hering, Susanne; Fan, Z Hugh; Wu, Chang-Yu

    2017-01-01

    The dynamics and significance of aerosol transmission of respiratory viruses are still controversial, for the major reasons that virus aerosols are inefficiently collected by commonly used air samplers and that the collected viruses are inactivated by the collection method. Without knowledge of virus viability, infection risk analyses lack accuracy. This pilot study was performed to (i) determine whether infectious (viable) respiratory viruses in aerosols could be collected from air in a real world environment by the viable virus aerosol sampler (VIVAS), (ii) compare and contrast the efficacy of the standard bioaerosol sampler, the BioSampler, with that of the VIVAS for the collection of airborne viruses in a real world environment, and (iii) gain insights for the use of the VIVAS for respiratory virus sampling. The VIVAS operates via a water vapor condensation process to enlarge aerosolized virus particles to facilitate their capture. A variety of viable human respiratory viruses, including influenza A H1N1 and H3N2 viruses and influenza B viruses, were collected by the VIVAS located at least 2 m from seated patients, during a late-onset 2016 influenza virus outbreak. Whereas the BioSampler when operated following our optimized parameters also collected virus aerosols, it was nevertheless overall less successful based on a lower frequency of virus isolation in most cases. This side-by-side comparison highlights some limitations of past studies based on impingement-based sampling, which may have generated false-negative results due to either poor collection efficiency and/or virus inactivation due to the collection process. IMPORTANCE The significance of virus aerosols in the natural transmission of respiratory diseases has been a contentious issue, primarily because it is difficult to collect or sample virus aerosols using currently available air sampling devices. We tested a new air sampler based on water vapor condensation for efficient sampling of viable

  9. [Genetic resources of nodule bacteria].

    Science.gov (United States)

    Rumiantseva, M L

    2009-09-01

    Nodule bacteria (rhizobia) form highly specific symbiosis with leguminous plants. The efficiency of accumulation of biological nitrogen depends on molecular-genetic interaction between the host plant and rhizobia. Genetic characteristics of microsymbiotic strains are crucial in developing highly productive and stress-resistant symbiotic pairs: rhizobium strain-host plant cultivar (species). The present review considers the issue of studying genetic resources of nodule bacteria to identify genes and their blocks, responsible for the ability of rhizobia to form highly effective symbiosis in various agroecological conditions. The main approaches to investigation of intraspecific and interspecific genetic and genomic diversity of nodule bacteria are considered, from MLEE analysis to the recent methods of genomic DNA analysis using biochips. The data are presented showing that gene centers of host plants are centers of genetic diversification of nodule bacteria, because the intraspecific polymorphism of genetic markers of the core and the accessory rhizobial genomes is extremely high in them. Genotypic features of trapped and nodule subpopulations of alfalfa nodule bacteria are discussed. A survey of literature showed that the genomes of natural strains in alfalfa gene centers exhibit significant differences in genes involved in control of metabolism, replication, recombination, and the formation of defense response (hsd genes). Natural populations of rhizobia are regarded as a huge gene pool serving as a source of evolutionary innovations.

  10. Soil bacteria for remediation of polluted soils

    Energy Technology Data Exchange (ETDEWEB)

    Springael, D.; Bastiaens, L.; Carpels, M.; Mergaey, M.; Diels, L.

    1996-09-18

    Soil bacteria, specifically adapted to contaminated soils, may be used for the remediation of polluted soils. The Flemish research institute VITO has established a collection of bacteria, which were isolated from contaminated areas. This collection includes microbacteria degrading mineral oils (Pseudomonas sp., Acinetobacter sp. and others), microbacteria degrading polycyclic aromatic hydrocarbons (genera Sphingomonas and Mycobacterium), microbacteria degrading polychlorobiphenyls (genus Ralstonia and strains related to beta-Proteobacteria), and metal resistant bacteria with plasmid borne resistances to Cd, Zn, Ni, Co, Cu, Hg, and Cr. Bench-scale reactors were developed to investigate the industrial feasibility of bioremediation. Batch Stirred Tank Reactors were used to evaluate the efficiency of oil degraders. Soils, contaminated with non-ferrous metals, were treated using a Bacterial Metal Slurry Reactor. It was found that the reduction of the Cd concentration may vary strongly from sample to sample: reduction factors vary from 95 to 50%. Is was shown that Cd contained in metallic sinter and biologically unavailable Cd could not be removed.

  11. Folate Production by Probiotic Bacteria

    Directory of Open Access Journals (Sweden)

    Stefano Raimondi

    2011-01-01

    Full Text Available Probiotic bacteria, mostly belonging to the genera Lactobacillus and Bifidobacterium, confer a number of health benefits to the host, including vitamin production. With the aim to produce folate-enriched fermented products and/or develop probiotic supplements that accomplish folate biosynthesis in vivo within the colon, bifidobacteria and lactobacilli have been extensively studied for their capability to produce this vitamin. On the basis of physiological studies and genome analysis, wild-type lactobacilli cannot synthesize folate, generally require it for growth, and provide a negative contribution to folate levels in fermented dairy products. Lactobacillus plantarum constitutes an exception among lactobacilli, since it is capable of folate production in presence of para-aminobenzoic acid (pABA and deserves to be used in animal trials to validate its ability to produce the vitamin in vivo. On the other hand, several folate-producing strains have been selected within the genus Bifidobacterium, with a great variability in the extent of vitamin released in the medium. Most of them belong to the species B. adolescentis and B. pseudocatenulatum, but few folate producing strains are found in the other species as well. Rats fed a probiotic formulation of folate-producing bifidobacteria exhibited increased plasma folate level, confirming that the vitamin is produced in vivo and absorbed. In a human trial, the same supplement raised folate concentration in feces. The use of folate-producing probiotic strains can be regarded as a new perspective in the specific use of probiotics. They could more efficiently confer protection against inflammation and cancer, both exerting the beneficial effects of probiotics and preventing the folate deficiency that is associated with premalignant changes in the colonic epithelia.

  12. CONCEIVING AND GENERATING A VIABLE COMPLEXITY MODEL FOR PERSONAL AND/OR ENTREPRENEURIAL CHANGE AND DEVELOPMENT

    Directory of Open Access Journals (Sweden)

    George Niculescu

    2012-03-01

    Full Text Available This article proposes on the one hand to do research and study – with a genuine approach, inspiredand deep-rooted in the method of the sociological school in Bucharest and creatively renewed and integrating thenewest acquisitions of complexity science – the representative intricate entity “man as an economic actor (resourceand potential within the industrial organization and corporation in mono-industrial area (region in the period inwhich the phenomenon of transition from an industrial society to knowledge society takes place; and on the otherhand our project proposes to conceive a viable model of change and career of the human resources in the ElectricPlant of Rovinari as well as to conceive and accomplish a pilot-model of a platform in order to support the efficientimplement through a research-action approach of the model of personal and/or entrepreneurship change and careerof the human resources in the Electric Plant of Rovinari.

  13. A fusion-driven subcritical system concept based on viable technologies

    Science.gov (United States)

    Wu, Y.; Jiang, J.; Wang, M.; Jin, M.; FDS Team

    2011-10-01

    A fusion-driven hybrid subcritical system (FDS) concept has been designed and proposed as spent fuel burner based on viable technologies. The plasma fusion driver can be designed based on relatively easily achieved plasma parameters extrapolated from the successful operation of existing fusion experimental devices such as the EAST tokamak in China and other tokamaks in the world, and the subcritical fission blanket can be designed based on the well-developed technologies of fission power plants. The simulation calculations and performance analyses of plasma physics, neutronics, thermal-hydraulics, thermomechanics and safety have shown that the proposed concept can meet the requirements of tritium self-sufficiency and sufficient energy gain as well as effective burning of nuclear waste from fission power plants and efficient breeding of nuclear fuel to feed fission power plants.

  14. Drug delivery interfaces in the 21st century: from science fiction ideas to viable technologies.

    Science.gov (United States)

    Chertok, Beata; Webber, Matthew J; Succi, Marc D; Langer, Robert

    2013-10-07

    Early science fiction envisioned the future of drug delivery as targeted micrometer-scale submarines and "cyborg" body parts. Here we describe the progression of the field toward technologies that are now beginning to capture aspects of this early vision. Specifically, we focus on the two most prominent types of systems in drug delivery: the intravascular micro/nano drug carriers for delivery to the site of pathology and drug-loaded implantable devices that facilitate release with the predefined kinetics or in response to a specific cue. We discuss the unmet clinical needs that inspire these designs, the physiological factors that pose difficult challenges for their realization, and viable technologies that promise robust solutions. We also offer a perspective on where drug delivery may be in the next 50 years based on expected advances in material engineering and in the context of future diagnostics.

  15. The viable but non-culturable state in pathogenic Escherichia coli: A general review

    Directory of Open Access Journals (Sweden)

    Jennifer A. Pienaar

    2016-05-01

    Objectives: This review discusses various general aspects of the VBNC state, the mechanisms and possible public health impact of indicator and pathogenic E. coli entering into the VBNC state. Method: A literature review was conducted to ascertain the possibleimpact of E. coli entering into the VBNC state. Results: Escherichia coli enter into the VBNC state by means of several induction mechanisms. Various authors have found that E. coli can be resuscitated post-VBNC. Certain strains of pathogenic E. coli are still able to produce toxins in the VBNC state, whilst others are avirulent during the VBNC state but are able to regain virulence after resuscitation. Conclusion: Pathogenic and indicator E. coli entering into the VBNC state could have an adverse effect on public health if conventional detection methods are used, where the number of viable cells could be underestimated and the VBNC cells still produce toxins or could, at anytime, be resuscitated and become virulent again.

  16. An online listserv for nurse practitioners: a viable venue for continuous nursing professional development?

    Science.gov (United States)

    Hew, Khe Foon; Hara, Noriko

    2008-05-01

    This study reports the results of a qualitative study involving a large and longstanding online nurse listserv in the United States. A sample of 27 critical care and advanced-practice nurse practitioners was interviewed using semi-structured individual interviews. This study found evidence that participation in an online listserv offers a viable avenue for the continuous professional development of nurses by providing nurses the opportunity to make more informed decisions about their professional practice and keeping abreast with up-to-date changes in their specialty areas when they shared knowledge with one another. Follow-up interviews with 10 nurses who frequently shared their knowledge revealed six motivators that helped promote knowledge sharing: (a) reciprocity, (b) collectivism, (c) personal gain, (d) respectful environment, (e) altruism, and (f) technology. Implications for sustaining knowledge sharing in an online listserv are discussed. The finding will inform educators and administrators who support continuing education and professional development of healthcare professionals.

  17. Environmental assessment and viable interdependence: the Great Whale River case in northern Quebec (First Nations)

    Energy Technology Data Exchange (ETDEWEB)

    Mulvihill, P. R.

    1997-12-31

    This study is based on the belief that environmental assessment (EA) can be supportive of viable interdependence between regions and cultures. The central focus is on the scoping stage of the EA conducted for the proposed Great Whale hydroelectric project in northern Quebec. The evaluative framework consists of 16 criteria divided into three interrelated categories, i.e. substantive, general process-oriented and specific process-oriented. The specific process-oriented criteria constitute the primary analytical focus and are the subject of five separate sub-analysis, which reveal various strengths and weaknesses in the performance of the case study. It was concluded that environmental assessment in an intercultural setting is largely within the control of EA panels and the key shortcoming of the process, namely the lack of dialogue between the proponents and the intervenors, could be addressed by making public hearings more dynamic and interactive.

  18. Is Telemental Health Services a Viable Alternative to Traditional Psychotherapy for Deaf Individuals?

    Science.gov (United States)

    Crowe, Teresa V

    2017-02-01

    Access to mental health treatment is a vital part of a comprehensive health care plan. Deaf individuals often have difficulty accessing mental health services. Four-hundred twenty-two participants completed an anonymous questionnaire about their perspectives of telemental health services for deaf individuals. Results showed that several variables, such as if the participant was unable to receive another type of psychotherapy and whether the therapist was ASL-fluent, were significantly related to whether the respondent would use TMH. The participants reported that TMH services are a viable option for treating a variety of mental health issues. Telemental health services can act as a bridge between consumers of mental health care and their providers allowing accessible and equitable healthcare opportunities.

  19. Drug Delivery Interfaces in the 21st Century: From Science Fiction Ideas to Viable Technologies

    Science.gov (United States)

    Chertok, Beata; Webber, Matthew J.; Succi, Marc D.; Langer, Robert S.

    2013-01-01

    Early science fiction envisioned the future of drug delivery as targeted micron-scale submarines and ‘Cyborg’ body parts. Here we describe the progression of the field toward technologies that are now beginning to capture aspects of this early vision. Specifically, we focus on the two most prominent types of systems in drug delivery – the intravascular micro/nano drug carriers for delivery to the site of pathology and drug-loaded implantable devices that facilitate release with the pre-defined kinetics or in response to a specific cue. We discuss the unmet clinical needs that inspire these designs, the physiological factors that pose difficult challenges for their realization, and viable technologies that promise robust solutions. We also offer a perspective on where drug delivery may be in the next 50 years based on expected advances in material engineering and in the context of future diagnostics. PMID:23915375

  20. Minimum Viable Product and the Importance of Experimentation in Technology Startups

    Directory of Open Access Journals (Sweden)

    Dobrila Rancic Moogk

    2012-03-01

    Full Text Available Entrepreneurs are often faced with limited resources in their quest to commercialize new technology. This article presents the model of a lean startup, which can be applied to an organization regardless of its size or environment. It also emphasizes the conditions of extreme uncertainty under which the commercialization of new technology is carried out. The lean startup philosophy advocates efficient use of resources by introducing a minimum viable product to the market as soon as possible in order to test its value and the entrepreneur’s growth projections. This testing is done by running experiments that examine the metrics relevant to three distinct types of the growth. These experiments bring about accelerated learning to help reduce the uncertainty that accompanies commercialization projects, thereby bringing the resulting new technology to market faster.

  1. FREE OPEN SOURCE AND SOFTWARE IN THE TEACHING OF CAT TOOLS: OMEGAT, A VIABLE ALTERNATIVE

    Directory of Open Access Journals (Sweden)

    Adauto Lúcio Caetano Villela

    2016-12-01

    Full Text Available The teaching of Computer Aided Translation (CAT tools is essential to all courses aimed at preparing students for the effective exercise of this profession, in particular those students who will translate technical texts, especially in the field of localization. As an alternative to the paid commercial software which dominate the translation industry (such as SDL Trados Studio, Wordfast Pro and MemoQ, there are free proprietary softwares (such as Wordfast Anywhere and Google Translator Toolkit, and free open source ones (such as OmegaT and Anaphraseus. Starting from a description of CAT types and main functions, the purpose of this article is to point out, through an evaluative-comparative analysis based on a research and on a comparison between OmegaT, free proprietary softwares and others open source softwares, why and for which situations OmegaT is a viable alternative for the teaching of CAT tools in higher education.

