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Sample records for pathogenic bacteria inoculated

  1. Transfer of foodborne pathogenic bacteria to non-inoculated beef fillets through meat mincing machine.

    PubMed

    Papadopoulou, O S; Chorianopoulos, N G; Gkana, E N; Grounta, A V; Koutsoumanis, K P; Nychas, G-J E

    2012-03-01

    The aim of this study was to evaluate the transfer of pathogens population to non-inoculated beef fillets through meat mincing machine. In this regard, cocktails of mixed strain cultures of each Listeria monocytogenes, Salmonella enterica ser. Typhimurium and Escherichia coli O157:H7 were used for the inoculation of beef fillets. Three different initial inoculum sizes (3, 5, or 7 log CFU/g) were tested. The inoculated beef fillets passed through meat mincing machine and then, six non-inoculated beef fillets passed in sequence through the same mincing machine without sanitation. The population of each pathogen was measured. It was evident that, all non-inoculated beef fillets were contaminated through mincing with all pathogens, regardless the inoculum levels used. This observation can be used to cover knowledge gaps in risk assessments since indicates the potential of pathogen contamination and provides significant insights for the risk estimation related to cross-contamination, aiming thus to food safety enhancement. PMID:22119672

  2. Application of gamma irradiation for inactivation of three pathogenic bacteria inoculated into meatballs

    NASA Astrophysics Data System (ADS)

    Gumus, Tuncay; Şukru Demirci, A.; Murat Velioglu, H.; Velioglu, Serap D.; Yilmaz, Ismail; Sagdic, Osman

    2008-09-01

    In this research, the effect of gamma irradiation on the inactivation of Escherichia coli O157:H7 (ATCC 33150), Staphylococcus aureus (ATCC 2392) and Salmonella typhimurium (NRRL 4463) inoculated into Tekirdag meatballs was investigated. The meatball samples were inoculated with pathogens and irradiated at the absorbed doses of 1, 2.2, 3.2, 4.5 and 5.2 kGy. E. coli O157:H7 count in 1 kGy irradiated meatballs stored in the refrigerator for 7 days was detected to be 4 log cfu/g lower than the count in nonirradiated samples ( p<0.05). S. aureus counts were decreased to 4 log cfu/g after being exposed to irradiation at a dose of 1 kGy. Although it was ineffective on elimination of S. typhimurium, irradiation at a dose of 3.2 kGy reduced E. coli O157:H7 and S. aureus counts under detectable values in the meatballs. However, none of the test organisms were detected in the samples after irradiation with 4.5 kGy doses.

  3. A gaseous acetic acid treatment to disinfect fenugreek seeds and black pepper inoculated with pathogenic and spoilage bacteria.

    PubMed

    Nei, Daisuke; Enomoto, Katsuyoshi; Nakamura, Nobutaka

    2015-08-01

    Contamination of spices by pathogenic and/or spoilage bacteria can be deleterious to consumer's health and cause deterioration of foods, and inactivation of such bacteria is necessary for the food industry. The present study examined the effect of gaseous acetic acid treatment in reducing Escherichia coli O157:H7, Salmonella Enteritidis and Bacillus subtilis populations inoculated on fenugreek seeds and black pepper. Treatment with gaseous acetic acid at 0.3 mmol/L, 0.6 mmol/L and 4.7 mmol/L for 1-3 h significantly reduced the populations of E. coli O157:H7 and Salmonella Enteritidis on black pepper and fenugreek seeds at 55 °C (p < 0.05). The gas treatments at 4.7 mmol/L were more effective in inactivating the pathogens than the treatment at 0.3 mmol/L. An approximately 5.0 log reduction was obtained after 3 h of treatment with 4.7 mmol/L acetic acid. No significant reductions in the population of B. subtilis spores inoculated on fenugreek seeds and black pepper were obtained after the gas treatments at 0.3 mmol/L or 0.6 mmol/L (p > 0.05). However, the gas treatment at 4.7 mmol/L significantly reduced B. subtilis spores (p < 0.05), and 4.0 log CFU/g and 3.5 log CFU/g reductions on fenugreek seeds and black pepper, respectively, were obtained after 3 h of treatment. PMID:25846935

  4. PATHOGENICITY OF BIOFILM BACTERIA

    EPA Science Inventory

    There is a paucity of information concerning any link between the microorganisms commonly found in biofilms of drinking water systems and their impacts on human health. For bacteria, culture-based techniques detect only a limited number of the total microorganisms associated wit...

  5. Plant Growth Promotion and Suppression of Bacterial Leaf Blight in Rice by Inoculated Bacteria

    PubMed Central

    Zaka, Abha; Imran, Asma; Zahid, Muhammad Awais; Yousaf, Sumaira; Rasul, Ghulam; Arif, Muhammad; Mirza, Muhammad Sajjad

    2016-01-01

    The present study was conducted to evaluate the potential of rice rhizosphere associated antagonistic bacteria for growth promotion and disease suppression of bacterial leaf blight (BLB). A total of 811 rhizospheric bacteria were isolated and screened against 3 prevalent strains of BLB pathogen Xanthomonas oryzae pv. oryzae (Xoo) of which five antagonistic bacteria, i.e., Pseudomonas spp. E227, E233, Rh323, Serratia sp. Rh269 and Bacillus sp. Rh219 showed antagonistic potential (zone of inhibition 1–19 mm). Production of siderophores was found to be the common biocontrol determinant and all the strains solubilized inorganic phosphate (82–116 μg mL-1) and produced indole acetic acid (0.48–1.85 mg L-1) in vitro. All antagonistic bacteria were non-pathogenic to rice, and their co-inoculation significantly improved plant health in terms of reduced diseased leaf area (80%), improved shoot length (31%), root length (41%) and plant dry weight (60%) as compared to infected control plants. Furthermore, under pathogen pressure, bacterial inoculation resulted in increased activity of defense related enzymes including phenylalanine ammonia-lyase and polyphenol oxidase, along with 86% increase in peroxidase and 53% increase in catalase enzyme activities in plants inoculated with Pseudomonas sp. Rh323 as well as co-inoculated plants. Bacterial strains showed good colonization potential in the rice rhizosphere up to 21 days after seed inoculation. Application of bacterial consortia in the field resulted in an increase of 31% in grain yield and 10% in straw yield over non-inoculated plots. Although, yield increase was statistically non-significant but was accomplished with overall saving of 20% chemical fertilizers. The study showed that Pseudomonas sp. Rh323 can be used to develop dual-purpose inoculum which can serve not only to suppress BLB but also to promote plant growth in rice. PMID:27532545

  6. Plant Growth Promotion and Suppression of Bacterial Leaf Blight in Rice by Inoculated Bacteria.

    PubMed

    Yasmin, Sumera; Zaka, Abha; Imran, Asma; Zahid, Muhammad Awais; Yousaf, Sumaira; Rasul, Ghulam; Arif, Muhammad; Mirza, Muhammad Sajjad

    2016-01-01

    The present study was conducted to evaluate the potential of rice rhizosphere associated antagonistic bacteria for growth promotion and disease suppression of bacterial leaf blight (BLB). A total of 811 rhizospheric bacteria were isolated and screened against 3 prevalent strains of BLB pathogen Xanthomonas oryzae pv. oryzae (Xoo) of which five antagonistic bacteria, i.e., Pseudomonas spp. E227, E233, Rh323, Serratia sp. Rh269 and Bacillus sp. Rh219 showed antagonistic potential (zone of inhibition 1-19 mm). Production of siderophores was found to be the common biocontrol determinant and all the strains solubilized inorganic phosphate (82-116 μg mL-1) and produced indole acetic acid (0.48-1.85 mg L-1) in vitro. All antagonistic bacteria were non-pathogenic to rice, and their co-inoculation significantly improved plant health in terms of reduced diseased leaf area (80%), improved shoot length (31%), root length (41%) and plant dry weight (60%) as compared to infected control plants. Furthermore, under pathogen pressure, bacterial inoculation resulted in increased activity of defense related enzymes including phenylalanine ammonia-lyase and polyphenol oxidase, along with 86% increase in peroxidase and 53% increase in catalase enzyme activities in plants inoculated with Pseudomonas sp. Rh323 as well as co-inoculated plants. Bacterial strains showed good colonization potential in the rice rhizosphere up to 21 days after seed inoculation. Application of bacterial consortia in the field resulted in an increase of 31% in grain yield and 10% in straw yield over non-inoculated plots. Although, yield increase was statistically non-significant but was accomplished with overall saving of 20% chemical fertilizers. The study showed that Pseudomonas sp. Rh323 can be used to develop dual-purpose inoculum which can serve not only to suppress BLB but also to promote plant growth in rice. PMID:27532545

  7. Sociomicrobiology and Pathogenic Bacteria.

    PubMed

    Xavier, Joao B

    2016-06-01

    The study of microbial pathogenesis has been primarily a reductionist science since Koch's principles. Reductionist approaches are essential to identify the causal agents of infectious disease, their molecular mechanisms of action, and potential drug targets, and much of medicine's success in the treatment of infectious disease stems from that approach. But many bacteria-caused diseases cannot be explained by a single bacterium. Several aspects of bacterial pathogenesis will benefit from a more holistic approach that takes into account social interaction among bacteria of the same species and between species in consortia such as the human microbiome. The emerging discipline of sociomicrobiology provides a framework to dissect microbial interactions in single and multi-species communities without compromising mechanistic detail. The study of bacterial pathogenesis can benefit greatly from incorporating concepts from other disciplines such as social evolution theory and microbial ecology, where communities, their interactions with hosts, and with the environment play key roles. PMID:27337482

  8. Plant growth-promoting bacteria as inoculants in agricultural soils.

    PubMed

    Souza, Rocheli de; Ambrosini, Adriana; Passaglia, Luciane M P

    2015-12-01

    Plant-microbe interactions in the rhizosphere are the determinants of plant health, productivity and soil fertility. Plant growth-promoting bacteria (PGPB) are bacteria that can enhance plant growth and protect plants from disease and abiotic stresses through a wide variety of mechanisms; those that establish close associations with plants, such as the endophytes, could be more successful in plant growth promotion. Several important bacterial characteristics, such as biological nitrogen fixation, phosphate solubilization, ACC deaminase activity, and production of siderophores and phytohormones, can be assessed as plant growth promotion (PGP) traits. Bacterial inoculants can contribute to increase agronomic efficiency by reducing production costs and environmental pollution, once the use of chemical fertilizers can be reduced or eliminated if the inoculants are efficient. For bacterial inoculants to obtain success in improving plant growth and productivity, several processes involved can influence the efficiency of inoculation, as for example the exudation by plant roots, the bacterial colonization in the roots, and soil health. This review presents an overview of the importance of soil-plant-microbe interactions to the development of efficient inoculants, once PGPB are extensively studied microorganisms, representing a very diverse group of easily accessible beneficial bacteria. PMID:26537605

  9. Plant growth-promoting bacteria as inoculants in agricultural soils

    PubMed Central

    de Souza, Rocheli; Ambrosini, Adriana; Passaglia, Luciane M.P.

    2015-01-01

    Abstract Plant-microbe interactions in the rhizosphere are the determinants of plant health, productivity and soil fertility. Plant growth-promoting bacteria (PGPB) are bacteria that can enhance plant growth and protect plants from disease and abiotic stresses through a wide variety of mechanisms; those that establish close associations with plants, such as the endophytes, could be more successful in plant growth promotion. Several important bacterial characteristics, such as biological nitrogen fixation, phosphate solubilization, ACC deaminase activity, and production of siderophores and phytohormones, can be assessed as plant growth promotion (PGP) traits. Bacterial inoculants can contribute to increase agronomic efficiency by reducing production costs and environmental pollution, once the use of chemical fertilizers can be reduced or eliminated if the inoculants are efficient. For bacterial inoculants to obtain success in improving plant growth and productivity, several processes involved can influence the efficiency of inoculation, as for example the exudation by plant roots, the bacterial colonization in the roots, and soil health. This review presents an overview of the importance of soil-plant-microbe interactions to the development of efficient inoculants, once PGPB are extensively studied microorganisms, representing a very diverse group of easily accessible beneficial bacteria. PMID:26537605

  10. Sociomicrobiology and pathogenic bacteria

    PubMed Central

    Xavier, Joao B.

    2015-01-01

    The study of microbial pathogenesis has been primarily a reductionist science since Koch's principles. Reductionist approaches are essential to identify the causal agents of infectious disease, their molecular mechanisms of action and potential drug targets, and much of medicine's success in the treatment of infectious disease comes from this approach. But many bacterial caused diseases cannot be explained by focusing on a single bacterium. Many aspects of bacterial pathogenesis will benefit from a more holistic approach that takes into account social interaction within bacteria of the same species and between different species in consortia such as the human microbiome. I discuss recent advances in the emerging discipline of sociomicrobiology and how it provides a framework to dissect microbial interactions in single and multispecies communities without compromising mechanistic detail. The study of bacterial pathogenesis can benefit greatly from incorporating concepts from other disciplines such as social evolution theory and microbial ecology where communities, their interactions with hosts and with the environment play key roles. PMID:27337482

  11. Multistep introduction of bacteria to natural substrates at different initial inoculation doses

    NASA Astrophysics Data System (ADS)

    Kupriyanov, A. A.; Semenov, A. M.; Kunenkova, N. N.; van Bruggen, A. H. C.

    2009-09-01

    The population dynamics of the saprotrophic Pseudomonas fluorescens 32 gfp bacteria and two conventionally pathogenic enterobacteria ( Escherichia coli 0157:H7 and Salmonella enterica var. Typhimurium) were investigated in their inoculation at different doses into cattle excreta and their subsequent entering soil and plants and migration through the gastroenteric tract of invertebrates. All the introduced bacteria investigated are shown to be able to overcome ecological barriers as they migrate through the natural substrates and habitats. The introduce microorganisms maintain their high population density even at the lowest initial inoculation dose—105 CFU/g of dry matter. Plants were found to be a favorable substrate for the survival of the bacteria investigated (for enteropathogens, in particular). Enteropathogens are able to pass through the gastroenteric tract of invertebrates. Therefore, these organisms can function as incubators and carriers of enteroinfections in nature.

  12. Pathogenic Roles of the Bacteria carried by Bursaphelenchus mucronatus.

    PubMed

    Zhao, Bo Guang; Lin, Feng; Guo, Daosen; Li, Ronggui; Li, Sheng-Nan; Kulinich, Oleg; Ryss, Alexander

    2009-03-01

    Fifty strains of bacteria were isolated from six isolates of the nematode Bursaphelenchus mucronatus (Bm) from China and Russia and identified using the BioMerieux Vitek 32 system. In bioassay, 3 bacterial strains showed the high levels of phytotoxin production while 19, 16, and 12 strains showed moderately, low and no phytotoxin production, respectively. Inoculation of 2-month-old Pinus thunbergii seedling with each of the six Bm isolates showed that the mean number of days from inoculation to death of 80% of the seedlings was significantly related to the ratio of the total number of bacterial strains for a nematode isolate to the number of pathogenic bacterial strains of the nematode isolate. The results of inoculation of 3-year-old P. thunbergii seedlings showed that inoculation with either axenic Bm (ABm) or axenic B. xylophilus (ABx) and the pathogenic bacterial strain together were essential for inducing pine wilt. These findings demonstrate that wilt symptoms caused by Bm conform to our earlier hypothesis (Zhao et al., 2003) that pine wilt disease, induced by certain Bx or Bm isolates, is caused by a complex of both the nematodes and their associated pathogenic bacteria. The results also account for the variation in pathogenicity of Bm populations from different parts of the world. PMID:22661772

  13. The dynamics of apoplast phenolics in tobacco leaves following inoculation with bacteria.

    PubMed

    Baker, Con J; Mock, Norton M; Smith, Jodi M; Aver'yanov, Andrey A

    2015-01-01

    This study demonstrates that the accumulation of apoplastic phenolics is stimulated in planta in response to bacterial inoculation. Past studies have shown that levels of extracellular phenolics are elicited in plant cell suspensions in response to bacteria, and that tomato plants infected with viroids showed changes in apoplastic phenolics. The method described here monitored changes in apoplastic phenolics in tobacco leaves following bacterial inoculation of the same tissue. Inoculation with a saprophyte, Pseudomonas fluorescens, which does not cause visible symptoms or physical damage, was used to elicit phenolics and examine the effects of variable parameters on phenolic composition. Location of the inoculation on the leaf, position, or developmental age of the leaf on the plant, and inoculum concentration were standardized for further experiments. The patterns of phenolic change in the apoplast were compared for tobacco inoculated with P. syringae pathovars, pv. syringae, which causes a resistant HR reaction within 15 h, and pv. tabaci, which causes a susceptible reaction with delayed visible symptoms. Both pathogens elicited lower increased levels of acetosyringone compared to the saprophyte, P. fluorescens but had greatly increased levels of the chlorogenic acid derivatives. The latter metabolites appear to have come from the intracellular stores, which could indicate a weakening of the apoplast/symplast barrier. This unexpected aspect will require further study of intracellular phenolics. PMID:26347765

  14. The dynamics of apoplast phenolics in tobacco leaves following inoculation with bacteria

    PubMed Central

    Baker, Con J.; Mock, Norton M.; Smith, Jodi M.; Aver'yanov, Andrey A.

    2015-01-01

    This study demonstrates that the accumulation of apoplastic phenolics is stimulated in planta in response to bacterial inoculation. Past studies have shown that levels of extracellular phenolics are elicited in plant cell suspensions in response to bacteria, and that tomato plants infected with viroids showed changes in apoplastic phenolics. The method described here monitored changes in apoplastic phenolics in tobacco leaves following bacterial inoculation of the same tissue. Inoculation with a saprophyte, Pseudomonas fluorescens, which does not cause visible symptoms or physical damage, was used to elicit phenolics and examine the effects of variable parameters on phenolic composition. Location of the inoculation on the leaf, position, or developmental age of the leaf on the plant, and inoculum concentration were standardized for further experiments. The patterns of phenolic change in the apoplast were compared for tobacco inoculated with P. syringae pathovars, pv. syringae, which causes a resistant HR reaction within 15 h, and pv. tabaci, which causes a susceptible reaction with delayed visible symptoms. Both pathogens elicited lower increased levels of acetosyringone compared to the saprophyte, P. fluorescens but had greatly increased levels of the chlorogenic acid derivatives. The latter metabolites appear to have come from the intracellular stores, which could indicate a weakening of the apoplast/symplast barrier. This unexpected aspect will require further study of intracellular phenolics. PMID:26347765

  15. Tree Growth Stage and Environment after Pathogen Inoculation Alters Susceptibility of Pear Trees to Phytophthora Canker

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We investigated whether growth stage of pear (Pyrus communis) tree rootstock and environment after inoculation with Phytophthora syringae influences tree susceptibility to infection. Trees at different stages of dormancy development were inoculated with the pathogen and maintained in different condi...

  16. Pathogenic bacteria and timing of laying

    PubMed Central

    Møller, Anders Pape; Soler, Juan J; Nielsen, Jan Tøttrup; Galván, Ismael

    2015-01-01

    Pathogenic bacteria constitute a serious threat to viability of many organisms. Because growth of most bacteria is favored by humid and warm environmental conditions, earlier reproducers in seasonal environments should suffer less from the negative consequences of pathogenic bacteria. These relationships, and the effects on reproductive success, should be particularly prominent in predators because they are frequently exposed to pathogenic microorganisms from sick prey. Here, we presented and tested this hypothesis by sampling bacteria on adult and nestling goshawks Accipiter gentilis. We predicted that early breeders and their offspring should have fewer bacteria than those reproducing later during the breeding season. Adult goshawks with a high abundance of Staphylococcus on their beak and claws were easier to capture and their laying date was delayed. Moreover, goshawks that laid their eggs later had offspring with more Staphylococcus on their beaks and claws. The strength of the association between laying date and bacterial density of nestlings was stronger during the warm spring of 2013, when nestlings suffered from a higher abundance of pathogenic bacteria. Hatching failure and fledging failure were more common in nests with a higher abundance of Staphylococcus independently of the number of years occupied, laying date, and age of the female nest owner. These findings imply that timing of reproduction may be under the influence of pathogenic bacteria. Because early breeding goshawks produce more recruits than later breeders, our results suggest a role for pathogenic bacteria in the optimal timing of reproduction. PMID:25937910

  17. Colonization of plants by human pathogenic bacteria in the course of organic vegetable production.

    PubMed

    Hofmann, Andreas; Fischer, Doreen; Hartmann, Anton; Schmid, Michael

    2014-01-01

    In recent years, increasing numbers of outbreaks caused by the consumption of vegetables contaminated with human pathogenic bacteria were reported. The application of organic fertilizers during vegetable production is one of the possible reasons for contamination with those pathogens. In this study laboratory experiments in axenic and soil systems following common practices in organic farming were conducted to identify the minimal dose needed for bacterial colonization of plants and to identify possible factors like bacterial species or serovariation, plant species or organic fertilizer types used, influencing the success of plant colonization by human pathogenic bacteria. Spinach and corn salad were chosen as model plants and were inoculated with different concentrations of Salmonella enterica sv. Weltevreden, Listeria monocytogenes sv. 4b and EGD-E sv. 1/2a either directly (axenic system) or via agricultural soil amended with spiked organic fertilizers (soil system). In addition to PCR- and culture-based detection methods, fluorescence in situ hybridization (FISH) was applied in order to localize bacteria on or in plant tissues. Our results demonstrate that shoots were colonized by the pathogenic bacteria at inoculation doses as low as 4 × 10 CFU/ml in the axenic system or 4 × 10(5) CFU/g in the soil system. In addition, plant species dependent effects were observed. Spinach was colonized more often and at lower inoculation doses compared to corn salad. Differential colonization sites on roots, depending on the plant species could be detected using FISH-CLSM analysis. Furthermore, the transfer of pathogenic bacteria to plants via organic fertilizers was observed more often and at lower initial inoculation doses when fertilization was performed with inoculated slurry compared to inoculated manure. Finally, it could be shown that by introducing a simple washing step, the bacterial contamination was reduced in most cases or even was removed completely in some

  18. Colonization of plants by human pathogenic bacteria in the course of organic vegetable production

    PubMed Central

    Hofmann, Andreas; Fischer, Doreen; Hartmann, Anton; Schmid, Michael

    2014-01-01

    In recent years, increasing numbers of outbreaks caused by the consumption of vegetables contaminated with human pathogenic bacteria were reported. The application of organic fertilizers during vegetable production is one of the possible reasons for contamination with those pathogens. In this study laboratory experiments in axenic and soil systems following common practices in organic farming were conducted to identify the minimal dose needed for bacterial colonization of plants and to identify possible factors like bacterial species or serovariation, plant species or organic fertilizer types used, influencing the success of plant colonization by human pathogenic bacteria. Spinach and corn salad were chosen as model plants and were inoculated with different concentrations of Salmonella enterica sv. Weltevreden, Listeria monocytogenes sv. 4b and EGD-E sv. 1/2a either directly (axenic system) or via agricultural soil amended with spiked organic fertilizers (soil system). In addition to PCR- and culture-based detection methods, fluorescence in situ hybridization (FISH) was applied in order to localize bacteria on or in plant tissues. Our results demonstrate that shoots were colonized by the pathogenic bacteria at inoculation doses as low as 4 × 10 CFU/ml in the axenic system or 4 × 105 CFU/g in the soil system. In addition, plant species dependent effects were observed. Spinach was colonized more often and at lower inoculation doses compared to corn salad. Differential colonization sites on roots, depending on the plant species could be detected using FISH-CLSM analysis. Furthermore, the transfer of pathogenic bacteria to plants via organic fertilizers was observed more often and at lower initial inoculation doses when fertilization was performed with inoculated slurry compared to inoculated manure. Finally, it could be shown that by introducing a simple washing step, the bacterial contamination was reduced in most cases or even was removed completely in some cases

  19. Effects of Lactic Acid-Forming Bacteria on Vibrio comma Inoculated into Intestinal Segments of Rabbits

    PubMed Central

    Hattori, Zenpachiro; Misawa, Hiroshi; Igarashi, Isamu; Sugiya, Yukio

    1965-01-01

    Hattori, H. (Sankyo Co., Ltd., Tokyo, Japan), H. Misawa, I. Igarashi, and Y. Sugiya. Effects of lactic acid-forming bacteria on Vibrio comma inoculated into intestinal segments of rabbits. J. Bacteriol. 90:541–545. 1965.—Mixed inocula of Vibrio comma KC-4 and various lactic acid-forming bacteria were injected into the intestinal segments of rabbits (De and Chatterje, 1953) to observe the effects of the latter agents in altering the changes produced by strain KC-4. The animals were sacrificed 10 and 20 hr after inoculation. The inoculated intestinal segments were first examined grossly, and the amount of exudate in the segments, if any, was measured, after which the tissues were subjected to pathological examination. When KC-4 cells together with spore-bearing lactic acid-forming bacilli, strain P-22, or Lactobacillus casei were introduced, the intestinal segments showed few or no macroscopic and microscopic changes, and no accumulation of exudate. With mixed inoculation with lactic acid bacteria such as L. bulgaricus, L. acidophilus, Streptococcus lactis, and S. faecalis, changes were produced by strain KC-4. Macroscopically, no difference was discernible between the changes caused by mixed inoculation and those produced by single inoculation of KC-4. Upon pathological examination, however, it was seen that changes resulting from mixed inoculation were slightly less severe than those produced by inoculation with strain KC-4 only. Images PMID:14329471

  20. Emerging Plant Pathogenic Bacteria and Global Warming

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Several bacteria, previously classified as non-fluorescent, oxidase positive pseudomonads, Ralstonia, Acidovorax, and Burkholdria have emerged as serious problems world-wide. Perhaps the most destructive is R. solanacearum (RS), a soilborne pathogen with a very wide host range. RS race 3, biovar 2...

  1. [RAPD analysis of plant pathogenic coryneform bacteria].

    PubMed

    Yin, Yan-Ni; Chen, Yong-Fang; Li, Shi-Mo; Guo, Jian-Hua

    2005-12-01

    RAPD analysis was used for the taxonomy of plant pathogenic coryneform bacteria, especially for the classification of two new pathogens (Curtobacterium flaccumfaciens pv. basellae pv. nov. and Curtobacterium flaccumfaciens pv. beticola pv. nov.). 20 random primers were screened from 50 ones to detect polymorphism among the total strains used. 80.4% were polymorphic bands among the 225 ones produced. The results of pairwise similarity and UPGMA cluster analysis suggest that the two new pathovars of sugar beet (Beta vulgaris var. saccharifera) and malabar spinach (Basella rubra) are genetically close related with Curtobacterium flacumfaciens, and the minimal similarity coefficient is 0.6511. According to the RAPD analysis and previous research, some newly made taxonomic changes of the plant pathogenic coryneform bacteria are discussed. PMID:16496687

  2. 9 CFR 113.36 - Detection of pathogens by the chicken inoculation test.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Detection of pathogens by the chicken... REQUIREMENTS Standard Procedures § 113.36 Detection of pathogens by the chicken inoculation test. The test for...,000 doses. (b) At least 25 healthy susceptible young chickens, properly identified and obtained...

  3. 9 CFR 113.36 - Detection of pathogens by the chicken inoculation test.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Detection of pathogens by the chicken... REQUIREMENTS Standard Procedures § 113.36 Detection of pathogens by the chicken inoculation test. The test for...,000 doses. (b) At least 25 healthy susceptible young chickens, properly identified and obtained...

  4. 9 CFR 113.36 - Detection of pathogens by the chicken inoculation test.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Detection of pathogens by the chicken... REQUIREMENTS Standard Procedures § 113.36 Detection of pathogens by the chicken inoculation test. The test for...,000 doses. (b) At least 25 healthy susceptible young chickens, properly identified and obtained...

  5. 9 CFR 113.36 - Detection of pathogens by the chicken inoculation test.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false Detection of pathogens by the chicken... REQUIREMENTS Standard Procedures § 113.36 Detection of pathogens by the chicken inoculation test. The test for...,000 doses. (b) At least 25 healthy susceptible young chickens, properly identified and obtained...

  6. 9 CFR 113.36 - Detection of pathogens by the chicken inoculation test.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false Detection of pathogens by the chicken... REQUIREMENTS Standard Procedures § 113.36 Detection of pathogens by the chicken inoculation test. The test for...,000 doses. (b) At least 25 healthy susceptible young chickens, properly identified and obtained...

  7. Effect of atmospheric pressure plasma on inactivation of pathogens inoculated onto bacon using two different gas compositions.

    PubMed

    Kim, Binna; Yun, Hyejeong; Jung, Samooel; Jung, Yeonkook; Jung, Heesoo; Choe, Wonho; Jo, Cheorun

    2011-02-01

    Atmospheric pressure plasma (APP) is an emerging non-thermal pasteurization method for the enhancement of food safety. In this study, the effect of APP on the inactivation of pathogens inoculated onto bacon was observed. Sliced bacon was inoculated with Listeria monocytogenes (KCTC 3596), Escherichia coli (KCTC 1682), and Salmonella Typhimurium (KCTC 1925). The samples were treated with APP at 75, 100, and 125 W of input power for 60 and 90 s. Two gases, helium (10 lpm) or a mixture of helium and oxygen, (10 lpm and 10 sccm, respectively) were used for the plasma generation. Plasma with helium could only reduce the number of inoculated pathogens by about 1-2 Log cycles. On the other hand, the helium/oxygen gas mixture was able to achieve microbial reduction of about 2-3 Log cycles. The number of total aerobic bacteria showed 1.89 and 4.58 decimal reductions after plasma treatment with helium and the helium/oxygen mixture, respectively. Microscopic observation of the bacon after plasma treatment did not find any significant changes, except that the L∗-value of the bacon surface was increased. These results clearly indicate that APP treatment is effective for the inactivation of the three pathogens used in this study, although further investigation is needed for elucidating quality changes after treatment. PMID:21056769

  8. Manganese homeostasis and utilization in pathogenic bacteria.

    PubMed

    Juttukonda, Lillian J; Skaar, Eric P

    2015-07-01

    Manganese (Mn) is a required cofactor for all forms of life. Given the importance of Mn to bacteria, the host has devised strategies to sequester Mn from invaders. In the macrophage phagosome, NRAMP1 removes Mn and other essential metals to starve intracellular pathogens; in the extracellular space, calprotectin chelates Mn and Zn. Calprotectin-mediated Mn sequestration is a newly appreciated host defense mechanism, and recent findings are highlighted herein. In order to acquire Mn when extracellular concentrations are low, bacteria have evolved efficient Mn acquisition systems that are under elegant transcriptional control. To counteract Mn overload, some bacteria possess Mn-specific export systems that are important in vivo, presumably for control of intracellular Mn levels. Mn transporters, their transcriptional regulators and some Mn-requiring enzymes are necessary for virulence of certain bacterial pathogens, as revealed by animal models of infection. Furthermore, Mn is an important facet of the cellular response to oxidative stress, a host antibacterial strategy. The battle for Mn between host and pathogen is now appreciated to be a major determinant of the outcome of infection. In this MicroReview, the contribution of Mn to the host-pathogen interaction is reviewed, and key questions are proposed for future study. PMID:25898914

  9. Quorum sensing in plant-pathogenic bacteria.

    PubMed

    Von Bodman, Susanne B; Bauer, W Dietz; Coplin, David L

    2003-01-01

    Quorum sensing (QS) allows bacteria to assess their local population density and/or physical confinement via the secretion and detection of small, diffusible signal molecules. This review describes how phytopathogenic bacteria have incorporated QS mechanisms into complex regulatory cascades that control genes for pathogenicity and colonization of host surfaces. Traits regulated by QS include the production of extracellular polysaccharides, degradative enzymes, antibiotics, siderophores, and pigments, as well as Hrp protein secretion, Ti plasmid transfer, motility, biofilm formation, and epiphytic fitness. Since QS regulatory systems are often required for pathogenesis, interference with QS signaling may offer a means of controlling bacterial diseases of plants. Several bacterial pathogens of plants that have been intensively studied and have revealed information of both fundamental and practical importance are reviewed here: Agrobacterium tumefaciens, Pantoea stewartii, Erwinia carotovora, Ralstonia solanacearum, Pseudomonas syringae, Pseudomonas aeruginosa, and Xanthomonas campestris. PMID:12730390

  10. RNA-Seq for Plant Pathogenic Bacteria.

    PubMed

    Kimbrel, Jeffrey A; Di, Yanming; Cumbie, Jason S; Chang, Jeff H

    2011-01-01

    The throughput and single-base resolution of RNA-Sequencing (RNA-Seq) have contributed to a dramatic change in transcriptomic-based inquiries and resulted in many new insights into the complexities of bacterial transcriptomes. RNA-Seq could contribute to similar advances in our understanding of plant pathogenic bacteria but it is still a technology under development with limitations and unknowns that need to be considered. Here, we review some new developments for RNA-Seq and highlight recent findings for host-associated bacteria. We also discuss the technical and statistical challenges in the practical application of RNA-Seq for studying bacterial transcriptomes and describe some of the currently available solutions. PMID:24710287

  11. Effect of Essential Oils on Pathogenic Bacteria

    PubMed Central

    Nazzaro, Filomena; Fratianni, Florinda; De Martino, Laura; Coppola, Raffaele; De Feo, Vincenzo

    2013-01-01

    The increasing resistance of microorganisms to conventional chemicals and drugs is a serious and evident worldwide problem that has prompted research into the identification of new biocides with broad activity. Plants and their derivatives, such as essential oils, are often used in folk medicine. In nature, essential oils play an important role in the protection of plants. Essential oils contain a wide variety of secondary metabolites that are capable of inhibiting or slowing the growth of bacteria, yeasts and moulds. Essential oils and their components have activity against a variety of targets, particularly the membrane and cytoplasm, and in some cases, they completely change the morphology of the cells. This brief review describes the activity of essential oils against pathogenic bacteria. PMID:24287491

  12. RNA-Seq for Plant Pathogenic Bacteria

    PubMed Central

    Kimbrel, Jeffrey A.; Di, Yanming; Cumbie, Jason S.; Chang, Jeff H.

    2011-01-01

    The throughput and single-base resolution of RNA-Sequencing (RNA-Seq) have contributed to a dramatic change in transcriptomic-based inquiries and resulted in many new insights into the complexities of bacterial transcriptomes. RNA-Seq could contribute to similar advances in our understanding of plant pathogenic bacteria but it is still a technology under development with limitations and unknowns that need to be considered. Here, we review some new developments for RNA-Seq and highlight recent findings for host-associated bacteria. We also discuss the technical and statistical challenges in the practical application of RNA-Seq for studying bacterial transcriptomes and describe some of the currently available solutions. PMID:24710287

  13. The dynamics of apoplast phenolics in tobacco leaves following inoculation with bacteria

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study demonstrates that the accumulation of apoplastic phenolics is stimulated in planta in response to bacterial inoculation. Past studies have shown that levels of extracellular phenolics are elicited in plant cell suspensions in response to bacteria, and that tomato plants infected with vir...

  14. Effects of gamma and electron beam irradiation on the survival of pathogens inoculated into sliced and pizza cheeses

    NASA Astrophysics Data System (ADS)

    Kim, Hyun-Joo; Ham, Jun-Sang; Lee, Ju-Woon; Kim, Keehyuk; Ha, Sang-Do; Jo, Cheorun

    2010-06-01

    The objective of this study was to identify the efficacy of gamma and electron beam irradiation of the food-borne pathogens ( Listeria monocytogenes and Staphylococcus aureus) in sliced and pizza cheeses commercially available in the Korean market. Total aerobic bacteria and yeast/mold in the cheeses ranged from 10 2 to 10 3 Log CFU/g. Irradiation of 1 kGy for sliced cheese and 3 kGy for pizza cheese were sufficient to lower the total aerobic bacteria to undetectable levels (10 1 CFU/g). Pathogen inoculation test revealed that gamma irradiation was more effective than electron beam irradiation at the same absorbed dose, and the ranges of the D 10 values were from 0.84 to 0.93 kGy for L. monocytogenes and from 0.60 to 0.63 kGy for S. aureus. Results suggest that a low dose irradiation can improve significantly the microbial quality and reduce the risk of contamination of sliced and pizza cheeses by the food-borne pathogens which can potentially occur during processing.

  15. Effect of microalgae inoculation on the start-up of microalgae-bacteria systems treating municipal, piggery and digestate wastewaters.

    PubMed

    Arango, Liz; Cuervo, Flor M; González-Sánchez, Armando; Buitrón, Germán

    2016-01-01

    The effect of the inoculation of a microalgae-bacteria system on the removal of nutrients and organic matter using municipal, piggery and digestate wastewaters was evaluated. Three conditions for each substrate were evaluated: (1) inoculation with activated sludge and illumination, (2) inoculation with activated sludge without illumination, and (3) inoculation with activated sludge plus a native microalgae consortium under illumination. The illuminated reactors that were inoculated only with activated sludge developed microalgae after 12 operation days. In these reactors, the formation of flocs was observed affecting the sedimentation of the biomass positively. The removal of chemical oxygen demand, ammonium and phosphorous reached 84%, 65% and 77%, respectively. PMID:26877054

  16. Effects of nitrogen fertilization and soil inoculation of sulfur oxidizing or nitrogen fixing bacteria on onion plant growth and yield

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A field experiment was conducted in a newly reclaimed soil at El-Saff region, El-Giza Governorate, Egypt to study the effects of different rates of nitrogen (N;62 to 248 kg ha-1) with or without soil inoculation of sulfur (S) oxidizing bacteria (SoxB), and combined inoculation of SoxB and N fixing b...

  17. Investigation of spoilage in saveloy samples inoculated with four potential spoilage bacteria.

    PubMed

    Holm, E S; Schäfer, A; Koch, A G; Petersen, M A

    2013-03-01

    Sliced saveloy samples were inoculated with monocultures of four potential spoilage bacteria and studied during a four week storage period. The objective was to investigate the resulting changes in the composition of Volatile Organic Compounds (VOCs) and the sensory quality of the product. Based on the sensory scores and the VOC composition Brochothrix thermosphacta, Chryseomonas luteola and Carnobacterium maltaromaticum were found to have a high spoilage potential in saveloy samples subjected to consumer simulated storage during the fourth week. Inoculation with Leuconostoc carnosum only resulted in a low level of spoilage. The sensory changes in the saveloy samples were modeled based on the VOC composition using Partial Least Squares Regression. The changes in the six sensory descriptors were closely related to the amount of diacetyl, acetoin, 2- and 3-methylbutanol, 2- and 3-methylbutanal and 2-methylpropanol found in the samples. These compounds are therefore potentially important for the shelf-life of sliced saveloy. PMID:23261532

  18. Molecular basis of host specificity in human pathogenic bacteria

    PubMed Central

    Pan, Xiaolei; Yang, Yang; Zhang, Jing-Ren

    2014-01-01

    Pathogenic bacteria display various levels of host specificity or tropism. While many bacteria can infect a wide range of hosts, certain bacteria have strict host selectivity for humans as obligate human pathogens. Understanding the genetic and molecular basis of host specificity in pathogenic bacteria is important for understanding pathogenic mechanisms, developing better animal models and designing new strategies and therapeutics for the control of microbial diseases. The molecular mechanisms of bacterial host specificity are much less understood than those of viral pathogens, in part due to the complexity of the molecular composition and cellular structure of bacterial cells. However, important progress has been made in identifying and characterizing molecular determinants of bacterial host specificity in the last two decades. It is now clear that the host specificity of bacterial pathogens is determined by multiple molecular interactions between the pathogens and their hosts. Furthermore, certain basic principles regarding the host specificity of bacterial pathogens have emerged from the existing literature. This review focuses on selected human pathogenic bacteria and our current understanding of their host specificity. PMID:26038515

  19. Laser-Based Identification of Pathogenic Bacteria

    ERIC Educational Resources Information Center

    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…

  20. Contamination of water resources by pathogenic bacteria

    PubMed Central

    2014-01-01

    Water-borne pathogen contamination in water resources and related diseases are a major water quality concern throughout the world. Increasing interest in controlling water-borne pathogens in water resources evidenced by a large number of recent publications clearly attests to the need for studies that synthesize knowledge from multiple fields covering comparative aspects of pathogen contamination, and unify them in a single place in order to present and address the problem as a whole. Providing a broader perceptive of pathogen contamination in freshwater (rivers, lakes, reservoirs, groundwater) and saline water (estuaries and coastal waters) resources, this review paper attempts to develop the first comprehensive single source of existing information on pathogen contamination in multiple types of water resources. In addition, a comprehensive discussion describes the challenges associated with using indicator organisms. Potential impacts of water resources development on pathogen contamination as well as challenges that lie ahead for addressing pathogen contamination are also discussed. PMID:25006540

  1. Interactions between the microbiota and pathogenic bacteria in the gut.

    PubMed

    Bäumler, Andreas J; Sperandio, Vanessa

    2016-07-01

    The microbiome has an important role in human health. Changes in the microbiota can confer resistance to or promote infection by pathogenic bacteria. Antibiotics have a profound impact on the microbiota that alters the nutritional landscape of the gut and can lead to the expansion of pathogenic populations. Pathogenic bacteria exploit microbiota-derived sources of carbon and nitrogen as nutrients and regulatory signals to promote their own growth and virulence. By eliciting inflammation, these bacteria alter the intestinal environment and use unique systems for respiration and metal acquisition to drive their expansion. Unravelling the interactions between the microbiota, the host and pathogenic bacteria will produce strategies for manipulating the microbiota against infectious diseases. PMID:27383983

  2. Discrimination and Integration of Stress Signals by Pathogenic Bacteria.

    PubMed

    Fang, Ferric C; Frawley, Elaine R; Tapscott, Timothy; Vázquez-Torres, Andrés

    2016-08-10

    For pathogenic bacteria, the ability to sense and respond to environmental stresses encountered within the host is critically important, allowing them to adapt to changing conditions and express virulence genes appropriately. This review considers the diverse molecular mechanisms by which stress conditions are sensed by bacteria, how related signals are discriminated, and how stress responses are integrated, highlighting recent studies in selected bacterial pathogens of clinical relevance. PMID:27512902

  3. Potential role of bacteria packaging by protozoa in the persistence and transmission of pathogenic bacteria

    PubMed Central

    Denoncourt, Alix M.; Paquet, Valérie E.; Charette, Steve J.

    2014-01-01

    Many pathogenic bacteria live in close association with protozoa. These unicellular eukaryotic microorganisms are ubiquitous in various environments. A number of protozoa such as amoebae and ciliates ingest pathogenic bacteria, package them usually in membrane structures, and then release them into the environment. Packaged bacteria are more resistant to various stresses and are more apt to survive than free bacteria. New evidence indicates that protozoa and not bacteria control the packaging process. It is possible that packaging is more common than suspected and may play a major role in the persistence and transmission of pathogenic bacteria. To confirm the role of packaging in the propagation of infections, it is vital that the molecular mechanisms governing the packaging of bacteria by protozoa be identified as well as elements related to the ecology of this process in order to determine whether packaging acts as a Trojan Horse. PMID:24904553

  4. Simultaneous and successive inoculations of yeasts and lactic acid bacteria on the fermentation of an unsulfited Tannat grape must

    PubMed Central

    Muñoz, Viviana; Beccaria, Bruno; Abreo, Eduardo

    2014-01-01

    Interactions between yeasts and lactic acid bacteria are strain specific, and their outcome is expected to change in simultaneous alcoholic - malolactic fermentations from the pattern observed in successive fermentations. One Oenococcus oeni strain Lalvin VP41™ was inoculated with two Saccharomyces cerevisiae strains either simultaneously, three days after the yeast inoculation, or when alcoholic fermentation was close to finish. Early bacterial inoculations with each yeast strain allowed for the growth of the bacterial populations, and the length of malolactic fermentation was reduced to six days. Alcoholic fermentation by Lalvin ICV D80® yeast strain left the highest residual sugar, suggesting a negative effect of the bacterial growth and malolactic activity on its performance. In sequential inoculations the bacterial populations did not show actual growth with either yeast strain. In this strategy, both yeast strains finished the alcoholic fermentations, and malolactic fermentations took longer to finish. Lalvin ICV D80® allowed for higher viability and activity of the bacterial strain than Fermicru UY4® under the three inoculation strategies. This was beneficial for the sequential completion of both fermentations, but negatively affected the completion of alcoholic fermentation by Lalvin ICV D80® in the early bacteria additions. Conversely, Fermicru UY4®, which was rather inhibitory towards the bacteria, favored the timely completion of both fermentations simultaneously. As bacteria in early inoculations with low or no SO2 addition can be expected to multiply and interact with fermenting yeasts, not only are the yeast-bacterium strains combination and time point of the inoculation to be considered, but also the amount of bacteria inoculated. PMID:24948914

  5. Subversion of inflammasome activation and pyroptosis by pathogenic bacteria

    PubMed Central

    Cunha, Larissa D.; Zamboni, Dario S.

    2013-01-01

    Activation of the inflammasome occurs in response to a notably high number of pathogenic microbes and is a broad innate immune response that effectively contributes to restriction of pathogen replication and generation of adaptive immunity. Activation of these platforms leads to caspase-1- and/or caspase-11-dependent secretion of proteins, including cytokines, and induction of a specific form of cell death called pyroptosis, which directly or indirectly contribute for restriction of pathogen replication. Not surprisingly, bona fide intracellular pathogens developed strategies for manipulation of cell death to guarantee intracellular replication. In this sense, the remarkable advances in the knowledge of the inflammasome field have been accompanied by several reports characterizing the inhibition of this platform by several pathogenic bacteria. Herein, we review some processes used by pathogenic bacteria, including Yersinia spp., Pseudomonas aeruginosa, Vibrio parahaemolyticus, Chlamydia trachomatis, Francisella tularensis, Shigella flexneri, Legionella pneumophila, and Coxiella burnetii to evade the activation of the inflammasome and the induction of pyroptosis. PMID:24324933

  6. Multiple sample flow through immunomagnetic separator for concentrating pathogenic bacteria

    NASA Astrophysics Data System (ADS)

    Rotariu, Ovidiu; Ogden, Iain D.; MacRae, Marion; Udrea, Laura Elena; Strachan, Norval J. C.

    2005-06-01

    The standard method of immunomagnetic separation for isolating pathogenic bacteria from food and environmental matrices processes 1 ml volumes. Pathogens present at low levels (<0.5 pathogenic bacteria/g) will not be consistently detected by this method. Here a multiple sample flow through immunomagnetic separator has been designed and tested to process large volume samples (50 to 250 ml). Preliminary results show >97% recovery of polydisperse magnetic particles (diameter range 1 to 8 µm) containing 29-33% w/w Fe3O4 content. Between 70 and 130 times more of the pathogenic bacteria Escherichia coli O157 is recovered from PBS compared with the standard 1 ml method. Also, the recovery of E. coli O157 from beef mince homogenates, after a 4 h incubation at 42 °C, is between 80 and 180 times higher than the standard 1 ml method.

  7. Cytochemical Labeling for Fungal and Host Components in Plant Tissues Inoculated with Fungal Wilt Pathogens

    NASA Astrophysics Data System (ADS)

    Ouellette, G. B.; Baayen, R. P.; Chamberland, H.; Simard, M.; Rioux, D.; Charest, P. M.

    2004-08-01

    Antibodies to detect pectin in present investigations attached to distinct fibrils in vessel lumina. In carnation infected with an isolate of Fusarium oxysporum f.sp., labeling of pathogen cells also occurred; in a resistant cultivar (cv.), it was coincident with proximate pectin fibrils and linked to altered fungal walls, which was the opposite in the susceptible cv., indicating that hindrance of pathogen ability to degrade pectin may be related to resistance. Labeling of the fungus in culture was nil, except in media containing pectin, showing that pectin is not native to the pathogen. Labeling of fungal walls for cellulose in elm (inoculated with Ophiostoma novo-ulmi) and carnation also occurred, linked to adsorbed host wall components. The chitin probe often attached to dispersed matter, in vessel lumina, traceable to irregularly labeled fungal cells and host wall degradation products. With an anti-horseradish peroxidase probe, host and fungal walls were equally labeled, and with a glucosidase, differences of labeling between these walls were observed, depending on pH of the test solution. Fungal extracellular matter and filamentous structures, present in fungal walls, predominantly in another elm isolate (Phaeotheca dimorphospora), did not label with any of the probes used. However, in cultures of this fungus, extracellular material labeled, even at a distance from the colony margin, with an anti-fimbriae probe.

  8. Natural soil reservoirs for human pathogenic and fecal indicator bacteria

    USGS Publications Warehouse

    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.

  9. Detection of pathogenic gram negative bacteria using infrared thermography

    NASA Astrophysics Data System (ADS)

    Lahiri, B. B.; Divya, M. P.; Bagavathiappan, S.; Thomas, Sabu; Philip, John

    2012-11-01

    Detection of viable bacteria is of prime importance in all fields of microbiology and biotechnology. Conventional methods of enumerating bacteria are often time consuming and labor-intensive. All living organisms generate heat due to metabolic activities and hence, measurement of heat energy is a viable tool for detection and quantification of bacteria. In this article, we employ a non-contact and real time method - infrared thermography (IRT) for measurement of temperature variations in four clinically significant gram negative pathogenic bacteria, viz. Vibrio cholerae, Vibrio mimicus, Proteus mirabilis and Pseudomonas aeruginosa. We observe that, the energy content, defined as the ratio of heat generated by bacterial metabolic activities to the heat lost from the liquid medium to the surrounding, vary linearly with the bacterial concentration in all the four pathogenic bacteria. The amount of energy content observed in different species is attributed to their metabolisms and morphologies that affect the convection velocity and hence heat transport in the medium.

  10. Pathogenicity and distribution of avian nephritis virus (G-4260 strain) in inoculated laying hens.

    PubMed

    Imada, T; Maeda, M; Furuta, K; Yamaguchi, S; Kawamura, H

    1983-01-01

    Specific-pathogen-free laying hens were inoculated intravenously with the G-4260 strain of avian nephritis virus (ANV). The distribution of the virus in organs, histological changes in main organs, the condition of laying, and egg transmission of the virus were examined in them. Over an experimental period of 27 days, no clinical sings were observed. In a chronological study on the distribution of the virus in organs, the virus was recovered from liver, kidney, jejunum, and rectum for 6 days postinoculation (PI). The virus titer in organ emulsion was the highest in the jejunum of all the main organs. The virus was recovered from the kidney for 8 days PI, although it was not so high in this organ. It was not recovered from the ovary or oviduct. Fluorescent antigens were not observed at all in any material. In a pathological examination, some local inflammatory changes were observed only in the kidney. There were no significant changes in the ovary, oviduct, or any other organ. Antibody appeared 10 days PI and was detectable even 27 days PI, although it was not so high in titer. There was no significant difference in the rate of egg-production between the infected and the sham inoculated groups. No virus was isolated from 111 fertile eggs laid by infected hens over a period from 2 to 27 days PI. PMID:6097821

  11. In ovo inoculation of chicken embryos with probiotic bacteria and its effect on posthatch Salmonella susceptibility.

    PubMed

    de Oliveira, J E; van der Hoeven-Hangoor, E; van de Linde, I B; Montijn, R C; van der Vossen, J M B M

    2014-04-01

    The feasibility of establishing probiotic bacteria in the intestine of broiler chickens by in ovo inoculation was investigated, followed by verifying possible subsequent protection against Salmonella Enteriditis infection. In a first study, 7 commercially available probiotics were screened for compatibility with in ovo inoculation. Two of these probiotics, one being a Enterococcus faecium and the other a Bacillus subtilis, were selected for colonizing the chick gut without compromising hatchability. In a second study, these 2 products were administered in ovo and in the feed to chicks reared until 18 d in comparison with noninoculated chicks and with chicks fed an antibiotic. All chicks were orally challenged with Salmonella Enteritidis at 4 d of age. Results showed reduced performance of Salmonella Enteritidis challenged chicks fed no additives compared with challenged chicks fed antibiotic, but no significant differences in mortality was observed. Probiotics offered in ovo or through the diet could only partially recover performance compared with antibiotic-fed chicks. A significant reduction in the number of Salmonella Enteritidis positive chicks was observed when chicks were in ovo inoculated with E. faecium and continued receiving it in the diet. This work establishes standards for future in ovo colonization research and emphasizes its value as a promising method to deliver individual precise dose of probiotics to poultry in mass scale at the earliest possible age based on the competitive exclusion concept. In ovo colonization with probiotic can therefore become an important ally in combination with other approaches to combat Salmonella and other intestinal bacterial infections in poultry. PMID:24706958

  12. Inoculation of tannin-degrading bacteria into novel hosts increases performance on tannin-rich diets.

    PubMed

    Kohl, Kevin D; Stengel, Ashley; Dearing, M Denise

    2016-06-01

    It has been hypothesized that herbivores host tannin-degrading bacteria (TDB) to overcome the toxic challenges posed by plant tannins. While TDB have been isolated from the guts of numerous mammals, their functional significance to their hosts has never been explicitly tested. We introduced TDB into lab rats, which do not host TDB, and measured host performance on tannin-rich diets. We first isolated three species of TDB, Escherichia coli, Bacillus subtilis and Enterococcus faecalis, from the guts of the desert woodrat (Neotoma lepida), which regularly feeds on tannin-rich plants. Then, we inoculated isolated TDB, as well as full woodrat microbial communities into laboratory rats. A control group was inoculated with sterilized woodrat faeces. Recipient lab rats were fed increasing concentrations of tannic acid, and we monitored tannic acid intake, body mass and liver damage as measured by serum alanine aminotransferase activity. Lab rats given TDB as isolates or full communities exhibited increased tannic acid intake, higher maintenance of body mass and lower indicators of liver damage compared with control animals. These differences were maintained when the trial was repeated after 6 weeks of feeding on tannin-free diets. Our results are the first to demonstrate that TDB significantly increase host performance on tannin-rich diets. PMID:25753857

  13. Inoculation of phosphate solubilizing bacteria for the improvement of lead accumulation by Brassica juncea.

    PubMed

    Ren, Y X; Zhu, X L; Fan, D D; Ma, P; Liang, L H

    2013-01-01

    Two phosphate-solubilizing bacterial strains were isolated and identified as Acinetobacter calcoaceticus YC-5a and Enterobacter agglomerans KMC-7 based on the 16S rRNA gene sequence analysis. A. calcoaceticus YC-5a is less well known as a phosphate-solubilizing plant-associated bacterium. The plant growth-promoting properties of the phosphate-solubilizing bacteria (PSB) were characterized in vitro, including their phosphate-solubilizing activities and their capabilities for producing indole-3-acetic acid and siderophores. A pot experiment was conducted to elucidate the effects of inoculating both strains on the growth and Pb uptake of Brassica juncea grown in different concentrations of Pb-contaminated soils. Inoculation with both PSB not only stimulated the growth of B. juncea, but it also influenced the accumulation of Pb in the shoots and roots of the host plant. The present study demonstrates that PSB are a valuable microbial resource that can be exploited to improve the efficiency of phytoextraction. PMID:23530360

  14. Comparison of pathogenicities of H7 avian influenza viruses via intranasal and conjunctival inoculation in cynomolgus macaques.