  2. Mathematical modelling of the viable epidermis: impact of cell shape and vertical arrangement

    KAUST Repository

    Wittum, Rebecca

    2017-12-07

    In-silico methods are valuable tools for understanding the barrier function of the skin. The key benefit is that mathematical modelling allows the interplay between cell shape and function to be elucidated. This study focuses on the viable (living) epidermis. For this region, previous works suggested a diffusion model and an approximation of the cells by hexagonal prisms. The work at hand extends this in three ways. First, the extracellular space is treated with full spatial resolution. This induces a decrease of permeability by about 10%. Second, cells of tetrakaidecahedral shape are considered, in addition to the original hexagonal prisms. For both cell types, the resulting membrane permeabilities are compared. Third, for the first time, the influence of cell stacking in the vertical direction is considered. This is particularly important for the stratum granulosum, where tight junctions are present.

  3. Heterogeneity, politics of ethnicity, and multiculturalism What is a viable framework for Indonesia?

    Directory of Open Access Journals (Sweden)

    Thung Ju Lan

    2011-10-01

    Full Text Available Indonesia is a plural society that consists of several hundred ethnic and sub-ethnic groups. One of its generic characteristics is heterogeneity. In the last ten years after the implementation of regional autonomy, we have witnessed the emergence of strong ethnic and religiously flavoured local identity politics in various places in Indonesia that created open and vicious conflicts. This periodical violence exploded especially during the election of district and provincial heads. The intimate relation multiculturalism, with the actual political praxis of everyday life as an alternative to the existing paradigm of the “homogenization” of nationhood, has not been discussed. I believe it is time to discuss the strategic junctures between heterogeneity, politics of ethnicity (and religion and multiculturalism as well as their possible realization at the local and national levels in order to find a viable framework for a future Indonesia.

  4. Progress in biocatalysis with immobilized viable whole cells: systems development, reaction engineering and applications.

    Science.gov (United States)

    Polakovič, Milan; Švitel, Juraj; Bučko, Marek; Filip, Jaroslav; Neděla, Vilém; Ansorge-Schumacher, Marion B; Gemeiner, Peter

    2017-05-01

    Viable microbial cells are important biocatalysts in the production of fine chemicals and biofuels, in environmental applications and also in emerging applications such as biosensors or medicine. Their increasing significance is driven mainly by the intensive development of high performance recombinant strains supplying multienzyme cascade reaction pathways, and by advances in preservation of the native state and stability of whole-cell biocatalysts throughout their application. In many cases, the stability and performance of whole-cell biocatalysts can be highly improved by controlled immobilization techniques. This review summarizes the current progress in the development of immobilized whole-cell biocatalysts, the immobilization methods as well as in the bioreaction engineering aspects and economical aspects of their biocatalytic applications.

  5. Radioresistant Bacteria Came From Mars?

    Science.gov (United States)

    Pavlov, A.; Kalinin, V.; Konstantinov, A.; Shelegedin, V.

    We propose that the radioresistant bacteria (i.e. Deinococcus radiodurans) has been originated on Mars. This bacteria possesses an ability which should have been ab- solutely "unnecessary" in the Earth environment. It can survive very high doses of the ionizing radiation. Our experiments demonstrate that different kinds of non- radioresistant bacteria are able to develop very high radioresistance ability also. To develop radioresistance we exposed different bacterial cultures to several dozens of cycles of high irradiation. Therefore, radioresistance is not a result of some early spontaneous bacterial mutation but rather a consequence of the very specific plane- tary environment. Polar regions of Mars are the most probable (if not the only) place in the Solar System for such a periodical high-dosage irradiation process. We pro- pose a plausible scenario of where and when such an adaptation process could have taken place and also discuss indirect arguments of the Martian origin of Deinococcus Radiodurans based on their specific genetic structure.

  6. Chitin Degradation In Marine Bacteria

    DEFF Research Database (Denmark)

    Paulsen, Sara; Machado, Henrique; Gram, Lone

    2015-01-01

    Introduction: Chitin is the most abundant polymer in the marine environment and the second most abundant in nature. Chitin does not accumulate on the ocean floor, because of microbial breakdown. Chitin degrading bacteria could have potential in the utilization of chitin as a renewable carbon...... and nitrogen source in the fermentation industry.Methods: Here, whole genome sequenced marine bacteria were screened for chitin degradation using phenotypic and in silico analyses.Results: The in silico analyses revealed the presence of three to nine chitinases in each strain, however the number of chitinases...... chitin regulatory system.Conclusions: This study has provided insight into the ecology of chitin degradation in marine bacteria. It also served as a basis for choosing a more efficient chitin degrading production strain e.g. for the use of chitin waste for large-scale fermentations....

  7. Extremophilic iron-reducing bacteria: Their implications for possible life in extraterrestrial environments

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, J.; Liu, S.V.; Zhang, C.; Palumbo, A.V.; Phelps, T.J.

    1998-06-01

    Iron reduction is believed to be an early form of respiration and iron-reducing bacteria might have evolved very early on Earth. To support this hypothesis, the authors began to search for both thermophilic and psychrophilic iron-reducing bacteria because iron-reducing capacity may be a widely distributed trait if ancestral microorganisms include extremophilic iron-reducing bacteria. To date, they have obtained thermophilic Fe(III)-reducing and magnetite-forming enrichment cultures from geologically and hydrologically isolated, millions of years-old deep terrestrial subsurface samples. Three dominant bacteria were identified based on 16S ribosomal RNA gene sequences. Phylogenetical analysis indicated that these bacteria were closely related to Thermoanaerobacter ethanoliticus. Two pure thermophilic iron-reducing bacteria have been isolated and characterized from these enrichments, they also are able to degrade cellulose and xylan. Geological evidence indicated that these bacteria were separated from modern organisms for about 200 million years, and they are the oldest isolated bacteria available now. Evolutionary sequence analysis showed that the 16S rRNA genes evolved extremely slowly in these bacteria. In addition, the authors have obtained about 30 psychrophilic iron-reducing bacteria in samples from Siberia and Alaska permafrost soils, Pacific marine sediments and Hawaii deep sea water. These bacteria were also able to reduce other heavy metals. The isolation of both thermophilic and psychrophilic iron-reducing bacteria from surface and subsurface environments has significant implications for microbial evolution and for studying the origin of life in extraterrestrial environments.

  8. Fern spore longevity in saline water: can sea bottom sediments maintain a viable spore bank?

    Directory of Open Access Journals (Sweden)

    G Arjen de Groot

    Full Text Available Freshwater and marine sediments often harbor reservoirs of plant diaspores, from which germination and establishment may occur whenever the sediment falls dry. Therewith, they form valuable records of historical inter- and intraspecific diversity, and are increasingly exploited to facilitate diversity establishment in new or restored nature areas. Yet, while ferns may constitute a considerable part of a vegetation's diversity and sediments are known to contain fern spores, little is known about their longevity, which may suffer from inundation and--in sea bottoms--salt stress. We tested the potential of ferns to establish from a sea or lake bottom, using experimental studies on spore survival and gametophyte formation, as well as a spore bank analysis on sediments from a former Dutch inland sea. Our experimental results revealed clear differences among species. For Asplenium scolopendrium and Gymnocarpium dryopteris, spore germination was not affected by inundated storage alone, but decreased with rising salt concentrations. In contrast, for Asplenium trichomanes subsp. quadrivalens germination decreased following inundation, but not in response to salt. Germination rates decreased with time of storage in saline water. Smaller and less viable gametophytes were produced when saline storage lasted for a year. Effects on germination and gametophyte development clearly differed among genotypes of A. scolopendrium. Spore bank analyses detected no viable spores in marine sediment layers. Only two very small gametophytes (identified as Thelypteris palustris via DNA barcoding emerged from freshwater sediments. Both died before maturation. We conclude that marine, and likely even freshwater sediments, will generally be of little value for long-term storage of fern diversity. The development of any fern vegetation on a former sea floor will depend heavily on the deposition of spores onto the drained land by natural or artificial means of dispersal.

  9. Allogeneic human dermal fibroblasts are viable in peripheral blood mononuclear co-culture

    Directory of Open Access Journals (Sweden)

    Restu Syamsul Hadi

    2014-08-01

    Full Text Available Background Transplanted allogeneic dermal fibroblasts retain stem cell subpopulations, and are easily isolated, expanded and stored using standard techniques. Their potential for regenerative therapy of chronic wounds should be evaluated. The aim of this study was to determine allogeneic fibroblast viability in the presence of peripheral blood mononuclear cells (PBMC. Methods In this experimental study, fibroblasts were isolated from foreskin explants, expanded in the presence of serum, and stored using slow-freezing. We used one intervention group of allogeneic fibroblasts co-cultured with PBMC and 2 control groups of separate fibroblast and PBMC cultures.Fibroblasts were characterized by their collagen secretion and octamer-binding transcription factor 4 (OCT4 expression. Viability was evaluated using water soluble tetrazolium-1 (WST-1 proliferation assay. Absorbances were measured at 450 nm. Data analysis was performed by student’s paired t-test. Results Dermal fibroblasts were shown to secrete collagen, express OCT4, be recoverable after cryopreservation, and become attached to the culture dish in a co-culture with PBMC. Co-cultured and control fibroblasts had no significantly different cell viabilities (p>0.05. Calculated viable cell numbers increased 1.8 and 5.1-fold, respectively, at days 2 and 4 in vitro. Both groups showed comparable doubling times at days 2 and 4 in vitro. PBMC did not interfere with allogeneic fibroblast viability and proliferative capacity Conclusions Allogeneic fibroblasts remain viable and proliferate in the presence of host PBMC. Future research should evaluate allogeneic human dermal fibroblast competency in clinical settings. Dermal fibroblasts are a potential source for cell therapy in chronic wound management.

  10. Fern spore longevity in saline water: can sea bottom sediments maintain a viable spore bank?

    Science.gov (United States)

    de Groot, G Arjen; During, Heinjo

    2013-01-01

    Freshwater and marine sediments often harbor reservoirs of plant diaspores, from which germination and establishment may occur whenever the sediment falls dry. Therewith, they form valuable records of historical inter- and intraspecific diversity, and are increasingly exploited to facilitate diversity establishment in new or restored nature areas. Yet, while ferns may constitute a considerable part of a vegetation's diversity and sediments are known to contain fern spores, little is known about their longevity, which may suffer from inundation and--in sea bottoms--salt stress. We tested the potential of ferns to establish from a sea or lake bottom, using experimental studies on spore survival and gametophyte formation, as well as a spore bank analysis on sediments from a former Dutch inland sea. Our experimental results revealed clear differences among species. For Asplenium scolopendrium and Gymnocarpium dryopteris, spore germination was not affected by inundated storage alone, but decreased with rising salt concentrations. In contrast, for Asplenium trichomanes subsp. quadrivalens germination decreased following inundation, but not in response to salt. Germination rates decreased with time of storage in saline water. Smaller and less viable gametophytes were produced when saline storage lasted for a year. Effects on germination and gametophyte development clearly differed among genotypes of A. scolopendrium. Spore bank analyses detected no viable spores in marine sediment layers. Only two very small gametophytes (identified as Thelypteris palustris via DNA barcoding) emerged from freshwater sediments. Both died before maturation. We conclude that marine, and likely even freshwater sediments, will generally be of little value for long-term storage of fern diversity. The development of any fern vegetation on a former sea floor will depend heavily on the deposition of spores onto the drained land by natural or artificial means of dispersal.

  11. Allogeneic human dermal fibroblasts are viable in peripheral blood mononuclear co-culture

    Directory of Open Access Journals (Sweden)

    Restu Syamsul Hadi

    2015-12-01

    Full Text Available BACKGROUND Transplanted allogeneic dermal fibroblasts retain stem cell subpopulations, and are easily isolated, expanded and stored using standard techniques. Their potential for regenerative therapy of chronic wounds should be evaluated. The aim of this study was to determine allogeneic fibroblast viability in the presence of peripheral blood mononuclear cells (PBMC. METHODS In this experimental study, fibroblasts were isolated from foreskin explants, expanded in the presence of serum, and stored using slow-freezing. We used one intervention group of allogeneic fibroblasts co-cultured with PBMC and 2 control groups of separate fibroblast and PBMC cultures.Fibroblasts were characterized by their collagen secretion and octamer-binding transcription factor 4 (OCT4 expression. Viability was evaluated using water soluble tetrazolium-1 (WST-1 proliferation assay. Absorbances were measured at 450 nm. Data analysis was performed by student’s paired t-test. RESULTS Dermal fibroblasts were shown to secrete collagen, express OCT4, be recoverable after cryopreservation, and become attached to the culture dish in a co-culture with PBMC. Co-cultured and control fibroblasts had no significantly different cell viabilities (p>0.05. Calculated viable cell numbers increased 1.8 and 5.1- fold, respectively, at days 2 and 4 in vitro. Both groups showed comparable doubling times at days 2 and 4 in vitro. PBMC did not interfere with allogeneic fibroblast viability and proliferative capacity CONCLUSIONS Allogeneic fibroblasts remain viable and proliferate in the presence of host PBMC. Future research should evaluate allogeneic human dermal fibroblast competency in clinical settings. Dermal fibroblasts are a potential source for cell therapy in chronic wound management.

  12. Review on Nano SeleniumProduced by Bacteria

    Directory of Open Access Journals (Sweden)

    LI Ji-xiang

    2014-12-01

    Full Text Available Selenium (Se is a kind of essential trace element for people and animal, while ionic state of selenium is toxic with high concentrations and will cause the selenium pollution. Nano-selenium is stable, nontoxic with higher biological activity. Application of bacteria reducing selenite or selenate to biological nano-selenium has great potential in selenium pollution control and nano-selenium production. This review summarizes the research progress of the red elemental nano-selenium reduced by bacteria including characteristics and application of nano-selenium, effects of carbon and nitrogen source, oxygen, temperature and pH in bacteria nano-selenium production, and molecular mechanisms of nano-selenium reduced by bacteria.

  13. Plant probiotic bacteria: solutions to feed the world

    Directory of Open Access Journals (Sweden)

    Esther Menendez

    2017-06-01

    Full Text Available The increasing human population expected in the next decades, the growing demand of livestock products—which production requires higher amounts of feed products fabrication, the collective concern about food quality in industrialized countries together with the need to protect the fertility of soils, in particular, and the environment, in general, constitute as a whole big challenge that worldwide agriculture has to face nowadays. Some soil bacteria harbor mechanisms to promote plant growth, which include phytostimulation, nutrient mobilization, biocontrol of plant pathogens and abiotic stresses protection. These bacteria have also been proved as promoters of vegetable food quality. Therefore, these microbes, also so-called Plant Probiotic Bacteria, applied as biofertilizers in crop production, constitute an environmental friendly manner to contribute to produce the food and feed needed to sustain world population. In this review, we summarize some of the best-known mechanisms of plant probiotic bacteria to improve plant growth and develop a more sustainable agriculture.

  14. Airborne bacteria in the atmosphere: Presence, purpose, and potential

    Science.gov (United States)

    Smets, Wenke; Moretti, Serena; Denys, Siegfried; Lebeer, Sarah

    2016-08-01

    Numerous recent studies have highlighted that the types of bacteria present in the atmosphere often show predictable patterns across space and time. These patterns can be driven by differences in bacterial sources of the atmosphere and a wide range of environmental factors, including UV intensity, precipitation events, and humidity. The abundance of certain bacterial taxa is of interest, not only for their ability to mediate a range of chemical and physical processes in the atmosphere, such as cloud formation and ice nucleation, but also for their implications -both beneficial and detrimental-for human health. Consequently, the widespread importance of airborne bacteria has stimulated the search for their applicability. Improving air quality, modelling the dispersal of airborne bacteria (e.g. pathogens) and biotechnological purposes are already being explored. Nevertheless, many technological challenges still need to be overcome to fully understand the roles of airborne bacteria in our health and global ecosystems.

  15. Advantageous direct quantification of viable closely related probiotics in petit-suisse cheeses under in vitro gastrointestinal conditions by Propidium Monoazide--qPCR.

    Science.gov (United States)

    Villarreal, Martha Lissete Morales; Padilha, Marina; Vieira, Antonio Diogo Silva; Franco, Bernadette Dora Gombossy de Melo; Martinez, Rafael Chacon Ruiz; Saad, Susana Marta Isay

    2013-01-01

    Species-specific Quantitative Real Time PCR (qPCR) alone and combined with the use of propidium monoazide (PMA) were used along with the plate count method to evaluate the survival of the probiotic strains Lactobacillus acidophilus La-5 and Bifidobacterium animalis subsp. lactis Bb-12, and the bacteriocinogenic and potentially probiotic strain Lactobacillus sakei subsp. sakei 2a in synbiotic (F1) and probiotic (F2) petit-suisse cheeses exposed throughout shelf-life to in vitro simulated gastrointestinal tract conditions. The three strains studied showed a reduction in their viability after the 6 h assay. Bb-12 displayed the highest survival capacity, above 72.6 and 74.6% of the initial populations, respectively, by plate count and PMA-qPCR, maintaining population levels in the range or above 6 log CFU/g. The prebiotic mix of inulin and FOS did not offer any additional protection for the strains against the simulated gastrointestinal environment. The microorganisms' populations were comparable among the three methods at the initial time of the assay, confirming the presence of mainly viable and culturable cells. However, with the intensification of the stress induced throughout the various stages of the in vitro test, the differences among the methods increased. The qPCR was not a reliable enumeration method for the quantification of intact bacterial populations, mixed with large numbers of injured and dead bacteria, as confirmed by the scanning electron microscopy results. Furthermore, bacteria plate counts were much lower (Ppetit-suisse cheeses and under stress conditions.

  16. Advantageous Direct Quantification of Viable Closely Related Probiotics in Petit-Suisse Cheeses under In Vitro Gastrointestinal Conditions by Propidium Monoazide - qPCR

    Science.gov (United States)

    Villarreal, Martha Lissete Morales; Padilha, Marina; Vieira, Antonio Diogo Silva; Franco, Bernadette Dora Gombossy de Melo; Martinez, Rafael Chacon Ruiz; Saad, Susana Marta Isay

    2013-01-01

    Species-specific Quantitative Real Time PCR (qPCR) alone and combined with the use of propidium monoazide (PMA) were used along with the plate count method to evaluate the survival of the probiotic strains Lactobacillus acidophilus La-5 and Bifidobacterium animalis subsp. lactis Bb-12, and the bacteriocinogenic and potentially probiotic strain Lactobacillus sakei subsp. sakei 2a in synbiotic (F1) and probiotic (F2) petit-suisse cheeses exposed throughout shelf-life to in vitro simulated gastrointestinal tract conditions. The three strains studied showed a reduction in their viability after the 6 h assay. Bb-12 displayed the highest survival capacity, above 72.6 and 74.6% of the initial populations, respectively, by plate count and PMA-qPCR, maintaining population levels in the range or above 6 log CFU/g. The prebiotic mix of inulin and FOS did not offer any additional protection for the strains against the simulated gastrointestinal environment. The microorganisms' populations were comparable among the three methods at the initial time of the assay, confirming the presence of mainly viable and culturable cells. However, with the intensification of the stress induced throughout the various stages of the in vitro test, the differences among the methods increased. The qPCR was not a reliable enumeration method for the quantification of intact bacterial populations, mixed with large numbers of injured and dead bacteria, as confirmed by the scanning electron microscopy results. Furthermore, bacteria plate counts were much lower (Ppetit-suisse cheeses and under stress conditions. PMID:24358142

  17. Antibiotic Susceptibility of Commensal Bacteria from Human Milk.

    Science.gov (United States)

    Chen, Po-Wen; Tseng, Shu-Ying; Huang, Mao-Sheng

    2016-02-01

    Recent studies have focused on foodborne or commensal bacteria as vehicles of antibiotic resistance. However, the antibiotic resistance of milk bacteria from healthy donors is still vague in Taiwan. For this purpose, human milk samples were obtained from randomly recruited 19 healthy women between 3 and 360 days post-partum. Antibiotic susceptibility profile of bacteria from milk samples was determined. About 20 bacterial species were isolated from milk samples including Staphylococcus (6 species), Streptococcus (4 species), Enterococcus (2 species), Lactobacillus (1 species), and bacteria belonging to other genera (7 species). Some opportunistic or potentially pathogenic bacteria including Kluyvera ascorbata, Klebsiella oxytoca, Klebsiella pneumoniae, Acinetobacter baumannii, Actinomyces bovis, and Staphylococcus aureus were also isolated. Intriguingly, Staphylococcus isolates (22 strains) were resistant to 2–8 of 8 antibiotics, while Streptococcus isolates (3 strains) were resistant to 3–7 of 9 antibiotics, and members of the genus Enterococcus (5 strains) were resistant to 3–8 of 9 antibiotics. Notably, Staphylococcus lugdunensis, S. aureus, Streptococcus parasanguinis, Streptococcus pneumonia, and Enterococcus faecalis were resistant to vancomycin, which is considered as the last-resort antibiotic. Therefore, this study shows that most bacterial strains in human milk demonstrate mild to strong antibiotic resistance. Whether commensal bacteria in milk could serve as vehicles of antibiotic resistance should be further investigated.

  18. Unmineralized fossil bacteria

    Science.gov (United States)

    Bradley, W.H.

    1963-01-01

    Unmineralized bacterial cells, mostly Micrococcus sp., but including also Streptococcus sp. and Actinomyces sp., were found in enormous numbers in lake beds of the Newark Canyon Formation of Early Cretaceous age, Eureka County, Nevada. The micrococci are black, and have an average diameter about 0.5 ??. Similar black micrococci (0.4 to 0.7 ??.) were found in profusion in the bottom mud of Green Lake, New York. About 80 percent of this mud consists of minute idiomorphic calcite crystals and about 20 percent of these contain enormous numbers of the black micrococci. It is suggested that the Early Cretaceous bacterial cells owe their preservation to occlusion in calcite crystals that grew in a black, bacterial mud in a meromictic lake in which part of the Newark Canyon Formation accumulated.

  19. Viable Cancer Cells in the Remnant Stomach are a Potential Source of Peritoneal Metastasis after Curative Distal Gastrectomy for Gastric Cancer.

    Science.gov (United States)

    Murata, Satoshi; Yamamoto, Hiroshi; Yamaguchi, Tsuyoshi; Kaida, Sachiko; Ishida, Mitsuaki; Kodama, Hirokazu; Takebayashi, Katsushi; Shimizu, Tomoharu; Miyake, Toru; Tani, Tohru; Kushima, Ryoji; Tani, Masaji

    2016-09-01

    The mechanisms underlying peritoneal metastasis (PM) after curative gastrectomy for gastric cancer (GC) are not well elucidated. This study assessed whether viable cancer cells, including cancer stemlike cells (CSCs), were present in the remnant stomach immediately before gastrointestinal (GI) tract reconstruction because these could be a source of PM after gastrectomy. Saline fluid used for remnant stomach lumen irrigation before GI reconstruction was prospectively collected from 142 consecutive patients undergoing distal gastrectomy for GC and cytologically examined. Proliferative activity (Ki67 staining) and stemness (expression of the CSC surface markers CD44s or CD44v6) were evaluated in detected cancer cells. Viable cancer cells were detected in 33 (23.2 %) of the 142 remnant stomachs. These cells formed clusters and stained positively for Ki67, indicating proliferation. Cancer cells in remnant stomachs and surface cancer cells in primary GCs from 10 (30.3 %) of these 33 cases also stained positively for CD44s or CD44v6. In a multiple logistic regression analysis, advanced cancer (odds ratio [OR], 4.65; 95 % confidence interval [CI], 1.32-16.4; P = 0.017), tumor size of 40 mm or larger (OR, 3.78; 95 % CI, 1.12-12.8; P = 0.033), and histologic differentiation (OR, 3.10; 95 % CI, 1.30-7.40; P = 0.011) were associated independently with the presence of cancer cells in the remnant stomach. Viable, proliferative, and clustered cancer cells, including CSCs, were found in remnant gastric lumens immediately before GI reconstruction, indicating a possible cellular source of PM after curative gastrectomy for GC. Dissemination of gastric contents into the peritoneal cavity should be avoided during GI reconstruction.

  20. Encapsulation of Autoinducer Sensing Reporter Bacteria in Reinforced Alginate-Based Microbeads.

    Science.gov (United States)

    Li, Ping; Müller, Mareike; Chang, Matthew Wook; Frettlöh, Martin; Schönherr, Holger

    2017-07-12

    Quorum sensing, in which bacteria communities use signaling molecules for inter- and intracellular communication, has been intensively studied in recent decades. In order to fabricate highly sensitive easy-to-handle point of care biosensors that detect quorum sensing molecules, we have developed, as is reported here, reporter bacteria loaded alginate-methacrylate (alginate-MA) hydrogel beads. The alginate-MA beads, which were obtained by electrostatic extrusion, were reinforced by photo-cross-linking to increase stability and thereby to reduce bacteria leaching. In these beads the genetically engineered fluorescent reporter bacterium Escherichia coli pTetR-LasR-pLuxR-GFP (E. coli pLuxR-GFP) was encapsulated, which responds to the autoinducer N-(3-oxododecanoyl)homoserine lactone secreted by Pseudomonas aeruginosa. After encapsulation in alginate-MA hydrogel beads with diameters in the range of 100-300 μm that were produced by an electrostatic extrusion method and rapid photo-cross-linking, the E. coli pLuxR-GFP were found to possess a high degree of viability and sensing activity. The encapsulated bacteria could proliferate inside the hydrogel beads, when exposed to bacteria culture medium. In media containing the autoinducer N-(3-oxododecanoyl)homoserine lactone, the encapsulated reporter bacteria responded with a strong fluorescence signal due to an increased green fluorescent protein (GFP) expression. A prototype dipstick type sensor developed here underlines the potential of encapsulation of viable and functional reporter bacteria inside reinforced alginate-methacrylate hydrogel beads for whole cell sensors for bacteria detection.

  1. Competition for Ammonium between Nitrifying and Heterotrophic Bacteria in Continuously Percolated Soil Columns.

    Science.gov (United States)

    Verhagen, F J; Duyts, H; Laanbroek, H J

    1992-10-01

    Although the absence of nitrate formation in grassland soils rich in organic matter has often been reported, low numbers of nitrifying bacteria are still found in these soils. To obtain more insight into these observations, we studied the competition for limiting amounts of ammonium between the chemolithotrophic ammonium-oxidizing species Nitrosomonas europaea and the heterotrophic species Arthrobacter globiformis in the presence of Nitrobacter winogradskyi with soil columns containing calcareous sandy soil. The soil columns were percolated continuously at a dilution rate of 0.007 h, based on liquid volumes, with medium containing 5 mM ammonium and different amounts of glucose ranging from 0 to 12 mM.A. globiformis was the most competitive organism for limiting amounts of ammonium. The numbers of N. europaea and N. winogradskyi cells were lower at higher glucose concentrations, and the potential ammonium-oxidizing activities in the uppermost 3 cm of the soil columns were nonexistent when at least 10 mM glucose was present in the reservoir, although 10 nitrifying cells per g of dry soil were still present. This result demonstrated that there was no correlation between the numbers of nitrifying bacteria and their activities. The numbers and activities of N. winogradskyi cells decreased less than those of N. europaea cells in all layers of the soil columns, probably because of heterotrophic growth of the nitrite-oxidizing bacteria on organic substrates excreted by the heterotrophic bacteria or because of nitrate reduction at reduced oxygen concentrations by the nitrite-oxidizing bacteria. Our conclusion was that the nitrifying bacteria were less competitive than the heterotrophic bacteria for ammonium in soil columns but that they survived as viable inactive cells. Inactive nitrifying bacteria may also be found in the rhizosphere of grassland plants, which is rich in organic carbon. They are possibly reactivated during periods of net mineralization.