    PubMed

    Shichinohe, Shintaro; Itoh, Yasushi; Nakayama, Misako; Ozaki, Hiroichi; Soda, Kosuke; Ishigaki, Hirohito; Okamatsu, Masatoshi; Sakoda, Yoshihiro; Kida, Hiroshi; Ogasawara, Kazumasa

    2016-06-01

    The outbreak of H7N9 low pathogenic avian influenza viruses in China has attracted attention to H7 influenza virus infection in humans. Since we have shown that the pathogenicity of H1N1 and H5N1 influenza viruses in macaques was almost the same as that in humans, we compared the pathogenicities of H7 avian influenza viruses in cynomolgus macaques via intranasal and conjunctival inoculation, which mimics natural infection in humans. H7N9 virus, as well as H7N7 highly pathogenic avian influenza virus, showed more efficient replication and higher pathogenicity in macaques than did H7N1 and H7N3 highly pathogenic avian influenza viruses. These results are different from pathogenicity in chickens as reported previously. Therefore, our results obtained in macaques help to estimate the pathogenicity of H7 avian influenza viruses in humans. PMID:26994587

  15. Spatiotemporal colonization of Xylella fastidiosa in its vector supports the role of egestion in the inoculation mechanism of foregut-borne plant pathogens.

    PubMed

    Backus, Elaine A; Morgan, David J W

    2011-08-01

    The pathogen that causes Pierce's disease of grapevine, Xylella fastidiosa, is the only known bacterial, arthropod-transmitted plant pathogen that does not circulate in the vector's hemolymph. Instead, bacteria are foregut-borne, persistent in adult vectors but semipersistent in immatures (i.e., bacteria colonize cuticular surfaces of the anterior foregut, are retained for hours to days, but are lost during molting). Yet, exactly how a sharpshooter vector inoculates bacteria from foregut acquisition sites is unknown. The present study used confocal laser-scanning microscopy to identify locations in undissected, anterior foreguts of the glassy-winged sharpshooter colonized by green fluorescent protein-expressing X. fastidiosa. Spatial and temporal distributions of colonizing X. fastidiosa were examined daily over acquisition access periods of 1 to 6 days for both contaminated field-collected and clean laboratory-reared Homalodisca vitripennis. Results provide the first direct, empirical evidence that established populations of X. fastidiosa can disappear from vector foreguts over time. When combined with existing knowledge on behavior, physiology, and functional anatomy of sharpshooter feeding, present results support the idea that the disappearance is caused by outward fluid flow (egestion) not inward flow (ingestion) (i.e., swallowing). Thus, results support the hypothesis that egestion is a critical part of the X. fastidiosa inoculation mechanism. Furthermore, results suggest a cyclical, spatiotemporal pattern of microbial colonization, disappearance, and recolonization in the precibarium. Colonization patterns also support two types of egestion, termed rinsing and discharging egestion herein. Finally, comparison of acquisition results for field-collected versus laboratory-reared sharpshooters suggest that there may be competitive binding for optimum acquisition sites in the foregut. Therefore, successful inoculation of X. fastidiosa may depend, in large part, on

  16. Effects of lactic acid bacteria silage inoculation on methane emission and productivity of Holstein Friesian dairy cattle.

    PubMed

    Ellis, J L; Hindrichsen, I K; Klop, G; Kinley, R D; Milora, N; Bannink, A; Dijkstra, J

    2016-09-01

    Inoculants of lactic acid bacteria (LAB) are used to improve silage quality and prevent spoilage via increased production of lactic acid and other organic acids and a rapid decline in silage pH. The addition of LAB inoculants to silage has been associated with increases in silage digestibility, dry matter intake (DMI), and milk yield. Given the potential change in silage and rumen fermentation conditions accompanying these silage additives, the aim of this study was to investigate the effect of LAB silage inoculants on DMI, digestibility, milk yield, milk composition, and methane (CH4) production from dairy cows in vivo. Eight mid-lactation Holstein-Friesian dairy cows were grouped into 2 blocks of 4 cows (multiparous and primiparous) and used in a 4×4 double Latin square design with 21-d periods. Methane emissions were measured by indirect calorimetry. Treatments were grass silage (mainly ryegrass) with no inoculant (GS), with a long-term inoculant (applied at harvest; GS+L), with a short-term inoculant (applied 16h before feeding; GS+S), or with both long and short-term inoculants (GS+L+S). All diets consisted of grass silage and concentrate (75:25 on a dry matter basis). The long-term inoculant consisted of a 10:20:70 mixture of Lactobacillus plantarum, Lactococcus lactis, and Lactobacillus buchneri, and the short-term inoculant was a preparation of Lc. lactis. Dry matter intake was not affected by long-term or short-term silage inoculation, nor was dietary neutral detergent fiber or fat digestibility, or N or energy balance. Milk composition (except milk urea) and fat and protein-corrected milk yield were not affected by long- or short-term silage inoculation, nor was milk microbial count. However, milk yield tended to be greater with long-term silage inoculation. Methane expressed in units of grams per day, grams per kilogram of DMI, grams per kilogram of milk, or grams per kilogram of fat and protein-corrected milk yield was not affected by long- or short

  17. [Analysis of Pathogenic Bacteria in Reclaimed Water and Impact of UV Disinfection on the Removal of Pathogenic Bacteria].

    PubMed

    Jing, Ming; Wang, Lei

    2016-02-15

    In the study, 454-pyrosequencing technology was employed to investigate the species of pathogenic bacteria and the proportion of each pathogen in secondary effluent. Culture-based, qPCR and Q-RT-PCR methods were employed to analyze the removal of indicator (E. coli) and pathogen (Salmonella and Mycobacterium) by ultraviolet (UV) disinfection at a dose of 60 mJ x Cm(-2). The results showed that 11 kinds of pathogenic bacteria were found and the most abundant potentially pathogenic bacteria in the secondary effluent were affiliated with the genera of Clostridium (2.96%), Arcobacter (0.82%) and Mycobacterium (0.36%). 99.9% of culturable E. coli and Salmonella were removed by UV disinfection (60 mJ x cm(-2), however, less than 90% of culturable Mycobacterium were removed. The removal efficiencies of viable E. coli, Salmonella and Mycobacterium were low. Q-RT-PCR seemed to be a promising method for evaluating viable microorganisms in samples. Besides, pathogenic bacteria entered into VBNC state at a UV dose of 60 mJ x cm(-2). Other advanced treatment processes were needed to ensure safe utilization of reclaimed water. PMID:27363153

  18. Accumulation and Distribution of Lead and Chromium in Laboratory-Scale Constructed Wetlands Inoculated with Metal-Tolerant Bacteria.

    PubMed

    Amabilis-Sosa, Leonel E; Siebe, Christina; Moeller-Chávez, Gabriela; Durán-Domínguez-de-Bazúa, María del Carmen

    2015-01-01

    The accumulation and distribution of lead and chromium was tested in a laboratory-scale constructed wetland (CW) inoculated with metal-tolerant bacteria. Two non-inoculated systems also were evaluated, one planted and the other unplanted. Mass balances indicated that 57% of chromium input was accumulated into inoculated CW after 151 days of operation. The distribution was similar in support media and vegetation, in which 78% was transferred to aerial part. Similarly Pb was accumulated 29% in the support media and 39% in vegetation, which was distributed 52% in rhizome and 48% in aerial part. Significantly lower amounts of heavy metals were accumulated in non-inoculated systems than in the inoculated wetlands (p < 0.005). In addition, a markedly higher proportion of chromium in aerial vegetation and of lead in the suspended fraction of the effluent was exhibited, which raises a subsequent recovery of the metal by harvest and settling, respectively. Results indicate that CW inoculated with metal-tolerant bacteria might be a suitable option for treating wastewater with content of lead and chromium. PMID:26023800

  19. Fluorescent homogeneous immunosensors for detecting pathogenic bacteria.

    PubMed

    Heyduk, Ewa; Heyduk, Tomasz

    2010-01-15

    We developed a straightforward antibody-based assay for rapid homogeneous detection of bacteria. Our sensors utilize antibody recognizing cell-surface epitopes of the target cell. Two samples of the antibody are prepared, each labeled via nanometer size flexible linkers with short complementary oligonucleotides that are modified with fluorochromes that could participate in fluorescence resonance energy transfer (FRET). The length of the complementary oligonucleotide sequences was designed such that very little annealing occurred in the absence of the target cells. In the presence of the target cells the two labeled antibodies bind to the surface of the cell resulting in a large local concentration of the complementary oligonucleotides that are attached to the antibody. This in turn drives the annealing of the complementary oligonucleotides which brings the fluorescence probes to close proximity producing large FRET signals proportional to the amount of target cells. Long flexible linkers used to attach the oligonucleotides to the antibody enable target-induced oligonucleotide annealing even if the density of surface antigens is only modest. We used Escherichia coli 0157:H7 and Salmonella typhimurium to demonstrate that this design produced sensors exhibiting rapid response time, high specificity, and sensitivity in detecting the target bacteria. PMID:19782039

  20. Development of a greenhouse-based inoculation protocol for the fungus Colletotrichum cereale pathogenic to annual bluegrass (Poa annua)

    PubMed Central

    Beirn, Lisa A.; Wang, Ruying; Clarke, Bruce B.

    2015-01-01

    The fungus Colletotrichum cereale incites anthracnose disease on Poa annua (annual bluegrass) turfgrass. Anthracnose disease is geographically widespread throughout the world and highly destructive to cool-season turfgrasses, with infections by C. cereale resulting in extensive turf loss. Comprehensive research aimed at controlling turfgrass anthracnose has been performed in the field, but knowledge of the causal organism and its basic biology is still needed. In particular, the lack of a reliable greenhouse-based inoculation protocol performed under controlled environmental conditions is an obstacle to the study of C. cereale and anthracnose disease. Our objective was to develop a consistent and reproducible inoculation protocol for the two major genetic lineages of C. cereale. By adapting previously successful field-based protocols and combining with components of existing inoculation procedures, the method we developed consistently produced C. cereale infection on two susceptible P. annua biotypes. Approximately 7 to 10 days post-inoculation, plants exhibited chlorosis and thinning consistent with anthracnose disease symptomology. Morphological inspection of inoculated plants revealed visual signs of the fungus (appressoria and acervuli), although acervuli were not always present. After stringent surface sterilization of inoculated host tissue, C. cereale was consistently re-isolated from symptomatic tissue. Real-time PCR detection analysis based on the Apn2 marker confirmed the presence of the pathogen in host tissue, with both lineages of C. cereale detected from all inoculated plants. When a humidifier was not used, no infection developed for any biotypes or fungal isolates tested. The inoculation protocol described here marks significant progress for in planta studies of C. cereale, and will enable scientifically reproducible investigations of the biology, infectivity and lifestyle of this important grass pathogen. PMID:26339538

  1. Radiation resistances and decontamination of common pathogenic bacteria contaminated in white scar oyster ( Crassostrea belcheri) in Thailand

    NASA Astrophysics Data System (ADS)

    Thupila, Nunticha; Ratana-arporn, Pattama; Wilaipun, Pongtep

    2011-07-01

    In Thailand, white scar oyster ( Crassostrea belcheri) was ranked for premium quality, being most expensive and of high demand. This oyster is often eaten raw, hence it may pose health hazards to consumers when contaminated with food-borne pathogens. As limited alternative methods are available to sterilize the oyster while preserving the raw characteristic, irradiation may be considered as an effective method for decontamination. In this study, the radiation resistance of pathogenic bacteria commonly contaminating the oyster and the optimum irradiation doses for sterilization of the most radiation resistant bacteria were investigated. The radiation decimal reduction doses ( D10) of Salmonella Weltevreden DMST 33380, Vibrio parahaemolyticus ATCC 17802 and Vibrio vulnificus DMST 5852 were determined in broth culture and inoculated oyster homogenate. The D10 values of S. Weltevreden, V. parahaemolyticus and V. vulnificus in broth culture were 0.154, 0.132 and 0.059 kGy, while those of inoculated oyster homogenate were 0.330, 0.159 and 0.140 kGy, respectively. It was found that among the pathogens tested, S. Weltevreden was proved to be the most resistant species. An irradiation dose of 1.5 kGy reduced the counts of 10 5 CFU/g S. Weltevreden inoculated in oyster meat to an undetectable level. The present study indicated that a low-dose irradiation can improve the microbial quality of oyster and further reduce the risks from the food-borne pathogens without adversely affecting the sensory attributes.

  2. Reduction of pathogenic bacteria in organic compost using gamma irradiation

    NASA Astrophysics Data System (ADS)

    Yun, Hye-Jeong; Lim, Sang-Yong; Song, Hyun-Pa; Kim, Byung-Keun; Chung, Byung-Yeoup; Kim, Dong-Ho

    2007-11-01

    Organic compost is a useful fertilizer for organic farming. However, it poses a microbiological hazard to the farm products because most of the composts are originated from excremental matters of domestic animals. In this study, the radiation treatment was performed to improve microbiological safety of organic compost and the effectiveness of gamma irradiation for inactivating Salmonella Typhimurium and Escherichia coli was investigated. The total aerobic and coliform bacteria in the 16 commercial composts were ranged from 10 5 to 10 7 CFU/ml and 0 to 10 3 CFU/ml, respectively. All coliform bacteria in the composts were eliminated by irradiation at a dose of 3 kGy, while about 10 2 CFU/ml of the total aerobic bacteria were survived up to 10 kGy. In the artificial inoculation test, the test organisms (inoculated at 10 7 CFU/g) were eliminated by irradiation at 3 kGy. Approximate D10 values of Salmonella Typhimurium and E. coli in the compost were 0.40 and 0.25 kGy, respectively. In the cultivation test, the test organisms of the compost had transfer a lettuce leaves. The growth pattern of lettuce was not different between irradiated and non-irradiated composts.

  3. Induction of Defense-Related Ultrastructural Modifications in Pea Root Tissues Inoculated with Endophytic Bacteria.

    PubMed Central

    Benhamou, N.; Kloepper, J. W.; Quadt-Hallman, A.; Tuzun, S.

    1996-01-01

    The stimulation exerted by the endophytic bacterium Bacillus pumilus strain SE34 in plant defense reactions was investigated at the ultrastructural level using an in vitro system in which root-inducing T-DNA pea (Pisum sativum L.) roots were infected with the pea root-rotting fungus Fusarium oxysporum f. sp. pisi. In nonbacterized roots, the pathogen multiplied abundantly through much of the tissue including the vascular stele, whereas in prebacterized roots, pathogen growth was restricted to the epidermis and the outer cortex In these prebacterized roots, typical host reactions included strengthening the epidermal and cortical cell walls and deposition of newly formed barriers beyond the infection sites. Wall appositions were found to contain large amounts of callose in addition to being infiltrated with phenolic compounds. The labeling pattern obtained with the gold-complexed laccase showed that phenolics were widely distributed in Fusarium-challenged, bacterized roots. Such compounds accumulated in the host cell walls and the intercellular spaces as well as at the surface or even inside of the invading hyphae of the pathogen. The wall-bound chitin component in Fusarium hyphae colonizing bacterized roots was preserved even when hyphae had undergone substantial degradation. These observations confirm that endophytic bacteria may function as potential inducers of plant disease resistance. PMID:12226427

  4. V-antigen homologs in pathogenic gram-negative bacteria.

    PubMed

    Sawa, Teiji; Katoh, Hideya; Yasumoto, Hiroaki

    2014-05-01

    Gram-negative bacteria cause many types of infections in animals from fish and shrimps to humans. Bacteria use Type III secretion systems (TTSSs) to translocate their toxins directly into eukaryotic cells. The V-antigen is a multifunctional protein required for the TTSS in Yersinia and Pseudomonas aeruginosa. V-antigen vaccines and anti-V-antigen antisera confer protection against Yersinia or P. aeruginosa infections in animal models. The V-antigen forms a pentameric cap structure at the tip of the Type III secretory needle; this structure, which has evolved from the bacterial flagellar cap structure, is indispensable for toxin translocation. Various pathogenic gram-negative bacteria such as Photorhabdus luminescens, Vibrio spp., and Aeromonas spp. encode homologs of the V-antigen. Because the V-antigens of pathogenic gram-negative bacteria play a key role in toxin translocation, they are potential therapeutic targets for combatting bacterial virulence. In the USA and Europe, these vaccines and specific antibodies against V-antigens are in clinical trials investigating the treatment of Yersinia or P. aeruginosa infections. Pathogenic gram-negative bacteria are of great interest because of their ability to infect fish and shrimp farms, their potential for exploitation in biological terrorism attacks, and their ability to cause opportunistic infections in humans. Thus, elucidation of the roles of the V-antigen in the TTSS and mechanisms by which these functions can be blocked is critical to facilitating the development of improved anti-V-antigen strategies. PMID:24641673

  5. Molecular battles between plant and pathogenic bacteria in the phyllosphere

    PubMed Central

    Baker, C.M.; Chitrakar, R.; Obulareddy, N.; Panchal, S.; Williams, P.; Melotto, M.

    2011-01-01

    The phyllosphere, i.e., the aerial parts of the plant, provides one of the most important niches for microbial colonization. This niche supports the survival and, often, proliferation of microbes such as fungi and bacteria with diverse lifestyles including epiphytes, saprophytes, and pathogens. Although most microbes may complete the life cycle on the leaf surface, pathogens must enter the leaf and multiply aggressively in the leaf interior. Natural surface openings, such as stomata, are important entry sites for bacteria. Stomata are known for their vital role in water transpiration and gas exchange between the plant and the environment that is essential for plant growth. Recent studies have shown that stomata can also play an active role in limiting bacterial invasion of both human and plant pathogenic bacteria as part of the plant innate immune system. As counter-defense, plant pathogens such as Pseudomonas syringae pv. tomato (Pst) DC3000 use the virulence factor coronatine to suppress stomata-based defense. A novel and crucial early battleground in host-pathogen interaction in the phyllosphere has been discovered with broad implications in the study of bacterial pathogenesis, host immunity, and molecular ecology of bacterial diseases. PMID:20602017

  6. Enumeration of potentially pathogenic bacteria from sewage sludges.

    PubMed Central

    Dudley, D J; Guentzel, M N; Ibarra, M J; Moore, B E; Sagik, B P

    1980-01-01

    To ascertain the health risks that may be posed by the land application of sewage sludges, a scheme was devised to determine the types and numbers of pathogenic and potentially pathogenic bacteria present in sludges. A processing treatment was adapted to sludge to give a homogenate which yielded the greatest numbers of viable bacteria. Conventional methods were successful in enumerating Klebsiella, Staphylococcus, gram-negative enteric bacteria, and commonly used indicator organisms. Modifications of conventional methods improved the enumeration of Salmonella, Mycobacterium sp., fluorescent Pseudomonas sp., and Clostridium perfringens. However, Shigella methodology yielded only one isolate. Utilizing the proposed scheme, the population densities of these organisms were estimated in three domestic wastewater sludges. In light of these results, the potential impact of land application of sewage sludges is discussed. PMID:6243900

  7. Inoculation of paperboard mill sludge versus mixed culture bacteria for hydrogen production from paperboard mill wastewater.

    PubMed

    Farghaly, Ahmed; Tawfik, Ahmed; Danial, Amal

    2016-02-01

    A comparative evaluation of paperboard mill sludge (PMS) versus mixed culture bacteria (MCB) as inoculum for hydrogen production from paperboard mill wastewater (PMW) was investigated. The experiments were conducted at different initial cultivation pHs, inoculums to substrate ratios (ISRs gVS/gCOD), and hydraulic retention times (HRTs). The peak hydrogen yield (HY) of 5.29 ± 0.16 and 1.22 ± 0.11 mmol/gCODinitial was occurred at pH = 5 for MCB and PMS, respectively. At pH of 5, the HY and COD removal achieved the highest values of 2.26 ± 0.14 mmol/gCODinitial and 86 ± 1.6% at ISR = 6 for MCB, and 2.38 ± 0.25 mmol/gCODinitial and 60.4 ± 2.5% at ISRs = 3 for PMS. The maximum hydrogen production rate was 93.75 ± 8.9 mmol/day at HRT = 9.6 h from continuous upflow anaerobic reactor inoculated with MCB. Meanwhile, the 16S ribosomal RNA (rRNA) gene fragments indicated a dominance of a novel hydrogen-producing bacterium of Stenotrophomonas maltophilia for PMS microbial community. On the other hand, Escherichia fergusonii and Enterobacter hormaechei were the predominant species for MCB. PMID:26498965

  8. Colonization of Flax Roots and Early Physiological Responses of Flax Cells Inoculated with Pathogenic and Nonpathogenic Strains of Fusarium oxysporum

    PubMed Central

    Olivain, Chantal; Trouvelot, Sophie; Binet, Marie-Noëlle; Cordier, Christelle; Pugin, Alain; Alabouvette, Claude

    2003-01-01

    Fusarium oxysporum includes nonpathogenic strains and pathogenic strains that can induce necrosis or tracheomycosis in plants. The objective of this study was to compare the abilities of a pathogenic strain (Foln3) and a nonpathogenic strain (Fo47) to colonize flax roots and to induce early physiological responses in flax cell culture suspensions. Both strains colonized the outer cortex of the root; however, plant defense reactions, i.e., the presence of wall appositions, osmiophilic material, and collapsed cells, were less frequent and less intense in a root colonized by Foln3 than by Fo47. Early physiological responses were measured in flax cell suspensions confronted with germinated microconidia of both strains. Both pathogenic (Foln3) and nonpathogenic strains (Fo47) triggered transient H2O2 production in the first few minutes of the interaction, but the nonpathogenic strain also induced a second burst 3 h postinoculation. Ca2+ influx was more intense in cells inoculated with Fo47 than in cells inoculated with Foln3. Similarly, alkalinization of the extracellular medium was higher with Fo47 than with Foln3. Inoculation of the fungi into flax cell suspensions induced cell death 10 to 20 h postinoculation, with a higher percentage of dead cells observed with Fo47 than with Foln3 beginning at 14 h. This is the first report showing that early physiological responses of flax cells can be used to distinguish pathogenic and nonpathogenic strains of the soil-borne fungus F. oxysporum. PMID:12957934

  9. Survival of pathogenic bacteria in pesticide solutions and on treated tomato plants.

    PubMed

    Guan, Tiffany T Y; Blank, Gregory; Holley, Richard A

    2005-02-01

    The ability of Salmonella, Escherichia coli O157:H7, Listeria monocytogenes, and Shigella to survive or grow in pesticide solutions (Ambush 240EC, Benlate T-N-G, Bravo 500, Botran 75WP, Captan 80WDG, Parasol, and Vendex 50W) used by the horticultural industry was examined. In the laboratory, individual cultures were inoculated at 4 log CFU/ml in pesticides diluted with sterile saline to the lowest recommended spray concentrations. During 21 degrees C incubation for < or =96 h, bacterial survivors in the samples and a control consisting of saline were enumerated either by agar surface plating or hydrophobic grid membrane filtration. Most formulations tested were somewhat inhibitory to the pathogenic bacteria. All inoculated bacteria survived or grew in Bravo 500. Among bacteria tested, Salmonella spp. were best able to survive and Listeria spp. were least able to survive in pesticide solutions. When the incubation temperature or pesticide concentration was increased, survival of Salmonella varied depending on the type of formulation. In the field, when a bacterial cocktail containing E. coli O157:H7 and Salmonella Enteritidis was added to Bravo 500 at 6 log CFU/ml, both organisms were recovered from leaves and fruit skins of sprayed tomato plants after the recommended 1 day-to-harvest interval. E. coli and Salmonella survived longer on tomato leaves when sprayed in saline (at least 26 and 56 days, respectively) than when sprayed in Bravo 500 (>45 h and <15 days, respectively). While Salmonella serovars Typhimurium and Heidelberg grew in the fungicide Bravo, and Enteritidis grew in the insecticide Vendex within 96 h at 21 degrees C in the laboratory, pathogen growth in other pesticide formulations did not occur. Higher temperature (< or =30 degrees C) or doubling pesticide concentrations had either no or a negative effect on Salmonella Heidelberg survival. Use of unexpired pesticide formulations may have contributed to the reduced bacterial survival and growth found

  10. Duck Tembusu Virus Exhibits Pathogenicity to Kunming Mice by Intracerebral Inoculation

    PubMed Central

    Ti, Jinfeng; Zhang, Min; Li, Zhijie; Li, Xiuli; Diao, Youxiang

    2016-01-01

    In this study, Kunming mice were used as the animal models to study the pathogenicity of TMUV. Three groups of 3-week-old female Kunming mice (n = 15 mice per group) were infected with the SDSG strain of TMUV in 50 μL allantoic fluid (104.8 ELD50/0.2 ml) respectively by the intracerebral (i.c.), subcutaneous (s.c.) and intranasal (i.n.) routes. The control group (n = 15 mice) was inoculated with 50 μL sterile phosphate-buffered saline. Clinical signs, gross, and microscopic lesions, viral loads in different tissues, and serum antibody titers were examined and recorded. Kunming mice infected intracerebrally showed typical clinical symptoms, including severe hindlimb paralysis, weight loss and death. Only dead mice presented severe intestinal mucosal edema. No gross lesions were observed in mice sequentially euthanized. However, microscopic lesions in the brain, spleen, liver, kidney, and lung were very typical including varying degrees of viral encephalitis, lymphocytes depletion, liver cell necrosis and nephritis, etc. Viral loads in different tissues were detected by the SYBR Green I real-time PCR assay. Viral loads in the brain, liver, and spleen were first detected and maintained a longer time, which indicated that these organs may be the target organs of TMUV. The level of viral loads was consistent with the severity of clinical signs and microscopic lesions in different tissues. The neutralizing antibody began to seroconvert at 8 dpi. Clinical signs, microscopic lesions, viral loads and serum neutralizing antibodies weren’t observed in other groups. In summary, TMUV can cause systemic infections and death in Kunming mice by i.c., which provides some experimental basis for further study of the significance of TMUV in public health. PMID:26925054

  11. Pathogenicity in six Australian reptile species following experimental inoculation with Bohle iridovirus.

    PubMed

    Ariel, E; Wirth, W; Burgess, G; Scott, J; Owens, L

    2015-08-20

    Ranaviruses are able to infect multiple species of fish, amphibian and reptile, and some strains are capable of interclass transmission. These numerous potential carriers and reservoir species compound efforts to control and contain infections in cultured and wild populations, and a comprehensive knowledge of susceptible species and life stage is necessary to inform such processes. Here we report on the challenge of 6 water-associated reptiles with Bohle iridovirus (BIV) to investigate its potential pathogenicity in common native reptiles of the aquatic and riparian fauna of northern Queensland, Australia. Adult tortoises Elseya latisternum and Emydura krefftii, snakes Boiga irregularis, Dendrelaphis punctulatus and Amphiesma mairii, and yearling crocodiles Crocodylus johnstoni were exposed via intracoelomic inoculation or co-habitation with infected con-specifics, but none were adversely affected by the challenge conditions applied here. Bohle iridovirus was found to be extremely virulent in hatchling tortoises E. latisternum and E. krefftii via intracoelomic challenge, as demonstrated by distinct lesions in multiple organs associated with specific immunohistochemistry staining and a lethal outcome (10/17) of the challenge. Virus was re-isolated from 2/5 E. latisternum, 4/12 E. krefftii and 1/3 brown tree snakes B. irregularis. Focal necrosis, haemorrhage and infiltration of granulocytes were frequently observed histologically in the pancreas, liver and sub-mucosa of the intestine of challenged tortoise hatchlings. Immunohistochemistry demonstrated the presence of ranavirus antigens in the necrotic lesions and in individual cells of the vascular endothelium, the connective tissue and in granulocytes associated with necrosis or present along serosal surfaces. The outcome of this study confirms hatchling tortoises are susceptible to BIV, thereby adding Australian reptiles to the host range of ranaviruses. Additionally, given that BIV was originally isolated from an

  12. Duck Tembusu Virus Exhibits Pathogenicity to Kunming Mice by Intracerebral Inoculation.

    PubMed

    Ti, Jinfeng; Zhang, Min; Li, Zhijie; Li, Xiuli; Diao, Youxiang

    2016-01-01

    In this study, Kunming mice were used as the animal models to study the pathogenicity of TMUV. Three groups of 3-week-old female Kunming mice (n = 15 mice per group) were infected with the SDSG strain of TMUV in 50 μL allantoic fluid (10(4.8) ELD50/0.2 ml) respectively by the intracerebral (i.c.), subcutaneous (s.c.) and intranasal (i.n.) routes. The control group (n = 15 mice) was inoculated with 50 μL sterile phosphate-buffered saline. Clinical signs, gross, and microscopic lesions, viral loads in different tissues, and serum antibody titers were examined and recorded. Kunming mice infected intracerebrally showed typical clinical symptoms, including severe hindlimb paralysis, weight loss and death. Only dead mice presented severe intestinal mucosal edema. No gross lesions were observed in mice sequentially euthanized. However, microscopic lesions in the brain, spleen, liver, kidney, and lung were very typical including varying degrees of viral encephalitis, lymphocytes depletion, liver cell necrosis and nephritis, etc. Viral loads in different tissues were detected by the SYBR Green I real-time PCR assay. Viral loads in the brain, liver, and spleen were first detected and maintained a longer time, which indicated that these organs may be the target organs of TMUV. The level of viral loads was consistent with the severity of clinical signs and microscopic lesions in different tissues. The neutralizing antibody began to seroconvert at 8 dpi. Clinical signs, microscopic lesions, viral loads and serum neutralizing antibodies weren't observed in other groups. In summary, TMUV can cause systemic infections and death in Kunming mice by i.c., which provides some experimental basis for further study of the significance of TMUV in public health. PMID:26925054

  13. Penetration of surface-inoculated bacteria as a result of electrically generated hydrodynamic shock wave treatment of boneless skinless chicken breasts.

    PubMed

    Lorca, T A; Claus, J R; Eifert, J D; Marcy, J E; Sumner, S S

    2003-07-01

    The top surface of boneless skinless chicken breasts was inoculated with either green fluorescent protein (GFP)-labeled Escherichia coli (E. coli-GFP) or rifampicin-resistant E. coli (E. coli-Rif) and subjected to electrically generated hydrodynamic shock wave treatment (HVADH). Cryostat sampling in concert with laser scanning confocal microscopy or plating onto antibiotic selective agar was used to determine if HVADH treatment resulted in the movement of the inoculated bacteria from the outer inoculated surface to the interior of intact boneless skinless chicken breasts. In HVADH-treated boneless skinless chicken breasts, marker bacteria were detected within the first 200 microm below the inoculated surface, 50 to 100 microm beyond the depth of untreated surface inoculated boneless skinless chicken breasts. The exact depth at which the marker bacteria were found was dependent on the cryostat sampling distance used. These results suggest that HVADH treatments affect the movement of surface bacteria. PMID:12872981

  14. Essential oils against foodborne pathogens and spoilage bacteria in minced meat.

    PubMed

    Barbosa, Lidiane Nunes; Rall, Vera Lucia Mores; Fernandes, Ana Angélica Henrique; Ushimaru, Priscila Ikeda; da Silva Probst, Isabella; Fernandes, Ary

    2009-01-01

    The antimicrobial activity of essential oils of oregano, thyme, basil, marjoram, lemongrass, ginger, and clove was investigated in vitro by agar dilution method and minimal inhibitory concentration (MIC) determination against Gram-positive (Staphylococcus aureus and Listeria monocytogenes) and Gram-negative strains (Escherichia coli and Salmonella Enteritidis). MIC(90%) values were tested against bacterial strains inoculated experimentally in irradiated minced meat and against natural microbiota (aerobic or facultative, mesophilic, and psychrotrophic bacteria) found in minced meat samples. MIC(90%) values ranged from 0.05%v/v (lemongrass oil) to 0.46%v/v (marjoram oil) to Gram-positive bacteria and from 0.10%v/v (clove oil) to 0.56%v/v (ginger oil) to Gram-negative strains. However, the MIC(90%) assessed on minced meat inoculated experimentally with foodborne pathogen strains and against natural microbiota of meat did not show the same effectiveness, and 1.3 and 1.0 were the highest log CFU/g reduction values obtained against tested microorganisms. PMID:19580445

  15. Growth Inhibition of Pathogenic Bacteria by Sulfonylurea Herbicides

    PubMed Central

    Kreisberg, Jason F.; Ong, Nicholas T.; Krishna, Aishwarya; Joseph, Thomas L.; Wang, Jing; Ong, Catherine; Ooi, Hui Ann; Sung, Julie C.; Siew, Chern Chiang; Chang, Grace C.; Biot, Fabrice; Cuccui, Jon; Wren, Brendan W.; Chan, Joey; Sivalingam, Suppiah P.; Zhang, Lian-Hui; Verma, Chandra

    2013-01-01

    Emerging resistance to current antibiotics raises the need for new microbial drug targets. We show that targeting branched-chain amino acid (BCAA) biosynthesis using sulfonylurea herbicides, which inhibit the BCAA biosynthetic enzyme acetohydroxyacid synthase (AHAS), can exert bacteriostatic effects on several pathogenic bacteria, including Burkholderia pseudomallei, Pseudomonas aeruginosa, and Acinetobacter baumannii. Our results suggest that targeting biosynthetic enzymes like AHAS, which are lacking in humans, could represent a promising antimicrobial drug strategy. PMID:23263008

  16. Antibacterial activity of caffeine against plant pathogenic bacteria.

    PubMed

    Sledz, Wojciech; Los, Emilia; Paczek, Agnieszka; Rischka, Jacek; Motyka, Agata; Zoledowska, Sabina; Piosik, Jacek; Lojkowska, Ewa

    2015-01-01

    The objective of the present study was to evaluate the antibacterial properties of a plant secondary metabolite - caffeine. Caffeine is present in over 100 plant species. Antibacterial activity of caffeine was examined against the following plant-pathogenic bacteria: Ralstonia solanacearum (Rsol), Clavibacter michiganesis subsp. sepedonicus (Cms), Dickeya solani (Dsol), Pectobacterium atrosepticum (Pba), Pectobacterium carotovorum subsp. carotovorum (Pcc), Pseudomonas syringae pv. tomato (Pst), and Xanthomonas campestris subsp. campestris (Xcc). MIC and MBC values ranged from 5 to 20 mM and from 43 to 100 mM, respectively. Caffeine increased the bacterial generation time of all tested species and caused changes in cell morphology. The influence of caffeine on the synthesis of DNA, RNA and proteins was investigated in cultures of plant pathogenic bacteria with labelled precursors: [(3)H]thymidine, [(3)H]uridine or (14)C leucine, respectively. RNA biosynthesis was more affected than DNA or protein biosynthesis in bacterial cells treated with caffeine. Treatment of Pba with caffeine for 336 h did not induce resistance to this compound. Caffeine application reduced disease symptoms caused by Dsol on chicory leaves, potato slices, and whole potato tubers. The data presented indicate caffeine as a potential tool for the control of diseases caused by plant-pathogenic bacteria, especially under storage conditions. PMID:26307771

  17. Differential effects of catecholamines on in vitro growth of pathogenic bacteria

    NASA Technical Reports Server (NTRS)

    Belay, Tesfaye; Sonnenfeld, Gerald

    2002-01-01

    Supplementation of minimal medium inoculated with bacterial cultures with norepinephrine, epinephrine, dopamine, or isoproterenol resulted in marked increases in growth compared to controls. Norepinephrine and dopamine had the greatest enhancing effects on growth of cultures of Pseudomonas aeruginosa and Klebsiella pneumoniae, while epinephrine and isoproterenol also enhanced growth to a lesser extent. The growth of Escherichia coli in the presence of norepinephrine was greater than growth in the presence of the three other neurochemicals used in the study. Growth of Staphylococcus aureus was also enhanced in the presence of norepinephrine, but not to the same degree as was the growth of gram negative bacteria. Addition of culture supernatants from E. coli cultures that had been grown in the presence of norepinephrine was able to enhance the growth of K. pneumoniae. Addition of the culture supernatant fluid culture from E. coli cultures that had been grown in the presence of norepinephrine did not enhance growth of P. aeruginosa or S. aureus. Culture supernatant fluids from bacteria other than E. coli grown in the presence of norepinephrine were not able to enhance the growth of any bacteria tested. The results suggest that catecholamines can enhance growth of pathogenic bacteria, which may contribute to development of pathogenesis; however, there is no uniform effect of catecholamines on bacterial growth.

  18. Comparative anatomy of gall development on Gypsophila paniculata induced by bacteria with different mechanisms of pathogenicity.

    PubMed

    Chalupowicz, L; Barash, I; Schwartz, M; Aloni, R; Manulis, S

    2006-07-01

    Galls induced on Gypsophila paniculata by Pantoea agglomerans pv. gypsophilae (Pag) and Agrobacterium tumefaciens (At), bacteria with different mechanisms of pathogenicity, were compared morphologically and anatomically. The pathogenicity of Pag is dependent on the presence of an indigenous plasmid that harbors hrp gene cluster, genes encoding Hop virulence proteins and biosynthetic genes for auxin (IAA) and cytokinins (CKs), whereas that of At involves host transformation. The Pag-induced gall was rough, brittle and exhibited limited growth, in contrast to the smooth, firm appearance and continuous growth of the At-induced gall. Anatomical analysis revealed the presence of cells with enlarged nuclei and multiple nucleoli, giant cells and suberin deposition in Pag that were absent from At-induced galls. Although circular vessels were observed in both gall types, they were more numerous and the vascular system was more organized in At. An aerenchymal tissue was observed in the upper part of the galls. Ethylene emission from Pag galls, recorded 6 days after inoculation, was eight times as great as that from non-infected controls. In contrast, a significant decrease in ethylene production was observed in Gypsophila cuttings infected with Pag mutants deficient in IAA and CK production. The results presented are best accounted for by the two pathogens having distinct pathogenicity mechanisms that lead to their differential recognition by the host as non-self (Pag) and self (At). PMID:16477460

  19. Detection of bacterial aggregation in cell suspensions treated with pathogenic bacteria

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The early interaction between plant cells and pathogenic bacteria were studied using tobacco cell suspensions treated with pathogenic and nonpathogenic Pseudomonas species. Previous studies of this system have documented that interactions with pathogens that cause a hypersensitive response on whole...

  20. Modeling the interactions between pathogenic bacteria, bacteriophage and immune response

    NASA Astrophysics Data System (ADS)

    Leung, Chung Yin (Joey); Weitz, Joshua S.

    The prevalence of antibiotic-resistant strains of pathogenic bacteria has led to renewed interest in the use of bacteriophage (phage), or virus that infects bacteria, as a therapeutic agent against bacterial infections. However, little is known about the theoretical mechanism by which phage therapy may work. In particular, interactions between the bacteria, the phage and the host immune response crucially influences the outcome of the therapy. Few models of phage therapy have incorporated all these three components, and existing models suffer from unrealistic assumptions such as unbounded growth of the immune response. We propose a model of phage therapy with an emphasis on nonlinear feedback arising from interactions with bacteria and the immune response. Our model shows a synergistic effect between the phage and the immune response which underlies a possible mechanism for phage to catalyze the elimination of bacteria even when neither the immune response nor phage could do so alone. We study the significance of this effect for different parameters of infection and immune response, and discuss its implications for phage therapy.

  1. Phytostabilization of moderate copper contaminated soils using co-inoculation of Vicia faba with plant growth promoting bacteria.

    PubMed

    Fatnassi, Imen Challougui; Chiboub, Manel; Saadani, Omar; Jebara, Moez; Jebara, Salwa Harzalli

    2015-03-01

    There is a need to conduct research on the selection of microbial isolates from rhizosphere of plants growing on heavy metal contaminated soils for specific restoration programs. This article suggest a consortium of bacteria combining Rhizobium sp. CCNWSX0481, Rhizobium leguminosarum bv. viciae, Enterobacter cloacae and Pseudomonas sp. 2(2010) that was examined for the ability to promote Vicia faba.L. growth when cultivated on the vineyard of soil moderately contaminated with copper. Data showed that inoculation was significant in nodulation; it increases the number and the weight of nodules of 50%. Co-inoculation was also found to positively influence growth and seed yield, through increasing fresh shoot and fresh root weights by 33 and 26%, respectively, and through rising numbers of seed per pod and pods per plant. In contrast, co-inoculation produced a significant reduction of accumulated copper in roots attending 35%, however, the treatment revealed no significant effects on the copper contents in pods and seeds. The tested inoculum could be an option to promote V. faba growth and to enhance soil fertilization in moderate copper contaminated soils. Further studies on the influence of co-inoculation practices on copper migration in soil-plant systems are recommended to acquire more information for evaluation of this legume safety. PMID:24338717

  2. Lactic acid as a potential decontaminant of selected foodborne pathogenic bacteria in shrimp (Penaeus merguiensis de Man).

    PubMed

    Shirazinejad, Alireza; Ismail, Noryati; Bhat, Rajeev

    2010-12-01

    Fresh raw shrimps were dipped for 10, 20, and 30 min at room temperature (25°C ± 1°C) in lactic acid (LA; 1.5%, 3.0%, v/v) to evaluate their antipathogenic effects against Vibrio cholerae, Vibrio parahaemolyticus, Salmonella entreitidis, and Escherichia coli O157:H7 inoculated at a level of 10(5) CFU/g. Significant reductions in the population of all these pathogenic bacteria were recorded after dipping treatments, which were correlated to the corresponding LA concentrations and treatment time. With respect to the microbial quality, 3.0% LA treatment for 10 min was acceptable in reducing the pathogenic bacteria. Additionally, sensory evaluation results revealed a 10-min dip in 3.0% LA to be more acceptable organoleptically compared with 20 and 30 min of treatments. Results of the present study are envisaged to be useful for commercial applications for effective decontamination of shrimp. PMID:21034165

  3. Effect of essential oil of Origanum rotundifolium on some plant pathogenic bacteria, seed germination and plant growth of tomato

    NASA Astrophysics Data System (ADS)

    Dadaşoǧlu, Fatih; Kotan, Recep; Karagöz, Kenan; Dikbaş, Neslihan; Ćakmakçi, Ramazan; Ćakir, Ahmet; Kordali, Şaban; Özer, Hakan

    2016-04-01

    The aim of this study is to determine effect of Origanum rotundifolium's essential oil on some plant pathogenic bacterias, seed germination and plant growth of tomato. Xanthomonas axanopodis pv. vesicatoria strain (Xcv-761) and Clavibacter michiganensis ssp. michiganensis strain (Cmm) inoculated to tomato seed. The seeds were tested for germination in vitro and disease severity and some plant growth parameters in vivo. In vitro assay, maximum seed germination was observed at 62,5 µl/ml essential oil treatment in seeds inoculated with Xcv-761 and at 62,5 µl/ml essential oil and streptomycin treatment in seeds inoculated with Cmm. The least infected cotiledon number was observed at 500 µg/ml streptomycin treatment in seeds inoculated with Cmm. In vivo assay, maximum seed germination was observed at 250 µl/ml essential oil teratment in tomato inoculated with Cmm. Lowest disease severity, is seen in the CMM infected seeds with 250 µl/ml essential oil application these results were statistically significant when compared with pathogen infected seeds. Similarly, in application conducted with XCV-761 infected seed, the lowest disease severity was observed for seeds as a result of 250 µl/ml essential oil application. Also according to the results obtained from essential oil application of CMM infected seeds conducted with 62,5 µl/ml dose; while disease severity was found statistically insignificant compared to 250 µl/ml to essential oil application, ıt was found statistically significant compared to pathogen infected seeds. The results showed that essential oil of O. rotundifolium has a potential for some suppressed plant disease when it is used in appropriate dose.

  4. Human pathogenic bacteria, fungi, and viruses in Drosophila

    PubMed Central

    Panayidou, Stavria; Ioannidou, Eleni; Apidianakis, Yiorgos

    2014-01-01

    Drosophila has been the invertebrate model organism of choice for the study of innate immune responses during the past few decades. Many Drosophila–microbe interaction studies have helped to define innate immunity pathways, and significant effort has been made lately to decipher mechanisms of microbial pathogenesis. Here we catalog 68 bacterial, fungal, and viral species studied in flies, 43 of which are relevant to human health. We discuss studies of human pathogens in flies revealing not only the elicitation and avoidance of immune response but also mechanisms of tolerance, host tissue homeostasis, regeneration, and predisposition to cancer. Prominent among those is the emerging pattern of intestinal regeneration as a defense response induced by pathogenic and innocuous bacteria. Immunopathology mechanisms and many microbial virulence factors have been elucidated, but their relevance to human health conventionally necessitates validation in mammalian models of infection. PMID:24398387

  5. Screening of endophytic bacteria against fungal plant pathogens.

    PubMed

    Ohike, Tatsuya; Makuni, Kohei; Okanami, Masahiro; Ano, Takashi

    2013-12-01

    Bacterial endophytes were found from 6 plant leaves among 35 plant leaves screened. Two of the isolated bacteria showed antagonistic activity against fungal plant pathogens. An isolate named KL1 showed the clear inihibition against plant pathogens, Fusarium oxysporum and Rhizoctonia solani, on PDA as well as TSA plate. Supernatant of the bacterial culture also showed the clear inhibition against the fungal growth on the plate and the antibiotic substance was identified as iturin A by HPLC analysis. KL1 was identified as Bacillus sp. from the 16S rRNA gene analysis. Very thin hyphae of R. solani was miccroscopically observed when the fungus was co-cultivated with KL1. PMID:25078813

  6. Implications of salivary protein binding to commensal and pathogenic bacteria

    PubMed Central

    Heo, Seok-Mo; Ruhl, Stefan; Scannapieco, Frank A.

    2013-01-01

    An important function of salivary proteins is to interact with microorganisms that enter the oral cavity. For some microbes, these interactions promote microbial colonization. For others, these interactions are deleterious and result in the elimination of the microbe from the mouth, This paper reviews recent studies of the interaction of salivary proteins with two model bacteria; the commensal species Streptococcus gordonii, and the facultative pathogen Staphylococcus aureus. These organisms selectively interact with a variety of salivary proteins to influence important functions such as bacterial adhesion to surfaces, evasion of host defense, bacterial nutrition and metabolism and gene expression. PMID:24707190

  7. Energetics of pathogenic bacteria and opportunities for drug development.

    PubMed

    Cook, Gregory M; Greening, Chris; Hards, Kiel; Berney, Michael

    2014-01-01

    The emergence and spread of drug-resistant pathogens and our inability to develop new antimicrobials to overcome resistance has inspired scientists to consider new targets for drug development. Cellular bioenergetics is an area showing promise for the development of new antimicrobials, particularly in the discovery of new anti-tuberculosis drugs where several new compounds have entered clinical trials. In this review, we have examined the bioenergetics of various bacterial pathogens, highlighting the versatility of electron donor and acceptor utilisation and the modularity of electron transport chain components in bacteria. In addition to re-examining classical concepts, we explore new literature that reveals the intricacies of pathogen energetics, for example, how Salmonella enterica and Campylobacter jejuni exploit host and microbiota to derive powerful electron donors and sinks; the strategies Mycobacterium tuberculosis and Pseudomonas aeruginosa use to persist in lung tissues; and the importance of sodium energetics and electron bifurcation in the chemiosmotic anaerobe Fusobacterium nucleatum. A combination of physiological, biochemical, and pharmacological data suggests that, in addition to the clinically-approved target F1Fo-ATP synthase, NADH dehydrogenase type II, succinate dehydrogenase, hydrogenase, cytochrome bd oxidase, and menaquinone biosynthesis pathways are particularly promising next-generation drug targets. The realisation of cellular energetics as a rich target space for the development of new antimicrobials will be dependent upon gaining increased understanding of the energetic processes utilised by pathogens in host environments and the ability to design bacterial-specific inhibitors of these processes. PMID:25476763

  8. Top 10 plant pathogenic bacteria in molecular plant pathology.

    PubMed

    Mansfield, John; Genin, Stephane; Magori, Shimpei; Citovsky, Vitaly; Sriariyanum, Malinee; Ronald, Pamela; Dow, Max; Verdier, Valérie; Beer, Steven V; Machado, Marcos A; Toth, Ian; Salmond, George; Foster, Gary D

    2012-08-01

    Many plant bacteriologists, if not all, feel that their particular microbe should appear in any list of the most important bacterial plant pathogens. However, to our knowledge, no such list exists. The aim of this review was to survey all bacterial pathologists with an association with the journal Molecular Plant Pathology and ask them to nominate the bacterial pathogens they would place in a 'Top 10' based on scientific/economic importance. The survey generated 458 votes from the international community, and allowed the construction of a Top 10 bacterial plant pathogen list. The list includes, in rank order: (1) Pseudomonas syringae pathovars; (2) Ralstonia solanacearum; (3) Agrobacterium tumefaciens; (4) Xanthomonas oryzae pv. oryzae; (5) Xanthomonas campestris pathovars; (6) Xanthomonas axonopodis pathovars; (7) Erwinia amylovora; (8) Xylella fastidiosa; (9) Dickeya (dadantii and solani); (10) Pectobacterium carotovorum (and Pectobacterium atrosepticum). Bacteria garnering honourable mentions for just missing out on the Top 10 include Clavibacter michiganensis (michiganensis and sepedonicus), Pseudomonas savastanoi and Candidatus Liberibacter asiaticus. This review article presents a short section on each bacterium in the Top 10 list and its importance, with the intention of initiating discussion and debate amongst the plant bacteriology community, as well as laying down a benchmark. It will be interesting to see, in future years, how perceptions change and which bacterial pathogens enter and leave the Top 10. PMID:22672649

  9. Endobiotic bacteria and their pathogenic potential in cnidarian tentacles

    NASA Astrophysics Data System (ADS)

    Schuett, Christian; Doepke, Hilke

    2010-09-01

    Endobiotic bacteria colonize the tentacles of cnidaria. This paper provides first insight into the bacterial spectrum and its potential of pathogenic activities inside four cnidarian species. Sample material originating from Scottish waters comprises the jellyfish species Cyanea capillata and C. lamarckii, hydrozoa Tubularia indivisa and sea anemone Sagartia elegans. Mixed cultures of endobiotic bacteria, pure cultures selected on basis of haemolysis, but also lyophilized samples were prepared from tentacles and used for DGGE-profiling with subsequent phylogenetic analysis of 16S rDNA fragments. Bacteria were detected in each of the cnidarian species tested. Twenty-one bacterial species including four groups of closely related organisms were found in culture material. The species within these groups could not be differentiated from each other (one group of Pseudoalteromonas spp., two groups of Shewanella spp., one group of Vibrio spp.). Each of the hosts exhibits a specific endobacterial spectrum. Solely Cyanea lamarckii harboured Moritella viscosa. Only in Cyanea capillata, members of the Shewanella group #2 and the species Pseudoalteromonas arctica, Shewanella violacea, Sulfitobacter pontiacus and Arcobacter butzleri were detected. Hydrozoa Tubularia indivisa provided an amazingly wide spectrum of nine bacterial species. Exclusively, in the sea anemone Sagartia elegans, the bacterial species P. aliena was found. Overall eleven bacterial species detected were described recently as novel species. Four 16S rDNA fragments generated from lyophilized material displayed extremely low relationship to their next neighbours. These organisms are regarded as members of the endobiotic “terra incognita”. Since the origin of cnidarian toxins is unclear, the possible pathogenic activity of endobiotic bacteria has to be taken into account. Literature data show that their next neighbours display an interesting diversity of haemolytic, septicaemic and necrotic actions including

  10. Effect of storage temperature on survival and growth of foodborne pathogens on whole, damaged, and internally inoculated jalapeños (Capsicum annuum var. annuum).

    PubMed

    Huff, Karleigh; Boyer, Renee; Denbow, Cynthia; O'Keefe, Sean; Williams, Robert

    2012-02-01

    There is a lack of general knowledge regarding the behavior of foodborne pathogenic bacteria associated with jalapeño peppers. The survival and growth behaviors of Listeria monocytogenes, Escherichia coli O157:H7, and Salmonella enterica on the interior and exterior of jalapeño peppers were determined under different storage conditions. Jalapeños were inoculated with a five-strain cocktail of L. monocytogenes, E. coli O157:H7, or S. enterica on the intact external surface, injured external surface, or intact internal cavity of jalapeño peppers and held at 7 or 12°C for a period of 14 days. Populations of each pathogen were determined at 0, 1, 2, 5, 7 10, and 14 days throughout storage. The uninjured, intact external surface of jalapeño peppers did not support growth of the pathogens tested under both storage conditions, with the exception of L. monocytogenes at 12°C. Populations of E. coli and S. enterica declined on the external injured surface of peppers at 7°C, but populations of L. monocytogenes remained consistent throughout the length of storage. At 12°C, L. monocytogenes and S. enterica populations increased throughout storage, and E. coli populations remained unchanged on injured surfaces. The uninjured internal cavity of the jalapeño supported growth of all pathogens at 12°C. Overall, L. monocytogenes was the microorganism most capable of growth and survival in association with jalapeño peppers for the scenarios tested. Results emphasize the importance of jalapeño pepper quality and proper storage conditions in preventing or reducing pathogen survival and growth. PMID:22289602

  11. Inoculation of bats with European Geomyces destructans supports the novel pathogen hypothesis for the origin of white-nose syndrome

    USGS Publications Warehouse

    Warnecke, Lisa; Turner, James M.; Bollinger, Trent K.; Lorch, Jeffrey M.; Misra, Vikram; Cryan, Paul M.; Wibbelt, Gudrun; Blehert, David S.; Willis, Craig K.R.

    2012-01-01

    White-nose syndrome (WNS) is an emerging disease of hibernating bats associated with cutaneous infection by the fungus Geomyces destructans (Gd), and responsible for devastating declines of bat populations in eastern North America. Affected bats appear emaciated and one hypothesis is that they spend too much time out of torpor during hibernation, depleting vital fat reserves required to survive the winter. The fungus has also been found at low levels on bats throughout Europe but without mass mortality. This finding suggests that Gd is either native to both continents but has been rendered more pathogenic in North America by mutation or environmental change, or that it recently arrived in North America as an invader from Europe. Thus, a causal link between Gd and mortality has not been established and the reason for its high pathogenicity in North America is unknown. Here we show that experimental inoculation with either North American or European isolates of Gd causes WNS and mortality in the North American bat, Myotis lucifugus. In contrast to control bats, individuals inoculated with either isolate of Gd developed cutaneous infections diagnostic of WNS, exhibited a progressive increase in the frequency of arousals from torpor during hibernation, and were emaciated after 3–4 mo. Our results demonstrate that altered torpor-arousal cycles underlie mortality from WNS and provide direct evidence that Gd is a novel pathogen to North America from Europe.

  12. Inoculation of bats with European Geomyces destructans supports the novel pathogen hypothesis for the origin of white-nose syndrome.

    PubMed

    Warnecke, Lisa; Turner, James M; Bollinger, Trent K; Lorch, Jeffrey M; Misra, Vikram; Cryan, Paul M; Wibbelt, Gudrun; Blehert, David S; Willis, Craig K R

    2012-05-01

    White-nose syndrome (WNS) is an emerging disease of hibernating bats associated with cutaneous infection by the fungus Geomyces destructans (Gd), and responsible for devastating declines of bat populations in eastern North America. Affected bats appear emaciated and one hypothesis is that they spend too much time out of torpor during hibernation, depleting vital fat reserves required to survive the winter. The fungus has also been found at low levels on bats throughout Europe but without mass mortality. This finding suggests that Gd is either native to both continents but has been rendered more pathogenic in North America by mutation or environmental change, or that it recently arrived in North America as an invader from Europe. Thus, a causal link between Gd and mortality has not been established and the reason for its high pathogenicity in North America is unknown. Here we show that experimental inoculation with either North American or European isolates of Gd causes WNS and mortality in the North American bat, Myotis lucifugus. In contrast to control bats, individuals inoculated with either isolate of Gd developed cutaneous infections diagnostic of WNS, exhibited a progressive increase in the frequency of arousals from torpor during hibernation, and were emaciated after 3-4 mo. Our results demonstrate that altered torpor-arousal cycles underlie mortality from WNS and provide direct evidence that Gd is a novel pathogen to North America from Europe. PMID:22493237

  13. Enhanced mineralization of polychlorinated biphenyls in soil inoculated with chlorobenzoate-degrading bacteria.

    PubMed Central

    Hickey, W J; Searles, D B; Focht, D D

    1993-01-01

    An Altamont soil containing no measurable population of chlorobenzoate utilizers was examined for the potential to enhance polychlorinated biphenyl (PCB) mineralization by inoculation with chlorobenzoate utilizers, a biphenyl utilizer, combinations of the two physiological types, and chlorobiphenyl-mineralizing transconjugants. Biphenyl was added to all soils, and biodegradation of 14C-Aroclor 1242 was assessed by disappearance of that substance and by production of 14CO2. Mineralization of PCBs was consistently greatest (up to 25.5%) in soils inoculated with chlorobenzoate degraders alone. Mineralization was significantly lower in soils receiving all other treatments: PCB cometabolizer (10.7%); chlorobiphenyl mineralizers (8.7 and 14.9%); and mixed inocula of PCB cometabolizers and chlorobenzoate utilizers (11.4 and 18.0%). However, all inoculated soils had higher mineralization than did the uninoculated control (3.1%). PCB disappearance followed trends similar to that observed with the mineralization data, with the greatest degradation occurring in soils inoculated with the chlorobenzoate-degrading strains Pseudomonas aeruginosa JB2 and Pseudomonas putida P111 alone. While the mechanism by which the introduction of chlorobenzoate degraders alone enhanced biodegradation of PCBs could not be elucidated, the possibility that chlorobenzoate inoculants acquired the ability to metabolize biphenyl and possibly PCBs was explored. When strain JB2, which does not utilize biphenyl, was inoculated into soil containing biphenyl and Aroclor 1242, the frequency of isolates able to utilize biphenyl and 2,5-dichlorobenzoate increased progressively with time from 3.3 to 44.4% between 15 and 48 days, respectively. Since this soil contained no measurable level of chlorobenzoate utilizers yet did contain a population of biphenyl utilizers, the possibility of genetic transfer between the latter group and strain JB2 cannot be excluded. PMID:8476293

  14. Effect of Simultaneous Inoculation with Yeast and Bacteria on Fermentation Kinetics and Key Wine Parameters of Cool-Climate Chardonnay

    PubMed Central

    Jussier, Delphine; Dubé Morneau, Amélie; Mira de Orduña, Ramón

    2006-01-01

    Inoculating grape musts with wine yeast and lactic acid bacteria (LAB) concurrently in order to induce simultaneous alcoholic fermentation (AF) and malolactic fermentation (MLF) can be an efficient alternative to overcome potential inhibition of LAB in wines because of high ethanol concentrations and reduced nutrient content. In this study, the simultaneous inoculation of yeast and LAB into must was compared with a traditional vinification protocol, where MLF was induced after completion of AF. For this, two suitable commercial yeast-bacterium combinations were tested in cool-climate Chardonnay must. The time courses of glucose and fructose, acetaldehyde, several organic acids, and nitrogenous compounds were measured along with the final values of other key wine parameters. Sensory evaluation was done after 12 months of storage. The current study could not confirm a negative impact of simultaneous AF/MLF on fermentation success and kinetics or on final wine parameters. While acetic acid concentrations were slightly increased in wines after simultaneous AF/MLF, the differences were of neither practical nor legal significance. No statistically significant differences were found with regard to the final values of pH or total acidity and the concentrations of ethanol, acetaldehyde, glycerol, citric and lactic acids, and the nitrogen compounds arginine, ammonia, urea, citrulline, and ornithine. Sensory evaluation by a semiexpert panel confirmed the similarity of the wines. However, simultaneous inoculation led to considerable reductions in overall fermentation durations. Furthermore, differences of physiological and microbiological relevance were found. Specifically, we report the vinification of “super-dry” wines devoid of glucose and fructose after simultaneous inoculation of yeast and bacteria. PMID:16391046

  15. Effects of the inoculation of Burkholderia vietnamensis and related endophytic diazotrophic bacteria on grain yield of rice.

    PubMed

    Govindarajan, Munusamy; Balandreau, Jacques; Kwon, Soon-Wo; Weon, Hang-Yeon; Lakshminarasimhan, Cunthipuram

    2008-01-01

    During a survey of endophytic diazotrophic bacteria associated with different rice varieties in Tamilnadu, some "endophytes" were obtained. Thirteen bacterial isolates from surface-sterilized roots and shoots were obtained in pure culture, which produced indole acetic acid (IAA) and reduced acetylene to ethylene. Polymerase chain reaction (PCR) amplification confirmed the presence of nif-H gene in all the isolates. Morphological, biochemical, and molecular characteristics indicated that all of them belonged to the genus Burkholderia One of them, MGK3, was consistently more active in reducing acetylene, and 16S rDNA sequences of isolate MGK3 confirmed its identification as Burkholderia vietnamiensis. Colonization of rice root was confirmed by strain MGK3 marked with gusA gene. The inoculated roots showed a blue color, which was most intense at the points of lateral root emergence and at the root tip. Transverse sections of roots, 15 days after inoculation, revealed beta-glucuronidase (GUS) activity within many of the cortical intercellular spaces next to the stele and within the aerenchyma. Nitrogen fixation was quantified by using (15)N isotope dilution method with two different cultivars grown in pot and field experiments. Higher nitrogen fixation was observed in variety Ponni than in ADT-43, where nearly 42% (field) and 40% (pot) of the nitrogen was derived from the atmosphere (% Ndfa). Isolate MGK3 was used to inoculate rice seedlings in a comparison with four other diazotrophs, viz., Gluconacetobacter diazotrophicus LMG7603, Herbaspirillum seropedicae LMG6513, Azospirillum lipoferum 4B LMG4348, and B. vietnamiensis LMG10929. They were used to conduct two pot and four field inoculation experiments. MGK3 alone, and combined with other diazotrophs, performed best under both pot and field conditions: combined inoculation produced yield increases between 9.5 and 23.6%, while MGK3 alone increased yield by 5.6 to 12.16% over the uninoculated control treatment. PMID

  16. List of New Names of Plant Pathogenic Bacteria (2008-2010)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In 2010 the International Society of Plant Pathology Committee on the Taxonomy of Plant Pathogenic Bacteria published the Comprehensive List of Names of Plant Pathogenic Bacteria, 1980-2007 to provide an authoritative register of names of plant pathogens. In this manuscript we up-date the list of na...

  17. Highly efficient removal of pathogenic bacteria with magnetic graphene composite.

    PubMed

    Zhan, Sihui; Zhu, Dandan; Ma, Shuanglong; Yu, Wenchao; Jia, Yanan; Li, Yi; Yu, Hongbing; Shen, Zhiqiang

    2015-02-25

    Magnetic Fe3O4/graphene composite (abbreviated as G-Fe3O4) was synthesized successfully by solvothermal method to effectively remove both bacteriophage and bacteria in water, which was tested by HRTEM, XRD, BET, XPS, FTIR, CV, magnetic property and zeta-potential measurements. Based on the result of HRTEM, the single-sheet structure of graphene oxide and the monodisperse Fe3O4 nanoparticles on the surface of graphene can be observed obviously. The G-Fe3O4 composite were attractive for removing a wide range of pathogens including not only bacteriophage ms2, but also various bacteria such as S. aureus, E. coli, Salmonella, E. Faecium, E. faecalis, and Shigella. The removal efficiency of E. coli for G-Fe3O4 composite can achieve 93.09%, whereas it is only 54.97% with pure Fe3O4 nanoparticles. Moreover, a detailed verification test of real water samples was conducted and the removal efficiency of bacteria in real water samples with G-Fe3O4 composite can also reach 94.8%. PMID:25634911

  18. Fluorimetric detection of pathogenic bacteria using magnetic carbon dots.

    PubMed

    Bhaisare, Mukesh Lavkush; Gedda, Gangaraju; Khan, M Shahnawaz; Wu, Hui-Fen

    2016-05-12

    A novel and facile approach of pathogenic bacteria detection, which utilizes fluorescent sensing and bacteria capture with Magnetic carbon dots (Mag-CDs), was proposed in this work. Magnetic nanoparticles were synthesized and then decorated with C-dots, and further functionalized with amine groups (chitosan). In this way, bacteria were strongly anchored on the hybrid material Mag-CDs for highly sensitive fluorescent detection. The Mag-CDs were characterized by UV-vis, FT-IR spectra, TEM images, XRD, and EDX. The characterizations validate the fabrication of amine-Mag-CDs and the promising applications of this material. Fluorescence spectroscope and MALDI-MS were used for the detection and identification of bacterial strains, respectively. The limit of detection for Staphylococcus aureus and Escherichia coli was found to be 3 × 10(2) and 3.5 × 10(2) cfu mL(-1), respectively. With these encouraging results, it is expected that it would open revenues for promising applications of Mag-CDs nanomaterial. PMID:27114224

  19. RARE OCCURRENCE OF HETEROTROPHIC BACTERIA WITH PATHOGENIC POTENTIAL IN POTABLE WATER

    EPA Science Inventory

    Since the discovery of Legionella pneumophila, an opportunistic pathogen that is indigenous to water, microbiologists have speculated that there may be other opportunistic pathogens among the numerous heterotrophic bacteria found in potable water. The USEPA developed a series of...

  20. Photochemical inactivation of pathogenic bacteria in human platelet concentrates.

    PubMed

    Lin, L; Londe, H; Janda, J M; Hanson, C V; Corash, L

    1994-05-01

    Platelet concentrates (PC) may be infrequently contaminated with low levels of bacteria that can cause septicemia and death in patients receiving transfusion therapy. We evaluated the efficacy of a photochemical decontamination (PCD) technique using 8-methoxypsoralen (8-MOP) and long wavelength UV light (UVA) to inactivate bacteria in standard therapeutic PC. Twelve phylogenetically distinct pathogenic bacteria, 5 gram-positive and 7 gram-negative organisms, were seeded into PC to a final challenge dose ranging from 10(5) to 10(7) colony-forming units (CFU)/mL. Contaminated PC were treated with 8-MOP (5 micrograms/mL) and 5 J/cm2 of UVA, a PCD treatment regimen found to adequately preserve in vitro platelet function. Greater than 10(5) CFU/mL of all 5 gram-positive (Staphylococcus aureus, Streptococcus epidermidis, Streptococcus pyogenes, Listeria monocytogenes, and Corynebacterium minutissimum) and 2 of the gram-negative (Escherichia coli and Yersinia enterocolitica) organisms were inactivated. The remaining 5 gram-negative organisms were more resistant, with less than 10(1) to 10(3.7) CFU/mL inactivated under these conditions. The inactivation efficiency for this resistant group of gram-negative organisms was improved when PC were resuspended in a synthetic storage medium with reduced plasma protein concentration (15%) and an increased 8-MOP concentration (23.4 micrograms/mL). Illumination with 3 J/cm2 of UVA in this system inactivated greater than 10(5) CFU/mL of 4 resistant gram-negative organisms (Salmonella choleraesuis, Enterobacter cloacae, Serratia marcescens, and Klebsiella pneumoniae) and 10(4.1) CFU/mL of the most resistant gram-negative organism (Pseudomonas aeruginosa). This level of PCD treatment did not adversely affect in vitro platelet function. These results demonstrate that PCD using 8-MOP (5 to 23.4 micrograms/mL) effectively inactivated high levels of pathogenic bacteria in PC with adequate preservation of in vitro platelet properties. PMID

  1. Assessing the efficacy of co-inoculation of wheat seedlings with the associative bacteria Paenibacillus polymyxa 1465 and Azospirillum brasilense Sp245.

    PubMed

    Yegorenkova, Irina V; Tregubova, Kristina V; Burygin, Gennady L; Matora, Larisa Y; Ignatov, Vladimir V

    2016-03-01

    Co-inoculation of associative bacteria, which have high nitrogen-fixing activity, tolerance for environmental conditions, and the ability to compete with the natural microflora, is used widely to enhance the growth and yields of agricultural plants. We evaluated the ability of 2 co-inoculated plant-growth-promoting rhizobacteria, Paenibacillus polymyxa 1465 and Azospirillum brasilense Sp245, to colonize roots of wheat (Triticum aestivum L. 'Saratovskaya 29') seedlings, and we assessed the morphometric parameters of wheat early in its development. Analysis by ELISA with polyclonal antibodies raised against the exopolysaccharide of P. polymyxa 1465 and the lipopolysaccharide of A. brasilense Sp245 demonstrated that the root-colonizing activity of A. brasilense was higher when the bacterium was co-inoculated with P. polymyxa than when it was inoculated singly. Immunofluorescence microscopy with Alexa Fluor 532-labeled antibodies revealed sites of attachment of co-inoculated P. polymyxa and A. brasilense and showed that the 2 bacteria colonized similar regions of the roots. Co-inoculation exerted a negative effect on wheat seedling development, inhibiting root length by 17.6%, total root weight by 11%, and total shoot weight by 12%. Under certain conditions, dual inoculation of wheat may prove ineffective, apparently owing to the competition between the rhizobacteria for colonization sites on the plant roots. The findings from this study may aid in developing techniques for mixed bacterial inoculation of cultivated plants. PMID:26863134

  2. Evolutionary aspects of collective motility in pathogenic bacteria

    NASA Astrophysics Data System (ADS)

    Deforet, Maxime; Xavier, Joao

    Pseudomonas aeruginosa is a pathogenic bacteria that can use its single polar flagellum to swim through liquids. It can move collectively over semisolid surfaces, a behavior called swarming. It can also settle and form surface-attached communities called biofilms that protect them from antibiotics. The transition from single motility (swimming) to collective motility (swarming) is biologically relevant as it enables exploring environments that a single bacterium cannot explore on its own. It is also clinically relevant since swarming and biofilm formation are thought to be antagonistic. We investigate the mechanisms of bacterial collective motility using a multidisciplinary approach that combines mathematical modeling, quantitative experiments, and microbial genetics. We aim to identify how these mechanisms may evolve under the selective pressure of population expansion, and consequently reinforce or hinder collective motility. In particular, we clarify the role of growth rate and motility in invasive populations.

  3. Transcriptomic profiling of apple in response to inoculation with a pathogen (P. expansum) and a non-pathogen (P. digitatum)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Penicillium expansum, the causal agent of blue mould of pome fruits, is a major postharvest pathogen in all producing countries. To develop a better understanding of disease resistance mechanisms in apples, a comprehensive transcriptional analysis of apple gene expression in response to a compatibl...

  4. Partial denture metal framework may harbor potentially pathogenic bacteria

    PubMed Central

    Bernardes, Luciano Angelo de Souza; Gomes, Sabrina Carvalho; Silva, Alecsandro Moura

    2015-01-01

    PURPOSE The aim of this study was to characterize and compare bacterial diversity on the removable partial denture (RPD) framework over time. MATERIALS AND METHODS This descriptive pilot study included five women who were rehabilitated with free-end mandibular RPD. The biofilm on T-bar clasps were collected 1 week (t1) and 4 months (t2) after the RPD was inserted (t0). Bacterial 16S rDNA was extracted and PCR amplified. Amplicons were cloned; clones were submitted to cycle sequencing, and sequences were compared with GenBank (98% similarity). RESULTS A total of 180 sequences with more than 499 bp were obtained. Two phylogenetic trees with 84 (t1) and 96 (t2) clones represented the bacteria biofilm at the RPD. About 93% of the obtained phylotypes fell into 25 known species for t1 and 17 for t2, which were grouped in 5 phyla: Firmicutes (t1=82%; t2=60%), Actinobacteria (t1=5%; t2=10%), Bacteroidetes (t1=2%; t2=6%), Proteobacteria (t1=10%; t2=15%) and Fusobacteria (t1=1%; t2=8%). The libraries also include 3 novel phylotypes for t1 and 11 for t2. Library t2 differs from t1 (P=.004); t1 is a subset of the t2 (P=.052). Periodontal pathogens, such as F. nucleatum, were more prevalent in t2. CONCLUSION The biofilm composition of the RPD metal clasps changed along time after RPD wearing. The RPD framework may act as a reservoir for potentially pathogenic bacteria and the RPD wearers may benefit from regular follow-up visits and strategies on prosthesis-related oral health instructions. PMID:26816577

  5. Function of site-2 proteases in bacteria and bacterial pathogens

    PubMed Central

    Schneider, Jessica S.; Glickman, Michael S.

    2014-01-01

    Site-2 Proteases (S2Ps) are a class of intramembrane metalloproteases named after the founding member of this protein family, human S2P, which cleaves Sterol Regulatory Element Binding Proteins which control cholesterol and fatty acid biosynthesis. S2Ps are widely distributed in bacteria and participate in diverse pathways that control such diverse functions as membrane integrity, sporulation, lipid biosynthesis, pheromone production, virulence, and others. The most common signaling mechanism mediated by S2Ps is the coupled degradation of transmembrane anti-Sigma factors to activate ECF Sigma factor regulons. However, additional signaling mechanisms continue to emerge as more prokaryotic S2Ps are characterized, including direct proteolysis of membrane embedded transcription factors and proteolysis of non-transcriptional membrane proteins or membrane protein remnants. In this review we seek to comprehensively review the functions of S2Ps in bacteria and bacterial pathogens and attempt to organize these proteases into conceptual groups that will spur further study. PMID:24099002

  6. Inoculating poultry manure with companion bacteria influences growth and development of black soldier fly (Diptera: Stratiomyidae) larvae.

    PubMed

    Yu, Guohui; Cheng, Ping; Chen, Yanhong; Li, Yongjian; Yang, Zihong; Chen, Yuanfeng; Tomberlin, Jeffery K

    2011-02-01

    The growth and development of black soldier fly, Hermetia illucens (L.), larvae fed chicken manure inoculated with bacteria isolated from black soldier fly larvae and associated larval feed was evaluated. Four strains of Bacillus subtilis were evaluated. B. subtilis strains S15, S16, S19, were isolated from the gut of black soldier fly larvae. B. natto strain D1 was isolated from the diet fed to black soldier fly larvae. These bacteria were added individually into nonsterile 200 g fresh hen manure at 10(6) cfu/g and homogenized. Treated manure was then inoculated with 4-d old black soldier fly larvae. Prepupal weight ranged from 0.0606 g in the control to 0.0946 g in manure treated with the S15 strain. Larval survivorship to the prepupal stage in all treatments ranged from 98.00 ± 2.65% to 99.33 ± 1.15%. Prepupal survivorship to the pupal stage ranged from 91.92 ± 1.87% to 97.95 ± 1.03%. Adult emergence from the pupal stage did not significantly (P < 0.05) differ across treatments and ranged from 98.95 ± 1.82% to 100.00 ± 0.00%. Adult body length resulting from the larvae in each of the treatments was significantly greater than those from the control. Longevity of adults did not differ significantly between treatments. Time from hatching to the development of the first pupa did not differ significantly across treatments; however, development time from hatching to 90% reaching the prepupual stage was significantly different between treatments and ranged from 29.00 ± 1.00 d to 34.33 ± 3.51 d. Development time from hatching to 90% reaching the adult stages was significantly different between treatments. Our results demonstrate that inoculating poultry manure with bacteria from black soldier fly larvae influences the growth and development of conspecific larvae feeding on the manure. PMID:22182608

  7. Response of endangered plant species to inoculation with arbuscular mycorrhizal fungi and soil bacteria.

    PubMed

    Zubek, Szymon; Turnau, Katarzyna; Tsimilli-Michael, Merope; Strasser, Reto J

    2009-02-01

    Three endangered plant species, Plantago atrata and Pulsatilla slavica, which are on the IUCN red list of plants, and Senecio umbrosus, which is extinct in the wild in Poland, were inoculated with soil microorganisms to evaluate their responsiveness to inoculation and to select the most effective microbial consortium for application in conservation projects. Individuals of these taxa were cultivated with (1) native arbuscular mycorrhizal fungi (AMF) isolated from natural habitats of the investigated species, (2) a mixture of AMF strains available in the laboratory, and (3) a combination of AMF lab strains with rhizobacteria. The plants were found to be dependent on AMF for their growth; the mycorrhizal dependency for P. atrata was 91%, S. umbrosus-95%, and P. slavica-65%. The applied inocula did not significantly differ in the stimulation of the growth of P. atrata and S. umbrosus, while in P. slavica, native AMF proved to be the less efficient. We therefore conclude that AMF application can improve the ex situ propagation of these three threatened taxa and may contribute to the success of S. umbrosus reintroduction. A multilevel analysis of chlorophyll a fluorescence transients by the JIP test permitted an in vivo evaluation of plant vitality in terms of biophysical parameters quantifying photosynthetic energy conservation, which was found to be in good agreement with the results concerning physiological parameters. Therefore, the JIP test can be used to evaluate the influence of AMF on endangered plants, with the additional advantage of being applicable in monitoring in a noninvasive way the acclimatization of reintroduced species in nature. PMID:19011910

  8. Effect of arsenic on tolerance mechanisms of two plant growth-promoting bacteria used as biological inoculants.

    PubMed

    Armendariz, Ana L; Talano, Melina A; Wevar Oller, Ana L; Medina, María I; Agostini, Elizabeth

    2015-07-01

    Bacterial ability to colonize the rhizosphere of plants in arsenic (As) contaminated soils is highly important for symbiotic and free-living plant growth-promoting rhizobacteria (PGPR) used as inoculants, since they can contribute to enhance plant As tolerance and limit metalloid uptake by plants. The aim of this work was to study the effect of As on growth, exopolysaccharide (EPS) production, biofilm formation and motility of two strains used as soybean inoculants, Bradyrhizobium japonicum E109 and Azospirillum brasilense Az39. The metabolism of arsenate (As(V)) and arsenite (As(III)) and their removal and/or possible accumulation were also evaluated. The behavior of both bacteria under As treatment was compared and discussed in relation to their potential for colonizing plant rhizosphere with high content of the metalloid. B. japonicum E109 growth was reduced with As(III) concentration from 10 μM while A. brasilense Az39 showed a reduction of growth with As(III) from 500 μM. EPS and biofilm production increased significantly under 25 μM As(III) for both strains. Moreover, this was more notorious for Azospirillum under 500 μM As(III), where motility was seriously affected. Both bacterial strains showed a similar ability to reduce As(V). However, Azospirillum was able to oxidize more As(III) (around 53%) than Bradyrhizobium (17%). In addition, both strains accumulated As in cell biomass. The behavior of Azospirillum under As treatments suggests that this strain would be able to colonize efficiently As contaminated soils. In this way, inoculation with A. brasilense Az39 would positively contribute to promoting growth of different plant species under As treatment. PMID:26141894

  9. Influence of bovine lactoferrin on selected probiotic bacteria and intestinal pathogens.

    PubMed

    Tian, Hong; Maddox, Ian S; Ferguson, Lynnette R; Shu, Quan

    2010-06-01

    This study investigated the effects of bovine lactoferrin (BLf) on the growth of different groups of bacteria in vitro. BLf showed a significant inhibitory effect on the growth of selected pathogens but not probiotics. BLf, in combination with probiotics, has the potential to influence the composition of the gut microflora via inhibition of intestinal pathogens with no significant effect on probiotic bacteria. PMID:20217186

  10. Species-specific fate of bacteria in house flies and impact on vector potential for pathogens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    House flies ingest bacteria during filth-feeding and consequently can transport microbes from septic environments to human habitats and food. Vector potential is influenced both by flies encountering pathogens and by the fate of bacteria in the fly alimentary canal. In order for pathogens to be tran...

  11. FISHing for bacteria in food--a promising tool for the reliable detection of pathogenic bacteria?

    PubMed

    Rohde, Alexander; Hammerl, Jens Andre; Appel, Bernd; Dieckmann, Ralf; Al Dahouk, Sascha

    2015-04-01

    Foodborne pathogens cause millions of infections every year and are responsible for considerable economic losses worldwide. The current gold standard for the detection of bacterial pathogens in food is still the conventional cultivation following standardized and generally accepted protocols. However, these methods are time-consuming and do not provide fast information about food contaminations and thus are limited in their ability to protect consumers in time from potential microbial hazards. Fluorescence in situ hybridization (FISH) represents a rapid and highly specific technique for whole-cell detection. This review aims to summarize the current data on FISH-testing for the detection of pathogenic bacteria in different food matrices and to evaluate its suitability for the implementation in routine testing. In this context, the use of FISH in different matrices and their pretreatment will be presented, the sensitivity and specificity of FISH tests will be considered and the need for automation shall be discussed as well as the use of technological improvements to overcome current hurdles for a broad application in monitoring food safety. In addition, the overall economical feasibility will be assessed in a rough calculation of costs, and strengths and weaknesses of FISH are considered in comparison with traditional and well-established detection methods. PMID:25475309

  12. Isolation of antibiotic-resistant pathogenic and potentially pathogenic bacteria from carpets of mosques in Tripoli, Libya

    PubMed Central

    Rahouma, Amal; Elghamoudi, Abdunabi; Nashnoush, Halima; Belhaj, Khalifa; Tawil, Khaled; Sifaw Ghenghesh, Khalifa

    2010-01-01

    Objective Isolation of potentially pathogenic bacteria from carpets in hospitals has been reported earlier, but not from carpets in mosques. The aim of the present study is to determine the pathogenic and potentially pathogenic bacteria that may exist on the carpets of mosques in Tripoli, Libya. Methods Dust samples from carpets were collected from 57 mosques in Tripoli. Samples were examined for pathogenic bacteria using standard bacteriological procedures. Susceptibility of isolated bacteria to antimicrobial agents was determined by the disc-diffusion method. Results Of dust samples examined, Salmonella spp. was detected in two samples (3.5%, 1 in group B and 1 in group C1), Escherichia coli in 16 samples (28.1%), Aeromonas spp. in one sample (1.8%), and Staphylococcus aureus in 12 samples (21.1%). Multiple drug resistance was observed in >16.7% of E. coli and in 25% of S. aureus. Conclusion Contamination of carpets in mosques of Tripoli with antibiotic-resistant pathogenic and potentially pathogenic bacteria may pose a health risk to worshipers, particularly, the very young, the old and the immunecompromised. Worshipers are encouraged to use personal praying mats when praying in mosques. PMID:21483559

  13. Inhibition of citrus fungal pathogens by using lactic acid bacteria.

    PubMed

    Gerez, C L; Carbajo, M S; Rollán, G; Torres Leal, G; Font de Valdez, G

    2010-08-01

    The effect of lactic acid bacteria (LAB) on pathogenic fungi was evaluated and the metabolites involved in the antifungal effect were characterized. Penicillium digitatum (INTA 1 to INTA 7) and Geotrichum citri-aurantii (INTA 8) isolated from decayed lemon from commercial packinghouses were treated with imazalil and guazatine to obtain strains resistant to these fungicides. The most resistant strains (4 fungal strains) were selected for evaluating the antifungal activity of 33 LAB strains, among which only 8 strains gave positive results. The antifungal activity of these LAB strains was related to the production of lactic acid, acetic acid, and phenyllactic acid (PLA). A central composite design and the response surface methodology were used to evaluate the inhibitory effect of the organic acids produced by the LAB cultures. The antifungal activity of lactic acid was directly related to its concentration; however, acetic acid and PLA showed a peak of activity at 52.5 and 0.8 mM, respectively, with inhibition rates similar to those obtained with Serenade((R)) (3.0 ppm) imazalil (50 ppm) and guazatine (50 ppm). Beyond the peak of activity, a reduction in effectiveness of both acetic acid and PLA was observed. Comparing the inhibition rate of the organic acids, PLA was about 66- and 600-fold more effective than acetic acid and lactic acid, respectively. This study presents evidences on the antifungal effect of selected LAB strains and their end products. Studies are currently being undertaken to evaluate the effectiveness in preventing postharvest diseases on citrus fruits. PMID:20722936

  14. Erythrophore cell response to food-associated pathogenic bacteria: implications for detection.

    PubMed

    Hutchison, Janine R; Dukovcic, Stephanie R; Dierksen, Karen P; Carlyle, Calvin A; Caldwell, Bruce A; Trempy, Janine E

    2008-09-01

    Cell-based biosensors have been proposed for use as function-based detectors of toxic agents. We report the use of Betta splendens chromatophore cells, specifically erythrophore cells, for detection of food-associated pathogenic bacteria. Evaluation of erythrophore cell response, using Bacillus spp., has revealed that this response can distinguish pathogenic Bacillus cereus from a non-pathogenic B. cereus ΔplcR deletion mutant and a non-pathogenic Bacillus subtilis. Erythrophore cells were exposed to Salmonella enteritidis, Clostridium perfringens and Clostridium botulinum. Each bacterial pathogen elicited a response from erythrophore cells that was distinguished from the corresponding bacterial growth medium, and this observed response was unique for each bacterial pathogen. These findings suggest that erythrophore cell response has potential for use as a biosensor in the detection and toxicity assessment for food-associated pathogenic bacteria. PMID:21261862

  15. The role of cell wall-based defences in the early restriction of non-pathogenic hrp mutant bacteria in Arabidopsis.

    PubMed

    Mitchell, Kathy; Brown, Ian; Knox, Paul; Mansfield, John

    2015-04-01

    We have investigated the cause of the restricted multiplication of hrp mutant bacteria in leaves of Arabidopsis. Our focus was on early interactions leading to differentiation between virulent wild-type and non-pathogenic hrpA mutant strains of Pseudomonas syringae pv. tomato. An initial drop in recoverable bacteria detected 0-4 h after inoculation with either strain was dependent on a functional FLS2 receptor and H2O2 accumulation in challenged leaves. Wild-type bacteria subsequently multiplied rapidly whereas the hrpA mutant was restricted within 6 h. Despite the early restriction, the hrpA mutant was still viable several days after inoculation. Analysis of intercellular washing fluids (IWFs), showed that high levels of nutrients were readily available to bacteria in the apoplast and that no diffusible inhibitors were produced in response to bacterial challenge. Histochemical and immunocytochemical methods were used to detect changes in polysaccharides (callose, two forms of cellulose, and pectin), arabinogalactan proteins (AGPs), H2O2 and peroxidase. Quantitative analysis showed very similar changes in localisation of AGPs, cellulose epitopes and callose 2 and 4 h after inoculation with either strain. However from 6 to 12 h after inoculation papillae expanded only next to the hrp mutant. In contrast to the similar patterns of secretory activity recorded from mesophyll cells, accumulation of H2O2 and peroxidase was significantly greater around the hrpA mutant within the first 4h after inoculation. A striking differential accumulation of H2O2 was also found in chloroplasts in cells next to the mutant. Ascorbate levels were lower in the IWFs recovered from sites inoculated with the hrp mutant than with wild-type bacteria. The critical response, observed at the right time and place to explain the observed differential behaviour of wild-type and hrpA mutant bacteria was the accumulation of H2O2, probably generated through Type III peroxidase activity and in

  16. Effect of clove oil on plant pathogenic bacteria and bacterial wilt of tomato and geranium

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We determined the antibacterial activity of clove oil against seven different genera of plant pathogenic bacteria including Gram-negative Agrobacterium tumefaciens, Erwinia carotovora pv. carotovora, Pseudomonas syringae pv. syringae, Ralstonia solanacearum, and Xanthomonas campestris pv. pelargonii...

  17. Promotion of arsenic phytoextraction efficiency in the fern Pteris vittata by the inoculation of As-resistant bacteria: a soil bioremediation perspective

    PubMed Central

    Lampis, Silvia; Santi, Chiara; Ciurli, Adriana; Andreolli, Marco; Vallini, Giovanni

    2015-01-01

    A greenhouse pot experiment was carried out to evaluate the efficiency of arsenic phytoextraction by the fern Pteris vittata growing in arsenic-contaminated soil, with or without the addition of selected rhizobacteria isolated from the polluted site. The bacterial strains were selected for arsenic resistance, the ability to reduce arsenate to arsenite, and the ability to promote plant growth. P. vittata plants were cultivated for 4 months in a contaminated substrate consisting of arsenopyrite cinders and mature compost. Four different experimental conditions were tested: (i) non-inoculated plants; (ii) plants inoculated with the siderophore-producing and arsenate-reducing bacteria Pseudomonas sp. P1III2 and Delftia sp. P2III5 (A); (iii) plants inoculated with the siderophore and indoleacetic acid-producing bacteria Bacillus sp. MPV12, Variovorax sp. P4III4, and Pseudoxanthomonas sp. P4V6 (B), and (iv) plants inoculated with all five bacterial strains (AB). The presence of growth-promoting rhizobacteria increased plant biomass by up to 45% and increased As removal efficiency from 13% without bacteria to 35% in the presence of the mixed inoculum. Molecular analysis confirmed the persistence of the introduced bacterial strains in the soil and resulted in a significant impact on the structure of the bacterial community. PMID:25741356

  18. Promotion of arsenic phytoextraction efficiency in the fern Pteris vittata by the inoculation of As-resistant bacteria: a soil bioremediation perspective.

    PubMed

    Lampis, Silvia; Santi, Chiara; Ciurli, Adriana; Andreolli, Marco; Vallini, Giovanni

    2015-01-01

    A greenhouse pot experiment was carried out to evaluate the efficiency of arsenic phytoextraction by the fern Pteris vittata growing in arsenic-contaminated soil, with or without the addition of selected rhizobacteria isolated from the polluted site. The bacterial strains were selected for arsenic resistance, the ability to reduce arsenate to arsenite, and the ability to promote plant growth. P. vittata plants were cultivated for 4 months in a contaminated substrate consisting of arsenopyrite cinders and mature compost. Four different experimental conditions were tested: (i) non-inoculated plants; (ii) plants inoculated with the siderophore-producing and arsenate-reducing bacteria Pseudomonas sp. P1III2 and Delftia sp. P2III5 (A); (iii) plants inoculated with the siderophore and indoleacetic acid-producing bacteria Bacillus sp. MPV12, Variovorax sp. P4III4, and Pseudoxanthomonas sp. P4V6 (B), and (iv) plants inoculated with all five bacterial strains (AB). The presence of growth-promoting rhizobacteria increased plant biomass by up to 45% and increased As removal efficiency from 13% without bacteria to 35% in the presence of the mixed inoculum. Molecular analysis confirmed the persistence of the introduced bacterial strains in the soil and resulted in a significant impact on the structure of the bacterial community. PMID:25741356

  19. Effect of fermented broth from lactic acid bacteria on pathogenic bacteria proliferation.

    PubMed

    Gutiérrez, S; Martínez-Blanco, H; Rodríguez-Aparicio, L B; Ferrero, M A

    2016-04-01

    In this study, the effect that 5 fermented broths of lactic acid bacteria (LAB) strains have on the viability or proliferation and adhesion of 7 potentially pathogenic microorganisms was tested. The fermented broth from Lactococcus lactis C660 had a growth inhibitory effect on Escherichia coli K92 that reached of 31%, 19% to Pseudomonas fluorescens, and 76% to Staphylococcus epidermidis. The growth of Staph. epidermidis was negatively affected to 90% by Lc. lactis 11454 broth, whereas the growth of P. fluorescens (25%) and both species of Staphylococcus (35% to Staphylococcus aureus and 76% to Staph. epidermidis) were inhibited when they were incubated in the presence of Lactobacillus casei 393 broth. Finally, the fermented broth of Lactobacillus rhamnosus showed an inhibitory effect on growth of E. coli K92, Listeria innocua, and Staph. epidermidis reached values of 12, 28, and 76%, respectively. Staphylococcus epidermidis was the most affected strain because the effect was detected from the early stages of growth and it was completely abolished. The results of bacterial adhesion revealed that broths from Lc. lactis strains, Lactobacillus paracasei, and Lb. rhamnosus caused a loss of E. coli K92 adhesion. Bacillus cereus showed a decreased of adhesion in the presence of the broths of Lc. lactis strains and Lb. paracasei. Listeria innocua adhesion inhibition was observed in the presence of Lb. paracasei broth, and the greatest inhibitory effect was registered when this pathogenic bacterium was incubated in presence of Lc. lactis 11454 broth. With respect to the 2 Pseudomonas, we observed a slight adhesion inhibition showed by Lactobacillus rhamnosus broth against Pseudomonas putida. These results confirm that the effect caused by the different LAB assayed is also broth- and species-specific and reveal that the broth from LAB tested can be used as functional bioactive compounds to regulate the adhesion and biofilm synthesis and ultimately lead to preventing food and

  20. Enhancement of microbial quality and inactivation of pathogenic bacteria by gamma irradiation of ready-to-cook Iranian barbecued chicken

    NASA Astrophysics Data System (ADS)

    Fallah, Aziz A.; Siavash Saei-Dehkordi, S.; Rahnama, Mohammad

    2010-10-01

    Ready-to-cook Iranian barbecued chicken consists of cubed chicken breast, lemon juice, salt, red pepper, onion, saffron and vegetable oil with an overall pH value of about 5.5. This product is sometimes consumed under-cooked, hence it may pose health hazards to consumers when contaminated with food-borne pathogens. In this study, the effect of gamma irradiation (0, 1.5, 3 and 4.5 kGy) on the microbial quality of ready-to-cook (RTC) barbecued chicken samples stored at 4 °C for 15 days was investigated. Moreover, the effectiveness of irradiation for inactivating Listeria monocytogenes, Escherichia coli O157:H7 and Salmonella typhimurium inoculated into the samples was also studied. Irradiation of the samples resulted in dose dependent reduction in counts of aerobic mesophilic bacteria, yeasts and molds, Enterobacteriaceae and lactic acid bacteria. Among the microbial flora, yeasts and molds and Enterobacteriaceae were more sensitive to irradiation and got completely eliminated at dose of 3 kGy. D10 values of L. monocytogenes, E. coli O157:H7 and S. typhimurium inoculated into the samples were 0.680, 0.397 and 0.601 kGy, respectively. An irradiation dose of 3 kGy reduced the counts of E. coli O157:H7 to an undetectable level in RTC barbecued chicken but was ineffective on elimination of L. monocytogenes and S. typhimurium. However, none of the food-borne pathogens were detected in the samples irradiated at 4.5 kGy. This study showed that irradiation had no undesirable effects on the initial sensory attributes of barbecued chicken. At the end of the storage period, irradiated samples were more acceptable compared to non-irradiated ones.

  1. Spatiotemporal colonization of Xyllela fastidiosa in its vector supports two types of egestion in the inoculation mechanism of foregut-borne plant pathogens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The bacterial agent that causes Pierce’s disease of grapevine, Xylella fastidiosa, is the only known arthropod-transmitted prokaryotic plant pathogen that does not circulate in the vector’s hemolymph. Instead, bacteria are foregut-borne and semi-persistent, i.e. bacteria colonize cuticular surface...

  2. Insights into Cross-Kingdom Plant Pathogenic Bacteria

    PubMed Central

    Kirzinger, Morgan W.B.; Nadarasah, Geetanchaly; Stavrinides, John

    2011-01-01

    Plant and human pathogens have evolved disease factors to successfully exploit their respective hosts. Phytopathogens utilize specific determinants that help to breach reinforced cell walls and manipulate plant physiology to facilitate the disease process, while human pathogens use determinants for exploiting mammalian physiology and overcoming highly developed adaptive immune responses. Emerging research, however, has highlighted the ability of seemingly dedicated human pathogens to cause plant disease, and specialized plant pathogens to cause human disease. Such microbes represent interesting systems for studying the evolution of cross-kingdom pathogenicity, and the benefits and tradeoffs of exploiting multiple hosts with drastically different morphologies and physiologies. This review will explore cross-kingdom pathogenicity, where plants and humans are common hosts. We illustrate that while cross-kingdom pathogenicity appears to be maintained, the directionality of host association (plant to human, or human to plant) is difficult to determine. Cross-kingdom human pathogens, and their potential plant reservoirs, have important implications for the emergence of infectious diseases. PMID:24710301

  3. Comparison of antibodies raised against heat-and gamma radiation-killed bacteria

    Technology Transfer Automated Retrieval System (TEKTRAN)

    For antibody generation, pathogenic bacteria are often heat-treated prior to inoculation into host animals in order to prevent infection and subsequently, premature death of the host. Inoculation of host rabbits with gamma radiation-killed pathogenic bacteria was employed with the hopes of generati...

  4. Evolution of temperate pathogens: the bacteriophage/bacteria paradigm

    PubMed Central

    Koch, Arthur L

    2007-01-01

    Background Taking as a pattern, the T4 and lambda viruses interacting with each other and with their Gram-negative host, Escherichia coli, a general model is constructed for the evolution of 'gentle' or temperate pathogens. This model is not simply either pure group or kin selection, but probably is common in a variety of host-parasite pairs in various taxonomic groups. The proposed mechanism is that for its own benefit the pathogen evolved ways to protect its host from attack by other pathogens and this has incidentally protected the host. Although appropriate mechanisms would have been developed and excluded related viral species and also other quite different pathogens, the important advance would have been when other individuals of the same species that arrive at the host subsequent to the first infecting one were excluded. Results Such a class of mechanisms would not compete one genotype with another, but simply would be of benefit to the first pathogen that had attacked a host organism. Conclusion This would tend to protect and extend the life of the host against the detrimental effects of a secondarily infecting pathogen. This leads to the pathogens becoming more temperate via the now favorable co-evolution with its host, which basically protects both host and virus against other pathogens but may cause slowing of the growth of the primary infecting pathogen. Evolution by a 'gentle' strategy would be favored as long as the increased wellbeing of the host also favored the eventual transmission of the early infecting pathogen to other hosts. PMID:17996103

  5. Essential oils have different effects on human pathogenic and commensal bacteria in mixed faecal fermentations compared with pure cultures.

    PubMed

    Thapa, Dinesh; Louis, Petra; Losa, Riccardo; Zweifel, Béatrice; Wallace, R John

    2015-02-01

    A static batch culture system inoculated with human faeces was used to determine the influence of essential oil compounds (EOCs) on mixed faecal microbiota. Bacteria were quantified using quantitative PCR of 16S rRNA genes. Incubation for 24 h of diluted faeces from six individuals caused enrichment of Bifidobacterium spp., but proportions of other major groups were unaffected. Thymol and geraniol at 500 p.p.m. suppressed total bacteria, resulting in minimal fermentation. Thymol at 100 p.p.m. had no effect, nor did eugenol or nerolidol at 100 or 500 p.p.m. except for a slight suppression of Eubacterium hallii. Methyl isoeugenol at 100 or 500 p.p.m. suppressed the growth of total bacteria, accompanied by a large fall in the molar proportion of propionate formed. The relative abundance of Faecalibacterium prausnitzii was unaffected except with thymol at 500 p.p.m. The ability of EOCs to control numbers of the pathogen Clostridium difficile was investigated in a separate experiment, in which the faecal suspensions were amended by the addition of pure culture of C. difficile. Numbers of C. difficile were suppressed by thymol and methyl isoeugenol at 500 p.p.m. and to a lesser extent at 100 p.p.m. Eugenol and geraniol gave rather similar suppression of C. difficile numbers at both 100 and 500 p.p.m. Nerolidol had no significant effect. It was concluded from these and previous pure-culture experiments that thymol and geraniol at around 100 p.p.m. could be effective in suppressing pathogens in the small intestine, with no concern for beneficial commensal colonic bacteria in the distal gut. PMID:25500493

  6. Megacities as Sources for Pathogenic Bacteria in Rivers and Their Fate Downstream

    PubMed Central

    Abraham, Wolf-Rainer

    2011-01-01

    Poor sanitation, poor treatments of waste water, as well as catastrophic floods introduce pathogenic bacteria into rivers, infecting and killing many people. The goal of clean water for everyone has to be achieved with a still growing human population and their rapid concentration in large cities, often megacities. How long introduced pathogens survive in rivers and what their niches are remain poorly known but essential to control water-borne diseases in megacities. Biofilms are often niches for various pathogens because they possess high resistances against environmental stress. They also facilitate gene transfers of antibiotic resistance genes which become an increasing health problem. Beside biofilms, amoebae are carriers of pathogenic bacteria and niches for their survival. An overview about our current understanding of the fate and niches of pathogens in rivers, the multitude of microbial community interactions, and the impact of severe flooding, a prerequisite to control pathogens in polluted rivers, is given. PMID:20885968

  7. Comprehensive list of names of plant pathogenic bacteria, 1980-2007.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This list contains the names of all plant pathogenic bacteria which have been effectively and validly published in terms of the International Code of Nomenclature of Bacteria and the Standards for Naming Pathovars and their revisions. Included are species names from the Approved Lists of Bacterial N...

  8. Antibacterial activity of plant extracts on foodborne bacterial pathogens and food spoilage bacteria

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacterial foodborne diseases are caused by consumption of foods contaminated with bacteria and/or their toxins. In this study, we evaluated antibacterial properties of twelve different extracts including turmeric, lemon and different kinds of teas against four major pathogenic foodborne bacteria inc...

  9. List of new names of plant pathogenic bacteria (2011-2012)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The International Society of Plant Pathology Committee on the Taxonomy of Plant Pathogenic Bacteria has responsibility to evaluate the names of newly proposed pathovars for adherence to the International Standards for Naming Pathovars of Phytopathogenic Bacteria. Currently, the Comprehensive List of...

  10. A mathematical model for expected time to extinction of pathogenic bacteria through antibiotic

    NASA Astrophysics Data System (ADS)

    Ghosh, M. K.; Nandi, S.; Roy, P. K.

    2016-04-01

    Application of antibiotics in human system to prevent bacterial diseases like Gastritis, Ulcers, Meningitis, Pneumonia and Gonorrhea are indispensable. Antibiotics saved innumerable lives and continue to be a strong support for therapeutic application against pathogenic bacteria. In human system, bacterial diseases occur when pathogenic bacteria gets into the body and begin to reproduce and crowd out healthy bacteria. In this process, immature bacteria releases enzyme which is essential for bacterial cell-wall biosynthesis. After complete formation of cell wall, immature bacteria are converted to mature or virulent bacteria which are harmful to us during bacterial infections. Use of antibiotics as drug inhibits the bacterial cell wall formation. After application of antibiotics within body, the released bacterial enzyme binds with antibiotic molecule instead of its functional site during the cell wall synthesis in a competitive inhibition approach. As a consequence, the bacterial cell-wall formation as well as maturation process of pathogenic bacteria is halted and the disease is cured with lysis of bacterial cells. With this idea, a mathematical model has been developed in the present research investigation to review the inhibition of biosynthesis of bacterial cell wall by the application of antibiotics as drug in the light of enzyme kinetics. This approach helps to estimate the expected time to extinction of the pathogenic bacteria. Our mathematical approach based on the enzyme kinetic model for finding out expected time to extinction contributes favorable results for understanding of disease dynamics. Analytical and numerical results based on simulated findings validate our mathematical model.

  11. Towards Q-PCR of pathogenic bacteria with improved electrochemical double-tagged genosensing detection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A very sensitive assay for the rapid detection of pathogenic bacteria based on electrochemical genosensing has been designed. The assay was performed by the PCR specific amplification of the eaeA gene, related with the pathogenic activity of Escherichia coli O157:H7. The efficiency and selectivity o...

  12. Glycans in pathogenic bacteria – potential for targeted covalent therapeutics and imaging agents

    PubMed Central

    Tra, Van N.; Dube, Danielle H.

    2014-01-01

    A substantial obstacle to the existing treatment of bacterial diseases is the lack of specific probes that can be used to diagnose and treat pathogenic bacteria in a selective manner while leaving the microbiome largely intact. To tackle this problem, there is an urgent need to develop pathogen-specific therapeutics and diagnostics. Here, we describe recent evidence that indicates distinctive glycans found exclusively on pathogenic bacteria could form the basis of targeted therapeutic and diagnostic strategies. In particular, we highlight the use of metabolic oligosaccharide engineering to covalently deliver therapeutics and imaging agents to bacterial glycans. PMID:24647371

  13. Protein-Based Microarray for the Detection of Pathogenic Bacteria

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Microarrays have been used for gene expression and protein interaction studies, but recently, multianalyte diagnostic assays have employed the microarray platform. We developed a microarray immunoassay for bacteria, with biotinylated capture antibodies on streptavidin slides. To complete the fluor...

  14. Comparison of different inoculating methods to evaluate the pathogenicity and virulence of Aspergillus niger on two maize hybrids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A two-year field study was conducted to determine the effects of inoculation techniques on the aggressiveness of Aspergillus niger kernel infection in A. flavus resistant and susceptible maize hybrids. Ears were inoculated with the silk-channel, side-needle, and spray techniques 7 days after midsilk...

  15. Morphological lesions of the rat urinary tract induced by inoculation of mycoplasmas and other urinary tract pathogens.

    PubMed

    Larsson, P A; Cano, M; Grenabo, L; Brorson, J E; Hedelin, H; Pettersson, S; Johansson, S L

    1989-01-01

    The effects on the urinary tract after inoculation of Ureaplasma urealyticum into the rat bladder were evaluated and compared to that seen after Mycoplasma hominis, Escherichia coli and Proteus mirabilis inoculation. The inoculation of the urease-producing organisms P. mirabilis and U. urealyticum were associated with the formation of struvite bladder stones and predominantly hyperplastic lesions of the bladder. The P. mirabilis inoculated rats also displayed marked pyelonephritis. A similar but much less pronounced reaction also occurred in the kidneys of some of the U. urealyticum inoculated rats. P. mirabilis could frequently be recultured. In contrast, this was not possible with U. urealyticum, but the organism was detected by scanning electron microscopy 2 weeks after the inoculation. Inoculation of M. hominis was associated with a few mild lesions of the bladder, but inflammatory lesions were not present in the kidneys. The study confirms the potential of Ureaplasma to form struvite stones in rat urinary tract. It also demonstrates that it can induce inflammatory changes in both bladder and kidney of rats without concomitant stone formation. PMID:2678669

  16. Multimodal plasmonic nanosensor for the detection of pathogenic bacteria

    NASA Astrophysics Data System (ADS)

    Tay, Li-Lin; Hulse, John; Ryan, Shannon; Tanha, Jamshid; Fraser, Jeff; Wu, Xiaohua

    2009-08-01

    Multi-modal sensing scheme significantly improves the detection accuracy but can also introduce extra complexity in the overall design of the sensor. We overcome this difficulty by utilizing the plasmonic properties of metallic nanoparticles. In this study, we will present a simple dual optical sensing mechanism which harvests signals of the resonantly excited metallic nanostructure in the form of surface enhanced Raman scattering (SERS) and resonant Rayleigh scattering. Silver and gold nanoparticles labeled with appropriate antibodies act as signal transduction units and upon exposure to the targeted pathogen render the targeted species optically active. We demonstrate that detection of a single pathogen cell is easily attainable with the dual detection scheme. Furthermore, we explore the markedly different SERS intensity observed from the use of two very different antibody recognition units during the pathogen labeling process.

  17. Biofilm Exopolysaccharides of Pathogenic Fungi: Lessons from Bacteria.

    PubMed

    Sheppard, Donald C; Howell, P Lynne

    2016-06-10

    Exopolysaccharides play an important structural and functional role in the development and maintenance of microbial biofilms. Although the majority of research to date has focused on the exopolysaccharide systems of biofilm-forming bacteria, recent studies have demonstrated that medically relevant fungi such as Candida albicans and Aspergillus fumigatus also form biofilms during infection. These fungal biofilms share many similarities with those of bacteria, including the presence of secreted exopolysaccharides as core components of the extracellular matrix. This review will highlight our current understanding of fungal biofilm exopolysaccharides, as well as the parallels that can be drawn with those of their bacterial counterparts. PMID:27129222

  18. A Complex Inoculant of N2-Fixing, P- and K-Solubilizing Bacteria from a Purple Soil Improves the Growth of Kiwifruit (Actinidia chinensis) Plantlets

    PubMed Central

    Shen, Hong; He, Xinhua; Liu, Yiqing; Chen, Yi; Tang, Jianming; Guo, Tao

    2016-01-01

    Limited information is available if plant growth promoting bacteria (PGPB) can promote the growth of fruit crops through improvements in soil fertility. This study aimed to evaluate the capacity of PGPB, identified by phenotypic and 16S rRNA sequencing from a vegetable purple soil in Chongqing, China, to increase soil nitrogen (N), phosphorus (P), and potassium (K) availability and growth of kiwifruit (Actinidia chinensis). In doing so, three out of 17 bacterial isolates with a high capacity of N2-fixation (Bacillus amyloliquefaciens, XD-N-3), P-solubilization (B. pumilus, XD-P-1) or K-solubilization (B. circulans, XD-K-2) were mixed as a complex bacterial inoculant. A pot experiment then examined its effects of this complex inoculant on soil microflora, soil N2-fixation, P- and K-solubility and kiwifruit growth under four treatments. These treatments were (1) no-fertilizer and no-bacterial inoculant (Control), (2) no-bacterial inoculant and a full-rate of chemical NPK fertilizer (CF), (3) the complex inoculant (CI), and (4) a half-rate CF and full CI (1/2CF+CI). Results indicated that significantly greater growth of N2-fixing, P- and K-solubilizing bacteria among treatments ranked from greatest to least as under 1/2CF+CI ≈ CI > CF ≈ Control. Though generally without significant treatment differences in soil total N, P, or K, significantly greater soil available N, P, or K among treatments was, respectively, patterned as under 1/2CF+CI ≈ CI > CF ≈ Control, under 1/2CF+CI > CF > CI > Control or under 1/2CF+CI > CF ≈ CI > Control, indicating an improvement of soil fertility by this complex inoculant. In regards to plant growth, significantly greater total plant biomass and total N, P, and K accumulation among treatments were ranked as 1/2CF+CI ≈ CI > CF > Control. Additionally, significantly greater leaf polyphenol oxidase activity ranked as under CF > 1/2CF+CI ≈ Control ≈ CI, while leaf malondialdehyde contents as under Control > CI ≈ CF > 1/2CF

  19. A Complex Inoculant of N2-Fixing, P- and K-Solubilizing Bacteria from a Purple Soil Improves the Growth of Kiwifruit (Actinidia chinensis) Plantlets.