  2. Adherence and viability of intestinal bacteria to differentiated Caco-2 cells quantified by flow cytometry.

    Science.gov (United States)

    Grootaert, Charlotte; Boon, Nico; Zeka, Fjoralba; Vanhoecke, Barbara; Bracke, Marc; Verstraete, Willy; Van de Wiele, Tom

    2011-07-01

    Recent developments in host-microbe research give rise to a growing demand for rapid and accurate methods to quantify bacterial adhesion to epithelial cells. Here, we describe a new flow cytometric method to determine the amount and viability of gut bacteria, adhered to a monolayer of differentiated cells. The latter is a more relevant epithelium model than the suspended eukaryotic cells currently used in flow cytometric protocols. During the development of the method, we monitored the adhesion potential of six bacterial species and an intestinal microbial community to Caco-2 cells. The combination of SYBR Green I/propidium iodide was more efficient than carboxyfluorescein diacetate to stain the bacterial cells. In addition, a better separation between the Caco-2 background signal and viable and dead bacteria was obtained. A precise amount of Triton X-100 was used to detach adhered bacteria from Caco-2 cells and cell debris. Yet, a limited decrease in viability was observed for the intestinal microbial community treated with Triton X-100. The flow cytometric lower detection limit for pure bacterial cultures was 3.0-4.0log/mL, whereas a 5.0-5.5log/mL detection limit was obtained in the presence of Caco-2 cell background. The latter was sufficient to quantify adhered bacteria. To the best of our knowledge, this is the first description of a flow cytometric protocol that quantifies adhesion of both pure and mixed gut microbial cultures to a differentiated monolayer of Caco-2 cells and that allows to distinguish between viable and dead adhered bacteria. Copyright © 2011 Elsevier B.V. All rights reserved.

  3. Programmed survival of soil bacteria

    DEFF Research Database (Denmark)

    Jensen, Lars Bogø; Molin, Søren; Sternberg, Claus

    Biological containment systems have been developed for Pseudomonas putida and related soil bacteria. The systems are based on combinations of lethal genes and regulated gene expression. Two types of killing function have been employed: 1) A membrane protein interfering with the membrane potential...

  4. ENDOSPORES OF THERMOPHILIC FERMENTATIVE BACTERIA

    DEFF Research Database (Denmark)

    Volpi, Marta

    2016-01-01

    solely based on endospores of sulphate-reducing bacteria (SRB), which presumably constitute only a small fraction of the total thermophilic endospore community reaching cold environments. My PhD project developed an experimental framework for using thermophilic fermentative endospores (TFEs) to trace...

  5. Biofilms: Community Behavior by Bacteria

    Indian Academy of Sciences (India)

    IAS Admin

    It has been found that waste water treated by the biofilm method (activated sludge) is very effective. Biofilms can also be used to 'eat up' petroleum and other oil products. There is also the concept of microbial leaching. For example, low grade ore is mildly acidified to encourage the growth of bacteria which oxidize the ore to ...

  6. Manipulating Genetic Material in Bacteria

    Science.gov (United States)

    1998-01-01

    Lisa Crawford, a graduate research assistant from the University of Toledo, works with Laurel Karr of Marshall Space Flight Center (MSFC) in the molecular biology laboratory. They are donducting genetic manipulation of bacteria and yeast for the production of large amount of desired protein. Photo credit: NASA/Marshall Space Flight Center (MSFC)

  7. Engineering robust lactic acid bacteria

    NARCIS (Netherlands)

    Bron, P.A.; Bokhorst-van de Veen, van H.; Wels, M.; Kleerebezem, M.

    2011-01-01

    For centuries, lactic acid bacteria (LAB) have been industrially exploited as starter cultures in the fermentation of foods and feeds for their spoilage-preventing and flavor-enhancing characteristics. More recently, the health-promoting effects of LAB on the consumer have been widely acknowledged,

  8. Photoreceptor proteins from purple bacteria

    NARCIS (Netherlands)

    Hendriks, J.; van der Horst, M.A.; Chua, T.K.; Ávila Pérez, M.; van Wilderen, L.J.; Alexandre, M.T.A.; Groot, M.-L.; Kennis, J.T.M.; Hellingwerf, K.J.; Hunter, C.N.; Daldal, F.; Thurnauer, M.C.; Beatty, J.T.

    2009-01-01

    Purple bacteria contain representatives of four of the six main families of photoreceptor proteins: phytochromes, BLUF domain containing proteins, xanthopsins (i.e., photoactive yellow proteins), and phototropins (containing one or more light, oxygen, or voltage (LOV) domains). Most of them have a

  9. Raman spectroscopy of oral bacteria

    Science.gov (United States)

    Berger, Andrew J.; Zhu, Qingyuan; Quivey, Robert G.

    2003-10-01

    Raman spectroscopy has been employed to measure the varying concentrations of two oral bacteria in simple mixtures. Evaporated droplets of centrifuged mixtures of Streptococcus sanguis and Streptococcus mutans were analyzed via Raman microspectroscopy. The concentration of s. sanguis was determined based upon the measured Raman spectrum, using partial least squares cross-validation, with an r2 value of 0.98.

  10. Functional genomics of intracellular bacteria.

    Science.gov (United States)

    de Barsy, Marie; Greub, Gilbert

    2013-07-01

    During the genomic era, a large amount of whole-genome sequences accumulated, which identified many hypothetical proteins of unknown function. Rapidly, functional genomics, which is the research domain that assign a function to a given gene product, has thus been developed. Functional genomics of intracellular pathogenic bacteria exhibit specific peculiarities due to the fastidious growth of most of these intracellular micro-organisms, due to the close interaction with the host cell, due to the risk of contamination of experiments with host cell proteins and, for some strict intracellular bacteria such as Chlamydia, due to the absence of simple genetic system to manipulate the bacterial genome. To identify virulence factors of intracellular pathogenic bacteria, functional genomics often rely on bioinformatic analyses compared with model organisms such as Escherichia coli and Bacillus subtilis. The use of heterologous expression is another common approach. Given the intracellular lifestyle and the many effectors that are used by the intracellular bacteria to corrupt host cell functions, functional genomics is also often targeting the identification of new effectors such as those of the T4SS of Brucella and Legionella.

  11. The viable but nonculturable state induction and genomic analyses of Lactobacillus casei BM-LC14617, a beer-spoilage bacterium.

    Science.gov (United States)

    Liu, Junyan; Li, Lin; Peters, Brian M; Li, Bing; Chen, Lequn; Deng, Yang; Xu, Zhenbo; Shirtliff, Mark E

    2017-10-01

    This study aimed to investigate the viable but nonculturable (VBNC) state and genomic features of a beer-spoilage strain, Lactobacillus caseiBM-LC14617. Induction on the VBNC state of L. casei strain BM-LC14617 was conducted by both low-temperature storage and continuous passage in beer, and formation of VBNC state was detected after 196 ± 3.3 days and 32 ± 1.6 subcultures, respectively. Resuscitation of VBNC cells was successfully induced by addition of catalase, and culturable, VBNC, and resuscitated cells shared similar beer-spoilage capability. Whole genome sequencing was performed, and out of a total of 3,964 predicted genes, several potential VBNC and beer-spoilage-associated genes were identified. L. casei is capable of entering into and resuscitating from the VBNC state and possesses beer-spoilage capability. The genomic characterization yield insightful elucidation of VBNC state for L. casei. This study represents the first evidence on VBNC state induction of L. casei and beer-spoilage capability of VBNC and resuscitated cells. Also, this is the first genomic characterization of L. casei as a beer-spoilage bacterium. The current study may aid in further study on L. casei and other beer-spoilage bacteria, and guide the prevention and control of beer spoilage. © 2017 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

  12. Bacteria-Targeting Nanoparticles for Managing Infections

    Science.gov (United States)

    Radovic-Moreno, Aleksandar Filip

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

  13. Fuzzy species among recombinogenic bacteria

    Directory of Open Access Journals (Sweden)

    Fraser Christophe

    2005-03-01

    Full Text Available Abstract Background It is a matter of ongoing debate whether a universal species concept is possible for bacteria. Indeed, it is not clear whether closely related isolates of bacteria typically form discrete genotypic clusters that can be assigned as species. The most challenging test of whether species can be clearly delineated is provided by analysis of large populations of closely-related, highly recombinogenic, bacteria that colonise the same body site. We have used concatenated sequences of seven house-keeping loci from 770 strains of 11 named Neisseria species, and phylogenetic trees, to investigate whether genotypic clusters can be resolved among these recombinogenic bacteria and, if so, the extent to which they correspond to named species. Results Alleles at individual loci were widely distributed among the named species but this distorting effect of recombination was largely buffered by using concatenated sequences, which resolved clusters corresponding to the three species most numerous in the sample, N. meningitidis, N. lactamica and N. gonorrhoeae. A few isolates arose from the branch that separated N. meningitidis from N. lactamica leading us to describe these species as 'fuzzy'. Conclusion A multilocus approach using large samples of closely related isolates delineates species even in the highly recombinogenic human Neisseria where individual loci are inadequate for the task. This approach should be applied by taxonomists to large samples of other groups of closely-related bacteria, and especially to those where species delineation has historically been difficult, to determine whether genotypic clusters can be delineated, and to guide the definition of species.

  14. Cecum lymph node dendritic cells harbor slow-growing bacteria phenotypically tolerant to antibiotic treatment.

    Science.gov (United States)

    Kaiser, Patrick; Regoes, Roland R; Dolowschiak, Tamas; Wotzka, Sandra Y; Lengefeld, Jette; Slack, Emma; Grant, Andrew J; Ackermann, Martin; Hardt, Wolf-Dietrich

    2014-02-01

    In vivo, antibiotics are often much less efficient than ex vivo and relapses can occur. The reasons for poor in vivo activity are still not completely understood. We have studied the fluoroquinolone antibiotic ciprofloxacin in an animal model for complicated Salmonellosis. High-dose ciprofloxacin treatment efficiently reduced pathogen loads in feces and most organs. However, the cecum draining lymph node (cLN), the gut tissue, and the spleen retained surviving bacteria. In cLN, approximately 10%-20% of the bacteria remained viable. These phenotypically tolerant bacteria lodged mostly within CD103⁺CX₃CR1⁻CD11c⁺ dendritic cells, remained genetically susceptible to ciprofloxacin, were sufficient to reinitiate infection after the end of the therapy, and displayed an extremely slow growth rate, as shown by mathematical analysis of infections with mixed inocula and segregative plasmid experiments. The slow growth was sufficient to explain recalcitrance to antibiotics treatment. Therefore, slow-growing antibiotic-tolerant bacteria lodged within dendritic cells can explain poor in vivo antibiotic activity and relapse. Administration of LPS or CpG, known elicitors of innate immune defense, reduced the loads of tolerant bacteria. Thus, manipulating innate immunity may augment the in vivo activity of antibiotics.

  15. Cecum lymph node dendritic cells harbor slow-growing bacteria phenotypically tolerant to antibiotic treatment.

    Directory of Open Access Journals (Sweden)

    Patrick Kaiser

    2014-02-01

    Full Text Available In vivo, antibiotics are often much less efficient than ex vivo and relapses can occur. The reasons for poor in vivo activity are still not completely understood. We have studied the fluoroquinolone antibiotic ciprofloxacin in an animal model for complicated Salmonellosis. High-dose ciprofloxacin treatment efficiently reduced pathogen loads in feces and most organs. However, the cecum draining lymph node (cLN, the gut tissue, and the spleen retained surviving bacteria. In cLN, approximately 10%-20% of the bacteria remained viable. These phenotypically tolerant bacteria lodged mostly within CD103⁺CX₃CR1⁻CD11c⁺ dendritic cells, remained genetically susceptible to ciprofloxacin, were sufficient to reinitiate infection after the end of the therapy, and displayed an extremely slow growth rate, as shown by mathematical analysis of infections with mixed inocula and segregative plasmid experiments. The slow growth was sufficient to explain recalcitrance to antibiotics treatment. Therefore, slow-growing antibiotic-tolerant bacteria lodged within dendritic cells can explain poor in vivo antibiotic activity and relapse. Administration of LPS or CpG, known elicitors of innate immune defense, reduced the loads of tolerant bacteria. Thus, manipulating innate immunity may augment the in vivo activity of antibiotics.

  16. Rapid quantification of rice root-associated bacteria by flow cytometry.

    Science.gov (United States)

    Valdameri, G; Kokot, T B; Pedrosa, F de O; de Souza, E M

    2015-03-01

    To understand the mechanism of plant-bacterium interaction, it is critical to enumerate epiphytic bacteria colonizing the roots of the host. We developed a new approach, based on flow cytometry, for enumerating these bacteria and used it with rice plants, 7 and 20 days after colonization with Herbaspirillum rubrisubalbicans and Azospirillum brasilense. The results were compared with those obtained with the traditional plate count method. Both methods gave similar numbers of H. rubrisubalbicans associated with rice roots (c. 10(9) CFU g(-1) ). However, flow cytometry gave a number of viable cells of rice-associated A. brasilense that was approx. 10-fold greater than that obtained with the plate count method. These results suggest that the plate count method can underestimate epiphytic populations. Flow cytometry has the additional advantage that it is more precise and much faster than the plate count method. Determination of precise number of root-associated bacteria is critical for plant-bacteria interaction studies. We developed a flow cytometry approach for counting bacteria and compared it with the plate count method. Our flow cytometry assay solves two major limitations of the plate count method, namely that requires long incubation times of up to 48 h and only determines culturable cells. This flow cytometry assay provides an efficient, precise and fast tool for enumerating epiphytic cells. © 2014 The Society for Applied Microbiology.

  17. Fighting Off Wound Pathogens in Horses with Honeybee Lactic Acid Bacteria.

    Science.gov (United States)

    Olofsson, Tobias C; Butler, Éile; Lindholm, Christina; Nilson, Bo; Michanek, Per; Vásquez, Alejandra

    2016-10-01

    In the global perspective of antibiotic resistance, it is urgent to find potent topical antibiotics for the use in human and animal infection. Healing of equine wounds, particularly in the limbs, is difficult due to hydrostatic factors and exposure to environmental contaminants, which can lead to heavy bio-burden/biofilm formation and sometimes to infection. Therefore, antibiotics are often prescribed. Recent studies have shown that honeybee-specific lactic acid bacteria (LAB), involved in honey production, and inhibit human wound pathogens. The aim of this pilot study was to investigate the effects on the healing of hard-to-heal equine wounds after treatment with these LAB symbionts viable in a heather honey formulation. For this, we included ten horses with wound duration of >1 year, investigated the wound microbiota, and treated wounds with the novel honeybee LAB formulation. We identified the microbiota using MALDI-TOF mass spectrometry and DNA sequencing. In addition, the antimicrobial properties of the honeybee LAB formulation were tested against all wound isolates in vitro. Our results indicate a diverse wound microbiota including fifty-three bacterial species that showed 90 % colonization by at least one species of Staphylococcus. Treatment with the formulation promoted wound healing in all cases already after the first application and the wounds were either completely healed (n = 3) in less than 20 days or healing was in progress. Furthermore, the honeybee LAB formulation inhibited all pathogens when tested in vitro. Consequently, this new treatment option presents as a powerful candidate for the topical treatment of hard-to-heal wounds in horses.