    PubMed

    Shen, Hong; He, Xinhua; Liu, Yiqing; Chen, Yi; Tang, Jianming; Guo, Tao

    2016-01-01

    Limited information is available if plant growth promoting bacteria (PGPB) can promote the growth of fruit crops through improvements in soil fertility. This study aimed to evaluate the capacity of PGPB, identified by phenotypic and 16S rRNA sequencing from a vegetable purple soil in Chongqing, China, to increase soil nitrogen (N), phosphorus (P), and potassium (K) availability and growth of kiwifruit (Actinidia chinensis). In doing so, three out of 17 bacterial isolates with a high capacity of N2-fixation (Bacillus amyloliquefaciens, XD-N-3), P-solubilization (B. pumilus, XD-P-1) or K-solubilization (B. circulans, XD-K-2) were mixed as a complex bacterial inoculant. A pot experiment then examined its effects of this complex inoculant on soil microflora, soil N2-fixation, P- and K-solubility and kiwifruit growth under four treatments. These treatments were (1) no-fertilizer and no-bacterial inoculant (Control), (2) no-bacterial inoculant and a full-rate of chemical NPK fertilizer (CF), (3) the complex inoculant (CI), and (4) a half-rate CF and full CI (1/2CF+CI). Results indicated that significantly greater growth of N2-fixing, P- and K-solubilizing bacteria among treatments ranked from greatest to least as under 1/2CF+CI ≈ CI > CF ≈ Control. Though generally without significant treatment differences in soil total N, P, or K, significantly greater soil available N, P, or K among treatments was, respectively, patterned as under 1/2CF+CI ≈ CI > CF ≈ Control, under 1/2CF+CI > CF > CI > Control or under 1/2CF+CI > CF ≈ CI > Control, indicating an improvement of soil fertility by this complex inoculant. In regards to plant growth, significantly greater total plant biomass and total N, P, and K accumulation among treatments were ranked as 1/2CF+CI ≈ CI > CF > Control. Additionally, significantly greater leaf polyphenol oxidase activity ranked as under CF > 1/2CF+CI ≈ Control ≈ CI, while leaf malondialdehyde contents as under Control > CI ≈ CF > 1/2CF

  20. ENGINEERING OF PEPTIDOGLYCAN HYDROLASES FOR CONTROL OF PATHOGENIC BACTERIA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacteriophages are viruses exclusively infecting bacteria and therefore offer suitable tools for their detection and control. At the end of their multiplication cycle, most phages lyse their hosts from within by means of an endolysin (peptidoglycan hydrolase), thereby enabling release of the phage p...

  1. AOTF hyperspectral microscope imaging for foodborne pathogenic bacteria detection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hyperspectral microscope imaging (HMI) method, which provides both spatial and spectral information, can be effective for foodborne pathogen detection. The acousto-optic tunable filter (AOTF)-based HMI method can be used to characterize spectral properties of biofilms formed by Salmonella enteritidi...

  2. Modulation of host microtubule dynamics by pathogenic bacteria

    PubMed Central

    Radhakrishnan, Girish K.; Splitter, Gary A.

    2013-01-01

    The eukaryotic cytoskeleton is a vulnerable target of many microbial pathogens during the course of infection. Rearrangements of host cytoskeleton benefit microbes in various stages of their infection cycle such as invasion, motility, and persistence. Bacterial pathogens deliver a number of effector proteins into host cells for modulating the dynamics of actin and microtubule cytoskeleton. Alteration of the actin cytoskeleton is generally achieved by bacterial effectors that target the small GTPases of the host. Modulation of microtubule dynamics involves direct interaction of effector proteins with the subunits of microtubules or recruiting cellular proteins that affect microtubule dynamics. This review will discuss effector proteins from animal and human bacterial pathogens that either destabilize or stabilize host micro-tubules to advance the infectious process. A compilation of these research findings will provide an overview of known and unknown strategies used by various bacterial effectors to modulate the host microtubule dynamics. The present review will undoubtedly help direct future research to determine the mechanisms of action of many bacterial effector proteins and contribute to understanding the survival strategies of diverse adherent and invasive bacterial pathogens. PMID:23585820

  3. Association of plasma 25-hydroxyvitamin D concentrations and pathogenic oral bacteria in postmenopausal women

    PubMed Central

    Sahli, Michelle W; Wactawski-Wende, Jean; Ram, Pavani K; LaMonte, Michael J.; Hovey, Kathleen M.; Genco, Robert J.; Andrews, Christopher A.; Millen, Amy E.

    2014-01-01

    Background Previous findings of an association between 25-hydroxyvitamin D (25(OH)D) concentrations and periodontal disease, may be partially explained by vitamin D’s antimicrobial properties. To our knowledge, no study has investigated the association between 25(OH)D and pathogenic oral bacteria, a putative cause of periodontal disease. Methods We examined the association between plasma 25(OH)D concentrations and pathogenic oral bacteria among postmenopausal women in the Buffalo Osteoporosis and Periodontal Disease Study (1997–2000), an ancillary study of the Women’s Health Initiative Observational Study. Subgingival plaque samples were assessed using immunofluorescence for the presence of Porphyromonas gingivalis, Tannerella forsythensis, Fusobacterium nucleatum, Prevotella intermedia and Campylobacter rectus. Logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for prevalent bacteria by quintile (Q) of 25(OH)D concentrations adjusting for age and body mass index. Results Of the 855 participants, 288 (34%) had deficient/inadequate (<50 nmol/L) 25(OH)D concentrations and 497 (58%) had at least one species of pathogenic bacteria. No significant association was found between 25(OH)D and presence of any of these bacteria (adjusted OR for high (Q5) compared to low (Q1) 25(OH)D=0.96; 95% CI: 0.61–1.50, p for trend=0.50). Inverse, although not statistically significant, associations were found between 25(OH)D and more than one species of pathogenic bacteria (adjusted OR for adequate compared to deficient/inadequate 25(OH)D=0.85; 95% CI: 0.60–1.19). Conclusions No association was observed between pathogenic oral bacteria and 25(OH)D concentrations in postmenopausal women. This may be due to the species of bacteria assessed, small effect size or a true absence of an association. PMID:24261910

  4. Population dynamics of bacteria associated with different strains of the pine wood nematode Bursaphelenchus xylophilus after inoculation in maritime pine (Pinus pinaster).

    PubMed

    Roriz, Mariana; Santos, Carla; Vasconcelos, Marta W

    2011-08-01

    For a long time it was thought that Bursaphelenchus xylophilus was the only agent of the pine wilt disease. Recently, it was discovered that there are bacteria associated with the nematodes that contribute to the pathogenesis of this disease, mainly through the release of toxins that promote the death of the pines. Among the species most commonly found, are bacteria belonging to the Bacillus, Pantoea, Pseudomonas and Xanthomonas genera. The main objective of this work was to study the effect of inoculation of maritime pine (Pinus pinaster) with four different nematode isolates, in the bacterial population of nematodes and trees, at different stages of disease progression. The monitoring of progression of disease symptoms was also recorded. Also, the identification of bacteria isolated from the xylem of trees and the surface of nematodes was performed by classical identification methods, by the API20E identification system and by sequencing of bacterial DNA. The results showed that for the symptoms progression, the most striking difference was observed for the pines inoculated with the avirulent isolate, C14-5, which led to a slower and less severe aggravation of symptoms than in pines inoculated with the virulent isolates. In general, it was found that bacterial population, inside the tree, increased with disease progression. A superior bacterial quantity was isolated from pines inoculated with the nematode isolates HF and 20, and, comparatively, few bacteria were isolated from pines inoculated with the avirulent isolate. The identification system API20E was insufficient in the identification of bacterial species; Enterobacter cloacae species was identified in 79% of the isolated bacterial colonies and seven of these colonies could not be identified by this method. Molecular identification methods, through bacterial DNA sequencing, allowed a more reliable identification: eleven different bacterial species within the Bacillus, Citrobacter, Enterobacter, Escherichia

  5. No effect of Wolbachia on resistance to intracellular infection by pathogenic bacteria in Drosophila melanogaster.

    PubMed

    Rottschaefer, Susan M; Lazzaro, Brian P

    2012-01-01

    Multiple studies have shown that infection with the endosymbiotic bacterium Wolbachia pipientis confers Drosophila melanogaster and other insects with resistance to infection by RNA viruses. Studies investigating whether Wolbachia infection induces the immune system or confers protection against secondary bacterial infection have not shown any effect. These studies, however, have emphasized resistance against extracellular pathogens. Since Wolbachia lives inside the host cell, we hypothesized that Wolbachia might confer resistance to pathogens that establish infection by invading host cells. We therefore tested whether Wolbachia-infected D. melanogaster are protected against infection by the intracellular pathogenic bacteria Listeria monocytogenes and Salmonella typhimurium, as well as the extracellular pathogenic bacterium Providencia rettgeri. We evaluated the ability of flies infected with Wolbachia to suppress secondary infection by pathogenic bacteria relative to genetically matched controls that had been cured of Wolbachia by treatment with tetracycline. We found no evidence that Wolbachia alters host ability to suppress proliferation of any of the three pathogenic bacteria. Our results indicate that Wolbachia-induced antiviral protection does not result from a generalized response to intracellular pathogens. PMID:22808174

  6. quenched-smFISH: Counting small RNA in Pathogenic Bacteria

    NASA Astrophysics Data System (ADS)

    Shepherd, Douglas; Li, Nan; Micheva-Viteva, Sofiya; Munsky, Brian; Hong-Geller, Elizabeth; Werner, James

    2014-03-01

    Here, we present a modification to single-molecule fluorescence in situ hybridization, quenched smFISH (q-smFISH), that enables quantitative detection and analysis of small RNA (sRNA) expressed in bacteria. We show that short nucleic acid targets can be detected when the background of unbound singly dye-labeled DNA oligomers is reduced through hybridization with a set of complementary DNA oligomers labeled with a fluorescence quencher. Exploiting an automated, multi-color wide-field microscope and GPU-accelerated data analysis package, we analyzed the statistics of sRNA expression in thousands of individual Yersinia pseudotuberculosis and Yersinia pestis bacteria before and during a simulated infection. Before infection, we find only a small fraction of either bacteria express the small RNAs YSR35 or YSP8. The copy numbers of these RNA are increased during simulated infection, suggesting a role in pathogenesis. The ability to directly quantify expression level changes of sRNA in single cells as a function of external stimuli provides key information on the role of sRNA in bacterial regulatory networks.

  7. 'Add, stir and reduce': Yersinia spp. as model bacteria for pathogen evolution.

    PubMed

    McNally, Alan; Thomson, Nicholas R; Reuter, Sandra; Wren, Brendan W

    2016-02-15

    Pathogenic species in the Yersinia genus have historically been targets for research aimed at understanding how bacteria evolve into mammalian pathogens. The advent of large-scale population genomic studies has greatly accelerated the progress in this field, and Yersinia pestis, Yersinia pseudotuberculosis and Yersinia enterocolitica have once again acted as model organisms to help shape our understanding of the evolutionary processes involved in pathogenesis. In this Review, we highlight the gene gain, gene loss and genome rearrangement events that have been identified by genomic studies in pathogenic Yersinia species, and we discuss how these findings are changing our understanding of pathogen evolution. Finally, as these traits are also found in the genomes of other species in the Enterobacteriaceae, we suggest that they provide a blueprint for the evolution of enteropathogenic bacteria. PMID:26876035

  8. Plant pathogenic anaerobic bacteria use aromatic polyketides to access aerobic territory.

    PubMed

    Shabuer, Gulimila; Ishida, Keishi; Pidot, Sacha J; Roth, Martin; Dahse, Hans-Martin; Hertweck, Christian

    2015-11-01

    Around 25% of vegetable food is lost worldwide because of infectious plant diseases, including microbe-induced decay of harvested crops. In wet seasons and under humid storage conditions, potato tubers are readily infected and decomposed by anaerobic bacteria (Clostridium puniceum). We found that these anaerobic plant pathogens harbor a gene locus (type II polyketide synthase) to produce unusual polyketide metabolites (clostrubins) with dual functions. The clostrubins, which act as antibiotics against other microbial plant pathogens, enable the anaerobic bacteria to survive an oxygen-rich plant environment. PMID:26542569

  9. Occurrence of airborne bacteria and pathogen indicators during land application of sewage sludge.

    PubMed Central

    Pillai, S D; Widmer, K W; Dowd, S E; Ricke, S C

    1996-01-01

    Glass impingers (AGI-30) were used at a commercial sludge application site to determine the levels of airborne bacteria and pathogen indicators. Even though heterotrophic bacteria averaged 10(5) CFU/m3, none of the sites showed the presence of Salmonella spp. or indicators such as fecal coliforms or coliphages. Indicators such as H2S producers and pathogenic clostridia were present in locations having significant physical agitation of the sludge material. PCR-based ribotyping using the 16S-23S interspacer region is a promising method to identify the genetic relatedness and origins of airborne clostridia. PMID:8572708

  10. Comparison of fecal indicators with pathogenic bacteria and rotavirus in groundwater

    PubMed Central

    Ferguson, Andrew S.; Layton, Alice C.; Mailloux, Brian J; Culligan, Patricia J.; Williams, Daniel E.; Smartt, Abby E.; Sayler, Gary S.; Feighery, John; McKay, Larry; Knappett, Peter S.K.; Alexandrova, Ekaterina; Arbit, Talia; Emch, Michael; Escamilla, Veronica; Ahmed, Kazi Matin; Alam, Md. Jahangir; Streatfield, P. Kim; Yunus, Mohammad; van Geen, Alexander

    2012-01-01

    Groundwater is routinely analyzed for fecal indicators but direct comparisons of fecal indicators to the presence of bacterial and viral pathogens are rare. This study was conducted in rural Bangladesh where the human population density is high, sanitation is poor, and groundwater pumped from shallow tubewells is often contaminated with fecal bacteria. Five indicator microorganisms (E. coli, total coliform, F+RNA coliphage, Bacteroides and human-associated Bacteroides) and various environmental parameters were compared to the direct detection of waterborne pathogens by quantitative PCR in groundwater pumped from 50 tubewells. Rotavirus was detected in groundwater filtrate from the largest proportion of tubewells (40%), followed by Shigella (10%), Vibrio (10%), and pathogenic E. coli (8%). Spearman rank correlations and sensitivity-specificity calculations indicate that some, but not all, combinations of indicators and environmental parameters can predict the presence of pathogens. Culture-dependent fecal indicator bacteria measured on a single date did not predict total bacterial pathogens, but annually averaged monthly measurements of culturable E. coli did improve prediction for total bacterial pathogens. A qPCR-based E. coli assay was the best indicator for the bacterial pathogens. F+RNA coliphage were neither correlated nor sufficiently sensitive towards rotavirus, but were predictive of bacterial pathogens. Since groundwater cannot be excluded as a significant source of diarrheal disease in Bangladesh and neighboring countries with similar characteristics, the need to develop more effective methods for screening tubewells with respect to microbial contamination is necessary. PMID:22705866

  11. Laboratory Evaluation of the Effectiveness of Pathogen Reduction Procedures for Bacteria

    PubMed Central

    Müller, Thomas H.; Montag, Thomas; Seltsam, Axel W.

    2011-01-01

    Summary Bacterial contamination remains a leading factor for transfusion-associated serious morbidity and mortality. Pathogen reduction procedures offer a pro-active approach to prevent bacterial contamination of cellular blood components and especially of platelet concentrates. In the past, the laboratory evaluation of the effectiveness of the pathogen reduction procedures to minimise the bacterial load of blood components has been primarily based on log reduction assays similar to the assessment of antiviral activities. Bacteria strains with the ability to multiply in the blood components are seeded in highest possible cell numbers, the pathogen reduction procedure is applied, and the post-treatment number of bacteria is measured. The effectiveness of the procedure is characterised by calculating the log reduction of the post- to pre-treatment bacteria titres. More recently, protocols have been developed for experiments starting with a low bacteria load and monitoring the sterility of the blood component during the entire storage period of the blood component. Results for 3 different pathogen reduction technologies in these experimental models are compared and critical determinants for the results are addressed. The heterogeneity of results observed for different strains suggests that the introduction of international transfusion-relevant bacterial reference strains may facilitate the validity of findings in pathogen reduction experiments. PMID:22016694

  12. Temperature-dependent expression of virulence genes in fish-pathogenic bacteria

    PubMed Central

    Guijarro, José A.; Cascales, Desirée; García-Torrico, Ana I.; García-Domínguez, Mario; Méndez, Jessica

    2015-01-01

    Virulence gene expression in pathogenic bacteria is modulated by environmental parameters. A key factor in this expression is temperature. Its effect on virulence gene expression in bacteria infecting warm-blooded hosts is well documented. Transcription of virulence genes in these bacteria is induced upon a shift from low environmental to a higher host temperature (37°C). Interestingly, host temperatures usually correspond to the optimum for growth of these pathogenic bacteria. On the contrary, in ectothermic hosts such as fish, molluscs, and amphibians, infection processes generally occur at a temperature lower than that for the optimal growth of the bacteria. Therefore, regulation of virulence gene expression in response to temperature shift has to be modulated in a different way to that which is found in bacteria infecting warm-blooded hosts. The current understanding of virulence gene expression and its regulation in response to temperature in fish-pathogenic bacteria is limited, but constant extension of our knowledge base is essential to enable a rational approach to the problem of the bacterial fish diseases affecting the aquaculture industry. This is an interesting issue and progress needs to be made in order to diminish the economic losses caused by these diseases. The intention of this review is, for the first time, to compile the scattered results existing in the field in order to lay the groundwork for future research. This article is an overview of those relevant virulence genes that are expressed at temperatures lower than that for optimal bacterial growth in different fish-pathogenic bacteria as well as the principal mechanisms that could be involved in their regulation. PMID:26217329

  13. Microbiological study of pathogenic bacteria isolated from paediatric wound infections following the 2008 Wenchuan earthquake.

    PubMed

    Ran, Ying-Chun; Ao, Xiao-Xiao; Liu, Lan; Fu, Yi-Long; Tuo, Hui; Xu, Feng

    2010-05-01

    On 12 May 2008, the Wenchuan earthquake struck in Sichuan, China. Within 1 month after the earthquake, 98 injured children were admitted to the Children's Hospital of Chongqing Medical University. According to clinical manifestations, 50 children were diagnosed with wound infections. Wound secretions were cultured for bacteria. Pathogen distribution and drug resistance were analyzed. A total of 99 pathogens were isolated; 16 (16%) were Gram-positive bacteria and 81 (82%) were Gram-negative bacteria. The distribution of pathogens isolated within 1 month after the earthquake was different to the distribution of pathogens in 546 general hospitalized cases in the y before the earthquake. The pathogens most frequently isolated 1 month after the earthquake were Acinetobacter baumannii (27%), Enterobacter cloacae (18%) and Pseudomonas aeruginosa (13%). The pathogens most frequently isolated in the y prior to the earthquake were Escherichia coli (27%), Staphylococcus aureus (23%) and coagulase-negative staphylococci (9%). The rate of isolated drug-resistant bacteria was higher in the earthquake cases than in the general hospitalized cases. In the cases injured in the earthquake, the rates of isolation of methicillin-resistant Staphylococcus aureus and extended-spectrum beta-lactamase-producing E. cloacae, E. coli and Klebsiella pneumoniae were higher than in the cases from before the earthquake. Multidrug-resistant and pandrug-resistant A. baumannii were isolated at a higher rate in cases after the earthquake than in those before the earthquake. These changes in the spectrum of pathogens and in the drug resistance of the pathogens isolated following an earthquake will provide the basis for emergency treatment after earthquakes. PMID:20095936

  14. Volatiles produced by soil-borne endophytic bacteria increase plant pathogen resistance and affect tritrophic interactions

    PubMed Central

    Ton, Jurriaan; Brandenburg, Anna; Karlen, Danielle; Zopfi, Jakob; Turlings, Ted C. J.

    2014-01-01

    Volatile organic compounds (VOCs) released by soil microorganisms influence plant growth and pathogen resistance. Yet, very little is known about their influence on herbivores and higher trophic levels. We studied the origin and role of a major bacterial VOC, 2,3-butanediol (2,3-BD), on plant growth, pathogen and herbivore resistance, and the attraction of natural enemies in maize. One of the major contributors to 2,3-BD in the headspace of soil-grown maize seedlings was identified as Enterobacter aerogenes, an endophytic bacterium that colonizes the plants. The production of 2,3-BD by E. aerogenes rendered maize plants more resistant against the Northern corn leaf blight fungus Setosphaeria turcica. On the contrary, E. aerogenes-inoculated plants were less resistant against the caterpillar Spodoptera littoralis. The effect of 2,3-BD on the attraction of the parasitoid Cotesia marginiventris was more variable: 2,3-BD application to the headspace of the plants had no effect on the parasitoids, but application to the soil increased parasitoid attraction. Furthermore, inoculation of seeds with E. aerogenes decreased plant attractiveness, whereas inoculation of soil with a total extract of soil microbes increased parasitoid attraction, suggesting that the effect of 2,3-BD on the parasitoid is indirect and depends on the composition of the microbial community. PMID:24127750

  15. Volatiles produced by soil-borne endophytic bacteria increase plant pathogen resistance and affect tritrophic interactions.

    PubMed

    D'Alessandro, Marco; Erb, Matthias; Ton, Jurriaan; Brandenburg, Anna; Karlen, Danielle; Zopfi, Jakob; Turlings, Ted C J

    2014-04-01

    Volatile organic compounds (VOCs) released by soil microorganisms influence plant growth and pathogen resistance. Yet, very little is known about their influence on herbivores and higher trophic levels. We studied the origin and role of a major bacterial VOC, 2,3-butanediol (2,3-BD), on plant growth, pathogen and herbivore resistance, and the attraction of natural enemies in maize. One of the major contributors to 2,3-BD in the headspace of soil-grown maize seedlings was identified as Enterobacter aerogenes, an endophytic bacterium that colonizes the plants. The production of 2,3-BD by E. aerogenes rendered maize plants more resistant against the Northern corn leaf blight fungus Setosphaeria turcica. On the contrary, E. aerogenes-inoculated plants were less resistant against the caterpillar Spodoptera littoralis. The effect of 2,3-BD on the attraction of the parasitoid Cotesia marginiventris was more variable: 2,3-BD application to the headspace of the plants had no effect on the parasitoids, but application to the soil increased parasitoid attraction. Furthermore, inoculation of seeds with E. aerogenes decreased plant attractiveness, whereas inoculation of soil with a total extract of soil microbes increased parasitoid attraction, suggesting that the effect of 2,3-BD on the parasitoid is indirect and depends on the composition of the microbial community. PMID:24127750

  16. Current Perspectives on Viable but Non-Culturable (VBNC) Pathogenic Bacteria

    PubMed Central

    Ramamurthy, Thandavarayan; Ghosh, Amit; Pazhani, Gururaja P.; Shinoda, Sumio

    2014-01-01

    Under stress conditions, many species of bacteria enter into starvation mode of metabolism or a physiologically viable but non-culturable (VBNC) state. Several human pathogenic bacteria have been reported to enter into the VBNC state under these conditions. The pathogenic VBNC bacteria cannot be grown using conventional culture media, although they continue to retain their viability and express their virulence. Though there have been debates on the VBNC concept in the past, several molecular studies have shown that not only can the VBNC state be induced under in vitro conditions but also that resuscitation from this state is possible under appropriate conditions. The most notable advance in resuscitating VBNC bacteria is the discovery of resuscitation-promoting factor (Rpf), which is a bacterial cytokines found in both Gram-positive and Gram-negative organisms. VBNC state is a survival strategy adopted by the bacteria, which has important implication in several fields, including environmental monitoring, food technology, and infectious disease management; and hence it is important to investigate the association of bacterial pathogens under VBNC state and the water/foodborne outbreaks. In this review, we describe various aspects of VBNC bacteria, which include their proteomic and genetic profiles under the VBNC state, conditions of resuscitation, methods of detection, antibiotic resistance, and observations on Rpf. PMID:25133139

  17. Commonalities and differences of T3SSs in rhizobia and plant pathogenic bacteria

    PubMed Central

    Tampakaki, Anastasia P.

    2014-01-01

    Plant pathogenic bacteria and rhizobia infect higher plants albeit the interactions with their hosts are principally distinct and lead to completely different phenotypic outcomes, either pathogenic or mutualistic, respectively. Bacterial protein delivery to plant host plays an essential role in determining the phenotypic outcome of plant-bacteria interactions. The involvement of type III secretion systems (T3SSs) in mediating animal- and plant-pathogen interactions was discovered in the mid-80's and is now recognized as a multiprotein nanomachine dedicated to trans-kingdom movement of effector proteins. The discovery of T3SS in bacteria with symbiotic lifestyles broadened its role beyond virulence. In most T3SS-positive bacterial pathogens, virulence is largely dependent on functional T3SSs, while in rhizobia the system is dispensable for nodulation and can affect positively or negatively the mutualistic associations with their hosts. This review focuses on recent comparative genome analyses in plant pathogens and rhizobia that uncovered similarities and variations among T3SSs in their genetic organization, regulatory networks and type III secreted proteins and discusses the evolutionary adaptations of T3SSs and type III secreted proteins that might account for the distinguishable phenotypes and host range characteristics of plant pathogens and symbionts. PMID:24723933

  18. The production and detoxification of a potent cytotoxin, nitric oxide, by pathogenic enteric bacteria.

    PubMed

    Arkenberg, Anke; Runkel, Sebastian; Richardson, David J; Rowley, Gary

    2011-12-01

    The nitrogen cycle is based on several redox reactions that are mainly accomplished by prokaryotic organisms, some archaea and a few eukaryotes, which use these reactions for assimilatory, dissimilatory or respiratory purposes. One group is the Enterobacteriaceae family of Gammaproteobacteria, which have their natural habitats in soil, marine environments or the intestines of humans and other warm-blooded animals. Some of the genera are pathogenic and usually associated with intestinal infections. Our body possesses several physical and chemical defence mechanisms to prevent pathogenic enteric bacteria from invading the gastrointestinal tract. One response of the innate immune system is to activate macrophages, which produce the potent cytotoxin nitric oxide (NO). However, some pathogens have evolved the ability to detoxify NO to less toxic compounds, such as the neuropharmacological agent and greenhouse gas nitrous oxide (N₂O), which enables them to overcome the host's attack. The same mechanisms may be used by bacteria producing NO endogenously as a by-product of anaerobic nitrate respiration. In the present review, we provide a brief introduction into the NO detoxification mechanisms of two members of the Enterobacteriaceae family: Escherichia coli and Salmonella enterica serovar Typhimurium. These are discussed as comparative non-pathogenic and pathogenic model systems in order to investigate the importance of detoxifying NO and producing N₂O for the pathogenicity of enteric bacteria. PMID:22103543

  19. Detection of Foodborne Pathogenic Bacteria using Bacteriophage Tail Spike Proteins

    NASA Astrophysics Data System (ADS)

    Poshtiban, Somayyeh

    Foodborne infections are worldwide health problem with tremendous social and financial impacts. Efforts are focused on developing accurate and reliable technologies for detection of food contaminations in early stages preferably on-site. This thesis focuses on interfacing engineering and biology by combining phage receptor binding proteins (RBPs) with engineered platforms including microresonator-based biosensors, magnetic particles and polymerase chain reaction (PCR) to develop bacterial detection sensors. We used phage RBPs as target specific bioreceptors to develop an enhanced microresonator array for bacterial detection. These resonator beams are optimized to feature a high natural frequency while offer large surface area for capture of bacteria. Theoretical analysis indicates a high mass sensitivity with a threshold for the detection of a single bacterial cell. We used phage RBPs as target specific bioreceptors, and successfully demonstrated the application of these phage RBB-immobilized arrays for specific detection of C. jejuni cells. We also developed a RBP-derivatized magnetic pre-enrichment method as an upstream sample preparation method to improve sensitivity and specificity of PCR for detection of bacterial cells in various food samples. The combination of RBP-based magnetic separation and real-time PCR allowed the detection of small number of bacteria in artificially contaminated food samples without any need for time consuming pre-enrichment step through culturing. We also looked into integration of the RBP-based magnetic separation with PCR onto a single microfluidic lab-on-a-chip to reduce the overall turnaround time.

  20. AOTF hyperspectral microscopic imaging for foodborne pathogenic bacteria detection

    NASA Astrophysics Data System (ADS)

    Park, Bosoon; Lee, Sangdae; Yoon, Seung-Chul; Sundaram, Jaya; Windham, William R.; Hinton, Arthur, Jr.; Lawrence, Kurt C.

    2011-06-01

    Hyperspectral microscope imaging (HMI) method which provides both spatial and spectral information can be effective for foodborne pathogen detection. The AOTF-based hyperspectral microscope imaging method can be used to characterize spectral properties of biofilm formed by Salmonella enteritidis as well as Escherichia coli. The intensity of spectral imagery and the pattern of spectral distribution varied with system parameters (integration time and gain) of HMI system. The preliminary results demonstrated determination of optimum parameter values of HMI system and the integration time must be no more than 250 ms for quality image acquisition from biofilm formed by S. enteritidis. Among the contiguous spectral imagery between 450 and 800 nm, the intensity of spectral images at 498, 522, 550 and 594 nm were distinctive for biofilm; whereas, the intensity of spectral images at 546 nm was distinctive for E. coli. For more accurate comparison of intensity from spectral images, a calibration protocol, using neutral density filters and multiple exposures, need to be developed to standardize image acquisition. For the identification or classification of unknown food pathogen samples, ground truth regions-of-interest pixels need to be selected for "spectrally pure fingerprints" for the Salmonella and E. coli species.

  1. Nature-inspired magnetoelastic biosentinels for the detection of pathogenic bacteria in stagnant liquids

    NASA Astrophysics Data System (ADS)

    Horikawa, Shin; Chai, Yating; Wikle, Howard C.; Dai, Jing; Hu, Jiajia; Suh, Sang-Jin; Vodyanoy, Vitaly; Chin, Bryan A.

    2015-05-01

    This paper presents an investigation into magnetoelastic (ME) biosentinels that capture and detect low-concentration pathogenic bacteria in stagnant liquids. The ME biosentinels are designed to mimic a variety of white blood cell types, known as the main defensive mechanism in the human body against different pathogenic invaders. The ME biosentinels are composed of a freestanding ME resonator coated with an engineered phage that specifically binds with the pathogens of interest. These biosentinels are ferromagnetic and thus can be moved through a liquid by externally applied magnetic fields. In addition, when a time-varying magnetic field is applied, the ME biosentinels can be placed into mechanical resonance by magnetostriction. As soon as the biosentinels bind with the target pathogen through the phage-based biomolecular recognition, a change in the biosentinel's resonant frequency occurs, and thereby the presence of the target pathogen can be detected. Detection of Bacillus anthracis spores under stagnant flow conditions was demonstrated.

  2. Pathogen translocation and histopathological lesions in an experimental model of Salmonella Dublin infection in calves receiving lactic acid bacteria and lactose supplements.

    PubMed

    Frizzo, Laureano S; Zbrun, María V; Soto, Lorena P; Bertozzi, Ezequiel; Sequeira, Gabriel J; Marti, Luis E; Signorini, Marcelo L; Armesto, Roberto Rodríguez; Rosmini, Marcelo R

    2012-09-01

    The purpose of this study was to evaluate the capacity of a lactic acid bacteria (LAB) inoculum to protect calves with or without lactose supplements against Salmonella Dublin infection by evaluating histopathological lesions and pathogen translocation. Fifteen calves were divided into three groups [control group (C-G), a group inoculated with LAB (LAB-G), and a group inoculated with LAB and given lactose supplements (L-LAB-G)] with five, six, and four animals, respectively. The inoculum, composed of Lactobacillus (L.) casei DSPV 318T, L. salivarius DSPV 315T, and Pediococcus acidilactici DSPV 006T, was administered with milk replacer. The LAB-G and L-LAB-G received a daily dose of 10(9) CFU/kg body weight of each strain throughout the experiment. Lactose was provided to the L-LAB-G in doses of 100 g/day. Salmonella Dublin (2 × 10(10) CFU) was orally administered to all animals on day 11 of the experiment. The microscopic lesion index values in target organs were 83%, 70%, and 64.3% (p < 0.05) for the C-G, LAB-G, and L-LAB-G, respectively. Administration of the probiotic inoculum was not fully effective against infection caused by Salmonella. Although probiotic treatment was unable to delay the arrival of pathogen to target organs, it was evident that the inoculum altered the response of animals against pathogen infection. PMID:23000583

  3. Pathogen translocation and histopathological lesions in an experimental model of Salmonella Dublin infection in calves receiving lactic acid bacteria and lactose supplements

    PubMed Central

    Zbrun, María V.; Soto, Lorena P.; Bertozzi, Ezequiel; Sequeira, Gabriel J.; Marti, Luis E.; Signorini, Marcelo L.; Armesto, Roberto Rodríguez; Rosmini, Marcelo R.

    2012-01-01

    The purpose of this study was to evaluate the capacity of a lactic acid bacteria (LAB) inoculum to protect calves with or without lactose supplements against Salmonella Dublin infection by evaluating histopathological lesions and pathogen translocation. Fifteen calves were divided into three groups [control group (C-G), a group inoculated with LAB (LAB-G), and a group inoculated with LAB and given lactose supplements (L-LAB-G)] with five, six, and four animals, respectively. The inoculum, composed of Lactobacillus (L.) casei DSPV 318T, L. salivarius DSPV 315T, and Pediococcus acidilactici DSPV 006T, was administered with milk replacer. The LAB-G and L-LAB-G received a daily dose of 109 CFU/kg body weight of each strain throughout the experiment. Lactose was provided to the L-LAB-G in doses of 100 g/day. Salmonella Dublin (2 × 1010 CFU) was orally administered to all animals on day 11 of the experiment. The microscopic lesion index values in target organs were 83%, 70%, and 64.3% (p < 0.05) for the C-G, LAB-G, and L-LAB-G, respectively. Administration of the probiotic inoculum was not fully effective against infection caused by Salmonella. Although probiotic treatment was unable to delay the arrival of pathogen to target organs, it was evident that the inoculum altered the response of animals against pathogen infection. PMID:23000583

  4. A COMPARISON OF THREE ASSAY PROCEDURES FOR DETERMINING CHLORINE INACTIVATION OF WATERBORNE PATHOGENIC BACTERIA

    EPA Science Inventory

    One criterion on which chlorine treatment of water may be based is the concentration (C) in mg/l multiplied by the time (t) in min of exposure or Ct values. We compared different Ct values on waterborne pathogenic bacteria by cultural assay for viability and 2 assays that mea...

  5. Potential human pathogenic bacteria in a mixed urban watershed as revealed by pyrosequencing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Current microbial source tracking (MST) methods for water depend on testing for fecal indicator bacterial counts or specific marker gene sequences to identify fecal contamination where potential human pathogenic bacteria could be present. In this study, we applied 454 high-throughput pyrosequencing ...

  6. Lack of Direct Effects of Agrochemicals on Zoonotic Pathogens and Fecal Indicator Bacteria

    PubMed Central

    Staley, Zachery R.; Senkbeil, Jacob K.; Rohr, Jason R.

    2012-01-01

    Agrochemicals, fecal indicator bacteria (FIB), and pathogens frequently contaminate water simultaneously. No significant direct effects of fertilizer, atrazine, malathion, and chlorothalonil on the survival of Escherichia coli, Enterococcus faecalis, Salmonella enterica, human polyomaviruses, and adenovirus were detected, supporting the assertion that previously observed effects of agrochemicals on FIB were indirect. PMID:22961900

  7. PATHOGENICITY OF DRINKING WATER ISOLATES OF HETEROTROPHIC BACTERIA WITH PUTATIVE VIRULENCE FACTORS

    EPA Science Inventory

    Although the heterotrophic plate count (HPC) bacteria normally found in potable water are not a threat to the healthy population, some of them may be opportunistic pathogens that could cause adverse health effects in individuals with impaired immune systems. Earlier studies of t...

  8. Hyperspectral microscope imaging methods to classify gram-positive and gram-negative foodborne pathogenic bacteria

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An acousto-optic tunable filter-based hyperspectral microscope imaging method has potential for identification of foodborne pathogenic bacteria from microcolony rapidly with a single cell level. We have successfully developed the method to acquire quality hyperspectral microscopic images from variou...

  9. Classification of gram-positive and gram-negative foodborne pathogenic bacteria with hyperspectral microscope imaging

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Optical method with hyperspectral microscope imaging (HMI) has potential for identification of foodborne pathogenic bacteria from microcolonies rapidly with a cell level. A HMI system that provides both spatial and spectral information could be an effective tool for analyzing spectral characteristic...

  10. Identification of DNA Methyltransferase Genes in Human Pathogenic Bacteria by Comparative Genomics.

    PubMed

    Brambila-Tapia, Aniel Jessica Leticia; Poot-Hernández, Augusto Cesar; Perez-Rueda, Ernesto; Rodríguez-Vázquez, Katya

    2016-06-01

    DNA methylation plays an important role in gene expression and virulence in some pathogenic bacteria. In this report, we describe DNA methyltransferases (MTases) present in human pathogenic bacteria and compared them with related species, which are not pathogenic or less pathogenic, based in comparative genomics. We performed a search in the KEGG database of the KEGG database orthology groups associated with adenine and cytosine DNA MTase activities (EC: 2.1.1.37, EC: 2.1.1.113 and EC: 2.1.1.72) in 37 human pathogenic species and 18 non/less pathogenic relatives and performed comparisons of the number of these MTases sequences according to their genome size, the DNA MTase type and with their non-less pathogenic relatives. We observed that Helicobacter pylori and Neisseria spp. presented the highest number of MTases while ten different species did not present a predicted DNA MTase. We also detected a significant increase of adenine MTases over cytosine MTases (2.19 vs. 1.06, respectively, p < 0.001). Adenine MTases were the only MTases associated with restriction modification systems and DNA MTases associated with type I restriction modification systems were more numerous than those associated with type III restriction modification systems (0.84 vs. 0.17, p < 0.001); additionally, there was no correlation with the genome size and the total number of DNA MTases, indicating that the number of DNA MTases is related to the particular evolution and lifestyle of specific species, regulating the expression of virulence genes in some pathogenic bacteria. PMID:27570304

  11. The Landscape of Realized Homologous Recombination in Pathogenic Bacteria

    PubMed Central

    Yahara, Koji; Didelot, Xavier; Jolley, Keith A.; Kobayashi, Ichizo; Maiden, Martin C.J.; Sheppard, Samuel K.; Falush, Daniel

    2016-01-01

    Recombination enhances the adaptive potential of organisms by allowing genetic variants to be tested on multiple genomic backgrounds. Its distribution in the genome can provide insight into the evolutionary forces that underlie traits, such as the emergence of pathogenicity. Here, we examined landscapes of realized homologous recombination of 500 genomes from ten bacterial species and found all species have “hot” regions with elevated rates relative to the genome average. We examined the size, gene content, and chromosomal features associated with these regions and the correlations between closely related species. The recombination landscape is variable and evolves rapidly. For example in Salmonella, only short regions of around 1 kb in length are hot whereas in the closely related species Escherichia coli, some hot regions exceed 100 kb, spanning many genes. Only Streptococcus pyogenes shows evidence for the positive correlation between GC content and recombination that has been reported for several eukaryotes. Genes with function related to the cell surface/membrane are often found in recombination hot regions but E. coli is the only species where genes annotated as “virulence associated” are consistently hotter. There is also evidence that some genes with “housekeeping” functions tend to be overrepresented in cold regions. For example, ribosomal proteins showed low recombination in all of the species. Among specific genes, transferrin-binding proteins are recombination hot in all three of the species in which they were found, and are subject to interspecies recombination. PMID:26516092

  12. [Prevention of bacterial risk: pathogen inactivation/detection of bacteria].

    PubMed

    Morel, P; Naegelen, C; Deschaseaux, M; Bardiaux, L

    2013-05-01

    Bacterial contamination of blood products remains the most important infectious risk of blood transfusion in 2013. Platelet concentrates (PC) are in cause in the majority of the transfusion reaction due to bacterial contaminations. A lot of prevention methods have been developed over the last 10 years (pre-donation interview, skin decontamination, diversion of the first 30 mL of the donation, leuko-reduction...), they have focused on limiting the contamination of the donations and prevent the bacterial growth in donations and/or in the blood products. These measures were effective and led to significantly reducing the risk of adverse effects associated with bacterial growth. However, every year there are about six accidents (with a high level of imputability) and one death. The reduction of the bacterial risk remains a priority for the French Blood Establishment (EFS). The procedure for skin disinfection is going to be improved in order to further strengthen this crucial step to avoid the contamination of donation. Methods of pathogen inactivation applied to plasma and PC are available in France and their effectiveness is demonstrated on the bacterial risk. Methods for bacterial detection of PC are used in many countries now. Automated culture is the most common. Alternatives are now available in the form of rapid tests able to analyze the PC just before the delivery and avoid false negatives observed with automated culture. Assessments are under way to confirm these benefits in 2013. PMID:23622837

  13. Muc2 Protects against Lethal Infectious Colitis by Disassociating Pathogenic and Commensal Bacteria from the Colonic Mucosa

    PubMed Central

    Bergstrom, Kirk S. B.; Kissoon-Singh, Vanessa; Gibson, Deanna L.; Ma, Caixia; Montero, Marinieve; Sham, Ho Pan; Ryz, Natasha; Huang, Tina; Velcich, Anna; Finlay, B. Brett; Chadee, Kris; Vallance, Bruce A.

    2010-01-01

    Despite recent advances in our understanding of the pathogenesis of attaching and effacing (A/E) Escherichia coli infections, the mechanisms by which the host defends against these microbes are unclear. The goal of this study was to determine the role of goblet cell-derived Muc2, the major intestinal secretory mucin and primary component of the mucus layer, in host protection against A/E pathogens. To assess the role of Muc2 during A/E bacterial infections, we inoculated Muc2 deficient (Muc2−/−) mice with Citrobacter rodentium, a murine A/E pathogen related to diarrheagenic A/E E. coli. Unlike wildtype (WT) mice, infected Muc2−/− mice exhibited rapid weight loss and suffered up to 90% mortality. Stool plating demonstrated 10–100 fold greater C. rodentium burdens in Muc2−/− vs. WT mice, most of which were found to be loosely adherent to the colonic mucosa. Histology of Muc2−/− mice revealed ulceration in the colon amid focal bacterial microcolonies. Metabolic labeling of secreted mucins in the large intestine demonstrated that mucin secretion was markedly increased in WT mice during infection compared to uninfected controls, suggesting that the host uses increased mucin release to flush pathogens from the mucosal surface. Muc2 also impacted host-commensal interactions during infection, as FISH analysis revealed C. rodentium microcolonies contained numerous commensal microbes, which was not observed in WT mice. Orally administered FITC-Dextran and FISH staining showed significantly worsened intestinal barrier disruption in Muc2−/− vs. WT mice, with overt pathogen and commensal translocation into the Muc2−/− colonic mucosa. Interestingly, commensal depletion enhanced C. rodentium colonization of Muc2−/− mice, although colonic pathology was not significantly altered. In conclusion, Muc2 production is critical for host protection during A/E bacterial infections, by limiting overall pathogen and commensal numbers associated with the colonic

  14. Antimicrobial activity of tissue and associated bacteria from benthic sea anemone Stichodactyla haddoni against microbial pathogens.

    PubMed

    Williams, G Prakash; Babu, S; Ravikumar, S; Kathiresan, K; Prathap, S Arul; Chinnapparaj, S; Marian, M P; Alikhan, S Liakath

    2007-10-01

    Associated bacteria from Stichodactyla haddoni are found maximum in tentacle tissues than the body tissue. There are eight associated bacterial species viz., Alcaligenes sp, Corynebacterium sp, Aeromonas sp, Sporosarcina sp, Renibacterium sp, Camobacterium sp1, Camobacterium sp2 and Salinococcus sp were recorded. The culture extracts from the associated bacterial species showed sensitivity against human bacterial and fungalpathogens. However, the hexane tissue extract of sea anemone showed maximum sensitivity (24 mm dia.) against the fish bacterial pathogen Aeromonas hydrophila than the other chosen pathogens. Comparatively the tissue extracts showed promising antimicrobial sensitivity than the cell free extracts of associated bacteria, and hence, the tissue samples from the sea anemone Stichodactyla haddoni is recommended for further exploration of novel antimicrobial drugs than the associated bacteria. PMID:18405113

  15. Effect of applying bacterial inoculants containing different types of bacteria to corn silage on the performance of dairy cattle.

    PubMed

    Arriola, K G; Kim, S C; Staples, C R; Adesogan, A T

    2011-08-01

    This study examined the effect of applying different bacterial inoculants to corn silage at the time of ensiling on the performance of lactating dairy cows. Corn plants were harvested at 35% dry matter (DM), chopped, and ensiled in 2.4-m-wide bags after application of (1) no inoculant (CON); (2) Biotal Plus II (B2) containing Pediococcus pentosaceus and Propionibacteria freudenreichii; (3) Buchneri 40788 (BUC) containing Lactobacillus buchneri; or (4) Buchneri 500 (B500) containing Pediococcus pentosaceus and L. buchneri. All inoculants were supplied by Lallemand Animal Nutrition (Milwaukee, WI). Each of the 4 silages was included in separate total mixed rations consisting of 44% corn silage, 50% concentrate, and 6% alfalfa hay (DM basis). Fifty-two lactating Holstein cows were stratified according to milk production and parity and randomly assigned at 22 d in milk to the 4 dietary treatments. Cows were fed for ad libitum consumption and milked twice daily for 49 d. Dietary treatment did not affect intakes (kg/d) of DM (20.0), crude protein (CP; 3.7), neutral detergent fiber (NDF; 5.7), or acid detergent fiber (ADF; 3.6), or digestibility (%) of DM (73.9) or CP (72.4). However, NDF digestibility was lower in cows fed B2 compared with those fed other diets (45.3 vs. 53.0%). Consequently, cows fed B2 had lower digestible NDF intake (kg/d) than those fed other diets (2.5 vs. 3.0 kg/d). Dietary treatment did not affect milk yield (32.3 kg/d), efficiency of milk production (1.61), concentrations of milk fat (3.18%) and protein (2.79%), or yields of milk fat (1.03 kg/d) and protein (1.26 kg/d). Inoculant application to corn silage did not affect milk yield or feed intake of cows. PMID:21787933

  16. In vitro competitive adhesion and production of antagonistic compounds by lactic acid bacteria against fish pathogens.

    PubMed

    Balcázar, José Luis; Vendrell, Daniel; de Blas, Ignacio; Ruiz-Zarzuela, Imanol; Gironés, Olivia; Múzquiz, José Luis

    2007-06-21

    The present study describes the screening of five lactic acid bacteria (LAB) for use as probiotics based on their competitive adhesion and production of antagonistic substances against some fish pathogens. A reduction of adhesion of all pathogenic strains tested was obtained with three of the LAB strains (Lactococcus lactis subsp. lactis CLFP100, Lactococcus lactis subsp. cremoris CLFP102 and Lactobacillus curvatus CLFP150). With the exception of fish pathogens Flavobacterium psychrophilum and Renibacterium salmoninarum that were not inhibited by LAB strains, production of antagonistic compounds by all tested LAB was observed against at least one of the indicator strains. Based on mucus adhesion, competitive exclusion, and suppression of fish pathogen growth, the selected LAB strains can be considered for future challenge experiments in fish as a very promising alternative to the use of chemotherapeutic agents. PMID:17336468

  17. Protozoan Cysts Act as a Survival Niche and Protective Shelter for Foodborne Pathogenic Bacteria

    PubMed Central

    Lambrecht, Ellen; Baré, Julie; Chavatte, Natascha; Bert, Wim; Sabbe, Koen

    2015-01-01

    The production of cysts, an integral part of the life cycle of many free-living protozoa, allows these organisms to survive adverse environmental conditions. Given the prevalence of free-living protozoa in food-related environments, it is hypothesized that these organisms play an important yet currently underinvestigated role in the epidemiology of foodborne pathogenic bacteria. Intracystic bacterial survival is highly relevant, as this would allow bacteria to survive the stringent cleaning and disinfection measures applied in food-related environments. The present study shows that strains of widespread and important foodborne bacteria (Salmonella enterica, Escherichia coli, Yersinia enterocolitica, and Listeria monocytogenes) survive inside cysts of the ubiquitous amoeba Acanthamoeba castellanii, even when exposed to either antibiotic treatment (100 μg/ml gentamicin) or highly acidic conditions (pH 0.2) and resume active growth in broth media following excystment. Strain- and species-specific differences in survival periods were observed, with Salmonella enterica surviving up to 3 weeks inside amoebal cysts. Up to 53% of the cysts were infected with pathogenic bacteria, which were located in the cyst cytosol. Our study suggests that the role of free-living protozoa and especially their cysts in the persistence and epidemiology of foodborne bacterial pathogens in food-related environments may be much more important than hitherto assumed. PMID:26070667

  18. Protozoan Cysts Act as a Survival Niche and Protective Shelter for Foodborne Pathogenic Bacteria.

    PubMed

    Lambrecht, Ellen; Baré, Julie; Chavatte, Natascha; Bert, Wim; Sabbe, Koen; Houf, Kurt

    2015-08-15

    The production of cysts, an integral part of the life cycle of many free-living protozoa, allows these organisms to survive adverse environmental conditions. Given the prevalence of free-living protozoa in food-related environments, it is hypothesized that these organisms play an important yet currently underinvestigated role in the epidemiology of foodborne pathogenic bacteria. Intracystic bacterial survival is highly relevant, as this would allow bacteria to survive the stringent cleaning and disinfection measures applied in food-related environments. The present study shows that strains of widespread and important foodborne bacteria (Salmonella enterica, Escherichia coli, Yersinia enterocolitica, and Listeria monocytogenes) survive inside cysts of the ubiquitous amoeba Acanthamoeba castellanii, even when exposed to either antibiotic treatment (100 μg/ml gentamicin) or highly acidic conditions (pH 0.2) and resume active growth in broth media following excystment. Strain- and species-specific differences in survival periods were observed, with Salmonella enterica surviving up to 3 weeks inside amoebal cysts. Up to 53% of the cysts were infected with pathogenic bacteria, which were located in the cyst cytosol. Our study suggests that the role of free-living protozoa and especially their cysts in the persistence and epidemiology of foodborne bacterial pathogens in food-related environments may be much more important than hitherto assumed. PMID:26070667

  19. Application of oligonucleotide array technology for the rapid detection of pathogenic bacteria of foodborne infections.

    PubMed

    Hong, Bang-Xing; Jiang, Li-Fang; Hu, Yu-Shan; Fang, Dan-Yun; Guo, Hui-Yu

    2004-09-01

    A rapid and accurate method for detection for common pathogenic bacteria in foodborne infections was established by using oligonucleotide array technology. Nylon membrane was used as the array support. A mutation region of the 23S rRNA gene was selected as the discrimination target from 14 species (genera) of bacteria causing foodborne infections and two unrelated bacterial species. A pair of universal primers was designed for PCR amplification of the 23S rRNA gene. Twenty-one species (genera)-specific oligonucleotide detection probes were synthesized and spotted onto the nylon membranes. The 23S rRNA gene amplification products of 14 species of pathogenic bacteria were hybridized to the oligonucleotide array. Hybridization results were analyzed with digoxigenin-linked enzyme reaction. Results indicated that nine species of pathogenic bacteria (Escherichia coli, Campylobacter jejuni, Shigella dysenteriae, Vibrio cholerae, Vibrio parahaemolyticus, Proteus vulgaris, Bacillus cereus, Listeria monocytogenes and Clostridium botulinum) showed high sensitivity and specificity for the oligonucleotide array. Two other species (Salmonella enterica and Yersinia enterocolitica) gave weak cross-reaction with E. coli, but the reaction did not affect their detection. After redesigning the probes, positive hybridization results were obtained with Staphylococcus aureus, but not with Clostridium perfringens and Streptococcus pyogenes. The oligonucleotide array can also be applied to samples collected in clinical settings of foodborne infections. The superiority of oligonucleotide array over other tests lies on its rapidity, accuracy and efficiency in the diagnosis, treatment and control of foodborne infections. PMID:15279944

  20. Bactericidal activities of GM flax seedcake extract on pathogenic bacteria clinical strains

    PubMed Central

    2014-01-01

    Background The antibiotic resistance of pathogenic microorganisms is a worldwide problem. Each year several million people across the world acquire infections with bacteria that are antibiotic-resistant, which is costly in terms of human health. New antibiotics are extremely needed to overcome the current resistance problem. Results Transgenic flax plants overproducing compounds from phenylpropanoid pathway accumulate phenolic derivatives of potential antioxidative, and thus, antimicrobial activity. Alkali hydrolyzed seedcake extract containing coumaric acid, ferulic acid, caffeic acid, and lignan in high quantities was used as an assayed against pathogenic bacteria (commonly used model organisms and clinical strains). It was shown that the extract components had antibacterial activity, which might be useful as a prophylactic against bacterial infection. Bacteria topoisomerase II (gyrase) inhibition and genomic DNA disintegration are suggested to be the main reason for rendering antibacterial action. Conclusions The data obtained strongly suggest that the seedcake extract preparation is a suitable candidate for antimicrobial action with a broad spectrum and partial selectivity. Such preparation can be applied in cases where there is a risk of multibacterial infection and excellent answer on global increase in multidrug resistance in pathogenic bacteria. PMID:25073883

  1. Comparison of the disinfection efficacy of chlorine-based products for inactivation of viral indicators and pathogenic bacteria in produce wash water.

    PubMed

    Chaidez, Cristobal; Moreno, Maria; Rubio, Werner; Angulo, Miguel; Valdez, Benigno

    2003-09-01

    Outbreaks of pathogenic bacteria infections associated with the consumption of fresh produce has occurred with increased frequency in recent years. This study was undertaken to determine the efficacy of three commonly used disinfectants in packing-houses of Culiacan, Mexico (sodium hypochlorite [NaOCl], trichlor-s-triazinetrione [TST] and thrichlormelamine [TCM]) for inactivation of viral indicators and pathogenic bacteria inoculated onto produce wash water. Each microbial challenge consisted of 2 L of water containing approximately 8 log10 bacterial CFU ml(-1), and 8 log10 viral PFU ml(-1) treated with 100 and 300 mg l(-1) of total chlorine with modified turbidity. Water samples were taken after 2 min of contact with chlorine-based products and assayed for the particular microorganisms. TST and NaOCl were found to effectively reduce for bacterial pathogens and viral indicators 8 log10 and 7 log10, respectively (alpha=0.05). The highest inactivation rate was observed when the turbidity was low and the disinfectant was applied at 300 mg l(-1). TCM did not show effective results when compared with the TST and NaOCl (P<0.05). These findings suggest that turbidity created by the organic and inorganic material present in the water tanks carried by the fresh produce may affect the efficacy of the chlorine-based products. PMID:12909560

  2. New Trends in Impedimetric Biosensors for the Detection of Foodborne Pathogenic Bacteria

    PubMed Central

    Wang, Yixian; Ye, Zunzhong; Ying, Yibin

    2012-01-01

    The development of a rapid, sensitive, specific method for the foodborne pathogenic bacteria detection is of great importance to ensure food safety and security. In recent years impedimetric biosensors which integrate biological recognition technology and impedance have gained widespread application in the field of bacteria detection. This paper presents an overview on the progress and application of impedimetric biosensors for detection of foodborne pathogenic bacteria, particularly the new trends in the past few years, including the new specific bio-recognition elements such as bacteriophage and lectin, the use of nanomaterials and microfluidics techniques. The applications of these new materials or techniques have provided unprecedented opportunities for the development of high-performance impedance bacteria biosensors. The significant developments of impedimetric biosensors for bacteria detection in the last five years have been reviewed according to the classification of with or without specific bio-recognition element. In addition, some microfluidics systems, which were used in the construction of impedimetric biosensors to improve analytical performance, are introduced in this review. PMID:22737018

  3. Simultaneous aptasensor for multiplex pathogenic bacteria detection based on multicolor upconversion nanoparticles labels.