  18. Detection of Only Viable Bacterial Spores Using a Live/Dead Indicator in Mixed Populations

    Science.gov (United States)

    Behar, Alberto E.; Stam, Christina N.; Smiley, Ronald

    2013-01-01

    This method uses a photoaffinity label that recognizes DNA and can be used to distinguish populations of bacterial cells from bacterial spores without the use of heat shocking during conventional culture, and live from dead bacterial spores using molecular-based methods. Biological validation of commercial sterility using traditional and alternative technologies remains challenging. Recovery of viable spores is cumbersome, as the process requires substantial incubation time, and the extended time to results limits the ability to quickly evaluate the efficacy of existing technologies. Nucleic acid amplification approaches such as PCR (polymerase chain reaction) have shown promise for improving time to detection for a wide range of applications. Recent real-time PCR methods are particularly promising, as these methods can be made at least semi-quantitative by correspondence to a standard curve. Nonetheless, PCR-based methods are rarely used for process validation, largely because the DNA from dead bacterial cells is highly stable and hence, DNA-based amplification methods fail to discriminate between live and inactivated microorganisms. Currently, no published method has been shown to effectively distinguish between live and dead bacterial spores. This technology uses a DNA binding photoaffinity label that can be used to distinguish between live and dead bacterial spores with detection limits ranging from 109 to 102 spores/mL. An environmental sample suspected of containing a mixture of live and dead vegetative cells and bacterial endospores is treated with a photoaffinity label. This step will eliminate any vegetative cells (live or dead) and dead endospores present in the sample. To further determine the bacterial spore viability, DNA is extracted from the spores and total population is quantified by real-time PCR. The current NASA standard assay takes 72 hours for results. Part of this procedure requires a heat shock step at 80 degC for 15 minutes before the

  19. Graphene oxide and carboxylated graphene oxide: Viable two-dimensional nanolabels for lateral flow immunoassays.

    Science.gov (United States)

    Yu, Li; Li, Peiwu; Ding, Xiaoxia; Zhang, Qi

    2017-04-01

    Graphene oxide (GO) and carboxylated GO were used as labels for lateral flow immunoassays, instead of the conventionally used colloidal gold and colored latex labels. A sensor is demonstrated that enables fast screening for aflatoxin B 1 (AFB 1 ) as a model analyte using the antibody-GO complex as the recognition element. The visual limit of detection and cut-off value for AFB 1 are 0.3 and 1ng/mL, respectively. It is shown that GO and carboxylated GO are viable black labels for use in lateral flow assays, one typical advantage being the saving cost (compared to the use of colloidal gold). Qualitative results are achieved within 15min, and the analytical results were in good agreement with the reference LC MS/MS method. The method was successfully applied to the on-site determination of AFB 1 in agricultural products. In our perception, it opens new possibilities for the screening of other toxins by lateral flow immunoassays using GO and carboxylated GO as labels. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Meatal Mobilization and Glanuloplasty: A Viable Option for Coronal and Glanular Hypospadias Repair.

    Science.gov (United States)

    Moradi, Mahmoudreza; Kazemzadeh, Babak; Hood, Brandy; Rezaee, Haress; Kaseb, Kaveh

    2016-08-01

    To present the meatal mobilization with glanuloplasty inclusive (MMGPI) modification of meatal advancement and glanuloplasty inclusive. A total of 120 patients with anterior hypospadias underwent MMGPI between September 2008 and October 2014 at Kermanshah University of Medical Sciences. Satisfactory outcomes were defined as continuous straight urinary flow and catheterization of new meatus without difficulty. Cosmetic outcomes were considered acceptable if patients maintained a slit-like meatus at the glanular tip. Patients were examined at 1 week, 1, 3, 6, 12, and 24 months. The 120 patients with anterior hypospadias underwent MMGPI. There were no hematoma, meatal necrosis, or other early complications. In patients with glanular hypospadias, there were no meatal regressions or stenosis, all voiding patterns were normal, and all patients maintained a slit-like meatus at the glanular tip. Two patients with coronal hypospadias had meatal stenosis and 2 patients had meatal regression. Five patients with sub-coronal hypospadias had 2-mm meatal regression with downward sloping urinary stream, and 2 patients had meatal stenosis. In all, meatus remained distal to the preoperative meatus with no necrosis. Small sample size was the major limitation of this study. MMGPI represents a viable option for glanular and coronal hypospadias repair. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Eradication of high viable loads of Listeria monocytogenes contaminating food-contact surfaces

    Directory of Open Access Journals (Sweden)

    Silvia ede Candia

    2015-07-01

    Full Text Available This study demonstrates the efficacy of cold gaseous ozone treatments at low concentrations in the eradication of high Listeria monocytogenes viable cell loads from glass, polypropylene, stainless steel and expanded polystyrene food-contact surfaces. Using a step by step approach, involving the selection of the most resistant strain-surface combinations, 11 Listeria spp. strains resulted inactivated by a continuous ozone flow at 1.07 mg m-3 after 24 or 48 h of cold incubation, depending on both strain and surface evaluated. Increasing the inoculum level to 9 log CFU coupon-1, the best inactivation rate was obtained after 48h of treatment at 3.21 mg m-3 ozone concentration when cells were deposited onto stainless steel and expanded polystyrene coupons, resulted the most resistant food-contact surfaces in the previous assays.The addition of naturally microbiologically contaminated meat extract to a high load of L. monocytogenes LMG 23775 cells, the most resistant strain out of the 11 assayed Listeria spp. strains, led to its complete inactivation after four days of treatment.To the best of our knowledge, this is the first report describing the survival of L. monocytogenes and the effect of ozone treatment under cold storage conditions on expanded polystyrene, a commonly-used material in food packaging. These results could be useful for reducing pathogen cross-contamination phenomena during cold food storage.

  2. Determining size and dispersion of minimum viable populations for land management planning and species conservation

    Science.gov (United States)

    Lehmkuhl, John F.

    1984-03-01

    The concept of minimum populations of wildlife and plants has only recently been discussed in the literature. Population genetics has emerged as a basic underlying criterion for determining minimum population size. This paper presents a genetic framework and procedure for determining minimum viable population size and dispersion strategies in the context of multiple-use land management planning. A procedure is presented for determining minimum population size based on maintenance of genetic heterozygosity and reduction of inbreeding. A minimum effective population size ( N e ) of 50 breeding animals is taken from the literature as the minimum shortterm size to keep inbreeding below 1% per generation. Steps in the procedure adjust N e to account for variance in progeny number, unequal sex ratios, overlapping generations, population fluctuations, and period of habitat/population constraint. The result is an approximate census number that falls within a range of effective population size of 50 500 individuals. This population range defines the time range of short- to long-term population fitness and evolutionary potential. The length of the term is a relative function of the species generation time. Two population dispersion strategies are proposed: core population and dispersed population.

  3. Birth of viable puppies derived from breeding cloned female dogs with a cloned male.

    Science.gov (United States)

    Park, J E; Hong, S G; Kang, J T; Oh, H J; Kim, M K; Kim, M J; Kim, H J; Kim, D Y; Jang, G; Lee, B C

    2009-09-15

    Since the establishment of production of viable cloned dogs by somatic cell nucleus transfer, great concern has been given to the reproductive abilities of these animals (Canis familiaris). Therefore, we investigated reproductive activity of cloned dogs by (1) performing sperm analysis using computer-assisted sperm analysis and early embryonic development, (2) assessing reproductive cycling by measuring serum progesterone (P4) levels and performing vaginal cytology, and (3) breeding cloned dogs using artificial insemination. Results showed that most parameters of sperm motility in a cloned male dog were within the reference range, and in vivo-matured oocytes from a noncloned female were successfully fertilized by spermatozoa from a cloned male dog and develop normally to the 8-cell stage. Three cloned female dogs displayed normal patterns of P4 levels and morphologic changes of the vaginal epithelium. Two cloned female dogs became pregnant using semen from a cloned male dog and successfully delivered 10 puppies by natural labor. In conclusion, these data demonstrated that both cloned male and female dogs are fertile, and their puppies are currently alive and healthy with normal growth patterns.

  4. Exploring viable vacua of the Z{sub 3}-symmetric NMSSM

    Energy Technology Data Exchange (ETDEWEB)

    Beuria, Jyotiranjan [Harish-Chandra Research Institute,Allahabad 211019 (India); Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400085 (India); Regional Centre for Accelerator-based Particle Physics, Harish-Chandra Research Institute,Allahabad 211019 (India); Chattopadhyay, Utpal [Department of Theoretical Physics, Indian Association for the Cultivation of Science, 2A & B Raja S. C. Mullick Road, Jadavpur, Kolkata 700 032 (India); Datta, AseshKrishna [Harish-Chandra Research Institute,Allahabad 211019 (India); Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400085 (India); Dey, Abhishek [Maulana Azad College, Government of West Bengal, 8 Rafi Ahmed Kidwai Road, Kolkata 700013 (India)

    2017-04-05

    We explore the vacua of the Z{sub 3}-symmetric Next-to-Minimal Supersymmetric Standard Model (NMSSM) and their stability by going beyond the simplistic paradigm that works with a tree-level neutral scalar potential and adheres to some specific flat directions in the field space. We work in the so-called phenomenological NMSSM (pNMSSM) scenario. Also, for our purpose, we adhere to a reasonably ‘natural’ setup by requiring |μ{sub eff}| not too large. Key effects are demonstrated by first studying the profiles of this potential under various circumstances of physical interest via a semi-analytical approach. The results thereof are compared to the ones obtained from a dedicated package like Vevacious which further incorporates the thermal effects to the potential. Regions of the pNMSSM parameter space that render the desired symmetry breaking (DSB) vacuum absolutely stable, long- or short-lived (in relation to the age of the Universe) under quantum/thermal tunneling are delineated. Regions that result in the appearance of color and charge breaking (CCB) minima are also presented. It is demonstrated that light singlet scalars along with a light LSP (lightest supersymmetric particle) having an appreciable singlino admixture are compatible with a viable DSB vacuum. Their implications for collider experiments are commented upon.

  5. The Independent Evolution Method Is Not a Viable Phylogenetic Comparative Method.

    Directory of Open Access Journals (Sweden)

    Randi H Griffin

    Full Text Available Phylogenetic comparative methods (PCMs use data on species traits and phylogenetic relationships to shed light on evolutionary questions. Recently, Smaers and Vinicius suggested a new PCM, Independent Evolution (IE, which purportedly employs a novel model of evolution based on Felsenstein's Adaptive Peak Model. The authors found that IE improves upon previous PCMs by producing more accurate estimates of ancestral states, as well as separate estimates of evolutionary rates for each branch of a phylogenetic tree. Here, we document substantial theoretical and computational issues with IE. When data are simulated under a simple Brownian motion model of evolution, IE produces severely biased estimates of ancestral states and changes along individual branches. We show that these branch-specific changes are essentially ancestor-descendant or "directional" contrasts, and draw parallels between IE and previous PCMs such as "minimum evolution". Additionally, while comparisons of branch-specific changes between variables have been interpreted as reflecting the relative strength of selection on those traits, we demonstrate through simulations that regressing IE estimated branch-specific changes against one another gives a biased estimate of the scaling relationship between these variables, and provides no advantages or insights beyond established PCMs such as phylogenetically independent contrasts. In light of our findings, we discuss the results of previous papers that employed IE. We conclude that Independent Evolution is not a viable PCM, and should not be used in comparative analyses.

  6. Survival of Erwinia amylovora in mature apple fruit calyces through the viable but nonculturable (VBNC) state.

    Science.gov (United States)

    Ordax, M; Biosca, E G; Wimalajeewa, S C; López, M M; Marco-Noales, E

    2009-07-01

    Survival of Erwinia amylovora, causal agent of fire blight in pome fruits and other rosaceous plants, was monitored inside mature apples calyces under some storage conditions utilized in fruit. Apple fruit calyces inoculated with two E. amylovora strains and their respective GFP-marked strains were maintained at 26 degrees and 5 degrees C, and the effect of copper treatment was assayed at 0.01 and 0.1 mmol l(-1) CuSO4. In nontreated apples at 26 degrees C, part of the population of E. amylovora survived in the 'viable but nonculturable' (VBNC) state, whereas at 5 degrees C the majority of the population retained culturability. In copper-treated apples, the whole population adopted the VBNC state irrespective of temperature. Regardless of temperature, copper and inoculum dose, VBNC cells recovered culturability and pathogenicity in King's B broth or by host plant passage. Erwinia amylovora survived for at least 35 days in mature apple calyces. Besides, the ability of the pathogen in the VBNC state to regain culturability and pathogenicity suggests that the apple fruit could be a potential carrier of E. amylovora contributing to the spreading of fire blight disease. The risk of E. amylovora dissemination through mature fruit transport, although low, has been demonstrated, and should be considered in pest risk assessments.

  7. Novel Approach for Enterocutaneous Fistula Treatment with the Use of Viable Cryopreserved Placental Membrane

    Directory of Open Access Journals (Sweden)

    Frederick Nichols

    2016-01-01

    Full Text Available Enterocutaneous fistulas (ECF are a difficult and costly surgical complication to manage. The standard treatment of nil per os (NPO and total paraenteral nutrition (TPN is not well tolerated by patients. TPN is also known for complications associated with long term central venous catheterization and for high cost of prolonged hospital stay. We present two low output ECF cases successfully treated with viable cryopreserved placental membrane (vCPM placed into the fistula tracts. One patient is a 59-year-old male with a low output ECF from a jejunostomy tube site four weeks after the surgery. The second patient is an 87-year-old male with a low output ECF following a small bowel resection secondary to a strangulated inguinal hernia. He was evaluated on day 41 after surgery. NPO and TPN for several weeks did not resolute the ECF. The fistulae were closed postoperatively in both patients with zero output on the same day after one vCPM application. On day 3 postoperatively both patients were started on clear liquid diets and subsequently advanced to regular diets. The ECF have remained resolved for over 2 months. The use of vCPM is a novel promising approach for treatment of ECF.