    PubMed

    Wu, Shijia; Duan, Nuo; Shi, Zhao; Fang, Congcong; Wang, Zhouping

    2014-03-18

    A highly sensitive and specific multiplex method for the simultaneous detection of three pathogenic bacteria was fabricated using multicolor upconversion nanoparticles (UCNPs) as luminescence labels coupled with aptamers as the molecular recognition elements. Multicolor UCNPs were synthesized via doping with various rare-earth ions to obtain well-separated emission peaks. The aptamer sequences were selected using the systematic evolution of ligands by exponential enrichment (SELEX) strategy for Staphylococcus aureus, Vibrio parahemolyticus, and Salmonella typhimurium. When applied in this method, aptamers can be used for the specific recognition of the bacteria from complex mixtures, including those found in real food matrixes. Aptamers and multicolor UCNPs were employed to selectively capture and simultaneously quantify the three target bacteria on the basis of the independent peaks. Under optimal conditions, the correlation between the concentration of three bacteria and the luminescence signal was found to be linear from 50-10(6) cfu mL(-1). Improved by the magnetic separation and concentration effect of Fe3O4 magnetic nanoparticles, the limits of detection of the developed method were found to be 25, 10, and 15 cfu mL(-1) for S. aureus, V. parahemolyticus, and S. typhimurium, respectively. The capability of the bioassay in real food samples was also investigated, and the results were consistent with experimental results obtained from plate-counting methods. This proposed method for the detection of various pathogenic bacteria based on multicolor UCNPs has great potential in the application of food safety and multiplex nanosensors. PMID:24568625

  4. Non-coding RNA regulation in pathogenic bacteria located inside eukaryotic cells

    PubMed Central

    Ortega, Álvaro D.; Quereda, Juan J.; Pucciarelli, M. Graciela; García-del Portillo, Francisco

    2014-01-01

    Intracellular bacterial pathogens have evolved distinct lifestyles inside eukaryotic cells. Some pathogens coexist with the infected cell in an obligate intracellular state, whereas others transit between the extracellular and intracellular environment. Adaptation to these intracellular lifestyles is regulated in both space and time. Non-coding small RNAs (sRNAs) are post-transcriptional regulatory molecules that fine-tune important processes in bacterial physiology including cell envelope architecture, intermediate metabolism, bacterial communication, biofilm formation, and virulence. Recent studies have shown production of defined sRNA species by intracellular bacteria located inside eukaryotic cells. The molecules targeted by these sRNAs and their expression dynamics along the intracellular infection cycle remain, however, poorly characterized. Technical difficulties linked to the isolation of “intact” intracellular bacteria from infected host cells might explain why sRNA regulation in these specialized pathogens is still a largely unexplored field. Transition from the extracellular to the intracellular lifestyle provides an ideal scenario in which regulatory sRNAs are intended to participate; so much work must be done in this direction. This review focuses on sRNAs expressed by intracellular bacterial pathogens during the infection of eukaryotic cells, strategies used with these pathogens to identify sRNAs required for virulence, and the experimental technical challenges associated to this type of studies. We also discuss varied techniques for their potential application to study RNA regulation in intracellular bacterial infections. PMID:25429360

  5. Antibacterial peptide nisin: a potential role in the inhibition of oral pathogenic bacteria.

    PubMed

    Tong, Zhongchun; Ni, Longxing; Ling, Junqi

    2014-10-01

    Although the antimicrobial peptide nisin has been extensively studied in the food industry for decades, its application in the oral cavity remains to develop and evaluate its feasibility in treating oral common diseases. Nisin is an odorless, colorless, tasteless substance with low toxicity and with antibacterial activities against Gram-positive bacteria. These biologic properties may establish its use in promising products for oral diseases. This article summarizes the antibacterial efficiency of nisin against pathogenic bacteria related to dental caries and root canal infection and discusses the combination of nisin and common oral drugs. PMID:25088158

  6. Antimicrobial activity of different Finnish monofloral honeys against human pathogenic bacteria

    PubMed Central

    Huttunen, Sanna; Riihinen, Kaisu; Kauhanen, Jussi; Tikkanen-Kaukanen, Carina

    2013-01-01

    The antimicrobial activity and phenolic compounds of five Finnish honey products against important human pathogens Streptococcus pneumoniae, S. pyogenes, Staphylococcus aureus, and methicillin-resistant S. aureus were analyzed. Microbroth dilution method and HPLC-DAD were used in antimicrobial testing and phenolic compound determination, respectively. Significant antimicrobial activity (p < 0.01) against all the tested pathogens was found from willow herb (Epilobium angustifolium), heather (Calluna vulgaris), and buckwheat (Fagopyrum esculentum) honeys. This is the first report on antimicrobial activity of Finnish monofloral honeys against streptococcal and staphylococcal bacteria. To our knowledge this is also the first report on the antimicrobial effect of honey against S. pneumoniae. PMID:23278378

  7. Antimicrobial activity of different Finnish monofloral honeys against human pathogenic bacteria.

    PubMed

    Huttunen, Sanna; Riihinen, Kaisu; Kauhanen, Jussi; Tikkanen-Kaukanen, Carina

    2013-09-01

    The antimicrobial activity and phenolic compounds of five Finnish honey products against important human pathogens Streptococcus pneumoniae, S. pyogenes, Staphylococcus aureus, and methicillin-resistant S. aureus were analyzed. Microbroth dilution method and HPLC-DAD were used in antimicrobial testing and phenolic compound determination, respectively. Significant antimicrobial activity (p < 0.01) against all the tested pathogens was found from willow herb (Epilobium angustifolium), heather (Calluna vulgaris), and buckwheat (Fagopyrum esculentum) honeys. This is the first report on antimicrobial activity of Finnish monofloral honeys against streptococcal and staphylococcal bacteria. To our knowledge this is also the first report on the antimicrobial effect of honey against S. pneumoniae. PMID:23278378

  8. Pathology and Virus Distribution in the Lung and Lymphoid Tissues of Pigs Experimentally Inoculated with Three Distinct Type 1 PRRS Virus Isolates of Varying Pathogenicity.

    PubMed

    Morgan, S B; Frossard, J P; Pallares, F J; Gough, J; Stadejek, T; Graham, S P; Steinbach, F; Drew, T W; Salguero, F J

    2016-06-01

    Porcine reproductive and respiratory syndrome (PRRS) continues to be the most economically important disease of swine worldwide. The appearance of highly pathogenic PRRS virus (PRRSV) strains in Europe and Asia has raised concerns about this disease and initiated increased efforts to understand the pathogenesis. In this study, we have compared the pathology and the virus distribution in tissues of pigs experimentally inoculated with three different genotype 1 PRRSV isolates. Sixty 5-week-old pigs were inoculated intranasally with a) the Lelystad virus (LV), b) a field strain from the UK causing respiratory clinical signs (UK) or c) a highly pathogenic strain from Belarus (BE). Sixteen animals were mock-infected and used as controls. The animals were euthanized at 3, 7 and 35 days post-infection (dpi), and lung and lymphoid tissues collected for histopathological examination and PRRSV detection by immunohistochemistry (IHC). Histopathological lesions consisted of interstitial pneumonia with mononuclear cell infiltrates in the lungs, lymphoid depletion, apoptosis and follicular hyperplasia in the spleen, lymph nodes and tonsil and lymphoid depletion in the thymus. Porcine reproductive and respiratory syndrome virus was detected mainly in monocytes-macrophages. BE-infected animals showed the highest pathological scores and the highest presence of virus at 3 and 7 dpi, followed by the UK field strain and then LV. Moderate lesions were observed at 35 dpi with lesser detection of PRRSV by IHC in each infected group. The highly pathogenic BE strain induced more severe pathology in both lungs and lymphoid organs of pigs compared with the classic field isolate and the prototype LV. The increased severity of pathology was in correlation with the presence of a higher number of PRRSV-infected cells in the tissues. PMID:25382098

  9. Rapid and High-Throughput Detection of Highly Pathogenic Bacteria by Ibis PLEX-ID Technology

    PubMed Central

    Jacob, Daniela; Sauer, Uschi; Housley, Roberta; Washington, Cicely; Sannes-Lowery, Kristin; Ecker, David J.; Sampath, Rangarajan; Grunow, Roland

    2012-01-01

    In this manuscript, we describe the identification of highly pathogenic bacteria using an assay coupling biothreat group-specific PCR with electrospray ionization mass spectrometry (PCR/ESI-MS) run on an Ibis PLEX-ID high-throughput platform. The biothreat cluster assay identifies most of the potential bioterrorism-relevant microorganisms including Bacillus anthracis, Francisella tularensis, Yersinia pestis, Burkholderia mallei and pseudomallei, Brucella species, and Coxiella burnetii. DNA from 45 different reference materials with different formulations and different concentrations were chosen and sent to a service screening laboratory that uses the PCR/ESI-MS platform to provide a microbial identification service. The standard reference materials were produced out of a repository built up in the framework of the EU funded project “Establishment of Quality Assurances for Detection of Highly Pathogenic Bacteria of Potential Bioterrorism Risk” (EQADeBa). All samples were correctly identified at least to the genus level. PMID:22768173

  10. Manufacturing a low-cost ceramic water filter and filter system for the elimination of common pathogenic bacteria

    NASA Astrophysics Data System (ADS)

    Simonis, J. J.; Basson, A. K.

    Africa is one of the most water-scarce continents in the world but it is the lack of potable water which results in diarrhoea being the leading cause of death amongst children under the age of five in Africa (696 million children under 5 years old in Africa contract diarrhoea resulting in 2000 deaths per day: WHO and UNICEF, 2009). Most potable water treatment methods use bulk water treatment not suitable or available to the majority of rural poor in Sub-Saharan Africa. One simple but effective way of making sure that water is of good quality is by purifying it by means of a household ceramic water filter. The making and supply of water filters suitable for the removal of suspended solids, pathogenic bacteria and other toxins from drinking water is therefore critical. A micro-porous ceramic water filter with micron-sized pores was developed using the traditional slip casting process. This locally produced filter has the advantage of making use of less raw materials, cost, labour, energy and expertise and being more effective and efficient than other low cost produced filters. The filter is fitted with a silicone tube inserted into a collapsible bag that acts as container and protection for the filter. Enhanced flow is obtained through this filter system. The product was tested using water inoculated with high concentrations of different bacterial cultures as well as with locally polluted stream water. The filter is highly effective (log10 > 4 with 99.99% reduction efficiency) in providing protection from bacteria and suspended solids found in natural water. With correct cleaning and basic maintenance this filter technology can effectively provide drinking water to rural families affected by polluted surface water sources. This is an African solution for the more than 340 million people in Africa without access to clean drinking water (WHO and UNICEF, 2008).

  11. The Mutualistic Side of Wolbachia-Isopod Interactions: Wolbachia Mediated Protection Against Pathogenic Intracellular Bacteria.

    PubMed

    Braquart-Varnier, Christine; Altinli, Mine; Pigeault, Romain; Chevalier, Frédéric D; Grève, Pierre; Bouchon, Didier; Sicard, Mathieu

    2015-01-01

    Wolbachia is a vertically transmitted endosymbiont whose radiative success is mainly related to various host reproductive manipulations that led to consider this symbiont as a conflictual reproductive parasite. However, lately, some Wolbachia have been shown to act as beneficial symbionts by protecting hosts against a broad range of parasites. Still, this protection has been mostly demonstrated in artificial Wolbachia-host associations between partners that did not co-evolved together. Here, we tested in two terrestrial isopod species Armadillidium vulgare and Porcellio dilatatus whether resident Wolbachia (native or non-native) could confer protection during infections with Listeria ivanovii and Salmonella typhimurium and also during a transinfection with a Wolbachia strain that kills the recipient host (i.e., wVulC in P. dilatatus). Survival analyses showed that (i) A. vulgare lines hosting their native Wolbachia (wVulC) always exhibited higher survival than asymbiotic ones when infected with pathogenic bacteria (ii) P. dilatatus lines hosting their native wDil Wolbachia strain survived the S. typhimurium infection better, while lines hosting non-native wCon Wolbachia strain survived the L. ivanovii and also the transinfection with wVulC from A. vulgare better. By studying L. ivanovii and S. typhimurium loads in the hemolymph of the different host-Wolbachia systems, we showed that (i) the difference in survival between lines after L. ivanovii infections were not linked to the difference between their pathogenic bacterial loads, and (ii) the difference in survival after S. typhimurium infections corresponds to lower loads of pathogenic bacteria. Overall, our results demonstrate a beneficial effect of Wolbachia on survival of terrestrial isopods when infected with pathogenic intracellular bacteria. This protective effect may rely on different mechanisms depending on the resident symbiont and the invasive bacteria interacting together within the hosts. PMID:26733946

  12. The Mutualistic Side of Wolbachia–Isopod Interactions: Wolbachia Mediated Protection Against Pathogenic Intracellular Bacteria

    PubMed Central

    Braquart-Varnier, Christine; Altinli, Mine; Pigeault, Romain; Chevalier, Frédéric D.; Grève, Pierre; Bouchon, Didier; Sicard, Mathieu

    2015-01-01

    Wolbachia is a vertically transmitted endosymbiont whose radiative success is mainly related to various host reproductive manipulations that led to consider this symbiont as a conflictual reproductive parasite. However, lately, some Wolbachia have been shown to act as beneficial symbionts by protecting hosts against a broad range of parasites. Still, this protection has been mostly demonstrated in artificial Wolbachia-host associations between partners that did not co-evolved together. Here, we tested in two terrestrial isopod species Armadillidium vulgare and Porcellio dilatatus whether resident Wolbachia (native or non-native) could confer protection during infections with Listeria ivanovii and Salmonella typhimurium and also during a transinfection with a Wolbachia strain that kills the recipient host (i.e., wVulC in P. dilatatus). Survival analyses showed that (i) A. vulgare lines hosting their native Wolbachia (wVulC) always exhibited higher survival than asymbiotic ones when infected with pathogenic bacteria (ii) P. dilatatus lines hosting their native wDil Wolbachia strain survived the S. typhimurium infection better, while lines hosting non-native wCon Wolbachia strain survived the L. ivanovii and also the transinfection with wVulC from A. vulgare better. By studying L. ivanovii and S. typhimurium loads in the hemolymph of the different host-Wolbachia systems, we showed that (i) the difference in survival between lines after L. ivanovii infections were not linked to the difference between their pathogenic bacterial loads, and (ii) the difference in survival after S. typhimurium infections corresponds to lower loads of pathogenic bacteria. Overall, our results demonstrate a beneficial effect of Wolbachia on survival of terrestrial isopods when infected with pathogenic intracellular bacteria. This protective effect may rely on different mechanisms depending on the resident symbiont and the invasive bacteria interacting together within the hosts. PMID:26733946

  13. Rapid detection of pathogenic bacteria by volatile organic compound (VOC) analysis

    NASA Astrophysics Data System (ADS)

    Senecal, Andre G.; Magnone, Joshua; Yeomans, Walter; Powers, Edmund M.

    2002-02-01

    Developments in rapid detection technologies have made countless improvements over the years. However, because of the limited sample that these technologies can process in a single run, the chance of capturing and identifying a small amount of pathogens is difficult. The problem is further magnified by the natural random distribution of pathogens in foods. Methods to simplify pathogenic detection through the identification of bacteria specific VOC were studied. E. coli O157:H7 and Salmonella typhimurium were grown on selected agar medium to model protein, and carbohydrate based foods. Pathogenic and common spoilage bacteria (Pseudomonas and Morexella) were screened for unique VOC production. Bacteria were grown on agar slants in closed vials. Headspace sampling was performed at intervals up to 24 hours using Solid Phase Micro-Extraction (SPME) techniques followed by GC/MS analysis. Development of unique volatiles was followed to establish sensitivity of detection. E. coli produced VOC not found in either Trypticase Soy Yeast (TSY) agar blanks or spoilage organism samples were - indole, 1-decanol, and 2-nonanone. Salmonella specific VOC grown on TSY were 3-methyl-1-butanol, dimethyl sulfide, 2-undecanol, 2-pentadecanol and 1-octanol. Trials on potato dextrose agar (PDA) slants indicated VOC specific for E. coli and Salmonella when compared to PDA blanks and Pseudomonas samples. However, these VOC peaks were similar for both pathogens. Morexella did not grow on PDA slants. Work will continue with model growth mediums at various temperatures, and mixed flora inoculums. As well as, VOC production based on the dynamics of bacterial growth.

  14. Elucidation of bacteria found in car interiors and strategies to reduce the presence of potential pathogens

    PubMed Central

    Stephenson, Rachel E.; Gutierrez, Daniel; Peters, Cindy; Nichols, Mark; Boles, Blaise R.

    2014-01-01

    The human microbiome is influenced by a number of factors, including environmental exposure to microbes. Because many humans spend a large amount of time in built environments, it can be expected that the microbial ecology of these environments will influence the human microbiome. In an attempt to further understand the microbial ecology of built environments, the microbiota of car interiors was analyzed using culture dependent and culture independent methods. While it was found that the number and type of bacteria varied widely among the cars and sites tested, Staphylococcus and Propionibacterium were nearly always the dominant genera found at the locations sampled. Because Staphylococcus is of particular concern to human health, the characteristics of this genus found in car interiors were investigated. Staphylococcus epidermidis, S. aureus, and S. warnerii were the most prevalent staphylococcal species found, and 22.6% of S. aureus strains isolated from shared community vehicles were resistant to methicillin. The reduction in the prevalence of pathogenic bacteria in cars by using silver-based antimicrobial surface coatings was also evaluated. Coatings containing 5% silver ion additives were applied to steering wheels, placed in cars for five months and were found to eliminate the presence of culturable pathogenic bacteria recovered from these sites relative to controls. Together, these results provide new insight into the microbiota found in an important built environment, the automobile, and potential strategies for controlling the presence of human pathogens. PMID:24564823

  15. The Use of Colorimetric Sensor Arrays to Discriminate between Pathogenic Bacteria

    PubMed Central

    Lonsdale, Claire L.; Taba, Brian; Queralto, Nuria; Lukaszewski, Roman A.; Martino, Raymond A.; Rhodes, Paul A.; Lim, Sung H.

    2013-01-01

    A colorimetric sensor array is a high-dimensional chemical sensor that is cheap, compact, disposable, robust, and easy to operate, making it a good candidate technology to detect pathogenic bacteria, especially potential bioterrorism agents like Yersinia pestis and Bacillus anthracis which feature on the Center for Disease Control and Prevention’s list of potential biothreats. Here, a colorimetric sensor array was used to continuously monitor the volatile metabolites released by bacteria in solid media culture in an Advisory Committee on Dangerous Pathogen Containment Level 3 laboratory. At inoculum concentrations as low as 8 colony-forming units per plate, 4 different bacterial species were identified with 100% accuracy using logistic regression to classify the kinetic profile of sensor responses to culture headspace gas. The sensor array was able to further discriminate between different strains of the same species, including 5 strains of Yersinia pestis and Bacillus anthracis. These preliminary results suggest that disposable colorimetric sensor arrays can be an effective, low-cost tool to identify pathogenic bacteria. PMID:23671629

  16. Long-term social dynamics drive loss of function in pathogenic bacteria.

    PubMed

    Andersen, Sandra Breum; Marvig, Rasmus Lykke; Molin, Søren; Krogh Johansen, Helle; Griffin, Ashleigh S

    2015-08-25

    Laboratory experiments show that social interactions between bacterial cells can drive evolutionary change at the population level, but significant challenges limit attempts to assess the relevance of these findings to natural populations, where selection pressures are unknown. We have increasingly sophisticated methods for monitoring phenotypic and genotypic dynamics in bacteria causing infectious disease, but in contrast, we lack evidence-based adaptive explanations for those changes. Evolutionary change during infection is often interpreted as host adaptation, but this assumption neglects to consider social dynamics shown to drive evolutionary change in vitro. We provide evidence to show that long-term behavioral dynamics observed in a pathogen are driven by selection to outcompete neighboring conspecific cells through social interactions. We find that Pseudomonas aeruginosa bacteria, causing lung infections in patients with cystic fibrosis, lose cooperative iron acquisition by siderophore production during infection. This loss could be caused by changes in iron availability in the lung, but surprisingly, we find that cells retain the ability to take up siderophores produced by conspecifics, even after they have lost the ability to synthesize siderophores. Only when cooperative producers are lost from the population is the receptor for uptake lost. This finding highlights the potential pitfalls of interpreting loss of function in pathogenic bacterial populations as evidence for trait redundancy in the host environment. More generally, we provide an example of how sequence analysis can be used to generate testable hypotheses about selection driving long-term phenotypic changes of pathogenic bacteria in situ. PMID:26240352

  17. In-situ detection of multiple pathogenic bacteria on food surfaces

    NASA Astrophysics Data System (ADS)

    Chai, Yating; Horikawa, Shin; Hu, Jiajia; Chen, I.-Hsuan; Hu, Jing; Barbaree, James M.; Chin, Bryan A.

    2015-05-01

    Real-time in-situ detection of pathogenic bacteria on fresh food surfaces was accomplished with phage-based magnetoelastic (ME) biosensors. The ME biosensor is constructed of a small rectangular strip of ME material that is coated with a biomolecular recognition element (phage, antibodies or proteins, etc.) that is specific to the target pathogen. This mass-sensitive ME biosensor is wirelessly actuated into mechanical resonance by an externally applied time-varying magnetic field. When the biosensor binds with target bacteria, the mass of the sensor increases, resulting in a decrease in the sensor's resonant frequency. In order to compensate for nonspecific binding, control biosensors without phage were used in this experiment. In previous research, the biosensors were measured one by one. However, the simultaneous measurement of multiple sensors was accomplished in this research, and promises to greatly shorten the analysis time for bacterial detection. Additionally, the use of multiple biosensors enables the possibility of simultaneous detection of different pathogenic bacteria. This paper presents results of experiments in which multiple phage-based ME biosensors were simultaneously monitored. The E2 phage and JRB7 phage from a landscape phage library served as the bio-recognition element that have the capability of binding specifically with Salmonella typhimurium and B. anthracis spores, respectively. Real-time in-situ detection of Salmonella typhimurium and B. anthracis spores on food surfaces are presented.

  18. Distribution and drug resistance of pathogenic bacteria isolated from cancer hospital in 2013

    PubMed Central

    Liu, Linjuan; Li, Qi; Zhang, Qingyun; Wang, Guohong; Xu, Guobin

    2014-01-01

    Objective To understand distribution and drug resistance of pathogenic bacteria from a specialized cancer hospital in 2013 in order to provide a basis for rational clinical antimicrobial agents. Methods Pathogenic bacteria identification and drug sensitivity tests were performed with a VITEK 2 compact automatic identification system and data were analyzed using WHONET5.6 software. Results Of the 1,378 strains tested, 980 were Gram-negative bacilli, accounting for 71.1%, in which Klebsiella pneumonia, Escherichia coli and Pseudomonas aeruginosa were the dominant strains. We found 328 Gram-positive coccus, accounting for 23.8%, in which the amount of Staphylococcus aureus was the highest. We identified 46 fungi, accounting for 4.1%. According to the departmental distribution within the hospital, the surgical departments isolated the major strains, accounting for 49.7%. According to disease types, lung cancer, intestinal cancer and esophagus cancer were the top three, accounting for 20.9%, 17.3% and 14.2%, respectively. No strains were resistant to imipenem, ertapenem or vancomycin. Conclusions Pathogenic bacteria isolated from the specialized cancer hospital have different resistance rates compared to commonly used antimicrobial agents; therefore antimicrobial agents to reduce the morbidity and mortality of infections should be used. PMID:25561768

  19. In vitro effects of food extracts on selected probiotic and pathogenic bacteria.

    PubMed

    Sutherland, Juliet; Miles, Michelle; Hedderley, Duncan; Li, Jessie; Devoy, Sarah; Sutton, Kevin; Lauren, Denis

    2009-12-01

    A panel of 148 extracts from 37 food products was prepared using organic and aqueous solvents and both neutral and acidic conditions. The panel of food products tested included fruits, vegetables, grains, herbs and spices, most of which are common in a normal European-style diet. The impact of these extracts on the growth of selected probiotic bacteria (Lactobacillus reuteri, Lactobacillus rhamnosus, Bifidobacteria lactis) and pathogenic bacteria (Escherichia coli 0157:H7 and Escherichia coli LF82) was assessed using a standard minimum inhibitory concentration method. The results showed that aqueous extractions of garlic and black peppercorns significantly enhanced the growth of one strain of probiotic bacteria (L. reuteri) whilst inhibiting both pathogenic strains of E. coli at a 1:50 dilution. Aqueous extracts of banana, apple and orange all enhanced the growth of the three probiotic strains significantly, and inhibited the pathogens to approximately 80% of the controls (not significant). Both aqueous and organic extractions of ginger significantly inhibited the growth of one or both E. coli strains, respectively (also at the 1:50 dilution). PMID:19919519

  20. Novel antibiotics targeting respiratory ATP synthesis in Gram-positive pathogenic bacteria.

    PubMed

    Balemans, Wendy; Vranckx, Luc; Lounis, Nacer; Pop, Ovidiu; Guillemont, Jérôme; Vergauwen, Karen; Mol, Selena; Gilissen, Ron; Motte, Magali; Lançois, David; De Bolle, Miguel; Bonroy, Kristien; Lill, Holger; Andries, Koen; Bald, Dirk; Koul, Anil

    2012-08-01

    Emergence of drug-resistant bacteria represents a high, unmet medical need, and discovery of new antibacterials acting on new bacterial targets is strongly needed. ATP synthase has been validated as an antibacterial target in Mycobacterium tuberculosis, where its activity can be specifically blocked by the diarylquinoline TMC207. However, potency of TMC207 is restricted to mycobacteria with little or no effect on the growth of other Gram-positive or Gram-negative bacteria. Here, we identify diarylquinolines with activity against key Gram-positive pathogens, significantly extending the antibacterial spectrum of the diarylquinoline class of drugs. These compounds inhibited growth of Staphylococcus aureus in planktonic state as well as in metabolically resting bacteria grown in a biofilm culture. Furthermore, time-kill experiments showed that the selected hits are rapidly bactericidal. Drug-resistant mutations were mapped to the ATP synthase enzyme, and biochemical analysis as well as drug-target interaction studies reveal ATP synthase as a target for these compounds. Moreover, knockdown of the ATP synthase expression strongly suppressed growth of S. aureus, revealing a crucial role of this target in bacterial growth and metabolism. Our data represent a proof of principle for using the diarylquinoline class of antibacterials in key Gram-positive pathogens. Our results suggest that broadening the antibacterial spectrum for this chemical class is possible without drifting off from the target. Development of the diarylquinolines class may represent a promising strategy for combating Gram-positive pathogens. PMID:22615276

  1. Long-term social dynamics drive loss of function in pathogenic bacteria

    PubMed Central

    Andersen, Sandra Breum; Marvig, Rasmus Lykke; Molin, Søren; Krogh Johansen, Helle; Griffin, Ashleigh S.

    2015-01-01

    Laboratory experiments show that social interactions between bacterial cells can drive evolutionary change at the population level, but significant challenges limit attempts to assess the relevance of these findings to natural populations, where selection pressures are unknown. We have increasingly sophisticated methods for monitoring phenotypic and genotypic dynamics in bacteria causing infectious disease, but in contrast, we lack evidence-based adaptive explanations for those changes. Evolutionary change during infection is often interpreted as host adaptation, but this assumption neglects to consider social dynamics shown to drive evolutionary change in vitro. We provide evidence to show that long-term behavioral dynamics observed in a pathogen are driven by selection to outcompete neighboring conspecific cells through social interactions. We find that Pseudomonas aeruginosa bacteria, causing lung infections in patients with cystic fibrosis, lose cooperative iron acquisition by siderophore production during infection. This loss could be caused by changes in iron availability in the lung, but surprisingly, we find that cells retain the ability to take up siderophores produced by conspecifics, even after they have lost the ability to synthesize siderophores. Only when cooperative producers are lost from the population is the receptor for uptake lost. This finding highlights the potential pitfalls of interpreting loss of function in pathogenic bacterial populations as evidence for trait redundancy in the host environment. More generally, we provide an example of how sequence analysis can be used to generate testable hypotheses about selection driving long-term phenotypic changes of pathogenic bacteria in situ. PMID:26240352

  2. Neighborhood diversity of potentially pathogenic bacteria in drinking water from the city of Maroua, Cameroon.

    PubMed

    Healy-Profitós, Jessica; Lee, Seungjun; Mouhaman, Arabi; Garabed, Rebecca; Moritz, Mark; Piperata, Barbara; Lee, Jiyoung

    2016-06-01

    This study examined the spatial variation of potential gastrointestinal pathogens within drinking water sources and home storage containers in four neighborhoods in Maroua, Cameroon. Samples were collected from source (n = 28) and home containers (n = 60) in each study neighborhood. Pathogen contamination was assessed using quantitative polymerase chain reaction, targeting Campylobacter spp., Shiga toxin producing Escherichia coli (virulence genes, stx1 and stx2), and Salmonella spp. Microbial source tracking (MST) targeted three different host-specific markers: HF183 (human), Rum2Bac (ruminant) and GFD (poultry) to identify contamination sources. Staphylococcus aureus and the tetracycline-resistance gene (tetQ) were assessed to measure human hand contact and presence of antibiotic-resistant bacteria. Pathogen/MST levels were compared statistically and spatially, and neighborhood variation was compared with previously collected demographic information. All the test fecal markers and pathogens (except Arcobacter) were detected in home and source samples. Two neighborhoods tested positive for most pathogens/MST while the others only tested positive for one or two. Spatial variation of pathogens/MST existed between sources, storage containers, and neighborhoods. Differing population density and ethno-economic characteristics could potentially explain variation. Future research should explore the influence of demographic and ethno-economic factors on water quality during microbial risk assessments in urban Africa. PMID:27280618

  3. Potential human pathogenic bacteria in a mixed urban watershed as revealed by pyrosequencing.

    PubMed

    Ibekwe, A Mark; Leddy, Menu; Murinda, Shelton E

    2013-01-01

    Current microbial source tracking (MST) methods for water depend on testing for fecal indicator bacterial counts or specific marker gene sequences to identify fecal contamination where potential human pathogenic bacteria could be present. In this study, we applied 454 high-throughput pyrosequencing to identify bacterial pathogen DNA sequences, including those not traditionally monitored by MST and correlated their abundances to specific sources of contamination such as urban runoff and agricultural runoff from concentrated animal feeding operations (CAFOs), recreation park area, waste-water treatment plants, and natural sites with little or no human activities. Samples for pyrosequencing were surface water, and sediment collected from 19 sites. A total of 12,959 16S rRNA gene sequences with average length of ≤400 bp were obtained, and were assigned to corresponding taxonomic ranks using ribosomal database project (RDP), Classifier and Greengenes databases. The percent of total potential pathogens were highest in urban runoff water (7.94%), agricultural runoff sediment (6.52%), and Prado Park sediment (6.00%), respectively. Although the numbers of DNA sequence tags from pyrosequencing were very high for the natural site, corresponding percent potential pathogens were very low (3.78-4.08%). Most of the potential pathogenic bacterial sequences identified were from three major phyla, namely, Proteobacteria, Bacteroidetes, and Firmicutes. The use of deep sequencing may provide improved and faster methods for the identification of pathogen sources in most watersheds so that better risk assessment methods may be developed to enhance public health. PMID:24278139

  4. Microbiologic characteristics of pathogenic bacteria from hospitalized trauma patients who survived Wenchuan earthquake.

    PubMed

    Zhang, B; Liu, Z; Lin, Z; Zhang, X; Fu, W

    2012-10-01

    The purpose of this study is to investigate the microbiological characterization of pathogenic bacteria isolated from trauma patients after Wenchuan earthquake in 2008. Most infections were identified in the patients over 60 years of age, with an incidence rate of 78.5%, and more infections in wound (43.3%) and respiratory tract (37.1%) sites were identified. A total of 97 non-duplicated clinical pathogens were isolated from 91 trauma patients. Of those pathogens, 62 (63.9%) were Gram-negative bacilli, 23 (23.7%) were Gram-positive cocci, 9 (9.3%) were fungi, and 3 (3.1%) were anaerobes, such as Clostridium perfringens. The distribution spectrum of pathogens isolated from trauma patients after earthquake was different to that from non-earthquake trauma patients in our hospital at the same time. The most prevalent pathogenic isolates were Escherichia coli (15.4%), Acinetobacter baumannii (14.4%), Staphylococcus aureus (12.3%), Burkholderia cepacia (11.3%), and Enterococcus spp. (9.3%). The drug susceptibility results showed that most of the Gram-negative bacilli, except for Pseudomonas aeruginosa and Burkholderia cepacia, were susceptible to imipenem, but resistant to the first- and the second-generation cephalosporins. Most of the Gram-positive cocci were susceptible to vancomycin, linezolid, and Synercid/dalfopristin. Characteristics of pathogenic bacterium isolated from trauma patients after earthquake have been demonstrated which play an important role in the appropriate treatment of infections. PMID:22910807

  5. Bronchointerstitial pneumonia in guinea pigs following inoculation with H5N1 high pathogenicity avian influenza virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The H5N1 high pathogenicity avian influenza (HPAI) viruses have caused widespread disease of poultry in Asia, Africa and the Middle East, and sporadic human infections. The guinea pig model has been used to study human H3N2 and H1N1 influenza viruses, but knowledge is lacking on H5N1 HPAI virus inf...

  6. Pathogenicity of three type 2 Porcine Reproductive and Respiratory Syndrome virus strains in experimentally inoculated pregnant gilts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mechanisms of reproductive failure resulting from infection with porcine reproductive and respiratory syndrome virus (PRRSv) are still poorly understood. The present study, a side-by-side evaluation of the pathogenicity of three type 2 PRRSv strains in a reproductive model, was used as a pilot study...

  7. Ultrarapid detection of pathogenic bacteria using a 3D immunomagnetic flow assay.

    PubMed

    Lee, Wonjae; Kwon, Donghoon; Chung, Boram; Jung, Gyoo Yeol; Au, Anthony; Folch, Albert; Jeon, Sangmin

    2014-07-01

    We developed a novel 3D immunomagnetic flow assay for the rapid detection of pathogenic bacteria in a large-volume food sample. Antibody-functionalized magnetic nanoparticle clusters (AbMNCs) were magnetically immobilized on the surfaces of a 3D-printed cylindrical microchannel. The injection of a Salmonella-spiked sample solution into the microchannel produced instant binding between the AbMNCs and the Salmonella bacteria due to their efficient collisions. Nearly perfect capture of the AbMNCs and AbMNCs-Salmonella complexes was achieved under a high flow rate by stacking permanent magnets with spacers inside the cylindrical separator to maximize the magnetic force. The concentration of the bacteria in solution was determined using ATP luminescence measurements. The detection limit was better than 10 cfu/mL, and the overall assay time, including the binding, rinsing, and detection steps for a 10 mL sample took less than 3 min. To our knowledge, the 3D immunomagnetic flow assay described here provides the fastest high-sensitivity, high-capacity method for the detection of pathogenic bacteria. PMID:24856003

  8. Ultrarapid Detection of Pathogenic Bacteria Using a 3D Immunomagnetic Flow Assay

    PubMed Central

    Lee, Wonjae; Kwon, Donghoon; Chung, Boram; Jung, Gyoo Yeol; Au, Anthony; Folch, Albert; Jeon, Sangmin

    2015-01-01

    We developed a novel 3D immunomagnetic flow assay for the rapid detection of pathogenic bacteria in a large-volume food sample. Antibody-functionalized magnetic nanoparticle clusters (AbMNCs) were magnetically immobilized on the surfaces of a 3D-printed cylindrical microchannel. The injection of a Salmonella-spiked sample solution into the microchannel produced instant binding between the AbMNCs and the Salmonella bacteria due to their efficient collisions. Nearly perfect capture of the AbMNCs and AbMNCs-Salmonella complexes was achieved under a high flow rate by stacking permanent magnets with spacers inside the cylindrical separator to maximize the magnetic force. The concentration of the bacteria in solution was determined using ATP luminescence measurements. The detection limit was better than 10 cfu/mL, and the overall assay time, including the binding, rinsing, and detection steps for a 10 mL sample took less than 3 min. To our knowledge, the 3D immunomagnetic flow assay described here provides the fastest high-sensitivity, high-capacity method for the detection of pathogenic bacteria. PMID:24856003

  9. Application of bacteriophages in post-harvest control of human pathogenic and food spoiling bacteria.

    PubMed

    Pérez Pulido, Rubén; Grande Burgos, Maria José; Gálvez, Antonio; Lucas López, Rosario

    2016-10-01

    Bacteriophages have attracted great attention for application in food biopreservation. Lytic bacteriophages specific for human pathogenic bacteria can be isolated from natural sources such as animal feces or industrial wastes where the target bacteria inhabit. Lytic bacteriophages have been tested in different food systems for inactivation of main food-borne pathogens including Listeria monocytogenes, Staphylococcus aureus, Escherichia coli O157:H7, Salmonella enterica, Shigella spp., Campylobacter jejuni and Cronobacter sakazkii, and also for control of spoilage bacteria. Application of lytic bacteriophages could selectively control host populations of concern without interfering with the remaining food microbiota. Bacteriophages could also be applied for inactivation of bacteria attached to food contact surfaces or grown as biofilms. Bacteriophages may receive a generally recognized as safe status based on their lack of toxicity and other detrimental effects to human health. Phage preparations specific for L. monocytogenes, E. coli O157:H7 and S. enterica serotypes have been commercialized and approved for application in foods or as part of surface decontamination protocols. Phage endolysins have a broader host specificity compared to lytic bacteriophages. Cloned endolysins could be used as natural preservatives, singly or in combination with other antimicrobials such as bacteriocins. PMID:26042353

  10. Location of Pathogenic Bacteria during Persistent Infections: Insights from an Analysis Using Game Theory

    PubMed Central

    Eswarappa, Sandeepa M.

    2009-01-01

    Bacterial persistent infections are responsible for a significant amount of the human morbidity and mortality. Unlike acute bacterial infections, it is very difficult to treat persistent bacterial infections (e.g. tuberculosis). Knowledge about the location of pathogenic bacteria during persistent infection will help to treat such conditions by designing novel drugs which can reach such locations. In this study, events of bacterial persistent infections were analyzed using game theory. A game was defined where the pathogen and the host are the two players with a conflict of interest. Criteria for the establishment of Nash equilibrium were calculated for this game. This theoretical model, which is very simple and heuristic, predicts that during persistent infections pathogenic bacteria stay in both intracellular and extracellular compartments of the host. The result of this study implies that a bacterium should be able to survive in both intracellular and extracellular compartments of the host in order to cause persistent infections. This explains why persistent infections are more often caused by intracellular pathogens like Mycobacterium and Salmonella. Moreover, this prediction is in consistence with the results of previous experimental studies. PMID:19401783

  11. [Selective detection of viable pathogenic bacteria in water using reverse transcription quantitative PCR].

    PubMed

    Lin, Yi-Wen; Li, Dan; Wu, Shu-Xu; He, Miao; Yang, Tian

    2012-11-01

    A reverse transcription q quantitative PCR (RT-qPCR) assay method was established, which can quantify the copy numbers of RNA in pathogenic bacteria of E. coli and Enterococcus faecium. The results showed that cDNA was generated with the RT-PCR reagents, target gene was quantified with the qPCR, the copy numbers of RNA were stable at about 1 copies x CFU(-1) for E. coli and 7.98 x 10(2) copies x CFU(-1) for Enterococcus faecium respectively during the stationary grow phase for the both indicator bacteria [E. coli (6-18 h) and Enterococcus faecium (10-38 h)]. The established RT-qPCR method can quantify the numbers of viable bacteria through detecting bacterial RNA targets. Through detecting the heat-treated E. coli and Enterococcus faecium by three methods (culture method, qPCR, RT-qPCR), we found that the qPCR and RT-qPCR can distinguish 1.43 lg copy non-viable E. coli and 2.5 lg copy non-viable Enterococcus faecium. These results indicated that the established methods could effectively distinguish viable bacteria from non-viable bacteria. Finally we used this method to evaluate the real effluents of the secondary sedimentation of wastewater treatment plant (WWTP), the results showed that the correlation coefficients (R2) between RT-qPCR and culture method were 0.930 (E. coli) and 0.948 (Enterococcus faecium), and this established RT-PCR method can rapidly detect viable pathogenic bacteria in genuine waters. PMID:23323443

  12. Effect of co-inoculations of native PGPR with nitrogen fixing bacteria on seedling traits in Prosopis cineraria.

    PubMed

    Singh, S K; Pancholy, Anjly; Jindal, S K; Pathak, Rakesh

    2014-09-01

    Prosopis cineraria significantly contribute to sand dune stabilization, soil fertility rejuvenation and is an integral component of agro-forestry systems in arid regions of India. Effect of different rhizobacterial seed treatments on seed germination and seedling traits in two genotypes of P. cineraria (HPY-1) and (FG-1) were tested. Observations on seed germination (%) and seedling traits viz., root length (cm), shoot length (cm), seedling weight (g) and seedling length of different treatments were recorded. Whereas, germination index (GI), seedling vigour index (SVI) and root/shoot length ratio were derived from the observed data. The scarification treatment with sulphuric acid for 10 minutes substantially enhanced germination from < 20% to 80-82% in control treatments. Treatments with co-inoculations of Bacillus licheniformis and Sinorhizobium kostiense or S. saheli supported the maximum seed germination and seedling growth and vigour. The maximum germination per cent (92.5%), seedling length (10.94 cm), seedling vigour index (10.12) and germination index (7.97) were recorded with treatment (V2T6) wherein seeds of high pod yielding genotype were co-inoculated with Bacillus licheniformis and S. kostiense. The higher positive correlations of seedling length v/s shoot length followed by SVI v/s seedling length, SVI v/s root length and seedling length v/s root length is a fair indicative of inter dependency of these characteristics. Higher R2 values of root length v/s shoot length followed by that of SVI v/s GI indicates that a regression line fits the data well and future outcomes of observed seedling traits are likely to be predicted by the model. PMID:25204069

  13. Fluorescence in situ hybridization investigation of potentially pathogenic bacteria involved in neonatal porcine diarrhea

    PubMed Central

    2014-01-01

    Background Neonatal diarrhea is a multifactorial condition commonly present on pig farms and leads to economic losses due to increased morbidity and mortality of piglets. Immature immune system and lack of fully established microbiota at birth predispose neonatal piglets to infection with enteric pathogens. The microorganisms that for decades have been associated with enteritis and diarrhea in suckling piglets are: rotavirus A, coronavirus, enterotoxigenic Escherichia coli (ETEC), Clostridium perfringens type C, Cryptosporidium spp., Giardia spp., Cystoisospora suis and Strongyloides ransomi. However, in recent years, the pig industry has experienced an increased number of neonatal diarrhea cases in which the above mentioned pathogens are no longer detected. Potentially pathogenic bacteria have recently received focus in the research on the possible etiology of neonatal diarrhea not caused by common pathogens. The primary aim of this study was to investigate the role of E. coli, Enterococcus spp., C. perfringens and C. difficile in the pathogenesis of neonatal porcine diarrhea with no established casual agents. Fluorescence in situ hybridization with oligonucleotide probes was applied on the fixed intestinal tissue samples from 51 diarrheic and 50 non-diarrheic piglets collected from four Danish farms during outbreaks of neonatal diarrhea not caused by well-known enteric pathogens. Furthermore, an association between the presence of these bacteria and histological lesions was evaluated. Results The prevalence of fluorescence signals specific for E. coli, C. perfringens and C. difficile was similar in both groups of piglets. However, Enterococcus spp. was primarily detected in the diarrheic piglets. Furthermore, adherent bacteria were detected in 37 % diarrheic and 14 % non-diarrheic piglets. These bacteria were identified as E. coli and Enterococcus spp. and their presence in the intestinal mucosa was associated with histopathological changes. Conclusions The

  14. Protective immunity against H7N3 highly pathogenic avian influenza induced following inoculation of chickens with H7 low pathogenic avian influenza virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In the poultry industry, live virus vaccines are used to induce immunity against numerous respiratory pathogens. These are typically lower virulent forms of virus which are limited in replication and pathology, but induce mucosal, humoral, and cellular immunity. Because of the potential for revers...

  15. Outer-Inner Membrane Vesicles Naturally Secreted by Gram-Negative Pathogenic Bacteria

    PubMed Central

    Pérez-Cruz, Carla; Delgado, Lidia; López-Iglesias, Carmen; Mercade, Elena

    2015-01-01

    Outer-inner membrane vesicles (O-IMVs) were recently described as a new type of membrane vesicle secreted by the Antarctic bacterium Shewanella vesiculosa M7T. Their formation is characterized by the protrusion of both outer and plasma membranes, which pulls cytoplasmic components into the vesicles. To demonstrate that this is not a singular phenomenon in a bacterium occurring in an extreme environment, the identification of O-IMVs in pathogenic bacteria was undertaken. With this aim, a structural study by Transmission Electron Microscopy (TEM) and Cryo-transmission electron microscopy (Cryo-TEM) was carried out, confirming that O-IMVs are also secreted by Gram-negative pathogenic bacteria such as Neisseria gonorrhoeae, Pseudomonas aeruginosa PAO1 and Acinetobacter baumannii AB41, in which they represent between 0.23% and 1.2% of total vesicles produced. DNA and ATP, which are components solely found in the cell cytoplasm, were identified within membrane vesicles of these strains. The presence of DNA inside the O-IMVs produced by N. gonorrhoeae was confirmed by gold DNA immunolabeling with a specific monoclonal IgM against double-stranded DNA. A proteomic analysis of N. gonorrhoeae-derived membrane vesicles identified proteins from the cytoplasm and plasma membrane. This confirmation of O-IMV extends the hitherto uniform definition of membrane vesicles in Gram-negative bacteria and explains the presence of components in membrane vesicles such as DNA, cytoplasmic and inner membrane proteins, as well as ATP, detected for the first time. The production of these O-IMVs by pathogenic Gram-negative bacteria opens up new areas of study related to their involvement in lateral gene transfer, the transfer of cytoplasmic proteins, as well as the functionality and role of ATP detected in these new vesicles. PMID:25581302

  16. Method for detection of a few pathogenic bacteria and determination of live versus dead cells

    NASA Astrophysics Data System (ADS)

    Horikawa, Shin; Chen, I.-Hsuan; Du, Songtao; Liu, Yuzhe; Wikle, Howard C.; Suh, Sang-Jin; Barbaree, James M.; Chin, Bryan A.

    2016-05-01

    This paper presents a method for detection of a few pathogenic bacteria and determination of live versus dead cells. The method combines wireless phage-coated magnetoelastic (ME) biosensors and a surface-scanning dectector, enabling real-time monitoring of the growth of specific bacteria in a nutrient broth. The ME biosensor used in this investigation is composed of a strip-shaped ME resonator upon which an engineered bacteriophage is coated to capture a pathogen of interest. E2 phage with high binding affinity for Salmonella Typhimurium was used as a model study. The specificity of E2 phage has been reported to be 1 in 105 background bacteria. The phage-coated ME biosensors were first exposed to a low-concentration Salmonella suspension to capture roughly 300 cells on the sensor surface. When the growth of Salmonella in the broth occurs, the mass of the biosensor increases, which results in a decrease in the biosensor's resonant frequency. Monitoring of this mass- induced resonant frequency change allows for real-time detection of the presence of Salmonella. Detection of a few bacteria is also possible by growing them to a sufficient number. The surface-scanning detector was used to measure resonant frequency changes of 25 biosensors sequentially in an automated manner as a function of time. This methodology offers direct, real-time detection, quantification, and viability determination of specific bacteria. The rate of the sensor's resonant frequency change was found to be largely dependent on the number of initially bound cells and the efficiency of cell growth.

  17. Temperature-dependent inhibition of opportunistic Vibrio pathogens by native coral commensal bacteria.

    PubMed

    Frydenborg, Beck R; Krediet, Cory J; Teplitski, Max; Ritchie, Kim B

    2014-02-01

    Bacteria living within the surface mucus layer of corals compete for nutrients and space. A number of stresses affect the outcome of this competition. The interactions between native microorganisms and opportunistic pathogens largely determine the coral holobiont's overall health and fitness. In this study, we tested the hypothesis that commensal bacteria isolated from the mucus layer of a healthy elkhorn coral, Acropora palmata, are capable of inhibition of opportunistic pathogens, Vibrio shiloi AK1 and Vibrio coralliilyticus. These vibrios are known to cause disease in corals and their virulence is temperature dependent. Elevated temperature (30 °C) increased the cell numbers of one commensal and both Vibrio pathogens in monocultures. We further tested the hypothesis that elevated temperature favors pathogenic organisms by simultaneously increasing the fitness of vibrios and decreasing the fitness of commensals by measuring growth of each species within a co-culture over the course of 1 week. In competition experiments between vibrios and commensals, the proportion of Vibrio spp. increased significantly under elevated temperature. We finished by investigating several temperature-dependent mechanisms that could influence co-culture differences via changes in competitive fitness. The ability of Vibrio spp. to utilize glycoproteins found in A. palmata mucus increased or remained stable when exposed to elevated temperature, while commensals' tended to decrease utilization. In both vibrios and commensals, protease activity increased at 30 °C, while chiA expression increased under elevated temperatures for Vibrio spp. These results provide insight into potential mechanisms through which elevated temperature may select for pathogenic bacterial dominance and lead to disease or a decrease in coral fitness. PMID:24370863

  18. Thermal inactivation of water-borne pathogenic and indicator bacteria at sub-boiling temperatures.

    PubMed

    Spinks, Anthony T; Dunstan, R H; Harrison, T; Coombes, P; Kuczera, G

    2006-03-01

    The use of harvested rainwater in domestic hot water systems can result in optimised environmental and economic benefits to urban water cycle management, however, the water quality and health risks of such a scenario have not been adequately investigated. Thermal inactivation analyses were carried out on eight species of non-spore-forming bacteria in a water medium at temperatures relevant to domestic hot water systems (55-65 degrees C), and susceptibilities to heat stress were compared using D-values. The D-value was defined as the time required to reduce a bacterial population by 90% or 1 log reduction. The results found that both tested strains of Enterococcus faecalis were the most heat resistant of the bacteria studied, followed by the pathogens Shigella sonnei biotype A and Escherichia coli O157:H7, and the non-pathogenic E. coli O3:H6. Pseudomonas aeruginosa was found to be less resistant to heat, while Salmonella typhimurium, Serratia marcescens, Klebsiella pneumoniae and Aeromonas hydrophila displayed minimal heat resistance capacities. At 65 degrees C, little thermal resistance was demonstrated by any species, with log reductions in concentration occurring within seconds. The results of this study suggested that the temperature range from 55 to 65 degrees C was critical for effective elimination of enteric/pathogenic bacterial components and supported the thesis that hot water systems should operate at a minimum of 60 degrees C. PMID:16524613

  19. A rifamycin inactivating phosphotransferase family shared by environmental and pathogenic bacteria

    PubMed Central

    Spanogiannopoulos, Peter; Waglechner, Nicholas; Koteva, Kalinka; Wright, Gerard D.

    2014-01-01

    Many environmental bacteria are multidrug-resistant and represent a reservoir of ancient antibiotic resistance determinants, which have been linked to genes found in pathogens. Exploring the environmental antibiotic resistome, therefore, reveals the diversity and evolution of antibiotic resistance and also provides insight into the vulnerability of clinically used antibiotics. In this study, we describe the identification of a highly conserved regulatory motif, the rifampin (RIF) -associated element (RAE), which is found upstream of genes encoding RIF-inactivating enzymes from a diverse collection of actinomycetes. Using gene expression assays, we confirmed that the RAE is involved in RIF-responsive regulation. By using the RAE as a probe for new RIF-associated genes in several actinomycete genomes, we identified a heretofore unknown RIF resistance gene, RIF phosphotransferase (rph). The RPH enzyme is a RIF-inactivating phosphotransferase and represents a new protein family in antibiotic resistance. RPH orthologs are widespread and found in RIF-sensitive bacteria, including Bacillus cereus and the pathogen Listeria monocytogenes. Heterologous expression and in vitro enzyme assays with purified RPHs from diverse bacterial genera show that these enzymes are capable of conferring high-level resistance to a variety of clinically used rifamycin antibiotics. This work identifies a new antibiotic resistance protein family and reinforces the fact that the study of resistance in environmental organisms can serve to identify resistance elements with relevance to pathogens. PMID:24778229

  20. Antagonistic Characteristics Against Food-borne Pathogenic Bacteria of Lactic Acid Bacteria and Bifidobacteria Isolated from Feces of Healthy Thai Infants

    PubMed Central

    Uraipan, Supansa; Hongpattarakere, Tipparat

    2015-01-01

    Background: Food-borne pathogens are among the most significant problems in maintaining the health of people. Many probiotics have been widely reported to alleviate and protect against gastrointestinal infections through antibacterial secretion. However, the majority of them cannot always play antagonistic roles under gut conditions. Probiotic bacteria of human origin must possess other protective mechanisms to survive, out-compete intestinal flora and to successfully establish in their new host at a significant level. Objectives: Probiotic characteristics of Lactic Acid Bacteria (LAB) and bifidobacteria isolated from the feces of Thai infants were primarily investigated in terms of gastric acid and bile resistances, antibacterial activity and mucin adhesion ability. Antagonistic interaction through secretion of antibacterial compounds and competitive exclusion against food-borne pathogens were also evaluated. Materials and Methods: Culturable LAB and bifidobacteria were isolated from feces of Thai infants. Their ability to withstand gastric acid and bile were then evaluated. Acid and bile salt tolerant LAB and bifidobacteria were identified. They were then further assessed according to their antagonistic interactions through antibacterial secretion, mucin adhesion and competitive mucin adhesion against various food-borne pathogenic bacteria. Results: Gastric acid and bile tolerant LAB and bifidobacteria isolated from healthy infant feces were identified and selected according to their antagonistic interaction against various food-borne pathogenic bacteria. These antagonistic probiotics included four strains of Lactobacillus rhamnosus, two strains of L. casei, five strains of L. plantarum, two strains of Bifidobacterium longum subsp. longum and three strains of B. bifidum. All strains of the selected LAB inhibited all pathogenic bacteria tested through antibacterial secretion, while bifidobacteria showed high level of competitive exclusion against the pathogenic

  1. Estimation of decay rates for fecal indicator bacteria and bacterial pathogens in agricultural field-applied manure

    EPA Science Inventory

    Field-applied manure is an important source of pathogenic exposure in surface water bodies for humans and ecological receptors. We analyzed the persistence and decay of fecal indicator bacteria and bacterial pathogens from three sources (cattle, poultry, swine) for agricultural f...

  2. Exploration of Simple Analytical Approaches for Rapid Detection of Pathogenic Bacteria

    SciTech Connect

    Salma Rahman

    2005-12-17

    Many of the current methods for pathogenic bacterial detection require long sample-preparation and analysis time, as well as complex instrumentation. This dissertation explores simple analytical approaches (e.g., flow cytometry and diffuse reflectance spectroscopy) that may be applied towards ideal requirements of a microbial detection system, through method and instrumentation development, and by the creation and characterization of immunosensing platforms. This dissertation is organized into six sections. In the general Introduction section a literature review on several of the key aspects of this work is presented. First, different approaches for detection of pathogenic bacteria will be reviewed, with a comparison of the relative strengths and weaknesses of each approach, A general overview regarding diffuse reflectance spectroscopy is then presented. Next, the structure and function of self-assembled monolayers (SAMs) formed from organosulfur molecules at gold and micrometer and sub-micrometer patterning of biomolecules using SAMs will be discussed. This section is followed by four research chapters, presented as separate manuscripts. Chapter 1 describes the efforts and challenges towards the creation of imunosensing platforms that exploit the flexibility and structural stability of SAMs of thiols at gold. 1H, 1H, 2H, 2H-perfluorodecyl-1-thiol SAM (PFDT) and dithio-bis(succinimidyl propionate)-(DSP)-derived SAMs were used to construct the platform. Chapter 2 describes the characterization of the PFDT- and DSP-derived SAMs, and the architectures formed when it is coupled to antibodies as well as target bacteria. These studies used infrared reflection spectroscopy (IRS), X-ray photoelectron spectroscopy (XPS), and electrochemical quartz crystal microbalance (EQCM), Chapter 3 presents a new sensitive, and portable diffuse reflection based technique for the rapid identification and quantification of pathogenic bacteria. Chapter 4 reports research efforts in the

  3. Use of mild irradiation doses to control pathogenic bacteria on meat trimmings for production of patties aiming at provoking minimal changes in quality attributes.