  8. Agouti regulation of intracellular calcium: Role in the insulin resistance of viable yellow mice

    Energy Technology Data Exchange (ETDEWEB)

    Zemel, M.B.; Kim, J.H. [Univ. of Tennessee, Knoxville, TN (United States); Woychik, R.P.; Michaud, E.J. [Oak Ridge National Laboratory, Oak Ridge, TN (United States); Hadwell, S.H.; Patel, I.R.; Wilkison, W.O. [Research Institute, Research Triangle Park, NC (United States)

    1995-05-23

    Several dominant mutations at the agouti locus in the mouse cause a syndrome of marked obesity, hyperinsulinemia, and insulin resistance. Although it is known that the agouti gene is expressed in an ectopic manner in these mutants, the precise mechanism by which the agouti gene product mediates these effects is unclear. Since intracellular Ca{sup 2+} is believed to play a role in mediating insulin action and dysregulation of Ca{sup 2+} flux is observed in diabetic animals and humans, we examined the status of intracellular Ca{sup 2+} in mice carrying the dominant agouti allele, viable yellow (A{sup vy}). We show here that in mice carrying this mutation, the intracellular free calcium concentration ([Ca{sup 2+}]{sub i}) is elevated in skeletal muscle, and the degree of elevation is closely correlated with the degree to which the mutant traits are expressed in individual animals. Moreover, we demonstrate that the agouti gene product is capable of inducing increased [Ca{sup 2+}]{sub i} in cultured and freshly isolated skeletal muscle myocytes from wild-type mice. Based on these findings, we present a model in which we propose that the agouti polypeptide promotes insulin resistance in mutant animals through its ability to increase [Ca{sup 2+}]{sub i}. 36 refs., 3 figs., 2 tabs.

  9. Low-dose dobutamine myocardial perfusion scintigraphy in the identification of viable myocardium

    Energy Technology Data Exchange (ETDEWEB)

    Moraes, Renata Freire de [Instituto Hermes Pardini, Belo Horizonte, MG (Brazil). Dept. of Molecular Imaging and Diagnosis. Div. of Nuclear Medicine; Meneghetti, Jose Claudio [Instituto do Coracao (InCor-HC/FM/USP), Sao Paulo, SP (Brazil). Unit of Nuclear Medicine and Molecular Imaging; Barroso, Adelanir Antonio, E-mail: renatafreire@yahoo.com.b [Nuclear Medcenter, Belo Horizonte, MG (Brazil)

    2010-09-15

    Objective: to evaluate the increase in specificity of dual isotope myocardial perfusion gated SPECT ({sup 99m}Tcsestamibi/thallium-201), a highly sensitive method to detect viable myocardium, with addition of data on contractile reserve simultaneously acquired by low-dose dobutamine gated SPECT, similarly to echocardiography. Materials and methods: a total of 260 myocardial segments were assessed in 13 patients with myocardial infarction referred for investigation of myocardial viability before undergoing revascularization. Cellular integrity and contractile reserve were evaluated by dual isotope perfusion myocardial gated SPECT with thallium rest and redistribution images and post-stress {sup 99m}Tc-sestamibi gated-SPECT images under basal conditions and with low-dose dobutamine. The improvement in the contractile performance detected by post-revascularization {sup 99m}Tc-sestamibi gated SPECT was the parameter considered for determining myocardial viability. For the purpose of results analysis, the functional parameters of the myocardial segments were quantified at the different phases of the study and stratified according to their viability for a later post-revascularization functional comparison. Results: in the statistical analysis, systolic wall thickening demonstrated to be a relevant parameter in the evaluation of myocardial contractile reserve by this method, with a tendency of improvement in the specificity (84%), demonstrating higher values than those observed in the literature. Conclusion: this method tends to present an effective contribution in the assessment of myocardial viability. (author)

  10. IN-VITRO BIOREDUCTION OF HEXAVALENT CHROMIUM BY VIABLE WHOLE CELLS OF Arthrobacter sp. SUK 1201

    Directory of Open Access Journals (Sweden)

    Satarupa Dey

    2014-08-01

    Full Text Available A chromium resistant and reducing bacterium Arthrobacter sp. SUK 1201 was isolated from chromite mine overburden dumps of Orissa, India. Viable whole cells of this isolate was capable of completely reducing 100 µM Cr(VI in chemically defined MS medium within 28 h of incubation under batch cultivation. Reduction of chromate increased with increased cell density and was maximum at a density of 1010 cells/ml, but the reduction potential of the suspended cells decreased with increase in Cr(VI concentration in the medium. Chromate reducing efficiency was promoted when glycerol and glucose was used as electron donors, while the optimum pH and temperature of Cr(VI reduction was found to be 7.0 and 35°C respectively. The reduction process was inhibited by divalent cations Ni, Co and Cd, but not by Cu and Fe. Similarly, carbonyl cyanide m-chlorophenylhydrazone (CCCP, N,N,-Di cyclohexyl carboiimide (DCC, sodium azide and sodium fluoride were inhibitory to chromate reduction, while in presence of 2,4 dinitrophenol (2,4 DNP chromate reduction by SUK 1201 cells remained unaffected.

  11. Maize Residue as a Viable Substrate for Farm Scale Cultivation of Oyster Mushroom (Pleurotus ostreatus

    Directory of Open Access Journals (Sweden)

    Abena O. Adjapong

    2015-01-01

    Full Text Available In the search for alternatives to sawdust as growing media in commercial mushroom cultivation, three organic substrates obtainable as crop residue, maize husk, maize cob, and maize stalk, with each being supplemented with rice bran, were evaluated as growth media for the oyster mushroom, Pleurotus ostreatus (Kummer. For the tested alternatives to sawdust, the harvested weight of fruiting bodies that sprouted on a kilogram maize husk media per crop (32.99 g was the highest. Sawdust media supported significantly (P<0.001 heavier fruiting bodies (42.18 than the maize residues. The peak mushroom harvests for the various substrates were obtained between the first and seventh fruiting body flushes. The biological efficiency of the substrates, which measured usable nutrients indicated that maize stalk supplemented with rice bran, was 39% compared to that of the sawdust media (60%. The maize husk media and the maize cob media had biological efficiencies of 32% and 9.5%, respectively. These results indicate that two of the tested growing media (maize stalk or husk produced mushrooms with yield characteristics that were comparable to the well-used sawdust in the cultivation of oyster mushrooms. The environmental and economic parameters involved in the use and carting of sawdust make these on-farm crop residues a viable alternative for mushroom cultivation in especially nonforest zones of Ghana.

  12. Viable cold-tolerant iron-reducing microorganisms in geographically diverse subglacial environments

    Science.gov (United States)

    Nixon, Sophie L.; Telling, Jon P.; Wadham, Jemma L.; Cockell, Charles S.

    2017-03-01

    Subglacial environments are known to harbour metabolically diverse microbial communities. These microbial communities drive chemical weathering of underlying bedrock and influence the geochemistry of glacial meltwater. Despite its importance in weathering reactions, the microbial cycling of iron in subglacial environments, in particular the role of microbial iron reduction, is poorly understood. In this study we address the prevalence of viable iron-reducing microorganisms in subglacial sediments from five geographically isolated glaciers. Iron-reducing enrichment cultures were established with sediment from beneath Engabreen (Norway), Finsterwalderbreen (Svalbard), Leverett and Russell glaciers (Greenland), and Lower Wright Glacier (Antarctica). Rates of iron reduction were higher at 4 °C compared with 15 °C in all but one duplicated second-generation enrichment culture, indicative of cold-tolerant and perhaps cold-adapted iron reducers. Analysis of bacterial 16S rRNA genes indicates Desulfosporosinus were the dominant iron-reducing microorganisms in low-temperature Engabreen, Finsterwalderbreen and Lower Wright Glacier enrichments, and Geobacter dominated in Russell and Leverett enrichments. Results from this study suggest microbial iron reduction is widespread in subglacial environments and may have important implications for global biogeochemical iron cycling and export to marine ecosystems.

  13. Flow Cytometry Sorting to Separate Viable Giant Viruses from Amoeba Co-culture Supernatants.

    Science.gov (United States)

    Khalil, Jacques Y B; Langlois, Thierry; Andreani, Julien; Sorraing, Jean-Marc; Raoult, Didier; Camoin, Laurence; La Scola, Bernard

    2016-01-01

    Flow cytometry has contributed to virology but has faced many drawbacks concerning detection limits, due to the small size of viral particles. Nonetheless, giant viruses changed many concepts in the world of viruses, as a result of their size and hence opened up the possibility of using flow cytometry to study them. Recently, we developed a high throughput isolation of viruses using flow cytometry and protozoa co-culture. Consequently, isolating a viral mixture in the same sample became more common. Nevertheless, when one virus multiplies faster than others in the mixture, it is impossible to obtain a pure culture of the minority population. Here, we describe a robust sorting system, which can separate viable giant virus mixtures from supernatants. We tested three flow cytometry sorters by sorting artificial mixtures. Purity control was assessed by electron microscopy and molecular biology. As proof of concept, we applied the sorting system to a co-culture supernatant taken from a sample containing a viral mixture that we couldn't separate using end point dilution. In addition to isolating the quick-growing Mimivirus, we sorted and re-cultured a new, slow-growing virus, which we named "Cedratvirus." The sorting assay presented in this paper is a powerful and versatile tool for separating viral populations from amoeba co-cultures and adding value to the new field of flow virometry.

  14. Wormholes in viable f(R) modified theories of gravity and weak energy condition

    Energy Technology Data Exchange (ETDEWEB)

    Pavlovic, Petar [Universitaet Hamburg, II. Institut fuer Theoretische Physik, Hamburg (Germany); Sossich, Marko [University of Zagreb, Department of Physics, Faculty of Electrical Engineering and Computing, Zagreb (Croatia)

    2015-03-01

    In this work wormholes in viable f(R) gravity models are analyzed. We are interested in exact solutions for stress-energy tensor components depending on different shape and redshift functions. Several solutions of gravitational equations for different f(R) models are examined. The solutions found imply no need for exotic material, while this need is implied in the standard general theory of relativity. A simple expression for weak energy condition (WEC) violation near the throat is derived and analyzed. High curvature regime is also discussed, as well as the question of the highest possible values of the Ricci scalar for which the WEC is not violated near the throat, and corresponding functions are calculated for several models. The approach here differs from the one that has been common since no additional assumptions to simplify the equations have been made, and the functions in f(R) models are not considered to be arbitrary functions, but rather a feature of the theory that has to be evaluated on the basis of consistency with observations for the Solar System and cosmological evolution. Therefore in this work we show that the existence of wormholes without exotic matter is not only possible in simple arbitrary f(R) models, but also in models that are in accordance with empirical data. (orig.)

  15. Estimation of Viable Biomass In Wastewater And Activated Sludge By Determination of ATP, Oxygen Utilization Rate And FDA Hydrolysis

    DEFF Research Database (Denmark)

    Jørgensen, Poul-Erik; Eriksen, T.; Jensen, B.K.

    1992-01-01

    ATP content, oxygen utilization rate (OUR) and fluorescein diacetate (FDA) hydrolysis were tested for the ability to express the amount of viable biomass in wastewater and activated sludge. The relationship between biomass and these activity parameters was established in growth cultures made...... with biomass, while FDA hydrolysis in the sludge failed to show any such correlation. Conversion factors of 3 mg ATP/g dw, 300 mg O2/h g dw and 0.4 A/h (mg dw/ml) for ATP, OUR and FDA methods, respectively, were calculated. When the methods were applied for in situ determinations in four different wastewater...... plants, it was found that ATP content and respiration rate estimated viable biomass to range from 81 to 293 mg dw/g SS for raw wastewater and from 67 to 187 mg dw/g SS for activated sludge with a rather weak correlation between ATP and respiration measurements. The FDA hydrolysis estimated viable biomass...

  16. Trypan blue dye enters viable cells incubated with the pore-forming toxin HlyII of Bacillus cereus.

    Directory of Open Access Journals (Sweden)

    Seav-Ly Tran

    Full Text Available Trypan blue is a dye that has been widely used for selective staining of dead tissues or cells. Here, we show that the pore-forming toxin HlyII of Bacillus cereus allows trypan blue staining of macrophage cells, despite the cells remaining viable and metabolically active. These findings suggest that the dye enters viable cells through the pores. To our knowledge, this is the first demonstration that trypan blue may enter viable cells. Consequently, the use of trypan blue staining as a marker of vital status should be interpreted with caution. The blue coloration does not necessarily indicate cell lysis, but may rather indicate pore formation in the cell membranes and more generally increased membrane permeability.

  17. Structural diversity and biological significance of lipoteichoic acid in Gram-positive bacteria: focusing on beneficial probiotic lactic acid bacteria.

    Science.gov (United States)

    Shiraishi, Tsukasa; Yokota, Shinichi; Fukiya, Satoru; Yokota, Atsushi

    2016-01-01

    Bacterial cell surface molecules are at the forefront of host-bacterium interactions. Teichoic acids are observed only in Gram-positive bacteria, and they are one of the main cell surface components. Teichoic acids play important physiological roles and contribute to the bacterial interaction with their host. In particular, lipoteichoic acid (LTA) anchored to the cell membrane has attracted attention as a host immunomodulator. Chemical and biological characteristics of LTA from various bacteria have been described. However, most of the information concerns pathogenic bacteria, and information on beneficial bacteria, including probiotic lactic acid bacteria, is insufficient. LTA is structurally diverse. Strain-level structural diversity of LTA is suggested to underpin its immunomodulatory activities. Thus, the structural information on LTA in probiotics, in particular strain-associated diversity, is important for understanding its beneficial roles associated with the modulation of immune response. Continued accumulation of structural information is necessary to elucidate the detailed physiological roles and significance of LTA. In this review article, we summarize the current state of knowledge on LTA structure, in particular the structure of LTA from lactic acid bacteria. We also describe the significance of structural diversity and biological roles of LTA.

  18. Endophytic bacteria associated with growing shoot tips of banana (Musa sp.) cv. Grand Naine and the affinity of endophytes to the host.