    PubMed

    Xavier, Ma de la Paz; Dauber, Cecilia; Mussio, Paula; Delgado, Enrique; Maquieira, Ana; Soria, Alejandra; Curuchet, Ana; Márquez, Rosa; Méndez, Carlos; López, Tomás

    2014-11-01

    The objectives of the present work were to assess the use of moderate doses of gamma irradiation (2 to 5 kGy) and to reduce the risk of pathogen presence without altering the quality attributes of bovine trimmings and of patties made of irradiated trimmings. Microbiological indicators (coliforms, Pseudomonas spp and mesophilic aerobic counts), physicochemical indicators (pH, color and tiobarbituric acid) and sensory changes were evaluated during storage. 5 kGy irradiation doses slightly increased off flavors in patties. Two pathogenic markers (Listeria monocytogenes and Escherichia coli O157:H7) were inoculated at high or low loads to trimming samples which were subsequently irradiated and lethality curves were obtained. Provided that using irradiation doses ≤2.5 kGy are used, reductions of 2 log CFU/g of L. monocytogenes and 5 log CFU/g of E. coli O157:H7 are expected. It seems reasonable to suppose that irradiation can be successfully employed to improve the safety of frozen trimmings when initial pathogenic bacteria burdens are not extremely high. PMID:25042241

  4. The Antibacterial Activity of Chitosan Products Blended with Monoterpenes and Their Biofilms against Plant Pathogenic Bacteria.

    PubMed

    Badawy, Mohamed E I; Rabea, Entsar I; Taktak, Nehad E M; El-Nouby, Mahmoud A M

    2016-01-01

    This study focuses on the biological activities of eleven chitosan products with a viscosity-average molecular weight ranging from 22 to 846 kDa in combination with the most active monoterpenes (geraniol and thymol), out of 10 tested, against four plant pathogenic bacteria, Agrobacterium tumefaciens, Erwinia carotovora, Corynebacterium fascians, and Pseudomonas solanacearum. The antibacterial activity was evaluated in vitro by the agar dilution technique as a minimum inhibitory concentration (MIC) that was found to be dependent on the type of the microorganism tested. The most active product of chitosan was used for biofilm production enriched with geraniol and thymol (0.1 and 0.5%) and the films were also evaluated against the tested bacteria. The biological bioactivities summarized here may provide novel insights into the functions of chitosan and some monoterpenes and potentially allow their use for food protection from microbial attack. PMID:27127676

  5. Rapid and Selective Detection of Pathogenic Bacteria in Bloodstream Infections with Aptamer-Based Recognition.

    PubMed

    Shen, Haijing; Wang, Jie; Liu, Haoyang; Li, Zhihao; Jiang, Fenglei; Wang, Fu-Bing; Yuan, Quan

    2016-08-01

    Sepsis and bacteremia are life-threatening clinical syndromes associated with significant patient morbidity and mortality. Rapid and sensitive detection of pathogenic bacteria is the key to improve patient survival rates. Herein, we have rationally constructed a simple aptamer-based capture platform to shorten the time needed for confirmation of bacterial bloodstream infection in clinical blood samples. This capture platform is made of a mesoporous TiO2-coated magnetic nanoparticle and is modified with target aptamer. It features excellent bacterial enrichment efficiency of about 80% even at low bacterial concentrations (10-2000 CFU mL(-1)). More importantly, the bacteria can be enriched within 2 h, and the time for bacterial identification is effectively shortened in comparison to the "gold standard" in clinical diagnosis of bloodstream infection. The aptamer-based capture platform may pave a way for the detection of biomarkers and find potential applications in disease diagnosis. PMID:27411775

  6. The Antibacterial Activity of Chitosan Products Blended with Monoterpenes and Their Biofilms against Plant Pathogenic Bacteria

    PubMed Central

    Badawy, Mohamed E. I.; Rabea, Entsar I.; Taktak, Nehad E. M.; El-Nouby, Mahmoud A. M.

    2016-01-01

    This study focuses on the biological activities of eleven chitosan products with a viscosity-average molecular weight ranging from 22 to 846 kDa in combination with the most active monoterpenes (geraniol and thymol), out of 10 tested, against four plant pathogenic bacteria, Agrobacterium tumefaciens, Erwinia carotovora, Corynebacterium fascians, and Pseudomonas solanacearum. The antibacterial activity was evaluated in vitro by the agar dilution technique as a minimum inhibitory concentration (MIC) that was found to be dependent on the type of the microorganism tested. The most active product of chitosan was used for biofilm production enriched with geraniol and thymol (0.1 and 0.5%) and the films were also evaluated against the tested bacteria. The biological bioactivities summarized here may provide novel insights into the functions of chitosan and some monoterpenes and potentially allow their use for food protection from microbial attack. PMID:27127676

  7. Living biointerfaces based on non-pathogenic bacteria to direct cell differentiation

    NASA Astrophysics Data System (ADS)

    Rodrigo-Navarro, Aleixandre; Rico, Patricia; Saadeddin, Anas; Garcia, Andres J.; Salmeron-Sanchez, Manuel

    2014-07-01

    Genetically modified Lactococcus lactis, non-pathogenic bacteria expressing the FNIII7-10 fibronectin fragment as a protein membrane have been used to create a living biointerface between synthetic materials and mammalian cells. This FNIII7-10 fragment comprises the RGD and PHSRN sequences of fibronectin to bind α5β1 integrins and triggers signalling for cell adhesion, spreading and differentiation. We used L. lactis strain to colonize material surfaces and produce stable biofilms presenting the FNIII7-10 fragment readily available to cells. Biofilm density is easily tunable and remains stable for several days. Murine C2C12 myoblasts seeded over mature biofilms undergo bipolar alignment and form differentiated myotubes, a process triggered by the FNIII7-10 fragment. This biointerface based on living bacteria can be further modified to express any desired biochemical signal, establishing a new paradigm in biomaterial surface functionalisation for biomedical applications.

  8. Potential Human Pathogenic Bacteria in a Mixed Urban Watershed as Revealed by Pyrosequencing

    PubMed Central

    Ibekwe, A. Mark; Leddy, Menu; Murinda, Shelton E.

    2013-01-01

    Current microbial source tracking (MST) methods for water depend on testing for fecal indicator bacterial counts or specific marker gene sequences to identify fecal contamination where potential human pathogenic bacteria could be present. In this study, we applied 454 high-throughput pyrosequencing to identify bacterial pathogen DNA sequences, including those not traditionally monitored by MST and correlated their abundances to specific sources of contamination such as urban runoff and agricultural runoff from concentrated animal feeding operations (CAFOs), recreation park area, waste-water treatment plants, and natural sites with little or no human activities. Samples for pyrosequencing were surface water, and sediment collected from 19 sites. A total of 12,959 16S rRNA gene sequences with average length of ≤400 bp were obtained, and were assigned to corresponding taxonomic ranks using ribosomal database project (RDP), Classifier and Greengenes databases. The percent of total potential pathogens were highest in urban runoff water (7.94%), agricultural runoff sediment (6.52%), and Prado Park sediment (6.00%), respectively. Although the numbers of DNA sequence tags from pyrosequencing were very high for the natural site, corresponding percent potential pathogens were very low (3.78–4.08%). Most of the potential pathogenic bacterial sequences identified were from three major phyla, namely, Proteobacteria, Bacteroidetes, and Firmicutes. The use of deep sequencing may provide improved and faster methods for the identification of pathogen sources in most watersheds so that better risk assessment methods may be developed to enhance public health. PMID:24278139

  9. Bacteria colonizing root nodules of wild legumes exhibit virulence-associated properties of mammalian pathogens.

    PubMed

    Muresu, Rosella; Maddau, Giuseppe; Delogu, Giuseppe; Cappuccinelli, Piero; Squartini, Andrea

    2010-02-01

    Bacteria not proficient in nitrogen fixing symbiosis were proven able to invade root nodules of three wild legumes of the genus Hedysarum in Algeria and to be multiplying in these in place of the natural rhizobium symbionts. The involved species featured taxa known as human pathogens including: Enterobacter cloacae, Enterobacter kobei, Escherichia vulneris, Pantoea agglomerans and Leclercia adecarboxylata. A direct screening of the phenotypic determinants of virulence using human cultured cells tested positive for the traits of cytotoxicity, vital stain exclusion and adhesion to epithelia. Antibiogram analyses revealed also a complex pattern of multiple antibiotic resistances. The data suggest that legume root nodules can be a site of survival and of active multiplication for populations of mammalian pathogens, which could thus alternate between the target animal and a number of neutral plant hosts. The worldwide distribution of as yet uninvestigated legumes raises the concern that these represent a general niche that could enhance the hazards posed by microorganisms of clinical nature. PMID:19916054

  10. Detection and Characterization of Cancer Cells and Pathogenic Bacteria Using Aptamer-Based Nano-Conjugates

    PubMed Central

    Gedi, Vinayakumar; Kim, Young-Pil

    2014-01-01

    Detection and characterization of cells using aptamers and aptamer-conjugated nanoprobes has evolved a great deal over the past few decades. This evolution has been driven by the easy selection of aptamers via in vitro cell-SELEX, permitting sensitive discrimination between target and normal cells, which includes pathogenic prokaryotic and cancerous eukaryotic cells. Additionally, when the aptamer-based strategies are used in conjunction with nanomaterials, there is the potential for cell targeting and therapeutic effects with improved specificity and sensitivity. Here we review recent advances in aptamer-based nano-conjugates and their applications for detecting cancer cells and pathogenic bacteria. The multidisciplinary research utilized in this field will play an increasingly significant role in clinical medicine and drug discovery. PMID:25268922

  11. Gluconacetobacter diazotrophicus Elicits a Sugarcane Defense Response Against a Pathogenic Bacteria Xanthomonas albilineans

    PubMed Central

    Vinagre, Fabiano; Estevez, Yandi; Bernal, Aydiloide; Perez, Juana; Cavalcanti, Janaina; Santana, Ignacio; Hemerly, Adriana S

    2006-01-01

    A new role for the plant growth-promoting nitrogen-fixing endophytic bacteria Gluconacetobacter diazotrophicus has been identified and characterized while it is involved in the sugarcane-Xanthomonas albilineans pathogenic interactions. Living G.diazotrophicus possess and/or produce elicitor molecules which activate the sugarcane defense response resulting in the plant resistance to X. albilineans, in this particular case controlling the pathogen transmission to emerging agamic shoots. A total of 47 differentially expressed transcript derived fragments (TDFs) were identified by cDNA-AFLP. Transcripts showed significant homologies to genes of the ethylene signaling pathway (26%), proteins regulates by auxins (9%), β-1,3 Glucanase proteins (6%) and ubiquitin genes (4%), all major signaling mechanisms. Results point toward a form of induction of systemic resistance in sugarcane-G. diazotrophicus interactions which protect the plant against X. albilineans attack. PMID:19516988

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

    PubMed

    Bierne, Hélène; Travier, Laetitia; Mahlakõiv, Tanel; Tailleux, Ludovic; Subtil, Agathe; Lebreton, Alice; Paliwal, Anupam; Gicquel, Brigitte; Staeheli, Peter; Lecuit, Marc; Cossart, Pascale

    2012-01-01

    Bacterial infections trigger the expression of type I and II interferon genes but little is known about their effect on type III interferon (IFN-λ) genes, whose products play important roles in epithelial innate immunity against viruses. Here, we studied the expression of IFN-λ genes in cultured human epithelial cells infected with different pathogenic bacteria and in the mouse placenta infected with Listeria monocytogenes. We first showed that in intestinal LoVo cells, induction of IFN-λ genes by L. monocytogenes required bacterial entry and increased further during the bacterial intracellular phase of infection. Other Gram-positive bacteria, Staphylococcus aureus, Staphylococcus epidermidis and Enterococcus faecalis, also induced IFN-λ genes when internalized by LoVo cells. In contrast, Gram-negative bacteria Salmonella enterica serovar Typhimurium, Shigella flexneri and Chlamydia trachomatis did not substantially induce IFN-λ. We also found that IFN-λ genes were up-regulated in A549 lung epithelial cells infected with Mycobacterium tuberculosis and in HepG2 hepatocytes and BeWo trophoblastic cells infected with L. monocytogenes. In a humanized mouse line permissive to fetoplacental listeriosis, IFN-λ2/λ3 mRNA levels were enhanced in placentas infected with L. monocytogenes. In addition, the feto-placental tissue was responsive to IFN-λ2. Together, these results suggest that IFN-λ may be an important modulator of the immune response to Gram-positive intracellular bacteria in epithelial tissues. PMID:22720036

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

    PubMed Central

    Dominici, Sabrina; Rinaldi, Laura; Cangiano, Alfonsina Mariarosaria; Brandi, Giorgio; Magnani, Mauro

    2016-01-01

    The infection of human macrophages by pathogenic bacteria induces different signaling pathways depending on the type of cellular receptors involved in the microorganism entry and on their mechanism(s) of survival and replication in the host cell. It was reported that Stat proteins play an important role in this process. In the present study, we investigate the changes in Stat-1 activation (phosphorylation in p-tyr701) after uptake of two Gram-positive (Listeria monocytogenes and Staphylococcus aureus) and two Gram-negative bacteria (Salmonella typhimurium and Legionella pneumophila) characterized by their varying abilities to enter, survive, and replicate in human macrophages. Comparing the results obtained with Gram-negative and Gram-positive bacteria, Stat-1 activation in macrophages does not seem to be related to LPS content. The p-tyr701Stat-1 expression levels were found to be independent of the internalized bacterial number and IFN-γ release. On the contrary, Jak/Stat-1 pathway activation only occurs when an active infection has been established in the host macrophage, and it is plausible that the differences in the expression levels of p-tyr701Stat-1 could be due to different survival mechanisms or to differences in bacteria life cycles within macrophages. PMID:27437406

  14. Anti-virulence potential of eugenyl acetate against pathogenic bacteria of medical importance.

    PubMed

    Musthafa, Khadar Syed; Voravuthikunchai, Supayang Piyawan

    2015-03-01

    Considering the role of virulence factors in bacterial pathogenicity, interfering with the virulence factor production could afford a novel way for the treatment of infections caused by pathogenic bacteria. In the present study, an effect of eugenyl acetate (EA), a well-known phytochemical from Syzygium aromaticum (clove bud) was assessed for its anti-virulence potential against both Gram-negative and Gram-positive pathogens. Eugenyl acetate at 150 µg/ml, significantly inhibited virulence factor production such as pyocyanin and pyoverdin by Pseudomonas aeruginosa ATCC 27853 up to 9.4 (P < 0.01) and 3.7 fold (P < 0.01), respectively. In addition, protease activity of P. aeruginosa was significantly reduced upon treatment with EA (P < 0.05). The test compound (150 µg/ml) lowered haemolytic activity of Staphylococcus aureus ATCC 29213 up to tenfold (P < 0.01). Furthermore, a decrease in staphyloxanthin pigment production was observed when S. aureus cells were treated with increasing concentrations of EA (37.5-150 µg/ml). The test compound at 75 µg/ml exhibited quorum sensing inhibitory potential in inhibiting violacein production by Chromobacterium violaceum DMST 21761 up to 27.7 fold (P < 0.01). Thus, results of the present work reveal the potential of EA as an alternative candidate to control pathogenicity of both Gram-negative and Gram-positive organisms. PMID:25613850

  15. Lactobacillus protects the integrity of intestinal epithelial barrier damaged by pathogenic bacteria

    PubMed Central

    Yu, Qinghua; Yuan, Lixia; Deng, Jun; Yang, Qian

    2015-01-01

    Pathogens invade intestinal mucosal barrier through phagocytosis of antigen presenting cells (dendritic cell, microfold cells), or through the invasion into the intestinal epithelial directly. Some pathogens could damage the cell junction between epithelial cells and use the paracellular pathway as an entrance to invade. Moreover, some Lactobacillus could inhibit the adhesion of the pathogens and protect the integrity of the cell junction and mucosal barrier. This research focused on the potential therapeutic effect of Lactobacillus fructosus (L. fructosus) C2 to attenuate ETEC K88 or S. typhimurium SL1344 induced changes to mucosal barrier. The results demonstrated that treatment of polarized Caco-2 cells with L. fructosus C2 reduced the permeation of dextran, and expression of IL-8, p-ERK, and p-JNK when cells were infected with pathogenic bacteria. The findings indicated that L. fructosus C2 exerted a protective effect against the damage to the integrity of Caco-2 cells by ETEC or S. typhimurium infection. PMID:25859435

  16. The Effects of Allium sativum Extracts on Biofilm Formation and Activities of Six Pathogenic Bacteria

    PubMed Central

    Mohsenipour, Zeinab; Hassanshahian, Mehdi

    2015-01-01

    Background: Garlic is considered a rich source of many compounds, which shows antimicrobial effects. The ability of microorganisms to adhere to both biotic and abiotic surfaces and to form biofilm is responsible for a number of diseases of chronic nature, demonstrating extremely high resistance to antibiotics. Bacterial biofilms are complex communities of sessile microorganisms, embedded in an extracellular matrix and irreversibly attached to various surfaces. Objectives: The present study evaluated the antimicrobial activity of Allium sativum extract against the biofilms of six pathogenic bacteria and their free-living forms. The clinical isolates in this study had not been studied in any other studies, especially in regard to biofilm disruption and inhibition of biofilm cell metabolic activity. Materials and Methods: Antimicrobial activities of A. sativum L. extracts (methanol and ethanol extracts) against planktonic forms of bacteria were determined using the disc diffusion method. The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) values were evaluated by a macrobroth dilution technique. The anti-biofilm effects were assessed by microtiter plate method. Results: The results showed that the A. sativum L. extract discs did not have any zone of inhibition for the tested bacteria. However, The MIC values of A. sativum L. extracts (0.078 - 2.5 mg/mL) confirmed the high ability of these extracts for inhibition of planktonic bacteria. A. sativum L. extracts were efficient to inhibit biofilm structures and the concentration of each extract had a direct relation with the inhibitory effect. Conclusions: Finally, it can be suggested that the extracts of this plant be applied as antimicrobial agents against these pathogens, particularly in biofilm forms. PMID:26464762

  17. A simple extraction procedure for efficient routine detection of pathogenic bacteria in plant material by polymerase chain reaction.

    PubMed

    Llop, P; Caruso, P; Cubero, J; Morente, C; López, M M

    1999-07-01

    A simple and rapid method for extracting DNA from plants based on the use of an extraction buffer and precipitation with isopropanol was assayed to see its usefulness in detecting pathogenic bacteria in plant material. The method was compared with a phenol-chloroform standard procedure obtaining higher sensitivity levels of detection. The protocol developed was efficient for detecting a Gram-positive bacterium, Clavibacter michiganensis subsp. sepedonicus and several Gram-negative pathogenic bacteria (Ralstonia solanacearum, Erwinia amylovora, Xanthomonas axonopodis pv. citri) with a sensitivity of 10(2)-10(3) cfu/ml in spiked samples. It was also efficient to specifically identify such bacteria in naturally infected plant material. This procedure is proposed as a routine tool for detection of plant pathogenic bacteria, as well as in environmental microbiology and biotechnology studies. PMID:10395461

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

    PubMed

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

    2016-07-01

    In this study, the beneficial prebiotic roles of Ecklonia cava (E. cava, EC) were evaluated on the growth of lactic acid bacteria (LAB) and pathogen bacteria and the mortality of pathogen-bacteria infected zebrafish model. The result showed that the original E. cava (EC) led to the highest growth effects on three LABs (Lactobacillus brevis, L. brevis; Lactobacillus pentosus, L. pentosus; Lactobacillus plantarum; L. plantarum) and it was dose-dependent manners. Also, EC, its Celluclast enzymatic (ECC) and 100% ethanol extracts (ECE) showed the anti-bacterial activities on the fish pathogenic bacteria such as (Edwardsiella tarda; E. tarda, Streptococcus iniae; S. iniae, and Vibrio harveyi; V. harveyi). Interestingly, EC induced the higher production of the secondary metabolites from L. plantarum in MRS medium. The secondary metabolites produced by EC significantly inhibited the growth of pathogen bacteria. In further in vivo study, the co-treatment of EC and L. plantarum improved the growth and mortality of E. tarda-infected zebrafish as regulating the expression of inflammatory molecules such as iNOS and COX2. Taken together, our present study suggests that the EC plays an important role as a potential prebiotic and has a protective effect against the infection caused by E. tarda injection in zebrafish. Also, our conclusion from this evidence is that EC can be used and applied as a useful prebiotic. PMID:27192145

  19. Developing Peptide Mimotopes of Capsular Polysaccharides and Lipopolysaccharides Protective Antigens of Pathogenic Burkholderia Bacteria.

    PubMed

    Guo, Pengfei; Zhang, Jing; Tsai, Shien; Li, Bingjie; Lo, Shyh-Ching

    2016-06-01

    Burkholderia pseudomallei (BP) and Burkholderia mallei (BM) are two species of pathogenic Burkholderia bacteria. Our laboratory previously identified four monoclonal antibodies (MAbs) that reacted against Burkholderia capsular polysaccharides (PS) and lipopolysaccharides (LPS) and effectively protected against a lethal dose of BP/BM infections in mice. In this study, we used phage display panning against three different phage peptide libraries to select phage clones specifically recognized by each of the four protective MAbs. After sequencing a total of 179 candidate phage clones, we examined in detail six selected phage clones carrying different peptide inserts for the specificity of binding by the respective target MAbs. Chemically synthesized peptides corresponding to those displayed by the six phage clones were conjugated to keyhole limpet hemocyanin carrier protein and tested for their binding specificity to the respective protective MAbs. The study revealed that four of the six peptides, all derived from the library displaying dodecapeptides, functioned well as "mimotopes" of Burkholderia PS and LPS as demonstrated by a high degree of specific competition against the binding of three protective MAbs to BP and BM. Our results suggest that the four selected peptide mimics corresponding to PS/LPS protective antigens of BP and BM could potentially be developed into peptide vaccines against pathogenic Burkholderia bacteria. PMID:27328059

  20. Detection methods for milk pathogenic bacteria by loop-mediated isothermal amplification.

    PubMed

    Yang, Wentao; Song, Xiaoning; Wang, Jingxin; Li, Zhen; Ji, Mingjiang; Li, Yufeng

    2014-12-01

    Milk is a common food, which is consumed all over the world. It is an important source of calcium. Meanwhile, it provides abundant protein, minerals and vitamins. However, pathogenic bacteria which exist in milk not only causes nutrition loss, but also produces toxins which may cause diarrhea, food poisoning, and even death. In order to control the microbial level of raw milk and eliminate the contamination of materials, this assay applied loop-mediated isothermal amplification to explore a new way to detect enterotoxigenic Escherichia coli (ETEC) in raw milk. The best reaction condition in detecting ETEC from raw milk was confirmed to be: 0.016 μM each of forward outer primer (primer F3) and backward outer primer (primer B3), 0.128 μM each of forward inner primer (primer FIP) and backward inner primer (primer BIP), 0.45 μM deoxy-ribonucleoside triphosphate (dNTPs), 2IU Bst DNA polymerase large fragment and template DNA were incubated at 63°C for 60 min. LAMP was proved to be specific, rapid and sensitive in detecting pathogenic bacteria which exist in milk. PMID:25641177

  1. Inexpensive and fast pathogenic bacteria screening using field-effect transistors.

    PubMed

    Formisano, Nello; Bhalla, Nikhil; Heeran, Mel; Reyes Martinez, Juana; Sarkar, Amrita; Laabei, Maisem; Jolly, Pawan; Bowen, Chris R; Taylor, John T; Flitsch, Sabine; Estrela, Pedro

    2016-11-15

    While pathogenic bacteria contribute to a large number of globally important diseases and infections, current clinical diagnosis is based on processes that often involve culturing which can be time-consuming. Therefore, innovative, simple, rapid and low-cost solutions to effectively reduce the burden of bacterial infections are urgently needed. Here we demonstrate a label-free sensor for fast bacterial detection based on metal-oxide-semiconductor field-effect transistors (MOSFETs). The electric charge of bacteria binding to the glycosylated gates of a MOSFET enables quantification in a straightforward manner. We show that the limit of quantitation is 1.9×10(5) CFU/mL with this simple device, which is more than 10,000-times lower than is achieved with electrochemical impedance spectroscopy (EIS) and matrix-assisted laser desorption ionisation time-of-flight mass spectrometry (MALDI-ToF) on the same modified surfaces. Moreover, the measurements are extremely fast and the sensor can be mass produced at trivial cost as a tool for initial screening of pathogens. PMID:27156019

  2. Environmental factors influencing Listeria monocytogenes survival and attachment on surfaces inoculated with droplets

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pathogenic microorganisms residing on food or food contact materials are important sources of food-borne microbial contamination. The objective of this study is to explore factors responsible for Listeria monocytogenes survival and colonization on surfaces when bacteria are inoculated from drying dr...

  3. Antimicrobial Property of Extracts of Indian Lichen against Human Pathogenic Bacteria

    PubMed Central

    Srivastava, Priya; Upreti, D. K.; Dhole, T. N.; Srivastava, Apurva K.; Nayak, Meghanand T.

    2013-01-01

    Context. Usnea ghattensis G. Awasthi (Usneaceae) endemic fruticose lichen found growing luxuriantly in Northern Western Ghats of India, it also contains Usnic acid as a major chemical and tested against some human pathogenic bacteria. Objective. To explore antimicrobial properties of Usnea ghattensis against some human pathogenic bacteria. Materials and Methods. The lichen was extracted in acetone, methanol, and ethanol. In vitro antimicrobial activity was tested initially by Kirby-Bauer technique of disc diffusion method and was confirmed by minimum inhibitory concentration using Broth microdilution method according to the NCCLS guidelines. Results. Ethanol extract was most effective against Bacillus cereus and Pseudomonas aeruginosa with a zone of inhibition 29.8 ± 0.6 mm and 12.3 ± 0.5 mm diameters at a concentration of 0.2 mg/mL. Acetone and methanol extract demonstrated almost similar activity against Staphylococcus aureus and the zone of inhibition was 24.6 ± 0.5 and 24.7 ± 0.4 mm. Only methanol extract was showing activity against Streptococcus faecalis with a 13.5 ± 0.8 mm zone. MIC value noted against Staphylococcus aureus and Streptococcus faecalis was 6.25 μg/mL and 25 μg/mL, whereas against Bacillus cereus and Pseudomonas aeruginosa, MIC calculated was 3.125 μg/mL and 200 μg/mL, respectively. Conclusion. The present study demonstrates the relatively higher activity of this lichen against not only gram (+) but significantly also against gram (−) bacteria. This indicates that this lichen might be a rich source of effective antimicrobial agents. PMID:24062769

  4. Antimicrobial Property of Extracts of Indian Lichen against Human Pathogenic Bacteria.

    PubMed

    Srivastava, Priya; Upreti, D K; Dhole, T N; Srivastava, Apurva K; Nayak, Meghanand T

    2013-01-01

    Context. Usnea ghattensis G. Awasthi (Usneaceae) endemic fruticose lichen found growing luxuriantly in Northern Western Ghats of India, it also contains Usnic acid as a major chemical and tested against some human pathogenic bacteria. Objective. To explore antimicrobial properties of Usnea ghattensis against some human pathogenic bacteria. Materials and Methods. The lichen was extracted in acetone, methanol, and ethanol. In vitro antimicrobial activity was tested initially by Kirby-Bauer technique of disc diffusion method and was confirmed by minimum inhibitory concentration using Broth microdilution method according to the NCCLS guidelines. Results. Ethanol extract was most effective against Bacillus cereus and Pseudomonas aeruginosa with a zone of inhibition 29.8 ± 0.6 mm and 12.3 ± 0.5 mm diameters at a concentration of 0.2 mg/mL. Acetone and methanol extract demonstrated almost similar activity against Staphylococcus aureus and the zone of inhibition was 24.6 ± 0.5 and 24.7 ± 0.4 mm. Only methanol extract was showing activity against Streptococcus faecalis with a 13.5 ± 0.8 mm zone. MIC value noted against Staphylococcus aureus and Streptococcus faecalis was 6.25  μ g/mL and 25  μ g/mL, whereas against Bacillus cereus and Pseudomonas aeruginosa, MIC calculated was 3.125  μ g/mL and 200  μ g/mL, respectively. Conclusion. The present study demonstrates the relatively higher activity of this lichen against not only gram (+) but significantly also against gram (-) bacteria. This indicates that this lichen might be a rich source of effective antimicrobial agents. PMID:24062769

  5. Antimicrobial activity of phenolics and glucosinolate hydrolysis products and their synergy with streptomycin against pathogenic bacteria.

    PubMed

    Saavedra, Maria J; Borges, Anabela; Dias, Carla; Aires, Alfredo; Bennett, Richard N; Rosa, Eduardo S; Simões, Manuel

    2010-05-01

    The purpose of the present study was to evaluate the in vitro antibacterial effects of different classes of important and common dietary phytochemicals (5 simple phenolics - tyrosol, gallic acid, caffeic acid, ferulic acid, and chlorogenic acid; chalcone - phloridzin; flavan-3-ol - (-) epicatechin; seco-iridoid - oleuropein glucoside; 3 glucosinolate hydrolysis products - allylisothiocyanate, benzylisothiocyanate and 2-phenylethylisothiocyanate) against Escherichia coli, Pseudomonas aeruginosa, Listeria monocytogenes and Staphylococcus aureus. Another objective of this study was to evaluate the effects of dual combinations of streptomycin with the different phytochemicals on antibacterial activity. A disc diffusion assay was used to evaluate the antibacterial activity of the phytochemicals and 3 standard antibiotics (ciprofloxacin, gentamicin and streptomycin) against the four bacteria. The antimicrobial activity of single compounds and dual combinations (streptomycin-phytochemicals) were quantitatively assessed by measuring the inhibitory halos. The results showed that all of the isothiocyanates had significant antimicrobial activities, while the phenolics were much less efficient. No antimicrobial activity was observed with phloridzin. In general P. aeruginosa was the most sensitive microorganism and L. monocytogenes the most resistant. The application of dual combinations demonstrated synergy between streptomycin and gallic acid, ferulic acid, chlorogenic acid, allylisothiocyanate and 2-phenylethylisothiocyanate against the Gram-negative bacteria. In conclusion, phytochemical products and more specifically the isothiocyanates were effective inhibitors of the in vitro growth of the Gram-negative and Gram-positive pathogenic bacteria. Moreover, they can act synergistically with less efficient antibiotics to control bacterial growth. PMID:20632977

  6. Channel formation by RTX-toxins of pathogenic bacteria: Basis of their biological activity.

    PubMed

    Benz, Roland

    2016-03-01

    The pore-forming cytolysins of the RTX-toxin (Repeats in ToXin) family are a relatively small fraction of a steadily increasing family of proteins that contain several functionally important glycine-rich and aspartate containing nonapeptide repeats. These cytolysins produced by a variety of Gram-negative bacteria form ion-permeable channels in erythrocytes and other eukaryotic cells. Hemolytic and cytolytic RTX-toxins represent pathogenicity factors of the toxin-producing bacteria and are very often important key factors in pathogenesis of the bacteria. Channel formation by RTX-toxins lead to the dissipation of ionic gradients and membrane potential across the cytoplasmic membrane of target cells, which results in cell death. Here we discuss channel formation and channel properties of some of the best known RTX-toxins, such as α-hemolysin (HlyA) of Escherichia coli and the uropathogenic EHEC strains, the adenylate cyclase toxin (ACT, CyaA) of Bordetella pertussis and the RTX-toxins (ApxI, ApxII and ApxIII) produced by different strains of Actinobacillus pleuropneumoniae. The channels formed by these RTX-toxins in lipid bilayers share some common properties such as cation selectivity and voltage-dependence. Furthermore the channels are transient and show frequent switching between different ion-conducting states. This article is part of a Special Issue entitled: Pore-Forming Toxins edited by Mauro Dalla Serra and Franco Gambale. PMID:26523409

  7. Colorimetric detection of pathogenic bacteria using platinum-coated magnetic nanoparticle clusters and magnetophoretic chromatography.

    PubMed

    Kwon, Donghoon; Lee, Sanghee; Ahn, Myung Mo; Kang, In Seok; Park, Ki-Hwan; Jeon, Sangmin

    2015-07-01

    A colorimetric method that uses platinum-coated magnetic nanoparticle clusters (Pt/MNCs) and magnetophoretic chromatography is developed to detect pathogenic bacteria. Half-fragments of monoclonal Escherichia coli O157:H7 (EC) antibodies were functionalized to Pt/MNCs and used to capture E. coli bacteria in milk. After magnetic separation of free Pt/MNCs and Pt/MNC-EC complexes from the milk, a precision pipette was used to imbibe the E. coli-containing solution, then a viscous polyethylene glycol solution. Due to difference in viscosities, the solutions separate into two liquid layers inside the pipette tip. The Pt/MNC-EC complexes were separated from the free Pt/MNCs by applying an external magnetic field, then added to a tetramethylbenzidine (TMB) solution. Catalytic oxidation of TMB by Pt produced color changes of the solution, which enabled identification of the presence of 10 cfu mL(-1) E. coli bacteria with the naked eye. The total assay time including separation, binding and detection was 30 min. PMID:26088777

  8. Rapid evolutionary adaptation to elevated salt concentrations in pathogenic freshwater bacteria Serratia marcescens.

    PubMed

    Ketola, Tarmo; Hiltunen, Teppo

    2014-10-01

    Rapid evolutionary adaptions to new and previously detrimental environmental conditions can increase the risk of invasion by novel pathogens. We tested this hypothesis with a 133-day-long evolutionary experiment studying the evolution of the pathogenic Serratia marcescens bacterium at salinity niche boundary and in fluctuating conditions. We found that S. marcescens evolved at harsh (80 g/L) and extreme (100 g/L) salt conditions had clearly improved salt tolerance than those evolved in the other three treatments (ancestral conditions, nonsaline conditions, and fluctuating salt conditions). Evolutionary theories suggest that fastest evolutionary changes could be observed in intermediate selection pressures. Therefore, we originally hypothesized that extreme conditions, such as our 100 g/L salinity treatment, could lead to slower adaptation due to low population sizes. However, no evolutionary differences were observed between populations evolved in harsh and extreme conditions. This suggests that in the study presented here, low population sizes did not prevent evolution in the long run. On the whole, the adaptive potential observed here could be important for the transition of pathogenic S. marcescens bacteria from human-impacted freshwater environments, such as wastewater treatment plants, to marine habitats, where they are known to infect and kill corals (e.g., through white pox disease). PMID:25505519

  9. Influence of lactic acid bacteria on survival of Escherichia coli O157:H7 in inoculated Minas cheese during storage at 8.5 degrees C.

    PubMed

    Saad, S M; Vanzin, C; Oliveira, M N; Franco, B D

    2001-08-01

    Minas cheese is a typical Brazilian fresh cheese, manufactured by addition of rennin and CaCl2 to milk, followed by draining the curd. The intrinsic characteristics of this product make it favorable for growth of pathogens, including Escherichia coli O157:H7. The influence of the addition of a commercial mesophilic type O lactic culture to this product on the growth of this pathogen during storage at 8.5 degrees C was evaluated. Eight different formulations of Minas cheese were manufactured using raw or pasteurized milk and with or without salt and lactic culture. Individual portions of each formulation were transferred to sterile plastic bags and inoculated with E. coli O157:H7 to yield ca. 10(3) or 10(6) CFU/g. After blending by hand massaging the bags, samples were stored at 8.5 degrees C for up to 14 days. E. coli O157:H7 was counted after 1, 2, 7, and 14 days of storage using 3M Petrifilm Test Kit-HEC. Counts in samples without added lactic culture showed a 2-log increase in the first 24 h and remained constant during the following 14 days. Counts in samples with added lactic culture showed a 0.5-log increase in the first 24 h, followed by a decrease. These variations were statistically significant (P < 0.05). No significant variations (P > 0.05) were obtained for cheese samples manufactured with pasteurized or raw milk, with or without salt. Results indicate that the addition of type O lactic culture may be an additional safeguard to well-established good manufacturing practices and hazard analysis and critical control point programs in the control of growth of E. coli O157:H7 in Minas cheese. PMID:11510651

  10. Bacteria-zinc co-localization implicates enhanced synthesis of cysteine-rich peptides in zinc detoxification when Brassica juncea is inoculated with Rhizobium leguminosarum.

    PubMed

    Adediran, Gbotemi A; Ngwenya, Bryne T; Mosselmans, J Frederick W; Heal, Kate V

    2016-01-01

    Some plant growth promoting bacteria (PGPB) are enigmatic in enhancing plant growth in the face of increased metal accumulation in plants. Since most PGPB colonize the plant root epidermis, we hypothesized that PGPB confer tolerance to metals through changes in speciation at the root epidermis. We employed a novel combination of fluorophore-based confocal laser scanning microscopic imaging and synchrotron based microscopic X-ray fluorescence mapping with X-ray absorption spectroscopy to characterize bacterial localization, zinc (Zn) distribution and speciation in the roots of Brassica juncea grown in Zn contaminated media (400 mg kg(-1) Zn) with the endophytic Pseudomonas brassicacearum and rhizospheric Rhizobium leguminosarum. PGPB enhanced epidermal Zn sequestration relative to PGBP-free controls while the extent of endophytic accumulation depended on the colonization mode of each PGBP. Increased root accumulation of Zn and increased tolerance to Zn was associated predominantly with R. leguminosarum and was likely due to the coordination of Zn with cysteine-rich peptides in the root endodermis, suggesting enhanced synthesis of phytochelatins or glutathione. Our mechanistic model of enhanced Zn accumulation and detoxification in plants inoculated with R. leguminosarum has particular relevance to PGPB enhanced phytoremediation of soils contaminated through mining and oxidation of sulphur-bearing Zn minerals or engineered nanomaterials such as ZnS. PMID:26263508

  11. Effect of plant growth-promoting bacteria (PGPR) and arbuscular mycorrhizal fungi (AMF) inoculation on oats in saline-alkali soil contaminated by petroleum to enhance phytoremediation.

    PubMed

    Xun, Feifei; Xie, Baoming; Liu, Shasha; Guo, Changhong

    2015-01-01

    To investigate the effect of plant growth-promoting bacteria (PGPR) and arbuscular mycorrhizal fungi (AMF) on phytoremediation in saline-alkali soil contaminated by petroleum, saline-alkali soil samples were artificially mixed with different amount of oil, 5 and 10 g/kg, respectively. Pot experiments with oat plants (Avena sativa) were conducted under greenhouse condition for 60 days. Plant biomass, physiological parameters in leaves, soil enzymes, and degradation rate of total petroleum hydrocarbon were measured. The result demonstrated that petroleum inhibited the growth of the plant; however, inoculation with PGPR in combination with AMF resulted in an increase in dry weight and stem height compared with noninoculated controls. Petroleum stress increased the accumulation of malondialdehyde (MDA) and free proline and the activities of the antioxidant enzyme such as superoxide dismutase, catalase, and peroxidase. Application of PGPR and AMF augmented the activities of three enzymes compared to their respective uninoculated controls, but decreased the MDA and free proline contents, indicating that PGPR and AMF could make the plants more tolerant to harmful hydrocarbon contaminants. It also improved the soil quality by increasing the activities of soil enzyme such as urease, sucrase, and dehydrogenase. In addition, the degradation rate of total petroleum hydrocarbon during treatment with PGPR and AMF in moderately contaminated soil reached a maximum of 49.73%. Therefore, we concluded the plants treated with a combination of PGPR and AMF had a high potential to contribute to remediation of saline-alkali soil contaminated with petroleum. PMID:25091168

  12. [Comparative analysis of the antibiotic sensitivity determination methods of conventionally pathogenic bacteria--agents of human opportunistic infections].

    PubMed

    Kulia, A F; Sabo, Iu; Koval', H M; Boĭko, N V

    2011-01-01

    Investigation of biological properties of pathogenic bacteria and, first of all, their sensitivity to antibiotics is the key to successful treatment of human opportunistic infections and to selection of appropriate tactics of their prevention. This paper is devoted to the comparative characteristic of modem and classical approaches to determination of sensitivities to antibiotics of conventionally pathogenic bacteria: methods applied in Ukraine and recommendations proposed by European Committee aimed to unify all the methods of testing sensitivity to antimicrobial agents (EUCAST). The major differences of the above-mentioned methods of testing sensitivity of clinical and non-clinical isolates of potentially pathogenic bacteria to antibiotics have been examined in order to confirm the feasibility of usage and permanent updating the EUCAST database and to promote creation of the appropriate unifield national electronic resource. PMID:22164699

  13. Development and application of a quantitative assay amenable for high-throughput screening to target the type II secretion system for new treatments against plant-pathogenic bacteria

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plant-pathogenic bacteria are the causative agents of diseases in important agricultural crops and ornamental plants. The severe economic burden of these diseases requires seeking new approaches, particularly because phytopathogenic bacteria are often resistant to currently available treatments. The...

  14. The blow fly, Chrysomya megacephala, and the house fly, Musca domestica, as mechanical vectors of pathogenic bacteria in Northeast Thailand.

    PubMed

    Chaiwong, T; Srivoramas, T; Sueabsamran, P; Sukontason, K; Sanford, M R; Sukontason, K L

    2014-06-01

    The Oriental latrine fly, Chrysomya megacephala (Fabricius) (Diptera: Calliphoridae) and the house fly, Musca domestica L., (Diptera: Muscidae) are synanthropic flies which are adapted to live in close association with human habitations, thereby making them likely mechanical vectors of several pathogens to humans. There were two main aims of this study. The first aim was to determine the prevalence of these two fly species from five types of human habitations including: fresh-food markets, garbage piles, restaurants, school cafeterias and paddy fields, in the Muang Ubon Ratchathani and Warinchamrap districts of Ubon Ratchathani province of Northeast Thailand. Flies collection were conducted monthly from September 2010-October 2011 using a reconstructable funnel trap, containing 1 day-tainted beef offal as bait. A total of 7 750 flies (6 401 C. megacephala and 1 349 M.domestica) were collected. The second aim was to examine the potential of these flies to carry pathogenic bacteria. Bacteria were isolated from 994 individual flies collected using a sweep net (555 C. megacephala and 439 M. domestica). A total of 15 bacterial genera were isolated from the external surfaces, comprising ten genera of gram-negative bacteria and five gram-positive bacteria. The most common bacteria isolated from both species were coagulase-negative staphylococci, followed by Streptococcus group D non-enterococci. Human pathogenic enteric bacteria isolated were Salmonella sp., Shigella sp., Escherichia coli O157:H7, Salmonella typhi, Bacillus sp., and Enterococcus sp., of which S. typhi is the first report of isolation from these fly species. Other human pathogens included Staphylococcus aureus and Pseudomonas aeruginosa. Not only were the number of C. megacephala positive for bacteria significantly higher than for M. domestica, but they were also carrying ~11-12 times greater bacterial load than M. domestica. These data suggest that both fly species should be considered potential

  15. Bacteriophages with Potential for Inactivation of Fish Pathogenic Bacteria: Survival, Host Specificity and Effect on Bacterial Community Structure

    PubMed Central

    Pereira, Carla; Silva, Yolanda J.; Santos, Ana L.; Cunha, Ângela; Gomes, Newton C. M.; Almeida, Adelaide

    2011-01-01

    Phage therapy may represent a viable alternative to antibiotics to inactivate fish pathogenic bacteria. Its use, however, requires the awareness of novel kinetics phenomena not applied to conventional drug treatments. The main objective of this work was to isolate bacteriophages with potential to inactivate fish pathogenic bacteria, without major effects on the structure of natural bacterial communities of aquaculture waters. The survival was determined in marine water, through quantification by the soft agar overlay technique. The host specificity was evaluated by cross infection. The ecological impact of phage addition on the structure of the bacterial community was evaluated by DGGE of PCR amplified 16S rRNA gene fragments. The survival period varied between 12 and 91 days, with a higher viability for Aeromonas salmonicida phages. The phages of Vibrio parahaemolyticus and of A. salmonicida infected bacteria of different families with a high efficacy of plating. The specific phages of pathogenic bacteria had no detectable impact on the structure of the bacterial community. In conclusion, V. parahaemolyticus and A. salmonicida phages show good survival time in marine water, have only a moderated impact on the overall bacterial community structure and the desired specificity for host pathogenic bacteria, being potential candidates for therapy of fish infectious diseases in marine aquaculture systems. PMID:22163184

  16. Poly-beta-hydroxybutyrate-accumulating bacteria protect gnotobiotic Artemia franciscana from pathogenic Vibrio campbellii.

    PubMed

    Halet, Dirk; Defoirdt, Tom; Van Damme, Petra; Vervaeren, Han; Forrez, Ilse; Van de Wiele, Tom; Boon, Nico; Sorgeloos, Patrick; Bossier, Peter; Verstraete, Willy

    2007-06-01

    A poly-beta-hydroxybutyrate (PHB)-accumulating enrichment culture was obtained using activated sludge from a polyphosphate-accumulating reactor as inoculum. PHB accumulated by the enrichment culture significantly enhanced the survival of Artemia nauplii, infected with the virulent pathogen Vibrio campbellii LMG 21363. A strain was isolated from the enrichment culture, based on its ability to accumulate PHB, and 16S rRNA gene sequencing of the isolate revealed 99% sequence similarity to Brachymonas denitrificans AS-P1. The isolate, named PHB2, showed good PHB-accumulating activity (up to 32% of the cell dry weight). PHB accumulated by isolate PHB2 was able to protect Artemia completely from the V. campbellii strain. Our data indicate that PHB-accumulating bacteria, such as B. denitrificans PHB2, could be used as an an effective and economically interesting alternative strategy to control infections in aquaculture. PMID:17391334

  17. Prevalence of indicator and pathogenic bacteria in a tropical river of Western Ghats, India

    NASA Astrophysics Data System (ADS)

    Vincy, M. V.; Brilliant, R.; Pradeepkumar, A. P.

    2015-05-01

    The Meenachil, the only river that flows through the heart of the Kottayam district of Kerala state, India was selected for the study. The present study has been carried out with an objective to systematically examine the prevalence of indicator and pathogenic microorganisms and to compare the microbiological quality of the river water during the pre-monsoon and post-monsoon seasons. Water samples from 44 different sites during pre-monsoon and post-monsoon seasons were collected for the analysis. During the pre-monsoon period, the faecal coliform count ranged from 230 to 110,000 MPN/100 ml while there was a variation from 200 to 4600 MPN/100 ml during the post-monsoon period. When the faecal streptococci count was analysed, it ranged from 140 to 110,000 MPN/100 ml during the pre-monsoon and 70 to 4600 MPN/100 ml during the post-monsoon seasons, respectively. All the samples collected were found to have total viable count (TVC) higher than those prescribed by Bureau of Indian Standards (ISI 1991). Total viable counts were found in the range of 1.1 × 102 to 32 × 102 cfu/ml in the pre-monsoon and 1.0 × 102 to 26 × 102 cfu/ml in the post-monsoon. The presence of faecal indicator bacteria, Escherichia coli and potentially pathogenic bacteria, Vibrio cholerae, Vibrio parahaemolyticus and Salmonella enterica in the Meenachil River indicates that the bacteriological quality of the Meenachil River is poor. Moreover, it sheds light to the fact that raw sewage is being dumped into the Meenachil River. Urban runoffs and effluents of rubber factories appear to be the important sources of faecal contamination in the river. From this study, we conclude that these water bodies pose significant public health hazards. Adequate sanitary infrastructure will help in preventing source water contamination. Besides this, public health education aimed at improving personal, household and community hygiene is urgent.

  18. [Development of molecular detection of food-borne pathogenic bacteria using miniaturized microfluidic devices].

    PubMed

    Iván, Kristóf; Maráz, Anna

    2015-12-20

    Detection and identification of food-borne pathogenic bacteria are key points for the assurance of microbiological food safety. Traditional culture-based methods are more and more replaced by or supplemented with nucleic acid based molecular techniques, targeting specific (preferably virulence) genes in the genomes. Internationally validated DNA amplification - most frequently real-time polymerase chain reaction - methods are applied by the food microbiological testing laboratories for routine analysis, which will result not only in shortening the time for results but they also improve the performance characteristics (e.g. sensitivity, specificity) of the methods. Beside numerous advantages of the polymerase chain reaction based techniques for routine microbiological analysis certain drawbacks have to be mentioned, such as the high cost of the equipment and reagents, as well as the risk of contamination of the laboratory environment by the polymerase chain reaction amplicons, which require construction of an isolated laboratory system. Lab-on-a-chip systems can integrate most of these laboratory processes within a miniaturized device that delivers the same specificity and reliability as the standard protocols. The benefits of miniaturized devices are: simple - often automated - use, small overall size, portability, sterility due to single use possibility. These miniaturized rapid diagnostic tests are being researched and developed at the best research centers around the globe implementing various sample preparation and molecular DNA amplification methods on-chip. In parallel, the aim of the authors' research is to develop microfluidic Lab-on-a-chip devices for the detection and identification of food-borne pathogenic bacteria. PMID:26654545

  19. Behavior of pathogenic bacteria in the oyster, Crassostrea commercialis, during depuration, re-laying, and storage.

    PubMed Central

    Son, N T; Fleet, G H

    1980-01-01

    Oysters (Crassostrea commercials) harvested from major cultivation areas within the state of New South Wales, Australia, were commonly contaminated with low levels of the food-poisoning organisms Bacillus cereus, Clostridium perfringens, and Vibrio parahaemolyticus. Salmonella was found in oysters on only one occasion. These bacteria were cleansed from oysters during oyster purification by re-laying in a non-polluted waterway. Oysters were laboratory contaminated to levels in excess 1,000 cells per g with either B. cereus, C. perfringens, V. parahaemolyticus, Salmonella typhimurium, or S. senftenberg. These species were cleansed from such oysters during purification in a laboratory depuration unit that used ultraviolet light for sterilizing the depuration water. Escherichia coli was also cleansed from oysters under the same re-laying or depuration conditions so that its measurement alone could be used to indicate the cleansing of the above pathogenic species. The levels of these bacteria were also measured during the storage of oysters under conditions that occur during marketing. While B. cereus counts remained relatively stable during storage, the Salmonella spp. gradually decreased in numbers and C. perfringens rapidly died off. V. parahaemolyticus counts increased slightly during the first 4 days of storage, after which decreases occurred. PMID:6257164

  20. Survival of Potentially Pathogenic Human-Associated Bacteria in the Rhizosphere of Hydroponically Grown Wheat

    NASA Technical Reports Server (NTRS)

    Morales, Anabelle; Garland, Jay L.; Lim, Daniel V.

    1996-01-01

    Plants may serve as reservoirs for human-associated bacteria (H-AB) in long-term space missions containing bioregenerative life support systems. The current study examined the abilities of five human-associated potential pathogens, Pseudomonas aeruginosa, Pseudomonas cepacia, Staphylococcus aureus, Streptococcus pyogenes, and Escherichia coli, to colonize and grow in the rhizosphere of hydroponically grown wheat, a candidate crop for life support. All of these bacteria have been recovered from past NASA missions and present potential problems for future missions. The abilities of these organisms to adhere to the roots of axenic five-day-old wheat (Triticum aestivum L. cv. Yecora rojo) were evaluated by enumeration of the attached organisms after a one hour incubation of roots in a suspension (approximately 10(exp 8 cu/ml)) of the H-AB. Results showed that a greater percentage of P. aeruginosa cells adhered to the wheat roots than the other four H-AB. Similarly incubated seedlings were also grown under attempted axenic conditions for seven days to examine the potential of each organism to proliferate in the rhizosphere (root colonization capacity). P. cepacia and P. aeruginosa showed considerable growth. E. coli and S. aureus showed no significant growth, and S. pyogenes died off in the wheat rhizosphere. Studies examining the effects of competition on the survival of these microorganisms indicated that P. aeruginosa was the only organism that survived in the rhizosphere of hydroponically grown wheat in the presence of different levels of microbial competition.

  1. Antibacterial effects of long-chain polyphosphates on selected spoilage and pathogenic bacteria.

    PubMed

    Obritsch, Jeremy A; Ryu, Dojin; Lampila, Lucina E; Bullerman, Lloyd B

    2008-07-01

    The antimicrobial activities of four long-chain food-grade polyphosphates were studied at concentrations allowed in the food industry (<5,000 ppm) in defined basal media by determining the inhibition of growth of three gram-negative and four gram-positive spoilage and pathogenic bacteria. Both generation time and lag phase of Escherichia coli K-12, E. coli O157: H7, and Salmonella Typhimurium were increased with all of the polyphosphates tested. Bacillus subtilis and Staphylococcus aureus were more sensitive to polyphosphates, but not in all cases, with multiphased growth. The growth of Lactobacillus plantarum was inhibited by polyphosphates at concentrations above 750 ppm, but the lag time of Listeria monocytogenes was shortened by the presence of polyphosphates. No single polyphosphate was maximally inhibitory against all bacteria. Polyphosphates with chain lengths of 12 to 15 were significantly different from those with chain lengths of 18 to 21 depending on the organism and concentrations of polyphosphate used. Overall, higher polyphosphate concentrations resulted in greater inhibition of bacterial growth. PMID:18680939

  2. Living biointerfaces based on non-pathogenic bacteria support stem cell differentiation

    PubMed Central

    Hay, Jake J.; Rodrigo-Navarro, Aleixandre; Hassi, Karoliina; Moulisova, Vladimira; Dalby, Matthew J.; Salmeron-Sanchez, Manuel

    2016-01-01

    Lactococcus lactis, a non-pathogenic bacteria, has been genetically engineered to express the III7–10 fragment of human fibronectin as a membrane protein. The engineered L. lactis is able to develop biofilms on different surfaces (such as glass and synthetic polymers) and serves as a long-term substrate for mammalian cell culture, specifically human mesenchymal stem cells (hMSC). This system constitutes a living interface between biomaterials and stem cells. The engineered biofilms remain stable and viable for up to 28 days while the expressed fibronectin fragment induces hMSC adhesion. We have optimised conditions to allow long-term mammalian cell culture, and found that the biofilm is functionally equivalent to a fibronectin-coated surface in terms of osteoblastic differentiation using bone morphogenetic protein 2 (BMP-2) added to the medium. This living bacteria interface holds promise as a dynamic substrate for stem cell differentiation that can be further engineered to express other biochemical cues to control hMSC differentiation. PMID:26902619

  3. Antimicrobial activity of essential oil of Eucalyptus globulus against fish pathogenic bacteria.

    PubMed

    Park, Joon-Woo; Wendt, Mitchell; Heo, Gang-Joon

    2016-06-01

    The antibacterial activities of the essential oil of Eucalyptus globulus (EOEG) was determined against 7 fish pathogenic bacteria (Edwardsiella tarda, Streptococcus iniae, S. parauberis, Lactococcus garviae, Vibrio harveyi, V. ichthyoenteri and Photobacterium damselae) obtained from farmed olive flounder. The inhibitory activity was evaluated by three methods: Disc diffusion method, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). According to the disc diffusion test, as the concentration of EOEG (5-40 µg) rises, the inhibitory zone increases in size. Compared with amoxicillin, tetracycline and chloramphenicol, EOEG showed similar antibacterial activity. The MIC of EOEG ranged from 7.8 to 125 mg/mL and MBC values ranged from 62 to 250 mg/mL. These results show that EOEG has antimicrobial activity against all seven bacteria, but there was no marked difference between each genus. From these results, it is suggested that EOEG can be used as an antimicrobial agent against fish bacterial diseases in the fish industry. PMID:27382376

  4. Membrane-Targeting DCAP Analogues with Broad-Spectrum Antibiotic Activity against Pathogenic Bacteria.

    PubMed

    Hurley, Katherine A; Heinrich, Victoria A; Hershfield, Jeremy R; Demons, Samandra T; Weibel, Douglas B

    2015-04-01

    We performed a structure-activity relationship study of 2-((3-(3,6-dichloro-9H-carbazol-9-yl)-2-hydroxypropyl)amino)-2-(hydroxymethyl)propane-1,3-diol (DCAP), which is an antibacterial agent that disrupts the membrane potential and permeability of bacteria. The stereochemistry of DCAP had no effect on the biological activity of DCAP. The aromaticity and electronegativity of the chlorine-substituted carbazole was required for activity, suggesting that its planar and dipolar characteristics orient DCAP in membranes. Increasing the hydrophobicity of the tail region of DCAP enhanced its antibiotic activity. Two DCAP analogues displayed promising antibacterial activity against the BSL-3 pathogens Bacillus anthracis and Francisella tularensis. Codosing DCAP analogues with ampicillin or kanamycin increased their potency. These studies demonstrate that DCAP and its analogues may be a promising scaffold for developing chemotherapeutic agents that bind to bacterial membranes and kill strains of slow-growing or dormant bacteria that cause persistent infections. PMID:25941556

  5. Antimicrobial activity of essential oil of Eucalyptus globulus against fish pathogenic bacteria

    PubMed Central

    Park, Joon-Woo; Wendt, Mitchell

    2016-01-01

    The antibacterial activities of the essential oil of Eucalyptus globulus (EOEG) was determined against 7 fish pathogenic bacteria (Edwardsiella tarda, Streptococcus iniae, S. parauberis, Lactococcus garviae, Vibrio harveyi, V. ichthyoenteri and Photobacterium damselae) obtained from farmed olive flounder. The inhibitory activity was evaluated by three methods: Disc diffusion method, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). According to the disc diffusion test, as the concentration of EOEG (5-40 µg) rises, the inhibitory zone increases in size. Compared with amoxicillin, tetracycline and chloramphenicol, EOEG showed similar antibacterial activity. The MIC of EOEG ranged from 7.8 to 125 mg/mL and MBC values ranged from 62 to 250 mg/mL. These results show that EOEG has antimicrobial activity against all seven bacteria, but there was no marked difference between each genus. From these results, it is suggested that EOEG can be used as an antimicrobial agent against fish bacterial diseases in the fish industry. PMID:27382376

  6. Survival of potentially pathogenic human-associated bacteria in the rhizosphere of hydroponically grown wheat.

    PubMed

    Morales, A; Garland, J L; Lim, D V

    1996-07-01

    Plants may serve as reservoirs for human-associated bacteria (H-AB) in long-term space missions containing bioregenerative life support systems. The current study examined the abilities of five human-associated potential pathogens, Pseudomonas aeruginosa, Pseudomonas cepacia, Staphylococcus aureus, Streptococcus pyogenes and Escherichia coli, to colonize and grow in the rhizosphere of hydroponically grown wheat, a candidate crop for life support. All of these bacteria have been recovered from past NASA missions and present potential problems for future missions. The abilities of these organisms to adhere to the roots of axenic five-day-old wheat (Triticum aestivum L. cv. Yecora rojo) were evaluated by enumeration of the attached organisms after a one hour incubation of roots in a suspension (approximately 10(8) cfu ml-1) of the H-AB. Results showed that a greater percentage of P. aeruginosa cells adhered to the wheat roots than the other four H-AB. Similarly incubated seedlings were also grown under attempted axenic conditions for seven days to examine the potential of each organism to proliferate in the rhizosphere (root colonization capacity). P. cepacia and P. aerogiunosa showed considerable growth, E. coli and S. aureus showed no significant growth, and S. pyogenes died off in the wheat rhizosphere. Studies examining the effects of competition on the survival of these microorganisms indicated that P. aeruginosa was the only organism that survived in the rhizosphere of hydroponically grown wheat in the presence of different levels of microbial competition. PMID:11539850

  7. Living biointerfaces based on non-pathogenic bacteria support stem cell differentiation

    NASA Astrophysics Data System (ADS)

    Hay, Jake J.; Rodrigo-Navarro, Aleixandre; Hassi, Karoliina; Moulisova, Vladimira; Dalby, Matthew J.; Salmeron-Sanchez, Manuel

    2016-02-01

    Lactococcus lactis, a non-pathogenic bacteria, has been genetically engineered to express the III7-10 fragment of human fibronectin as a membrane protein. The engineered L. lactis is able to develop biofilms on different surfaces (such as glass and synthetic polymers) and serves as a long-term substrate for mammalian cell culture, specifically human mesenchymal stem cells (hMSC). This system constitutes a living interface between biomaterials and stem cells. The engineered biofilms remain stable and viable for up to 28 days while the expressed fibronectin fragment induces hMSC adhesion. We have optimised conditions to allow long-term mammalian cell culture, and found that the biofilm is functionally equivalent to a fibronectin-coated surface in terms of osteoblastic differentiation using bone morphogenetic protein 2 (BMP-2) added to the medium. This living bacteria interface holds promise as a dynamic substrate for stem cell differentiation that can be further engineered to express other biochemical cues to control hMSC differentiation.

  8. Membrane-Targeting DCAP Analogues with Broad-Spectrum Antibiotic Activity against Pathogenic Bacteria

    PubMed Central

    2015-01-01

    We performed a structure–activity relationship study of 2-((3-(3,6-dichloro-9H-carbazol-9-yl)-2-hydroxypropyl)amino)-2-(hydroxymethyl)propane-1,3-diol (DCAP), which is an antibacterial agent that disrupts the membrane potential and permeability of bacteria. The stereochemistry of DCAP had no effect on the biological activity of DCAP. The aromaticity and electronegativity of the chlorine-substituted carbazole was required for activity, suggesting that its planar and dipolar characteristics orient DCAP in membranes. Increasing the hydrophobicity of the tail region of DCAP enhanced its antibiotic activity. Two DCAP analogues displayed promising antibacterial activity against the BSL-3 pathogens Bacillus anthracis and Francisella tularensis. Codosing DCAP analogues with ampicillin or kanamycin increased their potency. These studies demonstrate that DCAP and its analogues may be a promising scaffold for developing chemotherapeutic agents that bind to bacterial membranes and kill strains of slow-growing or dormant bacteria that cause persistent infections. PMID:25941556

  9. Diversity of honey stores and their impact on pathogenic bacteria of the honeybee, Apis mellifera.

    PubMed

    Erler, Silvio; Denner, Andreas; Bobiş, Otilia; Forsgren, Eva; Moritz, Robin F A

    2014-10-01

    Honeybee colonies offer an excellent environment for microbial pathogen development. The highest virulent, colony killing, bacterial agents are Paenibacillus larvae causing American foulbrood (AFB), and European foulbrood (EFB) associated bacteria. Besides the innate immune defense, honeybees evolved behavioral defenses to combat infections. Foraging of antimicrobial plant compounds plays a key role for this "social immunity" behavior. Secondary plant metabolites in floral nectar are known for their antimicrobial effects. Yet, these compounds are highly plant specific, and the effects on bee health will depend on the floral origin of the honey produced. As worker bees not only feed themselves, but also the larvae and other colony members, honey is a prime candidate acting as self-medication agent in honeybee colonies to prevent or decrease infections. Here, we test eight AFB and EFB bacterial strains and the growth inhibitory activity of three honey types. Using a high-throughput cell growth assay, we show that all honeys have high growth inhibitory activity and the two monofloral honeys appeared to be strain specific. The specificity of the monofloral honeys and the strong antimicrobial potential of the polyfloral honey suggest that the diversity of honeys in the honey stores of a colony may be highly adaptive for its "social immunity" against the highly diverse suite of pathogens encountered in nature. This ecological diversity may therefore operate similar to the well-known effects of host genetic variance in the arms race between host and parasite. PMID:25505523

  10. Short communication: Lactic acid bacteria from the honeybee inhibit the in vitro growth of mastitis pathogens.

    PubMed

    Piccart, K; Vásquez, A; Piepers, S; De Vliegher, S; Olofsson, T C

    2016-04-01

    Despite the increasing knowledge of prevention and control strategies, bovine mastitis remains one of the most challenging diseases in the dairy industry. This study investigated the antimicrobial activity of 13 species of lactic acid bacteria (LAB), previously isolated from the honey crop of the honeybee, on several mastitis pathogens. The viable LAB were first reintroduced into a sterilized heather honey matrix. More than 20 different bovine mastitis isolates were tested against the mixture of the 13 LAB species in the honey medium using a dual-culture overlay assay. The mastitis isolates were identified through bacteriological culturing, followed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Additionally, the mastitis isolates were subjected to antimicrobial susceptibility testing through disk diffusion. Growth of all tested mastitis pathogens, including the ones displaying antimicrobial resistance to one or more antimicrobial compounds, were inhibited to some extent by the honey and LAB combination. The antibacterial effect of these LAB opens up new perspectives on alternative treatment and prevention of bovine mastitis. PMID:26830735

  11. Diversity of honey stores and their impact on pathogenic bacteria of the honeybee, Apis mellifera

    PubMed Central

    Erler, Silvio; Denner, Andreas; Bobiş, Otilia; Forsgren, Eva; Moritz, Robin F A

    2014-01-01

    Honeybee colonies offer an excellent environment for microbial pathogen development. The highest virulent, colony killing, bacterial agents are Paenibacillus larvae causing American foulbrood (AFB), and European foulbrood (EFB) associated bacteria. Besides the innate immune defense, honeybees evolved behavioral defenses to combat infections. Foraging of antimicrobial plant compounds plays a key role for this “social immunity” behavior. Secondary plant metabolites in floral nectar are known for their antimicrobial effects. Yet, these compounds are highly plant specific, and the effects on bee health will depend on the floral origin of the honey produced. As worker bees not only feed themselves, but also the larvae and other colony members, honey is a prime candidate acting as self-medication agent in honeybee colonies to prevent or decrease infections. Here, we test eight AFB and EFB bacterial strains and the growth inhibitory activity of three honey types. Using a high-throughput cell growth assay, we show that all honeys have high growth inhibitory activity and the two monofloral honeys appeared to be strain specific. The specificity of the monofloral honeys and the strong antimicrobial potential of the polyfloral honey suggest that the diversity of honeys in the honey stores of a colony may be highly adaptive for its “social immunity” against the highly diverse suite of pathogens encountered in nature. This ecological diversity may therefore operate similar to the well-known effects of host genetic variance in the arms race between host and parasite. PMID:25505523

  12. A Sensitive and simple macrophage-based electrochemical biosensor for evaluating lipopolysaccharide cytotoxicity of pathogenic bacteria.

    PubMed

    Wang, Xiumei; Zhu, Pei; Pi, Fuwei; Jiang, Hui; Shao, Jingdong; Zhang, Yinzhi; Sun, Xiulan

    2016-07-15

    In this study, a sensitive and simple electrochemical murine macrophage (Ana-1) cell sensor has been developed for early detection of lipopolysaccharides (LPS) to evaluate the toxicity of pathogenic bacteria. Magnetic glassy carbon electrode (MGCE), which possesses excellent reproducibility and regeneration qualities, was modified with a nanocomposite to improve electrochemical signals and enhance the sensitivity. The synthesized magnetic nanoparticles (MNPs) were internalized into murine macrophages, which completed the immobilization of macrophages onto the modified electrode for evaluating the cytotoxicity of LPS by electrochemical impedance spectroscopy (EIS). The MNPs facilitated reusability of the proposed sensor by allowing removal of the magnetic core from the electrode. Our results indicated that LPS caused a marked decrease in electrochemical impedance in a dose-dependent manner in range of 1-5μg/mL. By SEM, we found that microvilli on the plasma membrane became scarce and the membrane became smooth on cells incubated with LPS, which lessens the absorption of cells to reduce the impedance. And biological assay indicated that EIS patterns were correlated with the calcium concentration in cells, and suggested that [Ca(2+)]i production increased in cells incubated with LPS and its mobilization altered electrochemical signals. Compared with conventional methods, this electrochemical test is inexpensive, highly sensitive, and has a quick response, and thus provides a new avenue for evaluating the cytotoxicity of pathogens. PMID:26991601

  13. Gluconobacter as well as Asaia species, newly emerging opportunistic human pathogens among acetic acid bacteria.

    PubMed

    Alauzet, Corentine; Teyssier, Corinne; Jumas-Bilak, Estelle; Gouby, Anne; Chiron, Raphael; Rabaud, Christian; Counil, François; Lozniewski, Alain; Marchandin, Hélène

    2010-11-01

    Acetic acid bacteria (AAB) are broadly used in industrial food processing. Among them, members of the genera Asaia, Acetobacter, and Granulibacter were recently reported to be human opportunistic pathogens. We isolated AAB from clinical samples from three patients and describe here the clinical and bacteriological features of these cases. We report for the first time (i) the isolation of a Gluconobacter sp. from human clinical samples; (ii) the successive isolation of different AAB, i.e., an Asaia sp. and two unrelated Gluconobacter spp., from a cystic fibrosis patient; and (iii) persistent colonization of the respiratory tract by a Gluconobacter sp. in this patient. We reviewed the main clinical features associated with AAB isolation identified in the 10 documented reports currently available in the literature. Albeit rare, infections as well as colonization with AAB are increasingly reported in patients with underlying chronic diseases and/or indwelling devices. Clinicians as well as medical microbiologists should be aware of these unusual opportunistic pathogens, which are difficult to detect during standard medical microbiological investigations and which are multiresistant to antimicrobial agents. Molecular methods are required for identification of genera of AAB, but the results may remain inconclusive for identification to the species level. PMID:20826638

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

    USGS Publications Warehouse

    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.

  15. Photodynamic Inactivation Mediated by Erythrosine and its Derivatives on Foodborne Pathogens and Spoilage Bacteria.

    PubMed

    Yassunaka, Natália Norika; Freitas, Camila Fabiano de; Rabello, Bruno Ribeiro; Santos, Patrícia Regina; Caetano, Wilker; Hioka, Noboru; Nakamura, Tania Ueda; Abreu Filho, Benício Alves de; Graton Mikcha, Jane Martha

    2015-08-01

    The purpose of the present study was to evaluate the efficacy of photodynamic inactivation (PDI) mediated by erythrosine (ERY) and its ester derivatives erythrosine methyl ester (ERYMET) and erythrosine butyl ester (ERYBUT) on foodborne pathogens and spoilage bacteria. We evaluated Staphylococcus aureus ATCC 25923, Aeromonas hydrophila ATCC 7966, Salmonella enterica serotype Typhimurium ATCC 14028, Escherichia coli ATCC 25922, and Pseudomonas aeruginosa ATCC 27853. The toxicity of all of the compounds was assessed in VERO cells. PDI mediated by ERY and its derivatives combined with a light-emitting diode was performed at different concentrations and exposure times. S. aureus was more photosensitive than Gram-negative bacteria to ERY, ERYMET, and ERYBUT. The ERY-mediated PDI of S. aureus induced a significant reduction of 4.0 log CFU/ml at a light dose of 40 J/cm(2). ERYMET and ERYBUT at lower light doses than ERY completely eradicated S. aureus. When photoirradiated with ERY at light doses of 156 and 234 J/cm(2), A. hydrophila was completely eradicated. ERYBUT was more efficient in the PDI of A. hydrophila than ERYMET, even at 1 x 10(-5) M and lower light doses. Salmonella Typhimurium, E. coli, and P. aeruginosa required higher concentrations of photosensitizers to reduce cell survival. ERYBUT and ERY may be promising photosensitizing agents against A. hydrophila and S. aureus. They were effective at reducing bacterial counts at nontoxic concentrations. The photoinactivation rate of the evaluated bacteria decreased in the following order: S. aureus > A. hydrophila > E. coli > S. Typhimurium > P. aeruginosa. PMID:25925153

  16. Antimicrobial Activity of Croton macrostachyus Stem Bark Extracts against Several Human Pathogenic Bacteria

    PubMed Central

    Obey, Jackie K.; von Wright, Atte; Orjala, Jimmy; Kauhanen, Jussi; Tikkanen-Kaukanen, Carina

    2016-01-01

    In Kenya, leaves and roots from Croton macrostachyus are used as a traditional medicine for infectious diseases such as typhoid and measles, but reports on possible antimicrobial activity of stem bark do not exist. In this study, the antibacterial and antifungal effects of methanol, ethyl acetate and butanol extracts, and purified lupeol of C. macrostachyus stem bark were determined against important human gram-negative pathogens Escherichia coli, Salmonella typhi, Klebsiella pneumoniae, and Enterobacter aerogenes, gram-positive Listeria monocytogenes, and a fungus Candida albicans. The most promising broad scale antimicrobial activity against all the studied pathogens was shown by the ethyl acetate extract. The ethyl acetate extract induced the zone of inhibition between 10.1 ± 0.6 mm and 16.0 ± 1.2 mm against S. typhi, E. coli, K. pneumoniae, E. aerogenes, and L. monocytogenes with weaker antimicrobial activity against C. albicans (zone of inhibition: 5.6 ± 1.0 mm). The antibiotic controls (amoxicillin, ciprofloxacin, ampicillin, benzylpenicillin, clotrimazole, and cefotaxime) showed antimicrobial activity with zones of inhibition within 13.4 ± 0.7–22.1 ± 0.9 mm. The ethyl acetate extract had MIC in the range of 125–250 mg/mL against all the studied bacteria and against C. albicans MIC was 500 mg/mL. The present results give scientific evidence and support the traditional use of C. macrostachyus stem bark as a source for antimicrobials. We show that C. macrostachyus stem bark lupeol is a promising antimicrobial agent against several important human pathogens. PMID:27293897

  17. Spontaenous Avian Leukosis Virus-like lymphomas in specific-pathogen-free chickens inoculated with serotype 2 Marek’s disease virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Chickens of Avian Disease and Oncology Laboratory (ADOL) line alv6, known to develop spontaneous avian leukosis virus (ALV)-like lymphomas at two years of age or older, were inoculated either in-ovo, or at 1 day of age with strain SB-1 of serotype 2 Marek’s disease virus (MDV). Inoculated and uninoc...

  18. Occurrence and distribution of fecal indicator bacteria and gene markers of pathogenic bacteria in Great Lakes tributaries, March-October 2011

    USGS Publications Warehouse

    Brennan, Angela K.; Johnson, Heather E.; Totten, Alexander R.; Duris, Joseph W.

    2015-01-01

    Water samples were analyzed for the presence of FIB concentrations (FIB; fecal coliform bacteria, Escherichia coli [E. coli], and enterococci) by using membrane filtration and serial dilution methods. The resulting enrichments from standard culturing of the samples were then analyzed by using polymerase chain reaction (PCR) to determine the occurrence of pathogen gene markers for Shigella species, Campylobacter jejuni and coli, Salmonellaspecies, and pathogenic E. coli, including Shiga toxin-producing E. coli (STEC).

  19. Cultivation and qPCR detection of pathogenic and antibiotic resistant bacteria establishment in naive broiler houses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    : Conventional commercial broiler production involves the rearing of more than 20,000 broilers in a single confined space, atop bedding material such as pine shavings or rice hulls, for approximately 6.5 weeks. This environment is known for harboring pathogens and antibiotic resistant bacteria, but ...

  20. Use of Extract of Citrus sinensis as an antimicrobial agent for foodborne zoonotic pathogens and spoilage bacteria

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Foodborne pathogens remain global health problems despite concerted efforts to control the transmission of these microorganisms through food. The resurgence of drug resistant bacteria has renewed interest in developing and testing new sources of antimicrobial agents to control foodborne illness. Thi...

  1. Pathogen prevalence and influence of composted dairy manure application on antimicrobial resistance profiles of commensal soil bacteria

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Manure production and its subsequent disposal is a continual problem for the livestock producer. Composting manure, if done properly should kill pathogenic bacteria such as Salmonella and E. coli O157:H7, providing for an environmentally safe product. Recently, large scale application of composted...

  2. The Anti-HIV Microbicide Candidate RC-101 Inhibits Pathogenic Vaginal Bacteria Without Harming Endogenous Flora or Mucosa

    PubMed Central

    Eade, Colleen R.; Cole, Amy L.; Diaz, Camila; Rohan, Lisa C.; Parniak, Michael A.; Marx, Preston; Tarwater, Patrick M.; Gupta, Phalguni; Cole, Alexander M.

    2012-01-01

    Problem Vaginal microbicides represent a promising approach for preventing heterosexual HIV transmission. However, preclinical evaluation should be conducted to ensure that microbicides will be safe for human cells and healthy microflora of the female reproductive tract. One microbicide candidate, RC-101, has been effective and well-tolerated in preliminary cell culture and macaque models. However, the effect of RC-101 on primary vaginal tissues and resident vaginal microflora requires further evaluation. Method of Study We treated primary vaginal tissues and vaginal bacteria, both pathogenic and commensal, with RC-101 to investigate effects of this microbicide. Results RC-101 was well-tolerated by host tissues, and also by commensal vaginal bacteria. Simultaneously, pathogenic vaginal bacteria, which are known to increase susceptibility to HIV acquisition, were inhibited by RC-101. Conclusions By establishing vaginal microflora, the specific antibacterial activity of RC-101 may provide a dual mechanism of HIV protection. These findings support advancement of RC-101 to clinical trials. PMID:23167830

  3. Influence of river discharge on abundance and dissemination of heterotrophic, indicator and pathogenic bacteria along the East Coast of India.

    PubMed

    Prasad, V R; Srinivas, T N R; Sarma, V V S S

    2015-06-15

    In order to examine the influence of discharge from different rivers from peninsular India and urban sewage on intensity and dissemination of heterotrophic, indicator and pathogenic bacteria, a study was carried out during peak discharge period along coastal Bay of Bengal. The coastal Bay received freshwater inputs from the river Ganges while Godavari and Krishna contributed to the south. Contrasting difference in salinity, temperature, nutrients and organic matter was observed between north and south east coast of India. The highest heterotrophic, indicator and pathogenic bacterial abundance was observed in the central coastal Bay that received urban sewage from the major city. Intensity and dissemination of heterotrophic, indicator and pathogenic bacteria displayed linear relation with magnitude of discharge. The coliform load was observed up to 100km from the coast suggesting that marine waters were polluted during the monsoon season and its impact on the ecosystem needs further studies. PMID:25934433

  4. NLRC4-driven production of IL-1β discriminates between pathogenic and commensal bacteria and promotes host intestinal defense.

    PubMed

    Franchi, Luigi; Kamada, Nobuhiko; Nakamura, Yuumi; Burberry, Aaron; Kuffa, Peter; Suzuki, Shiho; Shaw, Michael H; Kim, Yun-Gi; Núñez, Gabriel

    2012-05-01

    Intestinal phagocytes transport oral antigens and promote immune tolerance, but their role in innate immune responses remains unclear. Here we found that intestinal phagocytes were anergic to ligands for Toll-like receptors (TLRs) or commensals but constitutively expressed the precursor to interleukin 1β (pro-IL-1β). After infection with pathogenic Salmonella or Pseudomonas, intestinal phagocytes produced mature IL-1β through the NLRC4 inflammasome but did not produce tumor necrosis factor (TNF) or IL-6. BALB/c mice deficient in NLRC4 or the IL-1 receptor were highly susceptible to orogastric but not intraperitoneal infection with Salmonella. That enhanced lethality was preceded by impaired expression of endothelial adhesion molecules, lower neutrophil recruitment and poor intestinal pathogen clearance. Thus, NLRC4-dependent production of IL-1β by intestinal phagocytes represents a specific response that discriminates pathogenic bacteria from commensal bacteria and contributes to host defense in the intestine. PMID:22484733

  5. Effects of the Essential Oil from Origanum vulgare L. on Survival of Pathogenic Bacteria and Starter Lactic Acid Bacteria in Semihard Cheese Broth and Slurry.

    PubMed

    de Souza, Geany Targino; de Carvalho, Rayssa Julliane; de Sousa, Jossana Pereira; Tavares, Josean Fechine; Schaffner, Donald; de Souza, Evandro Leite; Magnani, Marciane

    2016-02-01

    This study assessed the inhibitory effects of the essential oil from Origanum vulgare L. (OVEO) on Staphylococcus aureus, Listeria monocytogenes, and a mesophilic starter coculture composed of lactic acid bacteria (Lactococcus lactis subsp. lactis and L. lactis subsp. cremoris) in Brazilian coalho cheese systems. The MIC of OVEO was 2.5 μl/ml against both S. aureus and L. monocytogenes and 0.6 μl/ml against the tested starter coculture. In cheese broth containing OVEO at 0.6 μl/ml, no decrease in viable cell counts (VCC) of both pathogenic bacteria was observed, whereas the initial VCC of the starter coculture decreased approximately 1.0 log CFU/ml after 24 h of exposure at 10°C. OVEO at 1.25 and 2.5 μl/ml caused reductions of up to 2.0 and 2.5 log CFU/ml in S. aureus and L. monocytogenes, respectively, after 24 h of exposure in cheese broth. At these same concentrations, OVEO caused a greater decrease of initial VCC of the starter coculture following 4 h of exposure. Higher concentrations of OVEO were required to decrease the VCC of all target bacteria in semisolid coalho cheese slurry compared with cheese broth. The VCC of Lactococcus spp. in coalho cheese slurry containing OVEO were always lower than those of pathogenic bacteria under the same conditions. These results suggest that the concentrations of OVEO used to control pathogenic bacteria in semihard cheese should be carefully evaluated because of its inhibitory effects on the growth of starter lactic acid cultures used during the production of the product. PMID:26818985

  6. Gorilla gorilla gorilla gut: a potential reservoir of pathogenic bacteria as revealed using culturomics and molecular tools

    PubMed Central

    Bittar, Fadi; Keita, Mamadou B.; Lagier, Jean-Christophe; Peeters, Martine; Delaporte, Eric; Raoult, Didier

    2014-01-01

    Wild apes are considered to be the most serious reservoir and source of zoonoses. However, little data are available about the gut microbiota and pathogenic bacteria in gorillas. For this propose, a total of 48 fecal samples obtained from 21 Gorilla gorilla gorilla individuals (as revealed via microsatellite analysis) were screened for human bacterial pathogens using culturomics and molecular techniques. By applying culturomics to one index gorilla and using specific media supplemented by plants, we tested 12,800 colonies and identified 147 different bacterial species, including 5 new species. Many opportunistic pathogens were isolated, including 8 frequently associated with human diseases; Mycobacterium bolletii, Proteus mirabilis, Acinetobacter baumannii, Klebsiella pneumoniae, Serratia marcescens, Escherichia coli, Staphylococcus aureus and Clostridium botulinum. The genus Treponema accounted for 27.4% of the total reads identified at the genus level via 454 pyrosequencing. Using specific real-time PCR on 48 gorilla fecal samples, in addition to classical human pathogens, we also observed the fastidious bacteria Bartonella spp. Borrelia spp., Coxiella burnetii and Tropheryma whipplei in the gorilla population. We estimated that the prevalence of these pathogens vary between 4.76% and 85.7%. Therefore, gorillas share many bacterial pathogens with humans suggesting that they could be a reservoir for their emergence. PMID:25417711

  7. High-throughput DNA microarray detection of pathogenic bacteria in shallow well groundwater in the Kathmandu Valley, Nepal.

    PubMed

    Inoue, Daisuke; Hinoura, Takuji; Suzuki, Noriko; Pang, Junqin; Malla, Rabin; Shrestha, Sadhana; Chapagain, Saroj Kumar; Matsuzawa, Hiroaki; Nakamura, Takashi; Tanaka, Yasuhiro; Ike, Michihiko; Nishida, Kei; Sei, Kazunari

    2015-01-01

    Because of heavy dependence on groundwater for drinking water and other domestic use, microbial contamination of groundwater is a serious problem in the Kathmandu Valley, Nepal. This study investigated comprehensively the occurrence of pathogenic bacteria in shallow well groundwater in the Kathmandu Valley by applying DNA microarray analysis targeting 941 pathogenic bacterial species/groups. Water quality measurements found significant coliform (fecal) contamination in 10 of the 11 investigated groundwater samples and significant nitrogen contamination in some samples. The results of DNA microarray analysis revealed the presence of 1-37 pathogen species/groups, including 1-27 biosafety level 2 ones, in 9 of the 11 groundwater samples. While the detected pathogens included several feces- and animal-related ones, those belonging to Legionella and Arthrobacter, which were considered not to be directly associated with feces, were detected prevalently. This study could provide a rough picture of overall pathogenic bacterial contamination in the Kathmandu Valley, and demonstrated the usefulness of DNA microarray analysis as a comprehensive screening tool of a wide variety of pathogenic bacteria. PMID:25146188

  8. Phytochemical, toxicological and antimicrobial evaluation of lawsonia inermis extracts against clinical isolates of pathogenic bacteria

    PubMed Central

    2013-01-01

    Background The emerging resistance of pathogen against the currently available antimicrobial agents demands the search of new antimicrobial agents. The use of medicinal plants as natural substitute is the paramount area of research to overwhelm the drug resistance of infectious agents. Scientists have not made enough effort on the evaluation of safety of medicinal plant yet. Methods In the present study antimicrobial activity of Lawsonia inermis is investigated against clinical isolates of seven bacteria including four Gram negative (Escherichia coli, Salmonella typhi, Klebsiella spp., Shigella sonnei) and three Gram positive (Bacillus subtilis, Staphylococcus aureus, Staphylococcus epidermidis) using disc diffusion method. Four types of Lawsonia inermis extracts were prepared using methanol, chloroform, acetone and water as extraction solvents, while DMSO (Dimethyl sulfoxide) and water as dissolution solvents. The rate and extent of bacterial killing was estimated by time-kill kinetic assay at 1× MIC of each bacterial isolate. The overall safety of Lawsonia inermis extracts was assessed in mice. Results Lawsonia inermis displayed noteworthy antimicrobial activity against both gram positive and gram negative bacterial strains used in the study. The minimum value of MIC for different bacterial strains ranged from 2.31 mg/ml to 9.27 mg/ml. At 1x MIC of each bacterial isolate, 3log10 decrease in CFU was recorded after 6 hours of drug exposure and no growth was observed in almost all tested bacteria after 24 hours of exposure. No sign of toxidrome were observed during in vivo toxicity evaluation in mice at 300 mg/kg concentration. Conclusion In conclusion, the present study provides the scientific rational for medicinal use of Lawsonia inermis. The use of Lawsonia inermis extracts is of great significance as substitute antimicrobial agent in therapeutics. PMID:24289297

  9. Studies on water quality and pathogenic bacteria in coastal water Langkawi, Malaysia.

    PubMed

    Jalal, K C A; Faizul, H N Noor; Naim, M Azrul; John, B Akbar; Kamaruzzaman, B Y

    2012-07-01

    A study on physico-chemical parameters and pathogenic bacterial community was carried out at the coastal waters of Pulau Tuba island, Langkawi. The physico-chemical parameters such as temperature (27.43-28.88 degrees C), dissolved oxygen (3.79-6.49 mg l(-1)), pH (7.72-8.20), salinity (33.10-33.96 ppt), total dissolved solids (32.27-32.77 g l(-1)) and specific conductivity (49.83-51.63 mS cm(-1)) were observed. Station 3 and station 4 showed highest amount of nitrates (26.93 and 14.61 microg at N l(-1)) than station 1 (2.04 microg at N l(-1)) and station 2 (4.18 microg at N l(-1)). The highest concentration (12.4 +/- microg l(-1)) of chlorophyll a was observed in station 4 in October 2005. High phosphorus content (561 microg P l(-1)) was found in the station 2. Thirteen bacterial isolates were successfully identified using API 20E system. The highest amount of bacteria was observed at Station 4 (3400 CFU ml(-1)) and the lowest numberwas at Station 2 (890 CFU ml(-1)). Out of identified 13 Gram-negative bacterial isolates dominant species were Aeromonas hydrophila, Klebsiella oxytoca, Pseudomonas baumannii, Vibrio vulnificus, Proteus mirabilis, Providencia alcalifaciens and Serratia liquefaciens. Apart from this, oil biodegrading Pseudomonas putida were also identified. The study reveals the existing status of water quality is still conducive and the reasonably diverse with Gram-negative bacteria along the Pulau Tuba Langkawi. PMID:23360015

  10. Fighting Off Wound Pathogens in Horses with Honeybee Lactic Acid Bacteria.

    PubMed

    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. PMID:27324340

  11. Changes in Aerobic Plate and Escherichia coli-Coliform Counts and in Populations of Inoculated Foodborne Pathogens on Inshell Walnuts during Storage.

    PubMed

    Frelka, John C; Davidson, Gordon R; Harris, Linda J

    2016-07-01

    After harvest, inshell walnuts are dried using low-temperature forced air and are then stored in bins or silos for up to 1 year. To better understand the survival of bacteria on inshell walnuts, aerobic plate counts (APCs) and Escherichia coli?coliform counts (ECCs) were evaluated during commercial storage (10 to 12°C and 63 to 65% relative humidity) over 9 months. APCs decreased by 1.4 to 2.0 log CFU per nut during the first 5 months of storage, and ECCs decreased by 1.3 to 2.2 log CFU per nut in the first month of storage. Through the remaining 4 to 8 months of storage, APCs and ECCs remained unchanged (P > 0.05) or decreased by <0.15 log CFU per nut per month. Similar trends were observed on kernels extracted from the inshell walnuts. APCs and ECCs were consistently and often significantly higher on kernels extracted from visibly broken inshell walnuts than on kernels extracted from visibly intact inshell walnuts. Parameters measured in this study were used to determine the survival of five-strain cocktails of E. coli O157:H7, Listeria monocytogenes, and Salmonella inoculated onto freshly hulled inshell walnuts (∼8 log CFU/g) after simulated commercial drying (10 to 12 h; 40°C) and simulated commercial storage (12 months at 10°C and 65% relative humidity). Populations declined by 2.86, 5.01, and 4.40 log CFU per nut for E. coli O157:H7, L. monocytogenes, and Salmonella, respectively, after drying and during the first 8 days of storage. Salmonella populations changed at a rate of -0.33 log CFU per nut per month between days 8 and 360, to final levels of 2.83 ± 0.79 log CFU per nut. E. coli and L. monocytogenes populations changed by -0.17 log CFU per nut per month and -0.26 log CFU per nut per month between days 8 and 360, respectively. For some samples, E. coli or L. monocytogenes populations were below the limit of detection by plating (0.60 log CFU per nut) by day 183 or 148, respectively; at least one of the six samples was positive at each subsequent

  12. Oligo-DNA Custom Macroarray for Monitoring Major Pathogenic and Non-Pathogenic Fungi and Bacteria in the Phyllosphere of Apple Trees

    PubMed Central

    He, Ying-Hong; Isono, Sayaka; Shibuya, Makoto; Tsuji, Masaharu; Adkar Purushothama, Charith-Raj; Tanaka, Kazuaki; Sano, Teruo

    2012-01-01

    Background To monitor the richness in microbial inhabitants in the phyllosphere of apple trees cultivated under various cultural and environmental conditions, we developed an oligo-DNA macroarray for major pathogenic and non-pathogenic fungi and bacteria inhabiting the phyllosphere of apple trees. Methods and Findings First, we isolated culturable fungi and bacteria from apple orchards by an agar-plate culture method, and detected 32 fungal and 34 bacterial species. Alternaria, Aureobasidium, Cladosporium, Rhodotorula, Cystofilobasidium, and Epicoccum genera were predominant among the fungi, and Bacillus, Pseudomonas, Sphingomonas, Methylobacterium, and Pantoea genera were predominant among the bacteria. Based on the data, we selected 29 major non-pathogenic and 12 phytopathogenic fungi and bacteria as the targets of macroarray. Forty-one species-specific 40-base pair long oligo-DNA sequences were selected from the nucleotide sequences of rDNA-internal transcribed spacer region for fungi and 16S rDNA for bacteria. The oligo-DNAs were fixed on nylon membrane and hybridized with digoxigenin-labeled cRNA probes prepared for each species. All arrays except those for Alternaria, Bacillus, and their related species, were specifically hybridized. The array was sensitive enough to detect 103 CFU for Aureobasidium pullulans and Bacillus cereus. Nucleotide sequencing of 100 each of independent fungal rDNA-ITS and bacterial 16S-rDNA sequences from apple tree was in agreement with the macroarray data obtained using the same sample. Finally, we analyzed the richness in the microbial inhabitants in the samples collected from apple trees in four orchards. Major apple pathogens that cause scab, Alternaria blotch, and Marssonina blotch were detected along with several non-phytopathogenic fungal and bacterial inhabitants. Conclusions The macroarray technique presented here is a strong tool to monitor the major microbial species and the community structures in the phyllosphere of

  13. The activity of ferulic and gallic acids in biofilm prevention and control of pathogenic bacteria.

    PubMed

    Borges, Anabela; Saavedra, Maria J; Simões, Manuel

    2012-01-01

    The activity of two phenolic acids, gallic acid (GA) and ferulic acid (FA) at 1000 μg ml(-1), was evaluated on the prevention and control of biofilms formed by Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Listeria monocytogenes. In addition, the effect of the two phenolic acids was tested on planktonic cell susceptibility, bacterial motility and adhesion. Biofilm prevention and control were tested using a microtiter plate assay and the effect of the phenolic acids was assessed on biofilm mass (crystal violet staining) and on the quantification of metabolic activity (alamar blue assay). The minimum bactericidal concentration for P. aeruginosa was 500 μg ml(-1) (for both phenolic acids), whilst for E. coli it was 2500 μg ml(-1) (FA) and 5000 μg ml(-1) (GA), for L. monocytogenes it was >5000 μg ml(-1) (for both phenolic acids), and for S. aureus it was 5000 μg ml(-1) (FA) and >5000 μg ml(-1) (GA). GA caused total inhibition of swimming (L. monocytogenes) and swarming (L. monocytogenes and E. coli) motilities. FA caused total inhibition of swimming (L. monocytogenes) and swarming (L. monocytogenes and E. coli) motilities. Colony spreading of S. aureus was completely inhibited by FA. The interference of GA and FA with bacterial adhesion was evaluated by the determination of the free energy of adhesion. Adhesion was less favorable when the bacteria were exposed to GA (P. aeruginosa, S. aureus and L. monocytogenes) and FA (P. aeruginosa and S. aureus). Both phenolics had preventive action on biofilm formation and showed a higher potential to reduce the mass of biofilms formed by the Gram-negative bacteria. GA and FA promoted reductions in biofilm activity >70% for all the biofilms tested. The two phenolic acids demonstrated the potential to inhibit bacterial motility and to prevent and control biofilms of four important human pathogenic bacteria. This study also emphasizes the potential of phytochemicals as an emergent source of biofilm

  14. Potentially pathogenic bacteria in shower water and air of a stem cell transplant unit.

    PubMed

    Perkins, Sarah D; Mayfield, Jennie; Fraser, Victoria; Angenent, Largus T

    2009-08-01

    Potential pathogens from shower water and aerosolized shower mist (i.e., shower aerosol) have been suggested as an environmental source of infection for immunocompromised patients. To quantify the microbial load in shower water and aerosol samples, we used culture, microscopic, and quantitative PCR methods to investigate four shower stalls in a stem cell transplant unit at Barnes-Jewish Hospital in St. Louis, MO. We also tested membrane-integrated showerheads as a possible mitigation strategy. In addition to quantification, a 16S rRNA gene sequencing survey was used to characterize the abundant bacterial populations within shower water and aerosols. The average total bacterial counts were 2.2 x 10(7) cells/liter in shower water and 3.4 x 10(4) cells/m(3) in shower aerosol, and these counts were reduced to 6.3 x 10(4) cells/liter (99.6% efficiency) and 8.9 x 10(3) cells/m(3) (82.4% efficiency), respectively, after membrane-integrated showerheads were installed. Potentially pathogenic organisms were found in both water and aerosol samples from the conventional showers. Most notable was the presence of Mycobacterium mucogenicum (99.5% identity) in the water and Pseudomonas aeruginosa (99.3% identity) in the aerosol samples. Membrane-integrated showerheads may protect immunocompromised patients from waterborne infections in a stem cell transplant unit because of efficient capture of vast numbers of potentially pathogenic bacteria from hospital water. However, an in-depth epidemiological study is necessary to investigate whether membrane-integrated showerheads reduce hospital-acquired infections. The microbial load in shower aerosols with conventional showerheads was elevated compared to the load in HEPA-filtered background air in the stem cell unit, but it was considerably lower than typical indoor air. Thus, in shower environments without HEPA filtration, the increase in microbial load due to shower water aerosolization would not have been distinguishable from

  15. Antibacterial activity of plasma from crocodile (Crocodylus siamensis) against pathogenic bacteria

    PubMed Central

    2012-01-01

    membranes. The effect of the crude plasma was not toxic by the yellow tetrazolium bromide (MTT) assay using a macrophage-like cell, RAW 264.7. The pooled four fractions, designated as fractions D1-D4, were obtained by column chromatography, and only fraction D1 showed growth inhibition in the reference strains and the clinical, human pathogenic isolates. Conclusions The crude and purified plasma from the Siamese crocodile significantly showed antibacterial activity against pathogenic bacteria and reference strains by damage cell membrane of target bacterial cells. From the MTT assay, the Siamese crocodile plasma was not cytotoxic to the cells. PMID:22846342

  16. Selected Pathogens of Concern to Industrial Food Processors: Infectious, Toxigenic, Toxico-Infectious, Selected Emerging Pathogenic Bacteria

    NASA Astrophysics Data System (ADS)

    Behling, Robert G.; Eifert, Joseph; Erickson, Marilyn C.; Gurtler, Joshua B.; Kornacki, Jeffrey L.; Line, Erick; Radcliff, Roy; Ryser, Elliot T.; Stawick, Bradley; Yan, Zhinong

    This chapter, written by several contributing authors, is devoted to discussing selected microbes of contemporary importance. Microbes from three categories are described by the following: (1) infectious invasive agents like Salmonella, Listeria monocytogenes, and Campylobacter; (2) toxigenic pathogens such as Staphylococcus aureus, Bacillus cereus, and Clostridium botulinum; and (3) toxico-infectious agents like enterohemorrhagic Escherichia coli and Clostridium perfringens. In addition, emerging pathogens, like Cronobacter (Enterobacter) sakazakii, Arcobacter spp., and Mycobacterium avium subspecies paratuberculosis are also described.

  17. Marine Antimicrobial Peptides: Nature Provides Templates for the Design of Novel Compounds against Pathogenic Bacteria

    PubMed Central

    Falanga, Annarita; Lombardi, Lucia; Franci, Gianluigi; Vitiello, Mariateresa; Iovene, Maria Rosaria; Morelli, Giancarlo; Galdiero, Massimiliano; Galdiero, Stefania

    2016-01-01

    The discovery of antibiotics for the treatment of bacterial infections brought the idea that bacteria would no longer endanger human health. However, bacterial diseases still represent a worldwide treat. The ability of microorganisms to develop resistance, together with the indiscriminate use of antibiotics, is mainly responsible for this situation; thus, resistance has compelled the scientific community to search for novel therapeutics. In this scenario, antimicrobial peptides (AMPs) provide a promising strategy against a wide array of pathogenic microorganisms, being able to act directly as antimicrobial agents but also being important regulators of the innate immune system. This review is an attempt to explore marine AMPs as a rich source of molecules with antimicrobial activity. In fact, the sea is poorly explored in terms of AMPs, but it represents a resource with plentiful antibacterial agents performing their role in a harsh environment. For the application of AMPs in the medical field limitations correlated to their peptide nature, their inactivation by environmental pH, presence of salts, proteases, or other components have to be solved. Thus, these peptides may act as templates for the design of more potent and less toxic compounds. PMID:27213366

  18. Soil bacteria as sources of virulence signal providers promoting plant infection by Phytophthora pathogens.

    PubMed

    Kong, Ping; Hong, Chuanxue

    2016-01-01

    Phytophthora species are known as "plant destroyers" capable of initiating single zoospore infection in the presence of a quorum of chemical signals from the same or closely related species of oomycetes. Since the natural oomycete population is too low to reach a quorum necessary to initiate a disease epidemic, creation of the quorum is reliant on alternate sources. Here, we show that a soil bacterial isolate, Bacillus megaterium Sb5, promotes plant infection by Phytophthora species. In the presence of Sb5 exudates, colonization of rhododendron leaf discs by 12 Phytophthora species/isolates was significantly enhanced, single zoospores of P. nicotianae infected annual vinca and P. sojae race 25 successfully attacked a non-host plant, Nicotiana benthamiana as well as resistant soybean cultivars with RPS1a or RPS3a. Sb5 exudates, most notably the fractions larger than 3 kDa, promoted plant infection by improving zoospore swimming, germination and plant attachment. Sb5 exudates also stimulated infection hypha growth and upregulated effector gene expression. These results suggest that environmental bacteria are important sources of virulence signal providers that promote plant infection by Phytophthora species, advancing our understanding of biotic factors in the environmental component of the Phytophthora disease triangle and of communal infection of plant pathogens. PMID:27616267

  19. Comparative Study of Eis-like Enzymes from Pathogenic and Nonpathogenic Bacteria.

    PubMed

    Green, Keith D; Pricer, Rachel E; Stewart, Megan N; Garneau-Tsodikova, Sylvie

    2015-06-12

    Antibiotic resistance is a growing problem worldwide. Of particular importance is the resistance of Mycobacterium tuberculosis (Mtb) to currently available antibiotics used in the treatment of infected patients. Up-regulation of an aminoglycoside (AG) acetyltransferase, the enhanced intracellular survival (Eis) protein of Mtb (Eis_Mtb), is responsible for resistance to the second-line injectable drug kanamycin A in a number of Mtb clinical isolates. This acetyltransferase is known to modify AGs, not at a single position, as usual for this type of enzyme, but at multiple amine sites. We identified, using in silico techniques, 22 homologues from a wide variety of bacteria, that we then cloned, purified, and biochemically studied. From the selected Eis homologues, 7 showed the ability to modify AGs to various degrees and displayed both similarities and differences when compared to Eis_Mtb. In addition, an inhibitor proved to be active against all homologues tested. Our findings show that this family of acetyltransferase enzymes exists in both mycobacteria and non-mycobacteria and in both pathogenic and nonpathogenic species. The bacterial strains described herein should be monitored for rising resistance rates to AGs. PMID:27622743

  20. Rapid Detection of Pathogenic Bacteria from Fresh Produce by Filtration and Surface-Enhanced Raman Spectroscopy

    NASA Astrophysics Data System (ADS)

    Wu, Xiaomeng; Han, Caiqin; Chen, Jing; Huang, Yao-Wen; Zhao, Yiping

    2016-04-01

    The detection of Salmonella Poona from cantaloupe cubes and E. coli O157:H7 from lettuce has been explored by using a filtration method and surface-enhanced Raman spectroscopy (SERS) based on vancomycin-functionalized silver nanorod array substrates. It is found that with a two-step filtration process, the limit of detection (LOD) of Salmonella Poona from cantaloupe cubes can be as low as 100 CFU/mL in less than 4 h, whereas the chlorophyll in the lettuce causes severe SERS spectral interference. To improve the LOD of lettuce, a three-step filtration method with a hydrophobic filter is proposed. The hydrophobic filter can effectively eliminate the interferences from chlorophyll and achieve a LOD of 1000 CFU/mL detection of E. coli O157:H7 from lettuce samples within 5 h. With the low LODs and rapid detection time, the SERS biosensing platform has demonstrated its potential as a rapid, simple, and inexpensive means for pathogenic bacteria detection from fresh produce.

  1. Perforin-2 is essential for intracellular defense of parenchymal cells and phagocytes against pathogenic bacteria.

    PubMed

    McCormack, Ryan M; de Armas, Lesley R; Shiratsuchi, Motoaki; Fiorentino, Desiree G; Olsson, Melissa L; Lichtenheld, Mathias G; Morales, Alejo; Lyapichev, Kirill; Gonzalez, Louis E; Strbo, Natasa; Sukumar, Neelima; Stojadinovic, Olivera; Plano, Gregory V; Munson, George P; Tomic-Canic, Marjana; Kirsner, Robert S; Russell, David G; Podack, Eckhard R

    2015-01-01

    Perforin-2 (MPEG1) is a pore-forming, antibacterial protein with broad-spectrum activity. Perforin-2 is expressed constitutively in phagocytes and inducibly in parenchymal, tissue-forming cells. In vitro, Perforin-2 prevents the intracellular replication and proliferation of bacterial pathogens in these cells. Perforin-2 knockout mice are unable to control the systemic dissemination of methicillin-resistant Staphylococcus aureus (MRSA) or Salmonella typhimurium and perish shortly after epicutaneous or orogastric infection respectively. In contrast, Perforin-2-sufficient littermates clear the infection. Perforin-2 is a transmembrane protein of cytosolic vesicles -derived from multiple organelles- that translocate to and fuse with bacterium containing vesicles. Subsequently, Perforin-2 polymerizes and forms large clusters of 100 Å pores in the bacterial surface with Perforin-2 cleavage products present in bacteria. Perforin-2 is also required for the bactericidal activity of reactive oxygen and nitrogen species and hydrolytic enzymes. Perforin-2 constitutes a novel and apparently essential bactericidal effector molecule of the innate immune system. PMID:26402460

  2. HVEM signalling at mucosal barriers provides host defence against pathogenic bacteria.

    PubMed

    Shui, Jr-Wen; Larange, Alexandre; Kim, Gisen; Vela, Jose Luis; Zahner, Sonja; Cheroutre, Hilde; Kronenberg, Mitchell

    2012-08-01

    The herpes virus entry mediator (HVEM), a member of the tumour-necrosis factor receptor family, has diverse functions, augmenting or inhibiting the immune response. HVEM was recently reported as a colitis risk locus in patients, and in a mouse model of colitis we demonstrated an anti-inflammatory role for HVEM, but its mechanism of action in the mucosal immune system was unknown. Here we report an important role for epithelial HVEM in innate mucosal defence against pathogenic bacteria. HVEM enhances immune responses by NF-κB-inducing kinase-dependent Stat3 activation, which promotes the epithelial expression of genes important for immunity. During intestinal Citrobacter rodentium infection, a mouse model for enteropathogenic Escherichia coli infection, Hvem−/− mice showed decreased Stat3 activation, impaired responses in the colon, higher bacterial burdens and increased mortality. We identified the immunoglobulin superfamily molecule CD160 (refs 7 and 8), expressed predominantly by innate-like intraepithelial lymphocytes, as the ligand engaging epithelial HVEM for host protection. Likewise, in pulmonary Streptococcus pneumoniae infection, HVEM is also required for host defence. Our results pinpoint HVEM as an important orchestrator of mucosal immunity, integrating signals from innate lymphocytes to induce optimal epithelial Stat3 activation, which indicates that targeting HVEM with agonists could improve host defence. PMID:22801499

  3. Perforin-2 is essential for intracellular defense of parenchymal cells and phagocytes against pathogenic bacteria

    PubMed Central

    McCormack, Ryan M; de Armas, Lesley R; Shiratsuchi, Motoaki; Fiorentino, Desiree G; Olsson, Melissa L; Lichtenheld, Mathias G; Morales, Alejo; Lyapichev, Kirill; Gonzalez, Louis E; Strbo, Natasa; Sukumar, Neelima; Stojadinovic, Olivera; Plano, Gregory V; Munson, George P; Tomic-Canic, Marjana; Kirsner, Robert S; Russell, David G; Podack, Eckhard R

    2015-01-01

    Perforin-2 (MPEG1) is a pore-forming, antibacterial protein with broad-spectrum activity. Perforin-2 is expressed constitutively in phagocytes and inducibly in parenchymal, tissue-forming cells. In vitro, Perforin-2 prevents the intracellular replication and proliferation of bacterial pathogens in these cells. Perforin-2 knockout mice are unable to control the systemic dissemination of methicillin-resistant Staphylococcus aureus (MRSA) or Salmonella typhimurium and perish shortly after epicutaneous or orogastric infection respectively. In contrast, Perforin-2-sufficient littermates clear the infection. Perforin-2 is a transmembrane protein of cytosolic vesicles -derived from multiple organelles- that translocate to and fuse with bacterium containing vesicles. Subsequently, Perforin-2 polymerizes and forms large clusters of 100 Å pores in the bacterial surface with Perforin-2 cleavage products present in bacteria. Perforin-2 is also required for the bactericidal activity of reactive oxygen and nitrogen species and hydrolytic enzymes. Perforin-2 constitutes a novel and apparently essential bactericidal effector molecule of the innate immune system. DOI: http://dx.doi.org/10.7554/eLife.06508.001 PMID:26402460

  4. Marine Antimicrobial Peptides: Nature Provides Templates for the Design of Novel Compounds against Pathogenic Bacteria.

    PubMed

    Falanga, Annarita; Lombardi, Lucia; Franci, Gianluigi; Vitiello, Mariateresa; Iovene, Maria Rosaria; Morelli, Giancarlo; Galdiero, Massimiliano; Galdiero, Stefania

    2016-01-01

    The discovery of antibiotics for the treatment of bacterial infections brought the idea that bacteria would no longer endanger human health. However, bacterial diseases still represent a worldwide treat. The ability of microorganisms to develop resistance, together with the indiscriminate use of antibiotics, is mainly responsible for this situation; thus, resistance has compelled the scientific community to search for novel therapeutics. In this scenario, antimicrobial peptides (AMPs) provide a promising strategy against a wide array of pathogenic microorganisms, being able to act directly as antimicrobial agents but also being important regulators of the innate immune system. This review is an attempt to explore marine AMPs as a rich source of molecules with antimicrobial activity. In fact, the sea is poorly explored in terms of AMPs, but it represents a resource with plentiful antibacterial agents performing their role in a harsh environment. For the application of AMPs in the medical field limitations correlated to their peptide nature, their inactivation by environmental pH, presence of salts, proteases, or other components have to be solved. Thus, these peptides may act as templates for the design of more potent and less toxic compounds. PMID:27213366

  5. Genotypic and antimicrobial characterization of pathogenic bacteria at different stages of cattle slaughtering in southern Brazil.