    Science.gov (United States)

    Thomas, Pious; Soly, Thyvalappil A

    2009-11-01

    A cultivation-based assessment of endophytic bacteria present in deep-seated shoot tips of banana suckers was made with a view to generate information on the associated organisms, potential endophytic contaminants in tissue-cultured bananas and to assess if the endophytes shared a beneficial relationship with the host. Plating the tissue homogenate from the central core of suckers showed colony growth on nutrient agar from just 75% and 42% of the 12 stocks during May and November, respectively (average 58%; 6 x 10(3) colony-forming units per gram), yielding diverse organisms belonging to firmicutes (Bacillus, Brevibacillus, Paenibacillus, Virgibacillus, Staphylococcus spp.), actinobacteria (Cellulomonas, Micrococcus, Corynebacterium, Kocuria spp.), alpha-proteobacteria (Paracoccus sp.), and gamma-proteobacteria (Pseudomonas, Acinetobacter spp.). Each shoot tip showed one to three different organisms and no specific organism appeared common to different sucker tips. Tissue homogenate from shoot tips including the ones that did not yield culturable bacteria displayed abundant bacterial cells during microscopic examination suggesting that a high proportion of cells were in viable-but-nonculturable state, or their cultivation requirements were not met. Direct application of cultivation-independent approach to study endophytic bacterial community using bacterial 16S ribosomal RNA universal primers resulted in high interference from chloroplast and mitochondrial genome sequences. Dislodging the bacterial cells from shoot tips that did not show cultivable bacteria and incubating the tissue crush in dilute-nutrient broth led to the activation of four organisms (Klebsiella, Agrobacterium, Pseudacidovorax spp., and an unidentified isolate). The endophytic organisms in general showed better growth at 30-37 degrees C compared with 25 degrees C, and the growth of endophytes as well as pathogenic Erwinia carotovora were promoted with the supply of host tissue extract (HTE) while

  19. Straining phenomena in bacteria transport through natural porous media.

    Science.gov (United States)

    Díaz, Jaime; Rendueles, Manuel; Díaz, Mario

    2010-02-01

    Transport of bacteria through natural porous media is an issue of increasing concern arising in several very important environmental processes. These include the percolation of bacteria from fecal waste to drinking water reservoirs, thus leading to a risk for human health, or the bioremediation of contaminated soils in which the bacteria are expected to travel long distances underground in order to reach contaminated areas and degrade chemicals originating from accidental spills. An understanding of bacterial retention and transport mechanisms in porous media would be of great help in the development of models able to predict the distance covered by bacterial suspensions in these situations. Experiments were carried out preparing columns filled of soil and sand, introducing bacteria culture (Escherichia coli, Pseudomona putida, and Listeria innocua) solutions by the top of the column. Breakthrough curves were obtained to see the transport of the bacteria in the column. The transport of different bacteria in the two soils aimed at establishing the relative importance of straining in different conditions. This has enabled us to obtain certain parameters, such as the sticking coefficients derived from the filtration theory or bacterial recoveries after multi-step elution, which aid our understanding of how bacteria are retained by mechanisms different to those usually included in the physico-chemical filtration theory. Several indicators may be used to determine the degree of relevance of straining as a mechanism acting during bacterial transport through porous media. Usually, in natural media, neither straining nor physico-chemical filtration is the sole mechanism contributing to bacterial retention. The retention of bacteria by straining mechanisms can be assessed by means of elution profiles under varying conditions. The inversion of flow in our experiments gave rise to secondary elution peaks, probably originating from bacteria retained in narrow pores According

  20. Genetics of Lactic Acid Bacteria

    Science.gov (United States)

    Zagorec, Monique; Anba-Mondoloni, Jamila; Coq, Anne-Marie Crutz-Le; Champomier-Vergès, Marie-Christine

    Many meat (or fish) products, obtained by the fermentation of meat originating from various animals by the flora that naturally contaminates it, are part of the human diet since millenaries. Historically, the use of bacteria as starters for the fermentation of meat, to produce dry sausages, was thus performed empirically through the endogenous micro-biota, then, by a volunteer addition of starters, often performed by back-slopping, without knowing precisely the microbial species involved. It is only since about 50 years that well defined bacterial cultures have been used as starters for the fermentation of dry sausages. Nowadays, the indigenous micro-biota of fermented meat products is well identified, and the literature is rich of reports on the identification of lactic acid bacteria (LAB) present in many traditional fermented products from various geographical origin, obtained without the addition of commercial starters (See Talon, Leroy, & Lebert, 2007, and references therein).

  1. Dissipative Shocks behind Bacteria Gliding

    CERN Document Server

    Virga, Epifanio G

    2014-01-01

    Gliding is a means of locomotion on rigid substrates utilized by a number of bacteria includingmyxobacteria and cyanobacteria. One of the hypotheses advanced to explain this motility mechanism hinges on the role played by the slime filaments continuously extruded from gliding bacteria. This paper solves in full a non-linear mechanical theory that treats as dissipative shocks both the point where the extruded slime filament comes in contact with the substrate, called the filament's foot, and the pore on the bacterium outer surface from where the filament is ejected. We prove that kinematic compatibility for shock propagation requires that the bacterium uniform gliding velocity (relative to the substrate) and the slime ejecting velocity (relative to the bacterium) must be equal, a coincidence that seems to have already been observed.

  2. [Diversity of culturable butane-oxidizing bacteria in oil and gas field soil].

    Science.gov (United States)

    Zhang, Ying; Li, Bao-Zhen; Yang, Jin-Shui; Wang, Shuang-Qing; Yuan, Hong-Li

    2012-01-01

    Butane-oxidizing bacteria in soil sample sites from Puguang gas field in Sichuan province and Jianghan oil field in Hubei province were isolated and 16S rRNA gene sequence and phylogenetic analysis were applied. The differences of number and phylogenetic position and population diversity of hydrocarbon-oxidizing bacteria in different environment were investigated. The results show that 25 strains of butane-oxidizing bacteria were isolated. Based on sequencing of 16S rRNA gene, the species of bacteria in two samples are classified into 3 phyla including Firmicutes, Actinobacteria and Proteobacteria. The community structure of butane-oxidizing bacteria isolated from two oil samples is simple, both of them contain 4 genus including Bacillus, Pseudomonas, Rhodococcus and Arthrobacter. Strains in the genus of Ochrobactrum and Mycobacterium were only isolated from Puguang gas field. The number and population diversity of butane-oxidizing bacteria in Puguang gas field was more than those in Jianghan oil field.

  3. Increased translocation of bacteria from the gastrointestinal tracts of tumor-bearing mice.

    Science.gov (United States)

    Penn, R L; Maca, R D; Berg, R D

    1985-03-01

    Aerobic gram-negative bacilli and other indigenous gastrointestinal (GI) bacteria are important opportunistic pathogens in immunosuppressed cancer patients. These same bacteria frequently translocate from the GI tracts of mice immunosuppressed by single injections of certain anticancer drugs or by T-lymphocyte impairments. Since similar cellular and humoral immune deficiencies may be present in the tumor-bearing host, we sought to determine if progressive growth of a tumor alone would be sufficient to enhance the translocation of indigenous bacteria from the murine GI tract. Pathogen-free DBA/2 mice were injected intraperitoneally with 10(6) viable sarcoma 180 (S-180) cells or 0.5 ml of sterile buffer. Mesenteric lymph nodes, livers, spleens, and kidneys were tested for the presence of translocated aerobic GI bacteria on various days after tumor injection. Immunity was assessed by measuring footpad delayed-type hypersensitivity and serum hemagglutinins to sheep erythrocytes. Overall, translocated aerobic GI bacteria infected 33 of 92 S-180-bearing mice (36%) and only 9 of 99 control mice (9%) (P less than 10(-6)). Cumulatively, 50 of 460 sites (10.9%) in S-180-bearing mice were infected with translocated GI bacteria as opposed to only 9 of 485 sites (1.9%) in control animals (P less than 10(-7)). GI bacteria often translocated to infect more than one site in tumor-bearing mice, but not in controls. Aerobic gram-negative bacilli translocated 11 times in tumor-bearing mice, but only once in controls, even though the mean cecal population levels of these bacteria were relatively low (range, 4.33 to 5.28 log10 bacteria per g). The population levels of cecal aerobic bacteria were similar in S-180 and control mice throughout the period of observation. S-180 mice had significantly suppressed (P less than 0.04) delayed-type hypersensitivity and serum hemagglutinin responses when sensitized 4 or 8 days after S-180 injection. S-180 growth was associated with a neutrophilic

  4. Re-engineering bacteria for ethanol production

    Science.gov (United States)

    Yomano, Lorraine P; York, Sean W; Zhou, Shengde; Shanmugam, Keelnatham; Ingram, Lonnie O

    2014-05-06

    The invention provides recombinant bacteria, which comprise a full complement of heterologous ethanol production genes. Expression of the full complement of heterologous ethanol production genes causes the recombinant bacteria to produce ethanol as the primary fermentation product when grown in mineral salts medium, without the addition of complex nutrients. Methods for producing the recombinant bacteria and methods for producing ethanol using the recombinant bacteria are also disclosed.

  5. Fluorescence characterization of clinically-important bacteria.

    Science.gov (United States)

    Dartnell, Lewis R; Roberts, Tom A; Moore, Ginny; Ward, John M; Muller, Jan-Peter

    2013-01-01

    Healthcare-associated infections (HCAI/HAI) represent a substantial threat to patient health during hospitalization and incur billions of dollars additional cost for subsequent treatment. One promising method for the detection of bacterial contamination in a clinical setting before an HAI outbreak occurs is to exploit native fluorescence of cellular molecules for a hand-held, rapid-sweep surveillance instrument. Previous studies have shown fluorescence-based detection to be sensitive and effective for food-borne and environmental microorganisms, and even to be able to distinguish between cell types, but this powerful technique has not yet been deployed on the macroscale for the primary surveillance of contamination in healthcare facilities to prevent HAI. Here we report experimental data for the specification and design of such a fluorescence-based detection instrument. We have characterized the complete fluorescence response of eleven clinically-relevant bacteria by generating excitation-emission matrices (EEMs) over broad wavelength ranges. Furthermore, a number of surfaces and items of equipment commonly present on a ward, and potentially responsible for pathogen transfer, have been analyzed for potential issues of background fluorescence masking the signal from contaminant bacteria. These include bedside handrails, nurse call button, blood pressure cuff and ward computer keyboard, as well as disinfectant cleaning products and microfiber cloth. All examined bacterial strains exhibited a distinctive double-peak fluorescence feature associated with tryptophan with no other cellular fluorophore detected. Thus, this fluorescence survey found that an emission peak of 340nm, from an excitation source at 280nm, was the cellular fluorescence signal to target for detection of bacterial contamination. The majority of materials analysed offer a spectral window through which bacterial contamination could indeed be detected. A few instances were found of potential problems

  6. Fluorescence characterization of clinically-important bacteria.

    Directory of Open Access Journals (Sweden)

    Lewis R Dartnell

    Full Text Available Healthcare-associated infections (HCAI/HAI represent a substantial threat to patient health during hospitalization and incur billions of dollars additional cost for subsequent treatment. One promising method for the detection of bacterial contamination in a clinical setting before an HAI outbreak occurs is to exploit native fluorescence of cellular molecules for a hand-held, rapid-sweep surveillance instrument. Previous studies have shown fluorescence-based detection to be sensitive and effective for food-borne and environmental microorganisms, and even to be able to distinguish between cell types, but this powerful technique has not yet been deployed on the macroscale for the primary surveillance of contamination in healthcare facilities to prevent HAI. Here we report experimental data for the specification and design of such a fluorescence-based detection instrument. We have characterized the complete fluorescence response of eleven clinically-relevant bacteria by generating excitation-emission matrices (EEMs over broad wavelength ranges. Furthermore, a number of surfaces and items of equipment commonly present on a ward, and potentially responsible for pathogen transfer, have been analyzed for potential issues of background fluorescence masking the signal from contaminant bacteria. These include bedside handrails, nurse call button, blood pressure cuff and ward computer keyboard, as well as disinfectant cleaning products and microfiber cloth. All examined bacterial strains exhibited a distinctive double-peak fluorescence feature associated with tryptophan with no other cellular fluorophore detected. Thus, this fluorescence survey found that an emission peak of 340nm, from an excitation source at 280nm, was the cellular fluorescence signal to target for detection of bacterial contamination. The majority of materials analysed offer a spectral window through which bacterial contamination could indeed be detected. A few instances were found of

  7. Close Encounters of Lymphoid Cells and Bacteria

    Science.gov (United States)

    Cruz-Adalia, Aranzazu; Veiga, Esteban

    2016-01-01

    During infections, the first reaction of the host against microbial pathogens is carried out by innate immune cells, which recognize conserved structures on pathogens, called pathogen-associated molecular patterns. Afterward, some of these innate cells can phagocytose and destroy the pathogens, secreting cytokines that would modulate the immune response to the challenge. This rapid response is normally followed by the adaptive immunity, more specific and essential for a complete pathogen clearance in many cases. Some innate immune cells, usually named antigen-presenting cells, such as macrophages or dendritic cells, are able to process internalized invaders and present their antigens to lymphocytes, triggering the adaptive immune response. Nevertheless, the traditional boundary of separated roles between innate and adaptive immunity has been blurred by several studies, showing that very specialized populations of lymphocytes (cells of the adaptive immunity) behave similarly to cells of the innate immunity. These “innate-like” lymphocytes include γδ T cells, invariant NKT cells, B-1 cells, mucosal-associated invariant T cells, marginal zone B cells, and innate response activator cells, and together with the newly described innate lymphoid cells are able to rapidly respond to bacterial infections. Strikingly, our recent data suggest that conventional CD4+ T cells, the paradigm of cells of the adaptive immunity, also present innate-like behavior, capturing bacteria in a process called transinfection. Transinfected CD4+ T cells digest internalized bacteria like professional phagocytes and secrete large amounts of proinflammatory cytokines, protecting for further bacterial challenges. In the present review, we will focus on the data showing such innate-like behavior of lymphocytes following bacteria encounter. PMID:27774092

  8. Theory including future not excluded

    DEFF Research Database (Denmark)

    Nagao, K.; Nielsen, H.B.

    2013-01-01

    We study a complex action theory (CAT) whose path runs over not only past but also future. We show that, if we regard a matrix element defined in terms of the future state at time T and the past state at time TA as an expectation value in the CAT, then we are allowed to have the Heisenberg equation......, Ehrenfest's theorem, and the conserved probability current density. In addition,we showthat the expectation value at the present time t of a future-included theory for large T - t and large t - T corresponds to that of a future-not-included theory with a proper inner product for large t - T. Hence, the CAT...

  9. Stopping Oxytocin in Active Labor Rather Than Continuing it until Delivery: A Viable Option for the Induction of Labor

    Directory of Open Access Journals (Sweden)

    Seema Chopra

    2015-09-01

    Full Text Available Objective: Induction of labor (IOL, using intravenous oxytocin, is the artificial initiation of labor before its spontaneous onset for the purpose of delivery of the fetoplacental unit. Although there are various studies looking at dosages of oxytocin, only a few have addressed the issue of discontinuation of oxytocin in the active stage of labor. Thus, our study was conducted to evaluate the need for continuation versus discontinuation of oxytocin during active labor. Methods: This prospective, randomized controlled trial included 106 women who needed IOL. Oxytocin infusion was initiated at a rate of 3mIU/min and was incremental until 4–6cm cervical dilation. At this point the patients were randomly assigned into one of two groups. In group one, oxytocin was discontinued, and infusion was continued with 0.9% sodium chloride solution. In group two, oxytocin was continued at the same dose until delivery. Results: The duration of oxytocin infusion was 5.5 hours in the oxytocin discontinuation group and 11.0 hours in oxytocin continuation group (p<0.001. The total dose of oxytocin was significantly higher in group two (6.1 units vs. 16.5 units; p=<0.001. The induction-delivery interval was significantly less in group one (9.1 and 11.2 hours in group one and group two, respectively; p=0.023. Conclusion: Oxytocin discontinuation in the active stage of labor did not prolong the active stage. The total duration of labor and total oxytocin dose were significantly less in the oxytocin discontinuation group. Our results suggest that oxytocin discontinuation is an alternative and viable option particularly in resource poor and economically challenged settings. It not only reduces the need for intense monitoring and prolonged oxytocin use-associated dangers but reduces the total cost of labor management.

  10. Abnormal human chorionic gonadotropin (hCG) trends after transfer of multiple embryos resulting in viable singleton pregnancies.

    Science.gov (United States)

    Brady, Paula C; Farland, Leslie V; Missmer, Stacey A; Racowsky, Catherine; Fox, Janis H

    2017-12-19

    The purpose of this study is to investigate whether abnormal hCG trends occur at a higher incidence among women conceiving singleton pregnancies following transfer of multiple (two or more) embryos (MET), as compared to those having a single embryo transfer (SET). Retrospective cohort study was performed of women who conceived singleton pregnancies following fresh or frozen autologous IVF/ICSI cycles with day 3 or day 5 embryo transfers between 2007 and 2014 at a single academic medical center. Cycles resulting in one gestational sac on ultrasound followed by singleton live birth beyond 24 weeks of gestation were included. Logistic regression models adjusted a priori for patient age at oocyte retrieval and day of embryo transfer were used to estimate the Odds Ratio of having an abnormal hCG rise (defined as a rise or hCG rises between the first and second measurements, compared to 2.7% (n = 17) of patients undergoing SET (OR 2.16, 95% CI 1.26-3.71). Among patients with initially abnormal hCG rises who had a third level checked (89%), three-quarters had normal hCG rises between the second and third measurements. Patients who deliver singletons following MET were more likely to have suboptimal initial hCG rises, potentially due to transient implantation of other non-viable embryo(s). While useful for counseling, these findings should not change standard management of abnormal hCG rises following IVF. The third hCG measurements may clarify pregnancy prognosis.

  11. Bacteria-Mineral Interactions on the Surfaces of Metal-Resistant Bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Malkin, A J

    2010-03-24

    chapters (1,2), and we anticipate one more publication (3). The publications describe development of methods and results of studies of structural dynamics of metal-resistant bacteria that contribute to more comprehensive understanding of the architecture, function, and environmental dynamics of bacterial and cellular systems. The results of this LDRD were presented in invited talks and contributed presentations at five national and international conferences and five seminar presentations at the external institutions. These included invited talks at the conferences of Gordon Research, Materials Research and American Chemical Societies. Our scientific results and methodologies developed in this project enabled us to receive new funding for the multiyear project 'Chromium transformation pathways in metal-reducing bacteria' funded by the University of California Lab Fees Program ($500,000, 5/1/09 - 4/30/2012), with our proposal being ranked 1st from a total of 138 in the Earth, Energy, Environmental & Space Sciences panel.

  12. Laser-Based Identification of Pathogenic Bacteria

    Science.gov (United States)

    Rehse, Steven J.

    2009-01-01

    Bacteria are ubiquitous in our world. From our homes, to our work environment, to our own bodies, bacteria are the omnipresent although often unobserved companions to human life. Physicists are typically untroubled professionally by the presence of these bacteria, as their study usually falls safely outside the realm of our typical domain. In the…

  13. Nitrogen-fixing methane-utilizing bacteria

    NARCIS (Netherlands)

    Bont, de J.A.M.

    1976-01-01

    Methane occurs abundantly in nature. In the presence of oxygen this gas may be metabolized by bacteria that are able to use it as carbon and energy source. Several types of bacteria involved in the oxidation of methane have been described in literature. Methane-utilizing bacteria have in

  14. Is repositioning of drugs a viable alternative in the treatment of tuberculosis?

    Science.gov (United States)

    Palomino, Juan Carlos; Martin, Anandi

    2013-02-01

    Antimicrobial resistance is a serious problem because of the scarcity of new antibiotics effective against pathogens such as methicillin-resistant Staphylococcus aureus, β-lactamase-producing Gram-negative bacteria and multidrug-resistant Mycobacterium tuberculosis. Extensively drug resistance is particularly worrying in tuberculosis (TB), since the causative bacteria have become resistant to almost all available first- and second-line drugs and resistance is a threat to achieving control of the disease. Development of new drugs is a lengthy and costly endeavour. This is a particular problem for antibiotics, usage of which is likely to be of limited duration, and is even more true of antibiotics whose use is restricted to the treatment of a disease, such as TB, that is considered to be 'poverty related', and for which the return on the investment is seen as non-attractive. In spite of this, there is an emerging pipeline of new drugs under development that hopefully will bring new anti-TB drugs to the market in the near future. The strategy of drug repurposing, finding new uses for existing approved medicines, has seen unexpected success in other medical areas. More than one blockbuster drug has originated from this strategy. And in the field of TB, there have been several examples in recent years of this approach leading to the use of drugs for which there is undeniable evidence of efficacy in the treatment of the disease, the best example being the fluoroquinolones, which were not developed originally to treat TB. This article reviews some examples of repurposing of drugs in the treatment of TB, newer candidates for repurposing for which there is already preliminary evidence of activity and possible new options that merit further investigation.

  15. Rapid Separation of Bacteria from Blood—Review and Outlook

    Science.gov (United States)

    Alizadeh, Mahsa; Husseini, Ghaleb A.; McClellan, Daniel S.; Buchanan, Clara M.; Bledsoe, Colin G.; Robison, Richard A.; Blanco, Rae; Roeder, Beverly L.; Melville, Madison; Hunter, Alex K.

    2017-01-01

    The high morbidity and mortality rate of bloodstream infections involving antibiotic-resistant bacteria necessitate a rapid identification of the infectious organism and its resistance profile. Traditional methods based on culturing the blood typically require at least 24 h, and genetic amplification by PCR in the presence of blood components has been problematic. The rapid separation of bacteria from blood would facilitate their genetic identification by PCR or other methods so that the proper antibiotic regimen can quickly be selected for the septic patient. Microfluidic systems that separate bacteria from whole blood have been developed, but these are designed to process only microliter quantities of whole blood or only highly diluted blood. However, symptoms of clinical blood infections can be manifest with bacterial burdens perhaps as low as 10 CFU/mL, and thus milliliter quantities of blood must be processed to collect enough bacteria for reliable genetic analysis. This review considers the advantages and shortcomings of various methods to separate bacteria from blood, with emphasis on techniques that can be done in less than 10 min on milliliter-quantities of whole blood. These techniques include filtration, screening, centrifugation, sedimentation, hydrodynamic focusing, chemical capture on surfaces or beads, field-flow fractionation, and dielectrophoresis. Techniques with the most promise include screening, sedimentation, and magnetic bead capture, as they allow large quantities of blood to be processed quickly. Some microfluidic techniques can be scaled up. PMID:27160415

  16. Transgenic plants and associated bacteria for phytoremediation of chlorinated compounds.

    Science.gov (United States)

    Van Aken, Benoit; Doty, Sharon Lafferty

    2010-01-01

    Phytoremediation is the use of plants for the treatment of environmental pollution, including chlorinated organics. Although conceptually very attractive, removal and biodegradation of chlorinated pollutants by plants is a rather slow and inefficient process resulting in incomplete treatment and potential release of toxic metabolites into the environment. In order to overcome inherent limitations of plant metabolic capabilities, plants have been genetically modified, following a strategy similar to the development of transgenic crops: genes from bacteria, fungi, and mammals involved in the metabolism of organic contaminants, such as cytochrome P-450 and glutathione S-transferase, have been introduced into higher plants, resulting in significant improvement of tolerance, removal, and degradation of pollutants. Recently, plant-associated bacteria have been recognized playing a significant role in phytoremediation, leading to the development of genetically modified rhizospheric and endophytic bacteria with improved biodegradation capabilities. Transgenic plants and associated bacteria constitute a new generation of genetically modified organisms for efficient and environmental-friendly treatment of polluted soil and water. This review focuses on recent advances in the development of transgenic plants and bacteria for the treatment of chlorinated pollutants, including chlorinated solvents, polychlorinated phenols, and chlorinated herbicides.

  17. Oral, intestinal, and skin bacteria in ventral hernia mesh implants

    Directory of Open Access Journals (Sweden)

    Odd Langbach

    2016-07-01

    Full Text Available Background: In ventral hernia surgery, mesh implants are used to reduce recurrence. Infection after mesh implantation can be a problem and rates around 6–10% have been reported. Bacterial colonization of mesh implants in patients without clinical signs of infection has not been thoroughly investigated. Molecular techniques have proven effective in demonstrating bacterial diversity in various environments and are able to identify bacteria on a gene-specific level. Objective: The purpose of this study was to detect bacterial biofilm in mesh implants, analyze its bacterial diversity, and look for possible resemblance with bacterial biofilm from the periodontal pocket. Methods: Thirty patients referred to our hospital for recurrence after former ventral hernia mesh repair, were examined for periodontitis in advance of new surgical hernia repair. Oral examination included periapical radiographs, periodontal probing, and subgingival plaque collection. A piece of mesh (1×1 cm from the abdominal wall was harvested during the new surgical hernia repair and analyzed for bacteria by PCR and 16S rRNA gene sequencing. From patients with positive PCR mesh samples, subgingival plaque samples were analyzed with the same techniques. Results: A great variety of taxa were detected in 20 (66.7% mesh samples, including typical oral commensals and periodontopathogens, enterics, and skin bacteria. Mesh and periodontal bacteria were further analyzed for similarity in 16S rRNA gene sequences. In 17 sequences, the level of resemblance between mesh and subgingival bacterial colonization was 98–100% suggesting, but not proving, a transfer of oral bacteria to the mesh. Conclusion: The results show great bacterial diversity on mesh implants from the anterior abdominal wall including oral commensals and periodontopathogens. Mesh can be reached by bacteria in several ways including hematogenous spread from an oral site. However, other sites such as gut and skin may also

  18. Acetic Acid Bacteria as Symbionts of Insects

    KAUST Repository

    Crotti, Elena

    2016-06-14

    Acetic acid bacteria (AAB) are being increasingly described as associating with different insect species that rely on sugar-based diets. AAB have been found in several insect orders, among them Diptera, Hemiptera, and Hymenoptera, including several vectors of plant, animal, and human diseases. AAB have been shown to associate with the epithelia of different organs of the host, they are able to move within the insect’s body and to be transmitted horizontally and vertically. Here, we review the ecology of AAB and examine their relationships with different insect models including mosquitoes, leafhoppers, and honey bees. We also discuss the potential use of AAB in symbiont-based control strategies, such as “Trojan-horse” agents, to block the transmission of vector-borne diseases.

  19. Commercializing Biorefinery Technology: A Case for the Multi-Product Pathway to a Viable Biorefinery

    Directory of Open Access Journals (Sweden)

    Shijie Liu

    2011-11-01

    Full Text Available While there may be many reasons why very interesting science ideas never reach commercial practice, one of the more prevalent is that the reaction or process, which is scientifically possible, cannot be made efficient enough to achieve economic viability. One pathway to economic viability for many business sectors is the multi-product portfolio. Research, development, and deployment of viable biorefinery technology must meld sound science with engineering and business economics. It is virtually axiomatic that increased value can be generated by isolating relatively pure substances from heterogeneous raw materials. Woody biomass is a heterogeneous raw material consisting of the major structural components, cellulose, lignin, and hemicelluloses, as well as minor components, such as extractives and ash. Cellulose is a linear homopolymer of D-glucopyrano-units with β-D(1®4 connections and is the wood component most resistant to chemical and biological degradation. Lignin is a macromolecule of phenylpropanoid units, second to cellulose in bio-resistance, and is the key component that is sought for removal from woody biomass in chemical pulping. Hemicelluloses are a collection of heteropolysaccharides, comprised mainly of 5- and 6-carbon sugars. Extractives, some of which have high commercial value, are a collection of low molecular weight organic and inorganic woody materials that can be removed, to some extent, under mild conditions. Applied Biorefinery Sciences, LLC (a private, New York, USA based company is commercializing a value-optimization pathway (the ABS Process™ for generating a multi-product portfolio by isolating and recovering homogeneous substances from each of the above mentioned major and minor woody biomass components. The ABS Process™ incorporates the patent pending, core biorefinery technology, “hot water extraction”, as developed at the State University of New York College of Environmental Science and Forestry (SUNY

  20. Comparison of radiorespirometric budemeyer assay with ATP assay and mouse foot pad test in detecting viable Mycobacterium leprae from clinical samples

    Directory of Open Access Journals (Sweden)

    Agrawal V

    2007-01-01

    Full Text Available Purpose: This study compares the results of radiorespirometric Buddemeyer assay with adenosine triphosphate (ATP assay and mouse foot pad (MFP test to validate the sensitivity of Buddemeyer assay in detecting viable M. leprae in clinical samples. Methods: Viability was assessed using all the three methods in 60 skin biopsy specimens, including 20 untreated lepromatous leprosy (BL-LL, 13 treated BL-LL, 12 untreated borderline tuberculoid to mid borderline (BT-BB and 15 treated BT-BB cases. Results: Of the 20 untreated BL-LL cases tested, positivity indicating the presence of viable M. leprae was detected in 85, 60 and 85% with Buddemeyer, ATP and MFP test, respectively. Among the 13 treated BL-LL cases, scores were 61, 54 and 0%; among the 12 untreated BT-BB cases, the scores were 58, 16 and 16% and among the 15 treated BT-BB cases, the scores were 46, 20, 0%, respectively. Conclusion: The detection sensitivity (positive scores with three tests were closely comparable in the two untreated groups of cases. On the other hand, in the two treated groups, a good proportion of cases scored positive in the in vitro tests but none in the MFP test. Among the two in vitro methods, the Buddemeyer assay emerged as a better test, in terms of sensitivity and specificity.