    PubMed

    Loiko, Márcia R; de Paula, Cheila M D; Langone, Ana C J; Rodrigues, Rochele Q; Cibulski, Samuel; Rodrigues, Rogério de O; Camargo, Anderson C; Nero, Luís A; Mayer, Fabiana Q; Tondo, Eduardo C

    2016-06-01

    Meat can be contaminated in different stages of the slaughtering process and the identification of these stages is the starting point to implement adequate control measures. The objectives of this study were to assess the presence of pathogenic microorganisms in cattle carcasses, to identify the most important contamination points of the slaughtering process, and to evaluate the possible risk factors related to them in a cattle slaughterhouse. To this aim, 108 cattle carcasses were sampled at three stages of the slaughtering process: Point 1 (hides after bleeding); Point 2 (carcasses after hide removal); and Point 3 (carcasses immediately after division). Escherichia coli O157:H7, Listeria monocytogenes and Salmonella Livingstone were isolated from the carcasses. Phenotypic and genotypic characterization indicated that there was cross-contamination among animals, since bacteria with identical genotypic and phenotypic profiles were isolated from different animals at the same sampling day. Furthermore, this is the first report about the isolation of E. coli O157:H7 in a bovine slaughterhouse from southern Brazil. PMID:26896744

  6. High-throughput real-time electrochemical monitoring of LAMP for pathogenic bacteria detection.

    PubMed

    Safavieh, Mohammadali; Ahmed, Minhaz Uddin; Ng, Andy; Zourob, Mohammed

    2014-08-15

    One of the significant challenges in healthcare is the development of point-of-care (POC) diagnostics. POC diagnostics require low-cost devices that offer portability, simplicity in operation and the ability for high-throughput and quantitative analysis. Here, we present a novel roll-to-roll ribbon fluid-handling device for electrochemical real-time monitoring of nucleic acid (NA) amplification and bacteria detection. The device rendered loop-mediated isothermal amplification (LAMP) and real-time electrochemical detection based on the interaction between LAMP amplicon and the redox-reactive osmium complex. We have shown the detection of 30CFU/ml of Escherichia coli (in the range between 30 and 3×10(7)CFU/ml) and 200CFU/ml of Staphylococcus aureus (in the range of 200-2×10(5)CFU/ml) cultured samples in both real-time and end point detection. This device can be used for the detection of various Gram-negative and a number of Gram-positive bacterial pathogens with high sensitivity and specificity in a high-throughput format. Using a roll-to-roll cassette approach, we could detect 12 samples in one assay. Since the LAMP and electrochemical analysis are implemented within sealed flexible biochips, time-consuming processing steps are not required and the risk of contamination is significantly reduced. PMID:24632135

  7. Microalgae mediated synthesis of silver nanoparticles and their antibacterial activity against pathogenic bacteria.

    PubMed

    Sudha, S S; Rajamanickam, Karthic; Rengaramanujam, J

    2013-05-01

    Silver nanoparticles is known to have antimicrobial affects. Cyanobacteria isolates from muthupet mangrove includes Aphanothece sp, Oscillatoria sp, Microcoleus sp, Aphanocapsa sp, Phormidium sp, Lyngbya sp, Gleocapsa sp, Synechococcus sp, Spirulina sp with were set in compliance with their cellular mechanism of nano silver creation, and were investigated by UV-VIS spectrophotometer, Energy-dispersive X-ray (EDX) and scanning electron microscopy (SEM). Silver nanoparticles were spherical shaped well distributed without aggregation in solution with an average size of about 40- 80 nm. Synthesised nano silver had antibacterial production on various organisms that provoked various diseases in humans. The cellular metabolites of Microcoleus sp. only created nano silver and it enhanced the antibacterial activity against test pathogenic bacteria from MTCC (Proteus vulgaris, Salmonella typhi, Vibrio cholera, Streptococcus sp., Bacillus subtilis, Staphylococcus aureus, Escherichia coli.) The antimicrobial assay was performed using 0.001 M concentration of nano silver in well diffusion method with positive control of appropriate standard antibiotic discs Cephotaxime, Ampicillin, Tetracyclin, Cephalexin etc. Synthesised silver nanoparticles acted as an effective antimicrobial agent and proved as an alternative for the development of new antimicrobial agents to combat the problem of resistance. PMID:23821828

  8. Cultured enterocytes internalise bacteria across their basolateral surface for, pathogen-inhibitable, trafficking to the apical compartment

    PubMed Central

    Dean, Paul; Quitard, Sabine; Bulmer, David M.; Roe, Andrew J.; Kenny, Brendan

    2015-01-01

    In vitro- and in vivo-polarised absorptive epithelia (enterocytes) are considered to be non-phagocytic towards bacteria with invasive pathogenic strains relying on virulence factors to ‘force’ entry. Here, we report a serendipitous discovery that questions these beliefs. Thus, we uncover in well-established models of human small (Caco-2; TC-7) and large (T84) intestinal enterocytes a polarization-dependent mechanism that can transfer millions of bacteria from the basal to apical compartment. Antibiotic-protection assays, confocal imaging and drug inhibitor data are consistent with a transcellular route in which internalized, basolateral-membrane enclosed bacteria are trafficked to and across the apical surface. Basal-to-apical transport of non-pathogenic bacteria (and inert beads) challenged the idea of pathogens relying on virulence factors to force entry. Indeed, studies with Salmonella demonstrated that it’s entry-forcing virulence factor (SPI-I) was not required to enter via the basolateral surface but to promote another virulence-associated event (intra-enterocyte accumulation). PMID:26612456

  9. Factors Affecting Microbial Load and Profile of Potential Pathogens and Food Spoilage Bacteria from Household Kitchen Tables

    PubMed Central

    Latouche, Melissa Cathleen

    2016-01-01

    The aim was to study the bacterial load and isolate potential pathogens and food spoilage bacteria from kitchen tables, including preparation tables and dining tables. Methods. A total of 53 households gave their consent for participation. The samples were collected by swabbing over an area of 5 cm by 5 cm of the tables and processed for bacterial count which was read as colony forming units (CFU), followed by isolation and identification of potential pathogens and food spoilage bacteria. Result. Knowledge about hygiene was not always put into practice. Coliforms, Enterococcus spp., Pseudomonas spp., Proteus spp., and S. aureus were detected from both dining and preparation tables. The mean CFU and presence of potential pathogens were significantly affected by the hygienic practices of the main food handler of the house, materials of kitchen tables, use of plastic covers, time of sample collection, use of multipurpose sponges/towels for cleaning, and the use of preparation tables as chopping boards (p < 0.05). Conclusion. Kitchen tables could be very important source of potential pathogens and food spoilage bacteria causing foodborne diseases. Lack of hygiene was confirmed by presence of coliforms, S. aureus, and Enterococcus spp. The use of plastic covers, multipurpose sponges, and towels should be discouraged. PMID:27446220

  10. The inhibitory effect of Thymus vulgaris extracts on the planktonic form and biofilm structures of six human pathogenic bacteria

    PubMed Central

    Mohsenipour, Zeinab; Hassanshahian, Mehdi

    2015-01-01

    Objective: Microorganisms are responsible for many problems in industry and medicine because of biofilm formation. Therefore, this study was aimed to examine the effect of Thymus vulgaris (T. vulgaris) extracts on the planktonic form and biofilm structures of six pathogenic bacteria. Materials and methods: Antimicrobial activities of the plant extracts against the planktonic form of the bacteria were determined using the disc diffusion method. MIC and MBC values were evaluated using macrobroth dilution technique. Anti-biofilm effects were assessed by microtiter plate method. Results: According to disc diffusion test (MIC and MBC), the ability of Thymus vulgaris (T. vulgaris ) extracts for inhibition of bacteria in planktonic form was confirmed. In dealing with biofilm structures, the inhibitory effect of the extracts was directly correlated to their concentration. Except for the inhibition of biofilm formation, efficacy of each extract was independent from type of solvent. Conclusion: According to the potential of Thymus vulgaris (T. vulgaris) extracts to inhibit the test bacteria in planktonic and biofilm form, it can be suggested that Thymus vulgaris (T. vulgaris) extracts can be applied as antimicrobial agents against the pathogenic bacteria particularly in biofilm forms. PMID:26442753

  11. The inhibitory activity of Lactobacillus spp. isolated from breast milk on gastrointestinal pathogenic bacteria of nosocomial origin.

    PubMed

    Jara, Solange; Sánchez, Magaly; Vera, Rodrigo; Cofré, Jaime; Castro, Erica

    2011-12-01

    Milk acts as a mean for transporting many essential substances from the mother to the child. In human beings, milk includes several predominant bacteria, such as staphylococci, streptococci, micrococci, lactobacilli, enterococci, lactococci and bifidobacteria. Besides, its intake favors the predominance of bifidobacteria and lactobacilli in the child's intestinal microbiota. The present work explores the isolation and selection of lactobacilli strains with probiotic potential, focusing in their degree of hydrophobicity and antagonism against important gastrointestinal nosocomial pathogens. 98 lactobacilli were isolated from 48 breast milk samples, with most strains belonging to the obligately homofermentative group (36.7%). 63% of the isolated strains showed a high degree of hydrophobicity when tested on three solvents and were selected for detecting antimicrobial activity against gastrointestinal pathogens, including Escherichia coli, Shigella spp, Pseudomonas spp and Salmonella spp strains. When applying the agar diffusion test, many isolated strains presented inhibitory activity against pathogenic strains. We observed that: Salmonella enteriditis was the most inhibited pathogen, and the strains with the most inhibitory power were AR2 and O1 (both highly hydrophobic lactic acid bacteria), which showed an opposing effect against all nosocomial pathogens tested. Although more in vitro, in vivo or clinical data would be needed before any conclusion on the probiotic properties of the strains can be drawn, our results demonstrate that some of the tested strains may have good probiotic potential for their inclusion in products targeting infants. PMID:21846506

  12. Biosensors based on modularly designed synthetic peptides for recognition, detection and live/dead differentiation of pathogenic bacteria.

    PubMed

    Liu, Xiaobo; Marrakchi, Mouna; Xu, Dawei; Dong, He; Andreescu, Silvana

    2016-06-15

    Rapid and sensitive detection of bacterial pathogens is critical for assessing public health, food and environmental safety. We report the use of modularly designed and site-specifically oriented synthetic antimicrobial peptides (sAMPs) as novel recognition agents enabling detection and quantification of bacterial pathogens. The oriented assembly of the synthetic peptides on electrode surfaces through an engineered cysteine residue coupled with impedimetric detection facilitated rapid and sensitive detection of bacterial pathogens with a detection limit of 10(2)CFU/mL for four bacterial strains including Escherichia coli (E. coli), Pseudomonas aeruginosa (P. aeruginosa), Staphylococcus aureus (S. aureus) and Staphylococcus epidermidis (S. epidermidis). The approach enabled differentiation between live and dead bacteria. The fabrication of the sAMPs functionalized surface and the importance of the sAMPs orientation for providing optimum recognition and detection ability against pathogens are discussed. The proposed methodology provides a universal platform for the detection of bacterial pathogens based on engineered peptides, as alternative to the most commonly used immunological and gene based assays. The method can also be used to fabricate antimicrobial coatings and surfaces for inactivation and screening of viable bacteria. PMID:26802747

  13. OEM--a new medium for rapid isolation of onion-pathogenic and onion-associated bacteria.

    PubMed

    Zaid, Ali M; Bonasera, Jean M; Beer, Steven V

    2012-12-01

    Onions (Allium cepa L.) are plagued by a number of bacterial pathogens including Pantoea ananatis, P. agglomerans, Burkholderia cepacia, Enterobacter cloacae, Pectobacterium carotovorum subsp. carotovorum, Xanthomonas axonopodis pv. axonopodis and several Pseudomonas spp. We developed a semi-selective medium, termed onion extract medium (OEM), to selectively and rapidly isolate bacteria pathogenic to and associated with onions and onion-related samples including bulbs, seeds, sets, transplant seedlings, soil and water. Most strains of interest grow sufficiently on OEM in 24h at 28°C for tentative identification based on colony morphology, facilitating further characterization by microbiological and/or molecular means. PMID:23041494

  14. Molecular characterization by amplified ribosomal DNA restriction analysis and antimicrobial potential of endophytic fungi isolated from Luehea divaricata (Malvaceae) against plant pathogenic fungi and pathogenic bacteria.

    PubMed

    Bernardi-Wenzel, J; Garcia, A; Azevedo, J L; Pamphile, J A

    2013-01-01

    Luehea divaricata is an important plant in popular medicine; it is used for its depurative, anti-inflammatory, and other therapeutic activities. We evaluated the antimicrobial activity of endophytic fungi isolated from leaves of L. divaricata against phytopathogens and pathogenic bacteria, and characterized the isolates based on amplified ribosomal DNA restriction analysis (ARDRA). The in vitro antagonistic activity of these endophytes against the phytopathogen Alternaria alternata was assayed by dual culture technique. Based on this evaluation of antimicrobial activity, we extracted secondary metabolites from nine endophytic fungi by partitioning in ethyl acetate and methanol. These were tested against the phytopathogens A. alternata, Colletotrichum sp and Moniliophthora perniciosa, and against the human pathogenic bacteria Escherichia coli and Staphylococcus aureus. Molecular characterization by ARDRA technique was used for phylogenetic analysis, based on comparison with sequences in GenBank. The endophytes had varied effects on A. alternata. One isolate produced an inhibition halo against M. perniciosa and against E. coli. This antibiosis activity indicates a role in the protection of the plant against microbial pathogens in nature, with potential for pharmaceutical and agricultural applications. Based on ARDRA, the 13 isolates were grouped. We found three different haplotypes of Phomopsis sp, showing interspecific variability. It appears that examination of the microbial community associated with medicinal plants of tropical regions has potential as a useful strategy to look for species with biotechnological applications. PMID:24301768

  15. The Phytoplankton Nannochloropsis oculata Enhances the Ability of Roseobacter Clade Bacteria to Inhibit the Growth of Fish Pathogen Vibrio anguillarum

    PubMed Central

    Sharifah, Emilia Noor; Eguchi, Mitsuru

    2011-01-01

    Background Phytoplankton cultures are widely used in aquaculture for a variety of applications, especially as feed for fish larvae. Phytoplankton cultures are usually grown in outdoor tanks using natural seawater and contain probiotic or potentially pathogenic bacteria. Some Roseobacter clade isolates suppress growth of the fish pathogen Vibrio anguillarum. However, most published information concerns interactions between probiotic and pathogenic bacteria, and little information is available regarding the importance of phytoplankton in these interactions. The objectives of this study, therefore, were to identify probiotic Roseobacter clade members in phytoplankton cultures used for rearing fish larvae and to investigate their inhibitory activity towards bacterial fish pathogens in the presence of the phytoplankton Nannochloropsis oculata. Methodology/Principal Findings The fish pathogen V. anguillarum, was challenged with 6 Roseobacter clade isolates (Sulfitobacter sp. (2 strains), Thalassobius sp., Stappia sp., Rhodobacter sp., and Antarctobacter sp.) from phytoplankton cultures under 3 different nutritional conditions. In an organic nutrient-rich medium (VNSS), 6 Roseobacter clade isolates, as well as V. anguillarum, grew well (109 CFU/ml), even when cocultured. In contrast, in a phytoplankton culture medium (ESM) based on artificial seawater, coculture with the 6 isolates decreased the viability of V. anguillarum by approximately more than 10-fold. Excreted substances in media conditioned by growth of the phytoplankton N. oculata (NCF medium) resulted in the complete eradication of V. anguillarum when cocultured with the roseobacters. Autoclaved NCF had the same inhibitory effect. Furthermore, Sulfitobacter sp. much more efficiently incorporated 14C- photosynthetic metabolites (14C-EPM) excreted by N. oculata than did V. anguillarum. Conclusion/Significance Cocultures of a phytoplankton species and Roseobacter clade members exhibited a greater antibacterial

  16. Inhibitory Effects of Gallic Acid Isolated from Caesalpinia mimosoides Lamk on Cholangiocarcinoma Cell Lines and Foodborne Pathogenic Bacteria.

    PubMed

    Rattanata, Narintorn; Klaynongsruang, Sompong; Daduang, Sakda; Tavichakorntrakool, Ratree; Limpaiboon, Temduang; Lekphrom, Ratsami; Boonsiri, Patcharee; Daduang, Jureerut

    2016-01-01

    Gallic acid was isolated from Caesalpinia mimosoides Lamk and the structure s identified based on spectroscopic analysis and comparison with authentic compound. In this study we compared the ability of natural gallic acid (nGA) and commercial gallic acid (cGA) to inhibit the proliferation of cholangiocarcinoma cell lines (M213, M214) and foodborne pathogenic bacteria (Salmonella spp. and Plesiomonas shigelloides). Both nGA and cGA had the same inhibitory effects on cell proliferation by inducing apoptosis of cholangiocarcinoma cell lines. In addition, nGA inhibited growth of foodborne pathogenic bacteria in the same manner as cGA. Our results suggest that nGA from Caesalpinia mimosoides Lamk is a potential anticancer and antibacterial compound. However, in vivo studies are needed to elucidate the specific mechanisms involved. PMID:27039769

  17. Detection and characterization of foodborne pathogenic bacteria with hyperspectral microscope imaging

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rapid detection and identification of pathogenic microorganisms naturally occurring during food processing are important in developing intervention and verification strategies. In the poultry industry, contamination of poultry meat with foodborne pathogens (especially, Salmonella and Campylobacter) ...

  18. Antimicrobial activities of chicken β-defensin (4 and 10) peptides against pathogenic bacteria and fungi

    PubMed Central

    Yacoub, Haitham A.; Elazzazy, Ahmed M.; Abuzinadah, Osama A. H.; Al-Hejin, Ahmed M.; Mahmoud, Maged M.; Harakeh, Steve M.

    2015-01-01

    Host Defense Peptides (HDPs) are small cationic peptides found in several organisms. They play a vital role in innate immunity response and immunomodulatory stimulation. This investigation was designed to study the antimicrobial activities of β-defensin peptide-4 (sAvBD-4) and 10 (sAvBD-4) derived from chickens against pathogenic organisms including bacteria and fungi. Ten bacterial strains and three fungal species were used in investigation. The results showed that the sAvBD-10 displayed a higher bactericidal potency against all the tested bacterial strains than that of sAvBD-4. The exhibited bactericidal activity was significant against almost the different bacterial strains at different peptide concentrations except for that of Pseudomonas aeruginosa (P. aeruginosa) and Streptococcus bovis (Str. bovis) strains where a moderate effect was noted. Both peptides were effective in the inactivation of fungal species tested yielding a killing rate of up to 95%. The results revealed that the synthetic peptides were resistant to salt at a concentration of 50 mM NaCl. However, they lost antimicrobial potency when applied in the presence of high salt concentrations. Based on blood hemolysis studies, a little hemolytic effect was showed in the case of both peptides even when applied at high concentrations. The data obtained from this study indicated that synthetic avian peptides exhibit strong antibacterial and antifungal activity. In conclusion, future work and research should be tailored to a better understanding of the mechanisms of action of those peptides and their potential use in the pharmaceutical industry to help reduce the incidence and impact of infectious agent and be marketed as a naturally occurring antibiotic. PMID:25941665

  19. Comparing wastewater chemicals, indicator bacteria concentrations, and bacterial pathogen genes as fecal pollution indicators

    USGS Publications Warehouse

    Haack, S.K.; Duris, J.W.; Fogarty, L.R.; Kolpin, D.W.; Focazio, M.J.; Furlong, E.T.; Meyer, M.T.

    2009-01-01

    The objective of this study was to compare fecal indicator bacteria (FIB) (fecal coliforms, Escherichia coli [EC], and enterococci [ENT]) concentrations with a wide array of typical organic wastewater chemicals and selected bacterial genes as indicators of fecal pollution in water samples collected at or near 18 surface water drinking water intakes. Genes tested included esp (indicating human-pathogenic ENT) and nine genes associated with various animal sources of shiga-toxin-producing EC (STEC). Fecal pollution was indicated by genes and/or chemicals for 14 of the 18 tested samples, with little relation to FIB standards. Of 13 samples with <50 EC 100 mL-1, human pharmaceuticals or chemical indicators of wastewater treatment plant effluent occurred in six, veterinary antibiotics were detected in three, and stx1 or stx2 genes (indicating varying animal sources of STEC) were detected in eight. Only the EC eaeA gene was positively correlated with FIB concentrations. Human-source fecal pollution was indicated by the esp gene and the human pharmaceutical carbamazepine in one of the nine samples that met all FIB recreational water quality standards. Escherichia coli rfbO157 and stx2c genes, which are typically associated with cattle sources and are of potential human health significance, were detected in one sample in the absence of tested chemicals. Chemical and gene-based indicators of fecal contamination may be present even when FIB standards are met, and some may, unlike FIB, indicate potential sources. Application of multiple water quality indicators with variable environmental persistence and fate may yield greater confidence in fecal pollution assessment and may inform remediation decisions. Copyright ?? 2009 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved.

  20. Suppression of Emergence of Resistance in Pathogenic Bacteria: Keeping Our Powder Dry, Part 1.

    PubMed

    Drusano, G L; Louie, Arnold; MacGowan, Alasdair; Hope, William

    2016-03-01

    We are in a crisis of bacterial resistance. For economic reasons, most pharmaceutical companies are abandoning antimicrobial discovery efforts, while, in health care itself, infection control and antibiotic stewardship programs have generally failed to prevent the spread of drug-resistant bacteria. At this point, what can be done? The first step has been taken. Governments and international bodies have declared there is a worldwide crisis in antibiotic drug resistance. As discovery efforts begin anew, what more can be done to protect newly developing agents and improve the use of new drugs to suppress resistance emergence? A neglected path has been the use of recent knowledge regarding antibiotic dosing as single agents and in combination to minimize resistance emergence, while also providing sufficient early bacterial kill. In this review, we look at the data for resistance suppression. Approaches include increasing the intensity of therapy to suppress resistant subpopulations; developing concepts of clinical breakpoints to include issues surrounding suppression of resistance; and paying attention to the duration of therapy, which is another important issue for resistance suppression. New understanding of optimizing combination therapy is of interest for difficult-to-treat pathogens like Pseudomonas aeruginosa, Acinetobacter spp., and multidrug-resistant (MDR) Enterobacteriaceae. These lessons need to be applied to our old drugs to preserve them as well and need to be put into national and international antibiotic resistance strategies. As importantly, from a regulatory perspective, new chemical entities should have a corresponding resistance suppression plan at the time of regulatory review. In this way, we can make the best of our current situation and improve future prospects. PMID:26711759

  1. Suppression of Emergence of Resistance in Pathogenic Bacteria: Keeping Our Powder Dry, Part 2.

    PubMed

    Drusano, G L; Hope, William; MacGowan, Alasdair; Louie, Arnold

    2016-03-01

    We are in a crisis of bacterial resistance. For economic reasons, most pharmaceutical companies are abandoning antimicrobial discovery efforts, while, in health care itself, infection control and antibiotic stewardship programs have generally failed to prevent the spread of drug-resistant bacteria. At this point, what can be done? The first step has been taken. Governments and international bodies have declared there is a worldwide crisis in antibiotic drug resistance. As discovery efforts begin anew, what more can be done to protect newly developing agents and improve the use of new drugs to suppress resistance emergence? A neglected path has been the use of recent knowledge regarding antibiotic dosing as single agents and in combination to minimize resistance emergence, while also providing sufficient early bacterial kill. In this review, we look at the data for resistance suppression. Approaches include increasing the intensity of therapy to suppress resistant subpopulations; developing concepts of clinical breakpoints to include issues surrounding suppression of resistance; and paying attention to the duration of therapy, which is another important issue for resistance suppression. New understanding of optimizing combination therapy is of interest for difficult-to-treat pathogens like Pseudomonas aeruginosa, Acinetobacter spp., and multidrug-resistant (MDR) Enterobacteriaceae. These lessons need to be applied to our old drugs as well to preserve them and to be put into national and international antibiotic resistance strategies. As importantly, from a regulatory perspective, new chemical entities should have a resistance suppression plan at the time of regulatory review. In this way, we can make the best of our current situation and improve future prospects. PMID:26711766

  2. Routine Testing for Anaerobic Bacteria in Cerebrospinal Fluid Cultures Improves Recovery of Clinically Significant Pathogens

    PubMed Central

    Pittman, Meredith E.; Thomas, Benjamin S.; Wallace, Meghan A.; Weber, Carol J.

    2014-01-01

    In North America, the widespread use of vaccines targeting Haemophilus influenzae type b and Streptococcus pneumoniae have dramatically altered the epidemiology of bacterial meningitis, while the methodology for culturing cerebrospinal fluid (CSF) specimens has remained largely unchanged. The aims of this study were 2-fold: to document the current epidemiology of bacterial meningitis at a tertiary care medical center and to assess the clinical utility of routinely querying for anaerobes in CSF cultures. To that end, we assessed CSF cultures submitted over a 2-year period. A brucella blood agar (BBA) plate, incubated anaerobically for 5 days, was included in the culture procedure for all CSF specimens during the second year of evaluation. In the pre- and postimplementation years, 2,353 and 2,302 CSF specimens were cultured, with 49 and 99 patients having positive culture results, respectively. The clinical and laboratory data for patients with positive cultures were reviewed. Anaerobic bacteria were isolated in the CSF samples from 33 patients post-BBA compared to two patients pre-BBA (P = 0.01). The anaerobic isolates included Bacteroides thetaiotaomicron (n = 1), Propionibacterium species (n = 15), and Propionibacterium acnes (n = 19) isolates; all of these isolates were recovered on the BBA. Eight of the 35 patients from whom anaerobic organisms were isolated received antimicrobial therapy. Although six of these patients had central nervous system hardware, two patients did not have a history of a neurosurgical procedure and had community-acquired anaerobic bacterial meningitis. This study demonstrates that the simple addition of an anaerobically incubated BBA to the culture of CSF specimens enhances the recovery of clinically significant anaerobic pathogens. PMID:24622102

  3. Antimicrobial activities of chicken β-defensin (4 and 10) peptides against pathogenic bacteria and fungi.

    PubMed

    Yacoub, Haitham A; Elazzazy, Ahmed M; Abuzinadah, Osama A H; Al-Hejin, Ahmed M; Mahmoud, Maged M; Harakeh, Steve M

    2015-01-01

    Host Defense Peptides (HDPs) are small cationic peptides found in several organisms. They play a vital role in innate immunity response and immunomodulatory stimulation. This investigation was designed to study the antimicrobial activities of β-defensin peptide-4 (sAvBD-4) and 10 (sAvBD-4) derived from chickens against pathogenic organisms including bacteria and fungi. Ten bacterial strains and three fungal species were used in investigation. The results showed that the sAvBD-10 displayed a higher bactericidal potency against all the tested bacterial strains than that of sAvBD-4. The exhibited bactericidal activity was significant against almost the different bacterial strains at different peptide concentrations except for that of Pseudomonas aeruginosa (P. aeruginosa) and Streptococcus bovis (Str. bovis) strains where a moderate effect was noted. Both peptides were effective in the inactivation of fungal species tested yielding a killing rate of up to 95%. The results revealed that the synthetic peptides were resistant to salt at a concentration of 50 mM NaCl. However, they lost antimicrobial potency when applied in the presence of high salt concentrations. Based on blood hemolysis studies, a little hemolytic effect was showed in the case of both peptides even when applied at high concentrations. The data obtained from this study indicated that synthetic avian peptides exhibit strong antibacterial and antifungal activity. In conclusion, future work and research should be tailored to a better understanding of the mechanisms of action of those peptides and their potential use in the pharmaceutical industry to help reduce the incidence and impact of infectious agent and be marketed as a naturally occurring antibiotic. PMID:25941665

  4. Genomic fluidity and pathogenic bacteria: applications in diagnostics, epidemiology and intervention.

    PubMed

    Ahmed, Niyaz; Dobrindt, Ulrich; Hacker, Jörg; Hasnain, Seyed E

    2008-05-01

    The increasing availability of DNA-sequence information for multiple pathogenic and non-pathogenic variants of individual bacterial species has indicated that both DNA acquisition and genome reduction have important roles in genome evolution. Such genomic fluidity, which is found in human pathogens such as Escherichia coli, Helicobacter pylori and Mycobacterium tuberculosis, has important consequences for the clinical management of the diseases that are caused by these pathogens and for the development of diagnostics and new molecular epidemiological methods. PMID:18392032

  5. An antibody microarray, in multiwell plate format, for multiplex screening of foodborne pathogenic bacteria and biomolecules

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Intoxication and infection caused by foodborne pathogens are important problems in the United States, and screening tests for multiple pathogen detection have been developed because food producers are known reservoirs of multiple pathogens. We developed a 96-well microplate, multiplex antibody micr...

  6. Antibacterial Activity of Euphorbia hebecarpa Alcoholic Extracts Against Six Human Pathogenic Bacteria in Planktonic and Biofilm Forms

    PubMed Central

    Mohsenipour, Zeinab; Hassanshahian, Mehdi

    2016-01-01

    Background Biofilm formation is a primary cause of considerable bacterial destruction. Objectives In an effort to combat these industrial and medical bacterial biofilm problems, our study aims to determine the antimicrobial effect of Euphorbia hebecarpa. Materials and Methods The inhibition efficiency of alcoholic extracts on the planktonic form of six pathogenic bacteria was evaluated using a disk diffusion technique. The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) values were determined by means of a macrobroth dilution method. The effects of the extracts on biofilms were calculated using a microtiter plate method. Results The results of the disk diffusion assay (MBC and MIC) confirmed that E. hebecarpa ethanolic extracts were more efficient than methanolic extracts in the inhibition of planktonic forms of bacteria. Also, the inhibitory effect of the extracts in a broth medium was greater than in a solid medium. Extracts of E. hebecarpa were found to inhibit biofilm formation better than demolish of biofilm and preventing metabolic activity of bacteria in biofilm structures. The greatest inhibitory effects of E. hebecarpa extracts were observed for the biofilm formation of B. cereus (92.81%). In addition, the greatest demolition was observed for the S. aureus biofilm (74.49%), and the metabolic activity decrement of this bacteria was highest (78.21%) of all the tested bacteria. Conclusions The results of this study suggest that E. hebecarpa extracts can be used to inhibit the planktonic and biofilm forms of these selected bacteria.

  7. NLRC4-driven interleukin-1β production discriminates between pathogenic and commensal bacteria and promotes host intestinal defense

    PubMed Central

    Franchi, Luigi; Kamada, Nobuhiko; Nakamura, Yuumi; Burberry, Aaron; Kuffa, Peter; Suzuki, Shiho; Shaw, Michael H.; Kim, Yun-Gi; Núñez, Gabriel

    2012-01-01

    Intestinal phagocytes transport oral antigens and promote immune tolerance, but their role in innate immune responses remains unclear. Here we report that intestinal phagocytes are anergic to Toll-like receptor ligands or commensals, but constitutively express pro-interleukin-1β (proIL-1β). Upon infection with pathogenic Salmonella or Pseudomonas, intestinal phagocytes produce mature IL-1β through the NLRC4 inflammasome, but not tumor necrosis factor or IL-6. Mice deficient in NLRC4 or IL-1 receptor on a Balb/c background were highly susceptible to orogastric but not intraperitoneal infection with Salmonella. Increased lethality was preceded by impaired expression of endothelial adhesion molecules, lower neutrophil recruitment, and poor intestinal pathogen clearance. Thus, NLRC4-dependent IL-1β production by intestinal phagocytes represents a specific response discriminating pathogenic from commensal bacteria and contributes to host defense in the intestine. PMID:22484733

  8. Collaborative action of Toll-like and NOD-like receptors as modulators of the inflammatory response to pathogenic bacteria.

    PubMed

    Oviedo-Boyso, Javier; Bravo-Patiño, Alejandro; Baizabal-Aguirre, Víctor M

    2014-01-01

    Early sensing of pathogenic bacteria by the host immune system is important to develop effective mechanisms to kill the invader. Microbial recognition, activation of signaling pathways, and effector mechanisms are sequential events that must be highly controlled to successfully eliminate the pathogen. Host recognizes pathogens through pattern-recognition receptors (PRRs) that sense pathogen-associated molecular patterns (PAMPs). Some of these PRRs include Toll-like receptors (TLRs), nucleotide-binding oligomerization domain-like receptors (NLRs), retinoic acid-inducible gene-I- (RIG-I-) like receptors (RLRs), and C-type lectin receptors (CLRs). TLRs and NLRs are PRRs that play a key role in recognition of extracellular and intracellular bacteria and control the inflammatory response. The activation of TLRs and NLRs by their respective ligands activates downstream signaling pathways that converge on activation of transcription factors, such as nuclear factor-kappaB (NF-κB), activator protein-1 (AP-1) or interferon regulatory factors (IRFs), leading to expression of inflammatory cytokines and antimicrobial molecules. The goal of this review is to discuss how the TLRs and NRLs signaling pathways collaborate in a cooperative or synergistic manner to counteract the infectious agents. A deep knowledge of the biochemical events initiated by each of these receptors will undoubtedly have a high impact in the design of more effective strategies to control inflammation. PMID:25525300

  9. Collaborative Action of Toll-Like and Nod-Like Receptors as Modulators of the Inflammatory Response to Pathogenic Bacteria

    PubMed Central

    Bravo-Patiño, Alejandro; Baizabal-Aguirre, Víctor M.

    2014-01-01

    Early sensing of pathogenic bacteria by the host immune system is important to develop effective mechanisms to kill the invader. Microbial recognition, activation of signaling pathways, and effector mechanisms are sequential events that must be highly controlled to successfully eliminate the pathogen. Host recognizes pathogens through pattern-recognition receptors (PRRs) that sense pathogen-associated molecular patterns (PAMPs). Some of these PRRs include Toll-like receptors (TLRs), nucleotide-binding oligomerization domain-like receptors (NLRs), retinoic acid-inducible gene-I- (RIG-I-) like receptors (RLRs), and C-type lectin receptors (CLRs). TLRs and NLRs are PRRs that play a key role in recognition of extracellular and intracellular bacteria and control the inflammatory response. The activation of TLRs and NLRs by their respective ligands activates downstream signaling pathways that converge on activation of transcription factors, such as nuclear factor-kappaB (NF-κB), activator protein-1 (AP-1) or interferon regulatory factors (IRFs), leading to expression of inflammatory cytokines and antimicrobial molecules. The goal of this review is to discuss how the TLRs and NRLs signaling pathways collaborate in a cooperative or synergistic manner to counteract the infectious agents. A deep knowledge of the biochemical events initiated by each of these receptors will undoubtedly have a high impact in the design of more effective strategies to control inflammation. PMID:25525300

  10. PCR primers and probes for the 16S rRNA gene of most species of pathogenic bacteria, including bacteria found in cerebrospinal fluid.

    PubMed Central

    Greisen, K; Loeffelholz, M; Purohit, A; Leong, D

    1994-01-01

    A set of broad-range PCR primers for the 16S rRNA gene in bacteria were tested, along with three series of oligonucleotide probes to detect the PCR product. The first series of probes is broad in range and consists of a universal bacterial probe, a gram-positive probe, a Bacteroides-Flavobacterium probe, and two probes for other gram-negative species. The second series was designed to detect PCR products from seven major bacterial species or groups frequently causing meningitis: Neisseria meningitidis, Haemophilus influenzae, Streptococcus pneumoniae, S. agalactiae, Escherichia coli and other enteric bacteria, Listeria monocytogenes, and Staphylococcus aureus. The third series was designed for the detection of DNA from species or genera commonly considered potential contaminants of clinical samples, including cerebrospinal fluid (CSF): Bacillus, Corynebacterium, Propionibacterium, and coagulase-negative Staphylococcus spp. The primers amplified DNA from all 124 different species of bacteria tested. Southern hybridization testing of the broad-range probes with washes containing 3 M tetramethylammonium chloride indicated that this set of probes correctly identified all but two of the 102 bacterial species tested, the exceptions being Deinococcus radiopugnans and Gardnerella vaginalis. The gram-negative and gram-positive probes hybridized to isolates of two newly characterized bacteria, Alloiococcus otitis and Rochalimaea henselii, as predicted by Gram stain characteristics. The CSF pathogen and contaminant probe sequences were compared with available sequence information and with sequencing data for 32 different species. Testing of the CSF pathogen and contaminant probes against DNA from over 60 different strains indicated that, with the exception of the coagulase-negative Staphylococcus probes, these probes provided the correct identification of bacterial species known to be found in CSF. Images PMID:7512093

  11. Using SWAT, Bacteroidales microbial source tracking markers, and fecal indicator bacteria to predict waterborne pathogen occurrence in an agricultural watershed.

    PubMed

    Frey, Steven K; Topp, Edward; Edge, Thomas; Fall, Claudia; Gannon, Victor; Jokinen, Cassandra; Marti, Romain; Neumann, Norman; Ruecker, Norma; Wilkes, Graham; Lapen, David R

    2013-10-15

    Developing the capability to predict pathogens in surface water is important for reducing the risk that such organisms pose to human health. In this study, three primary data source scenarios (measured stream flow and water quality, modelled stream flow and water quality, and host-associated Bacteroidales) are investigated within a Classification and Regression Tree Analysis (CART) framework for classifying pathogen (Escherichia coli 0157:H7, Salmonella, Campylobacter, Cryptosporidium, and Giardia) presence and absence (P/A) for a 178 km(2) agricultural watershed. To provide modelled data, a Soil Water Assessment Tool (SWAT) model was developed to predict stream flow, total suspended solids (TSS), total N and total P, and fecal indicator bacteria loads; however, the model was only successful for flow and total N and total P simulations, and did not accurately simulate TSS and indicator bacteria transport. Also, the SWAT model was not sensitive to an observed reduction in the cattle population within the watershed that may have resulted in significant reduction in E. coli concentrations and Salmonella detections. Results show that when combined with air temperature and precipitation, SWAT modelled stream flow and total P concentrations were useful for classifying pathogen P/A using CART methodology. From a suite of host-associated Bacteroidales markers used as independent variables in CART analysis, the ruminant marker was found to be the best initial classifier of pathogen P/A. Of the measured sources of independent variables, air temperature, precipitation, stream flow, and total P were found to be the most important variables for classifying pathogen P/A. Results indicate a close relationship between cattle pollution and pathogen occurrence in this watershed, and an especially strong link between the cattle population and Salmonella detections. PMID:24079968

  12. Non-pathogenic bacteria elicit a differential cytokine response by intestinal epithelial cell/leucocyte co-cultures

    PubMed Central

    Haller, D; Bode, C; Hammes, W; Pfeifer, A; Schiffrin, E; Blum, S

    2000-01-01

    BACKGROUND AND AIM—Intestinal epithelial cells (IEC) are thought to participate in the mucosal defence against bacteria and in the regulation of mucosal tissue homeostasis. Reactivity of IEC to bacterial signals may depend on interactions with immunocompetent cells. To address the question of whether non-pathogenic bacteria modify the immune response of the intestinal epithelium, we co-cultivated enterocyte-like CaCO-2 cells with human blood leucocytes in separate compartments of transwell cultures.
METHODS—CaCO-2/PBMC co-cultures were stimulated with non-pathogenic bacteria and enteropathogenic Escherichia coli. Expression of tumour necrosis factor alpha (TNF-α), interleukin (IL)-1β, IL-8, monocyte chemoattracting protein 1 (MCP-1), and IL-10 was studied by enzyme linked immunosorbent assays (cytokine secretion) and by semiquantitative reverse transcription-polymerase chain reaction.
RESULTS—Challenge of CaCO-2 cells with non-pathogenic E coli and Lactobacillus sakei induced expression of IL-8, MCP-1, IL-1β, and TNF-α mRNA in the presence of underlying leucocytes. Leucocyte sensitised CaCO-2 cells produced TNF-α and IL-1β whereas IL-10 was exclusively secreted by human peripheral blood mononuclear cells. CaCO-2 cells alone remained hyporesponsive to the bacterial challenge. Lactobacillus johnsonii, an intestinal isolate, showed reduced potential to induce proinflammatory cytokines but increased transforming growth factor beta mRNA in leucocyte sensitised CaCO-2 cells. TNF-α was identified as one of the early mediators involved in cellular cross talk. In the presence of leucocytes, discriminative activation of CaCO-2 cells was observed between enteropathogenic E coli and non-pathogenic bacteria.
CONCLUSION—The differential recognition of non-pathogenic bacteria by CaCO-2 cells required the presence of underlying leucocytes. These results strengthen the hypothesis that bacterial signalling at the mucosal surface is dependent on a network of

  13. Commensal bacteria can enter colonic epithelial cells and induce proinflammatory cytokine secretion: a possible pathogenic mechanism of ulcerative colitis.

    PubMed

    Ohkusa, Toshifumi; Yoshida, Tsutomu; Sato, Nobuhiro; Watanabe, Sumio; Tajiri, Hisao; Okayasu, Isao

    2009-05-01

    Interleukin 2 (IL-2)- and IL-10-knockout mice develop spontaneous colitis under conventional but not germ-free conditions, suggesting that commensal bacteria play an important role in the pathogenesis of colitis. However, interactions between commensal bacteria and colonic epithelial cells have not been fully investigated. We therefore assessed the ability of various commensal bacteria and probiotics to adhere to and invade colonic epithelial cells. Effects of the bacteria on production of proinflammatory cytokines were also measured. Commensal bacteria, including mucosal organisms isolated from ulcerative colitis (UC) patients, such as Fusobacterium varium, reported as a possible pathogen in UC, Bacteroides vulgatus, Escherichia coli and Clostridium clostridioforme, as well as their type strains and probiotics, were assessed for their ability to adhere to and invade colonic epithelial cells using two cell lines, SW-480 and HT-29. Our experiments employed co-incubation, a combination of scanning and transmission electron microscopy and recovery of bacteria from infected-cell lysates. F. varium and several other commensal bacteria, but not probiotics, adhered to colonic epithelial cells and invaded their cytoplasm. ELISA and real-time PCR revealed that the host cells, particularly those invaded by F. varium, showed significant increases in IL-8 and TNF-alpha concentrations in supernatants, with elevation of IL-8, TNF-alpha, MCP-1 and IL-6 mRNAs. Furthermore, IL-8 and TNF-alpha expression and nuclear phosphorylated NF-kappaB p65 expression could be immunohistochemically confirmed in inflamed epithelium with cryptitis or crypt abscess in UC patients. Certain commensal bacteria can invade colonic epithelial cells, activating early intracellular signalling systems to trigger host inflammatory reactions. PMID:19369513

  14. Combined antibacterial activity of stingless bee (Apis mellipodae) honey and garlic (Allium sativum) extracts against standard and clinical pathogenic bacteria

    PubMed Central

    Andualem, Berhanu

    2013-01-01

    Objective To investigate the synergic antibacterial activity of garlic and tazma honey against standard and clinical pathogenic bacteria. Methods Antimicrobial activity of tazma honey, garlic and mixture of them against pathogenic bacteria were determined. Chloramphenicol and water were used as positive and negative controls, respectively. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration of antimicrobial samples were determined using standard methods. Results Inhibition zone of mixture of garlic and tazma honey against all tested pathogens was significantly (P≤0.05) greater than garlic and tazma honey alone. The diameter zone of inhibition ranged from (18±1) to (35±1) mm for mixture of garlic and tazma honey, (12±1) to (20±1) mm for tazma honey and (14±1) to (22±1) mm for garlic as compared with (10±1) to (30±1) mm for chloramphenicol. The combination of garlic and tazma honey (30-35 mm) was more significantly (P≤0.05) effective against Salmonella (NCTC 8385), Staphylococcus aureus (ATCC 25923), Lyesria moncytogenes (ATCC 19116) and Streptococcus pneumonia (ATCC 63). Results also showed considerable antimicrobial activity of garlic and tazma honey. MIC of mixture of garlic and tazma honey at 6.25% against total test bacteria was 88.9%. MIC of mixture of garlic and tazma honey at 6.25% against Gram positive and negative were 100% and 83.33%, respectively. The bactericidal activities of garlic, tazma honey, and mixture of garlic and tazma honey against all pathogenic bacteria at 6.25% concentration were 66.6%, 55.6% and 55.6%, respectively. Conclusions This finding strongly supports the claim of the local community to use the combination of tazma honey and garlic for the treatment of different pathogenic bacterial infections. Therefore, garlic in combination with tazma honey can serve as an alternative natural antimicrobial drug for the treatment of pathogenic bacterial infections. Further in vivo study is recommended to come

  15. Selection and identification of non-pathogenic bacteria isolated from fermented pickles with antagonistic properties against two shrimp pathogens

    PubMed Central

    Zokaeifar, Hadi; Luis Balcázar, José; Kamarudin, Mohd Salleh; Sijam, Kamaruzaman; Arshad, Aziz; Saad, Che Roos

    2012-01-01

    In this study, potential probiotic strains were isolated from fermented pickles based on antagonistic activity against two shrimp pathogens (Vibrio harveyi and Vibrio parahaemolyticus). Two strains L10 and G1 were identified by biochemical tests, followed by16S ribosomal RNA gene sequence analysis as Bacillus subtilis, and characterized by PCR amplification of repetitive bacterial DNA elements (Rep-PCR). Subsequently, B. subtilis L10 and G1 strains were tested for antibacterial activity under different physical conditions, including culture medium, salinity, pH and temperature using the agar well diffusion assay. Among the different culture media, LB broth was the most suitable medium for antibacterial production. Both strains showed the highest level of antibacterial activity against two pathogens at 30 °C and 1.0% NaCl. Under the pH conditions, strain G1 showed the greatest activity against V. harveyi at pH 7.3–8.0 and against V. parahaemolyticus at pH 6.0–8.0, whereas strain L10 showed the greatest activity against two pathogens at pH 7.3. The cell-free supernatants of both strains were treated with four different enzymes in order to characterize the antibacterial substances against V. harveyi. The result showed considerable reduction of antibacterial activity for both strains, indicating the proteinaceous nature of the antibacterial substances. A wide range of tolerance to NaCl, pH and temperature was also recorded for both strains. In addition, both strains showed no virulence effect in juvenile shrimp Litopenaeus vannamei. On the basis of these results and safety of strains to L. vannamei, they may be considered for future challenge experiments in shrimp as a very promising alternative to the use of antibiotics. PMID:22491136

  16. Selection and identification of non-pathogenic bacteria isolated from fermented pickles with antagonistic properties against two shrimp pathogens.

    PubMed

    Zokaeifar, Hadi; Balcázar, José Luis; Kamarudin, Mohd Salleh; Sijam, Kamaruzaman; Arshad, Aziz; Saad, Che Roos

    2012-06-01

    In this study, potential probiotic strains were isolated from fermented pickles based on antagonistic activity against two shrimp pathogens (Vibrio harveyi and Vibrio parahaemolyticus). Two strains L10 and G1 were identified by biochemical tests, followed by16S ribosomal RNA gene sequence analysis as Bacillus subtilis, and characterized by PCR amplification of repetitive bacterial DNA elements (Rep-PCR). Subsequently, B. subtilis L10 and G1 strains were tested for antibacterial activity under different physical conditions, including culture medium, salinity, pH and temperature using the agar well diffusion assay. Among the different culture media, LB broth was the most suitable medium for antibacterial production. Both strains showed the highest level of antibacterial activity against two pathogens at 30 °C and 1.0% NaCl. Under the pH conditions, strain G1 showed the greatest activity against V. harveyi at pH 7.3-8.0 and against V. parahaemolyticus at pH 6.0-8.0, whereas strain L10 showed the greatest activity against two pathogens at pH 7.3. The cell-free supernatants of both strains were treated with four different enzymes in order to characterize the antibacterial substances against V. harveyi. The result showed considerable reduction of antibacterial activity for both strains, indicating the proteinaceous nature of the antibacterial substances. A wide range of tolerance to NaCl, pH and temperature was also recorded for both strains. In addition, both strains showed no virulence effect in juvenile shrimp Litopenaeus vannamei. On the basis of these results and safety of strains to L. vannamei, they may be considered for future challenge experiments in shrimp as a very promising alternative to the use of antibiotics. PMID:22491136

  17. Evaluation of the use of PCR and reverse transcriptase PCR for detection of pathogenic bacteria in biosolids from anaerobic digestors and aerobic composters.

    PubMed

    Burtscher, Carola; Wuertz, Stefan

    2003-08-01

    A PCR-based method and a reverse transcriptase PCR (RT-PCR)-based method were developed for the detection of pathogenic bacteria in organic waste, using Salmonella spp., Listeria monocytogenes, Yersinia enterocolitica, and Staphylococcus aureus as model organisms. In seeded organic waste samples, detection limits of less than 10 cells per g of organic waste were achieved after one-step enrichment of bacteria, isolation, and purification of DNA or RNA before PCR or RT-PCR amplification. To test the reproducibility and reliability of the newly developed methods, 46 unseeded samples were collected from diverse aerobic (composting) facilities and anaerobic digestors and analyzed by both culture-based classical and newly developed PCR-based procedures. No false-positive but some false-negative results were generated by the PCR- or RT-PCR-based methods after one-step enrichment when compared to the classical detection methods. The results indicated that the level of activity of the tested bacteria in unseeded samples was very low compared to that of freshly inoculated cells, preventing samples from reaching the cell density required for PCR-based detection after one-step enrichment. However, for Salmonella spp., a distinct PCR product could be obtained for all 22 nonamended samples that tested positive for Salmonella spp. by the classical detection procedure when a selective two-step enrichment (20 h in peptone water at 37 degrees C and 24 h in Rappaport Vassiliadis medium at 43 degrees C) was performed prior to nucleic acid extraction and PCR. Hence, the classical procedure was shortened, since cell plating and further differentiation of isolated colonies can be omitted, substituted for by highly sensitive and reliable detection based on nucleic acid extraction and PCR. Similarly, 2 of the 22 samples in which Salmonella spp. were detected also tested positive for Listeria monocytogenes according to a two-step enrichment procedure followed by PCR, compared to 3 samples

  18. Interrelationship between type three secretion system and metabolism in pathogenic bacteria

    PubMed Central

    Wilharm, Gottfried; Heider, Christine

    2014-01-01

    Before the advent of molecular biology methods, studies of pathogens were dominated by analyses of their metabolism. Development of molecular biology techniques then enabled the identification and functional characterisation of the fascinating toolbox of virulence factors. Increasing, genomic and proteomic approaches form the basis for a more systemic view on pathogens' functions in the context of infection. Re-emerging interest in the metabolism of pathogens and hosts further expands our view of infections. There is increasing evidence that virulence functions and metabolism of pathogens are extremely intertwined. Type three secretion systems (T3SSs) are major virulence determinants of many Gram-negative pathogens and it is the objective of this review to illustrate the intertwined relationship between T3SSs and the metabolism of the pathogens deploying them. PMID:25386411

  19. Effects of associated bacteria on the pathogenicity and reproduction of the insect-parasitic nematode Rhabditis blumi (Nematoda: Rhabditida).

    PubMed

    Park, Hae Woong; Kim, Yong Ook; Ha, Jae-Seok; Youn, Sung Hun; Kim, Hyeong Hwan; Bilgrami, Anwar L; Shin, Chul Soo

    2011-09-01

    Three bacteria, Alcaligenes faecalis , Flavobacterium sp., and Providencia vermicola , were isolated from dauer juveniles of Rhabditis blumi . The pathogenic effects of the bacteria against 4th instar larvae of Galleria mellonella were investigated. Providencia vermicola and Flavobacterium sp. showed 100% mortality at 48 h after haemocoelic injection, whereas A. faecalis showed less than 30% mortality. Dauer juveniles showed 100% mortality against G. mellonella larvae, whereas axenic juveniles, which do not harbor associated bacteria, exhibited little mortality. All of the associated bacteria were used as a food source for nematode growth, and nematode yield differed with bacterial species. Among the bacterial species, P. vermicola was most valued for nematode yield, showing the highest yield of 5.2 × 10(4) nematodes/mL in the plate. In bacterial cocultures using two of the three associated bacteria, one kind stimulated the other. The highest total bacterial yield of 12.6 g/L was obtained when the inoculum ratio of P. vermicola to A. faecalis was 10:1. In air-lift bioreactors, the nematode growth rate increased with an increasing level of dissolved oxygen. The maximum nematode yield of 1.75 × 10(5) nematodes/mL was obtained at 192 h with an aeration rate of 6 vvm. PMID:21867444

  20. Antimicrobial activities of commercial essential oils and their components against food-borne pathogens and food spoilage bacteria.

    PubMed

    Mith, Hasika; Duré, Rémi; Delcenserie, Véronique; Zhiri, Abdesselam; Daube, Georges; Clinquart, Antoine

    2014-07-01

    This study was undertaken to determine the in vitro antimicrobial activities of 15 commercial essential oils and their main components in order to pre-select candidates for potential application in highly perishable food preservation. The antibacterial effects against food-borne pathogenic bacteria (Listeria monocytogenes, Salmonella Typhimurium, and enterohemorrhagic Escherichia coli O157:H7) and food spoilage bacteria (Brochothrix thermosphacta and Pseudomonas fluorescens) were tested using paper disk diffusion method, followed by determination of minimum inhibitory (MIC) and bactericidal (MBC) concentrations. Most of the tested essential oils exhibited antimicrobial activity against all tested bacteria, except galangal oil. The essential oils of cinnamon, oregano, and thyme showed strong antimicrobial activities with MIC ≥ 0.125 μL/mL and MBC ≥ 0.25 μL/mL. Among tested bacteria, P. fluorescens was the most resistant to selected essential oils with MICs and MBCs of 1 μL/mL. The results suggest that the activity of the essential oils of cinnamon, oregano, thyme, and clove can be attributed to the existence mostly of cinnamaldehyde, carvacrol, thymol, and eugenol, which appear to possess similar activities against all the tested bacteria. These materials could be served as an important natural alternative to prevent bacterial growth in food products. PMID:25473498

  1. Antimicrobial activities of commercial essential oils and their components against food-borne pathogens and food spoilage bacteria

    PubMed Central

    Mith, Hasika; Duré, Rémi; Delcenserie, Véronique; Zhiri, Abdesselam; Daube, Georges; Clinquart, Antoine

    2014-01-01

    This study was undertaken to determine the in vitro antimicrobial activities of 15 commercial essential oils and their main components in order to pre-select candidates for potential application in highly perishable food preservation. The antibacterial effects against food-borne pathogenic bacteria (Listeria monocytogenes, Salmonella Typhimurium, and enterohemorrhagic Escherichia coli O157:H7) and food spoilage bacteria (Brochothrix thermosphacta and Pseudomonas fluorescens) were tested using paper disk diffusion method, followed by determination of minimum inhibitory (MIC) and bactericidal (MBC) concentrations. Most of the tested essential oils exhibited antimicrobial activity against all tested bacteria, except galangal oil. The essential oils of cinnamon, oregano, and thyme showed strong antimicrobial activities with MIC ≥ 0.125 μL/mL and MBC ≥ 0.25 μL/mL. Among tested bacteria, P. fluorescens was the most resistant to selected essential oils with MICs and MBCs of 1 μL/mL. The results suggest that the activity of the essential oils of cinnamon, oregano, thyme, and clove can be attributed to the existence mostly of cinnamaldehyde, carvacrol, thymol, and eugenol, which appear to possess similar activities against all the tested bacteria. These materials could be served as an important natural alternative to prevent bacterial growth in food products. PMID:25473498

  2. Lab-on-a-chip modules for detection of highly pathogenic bacteria: from sample preparation to detection

    NASA Astrophysics Data System (ADS)

    Julich, S.; Kopinč, R.; Hlawatsch, N.; Moche, C.; Lapanje, A.; Gärtner, C.; Tomaso, H.

    2014-05-01

    Lab-on-a-chip systems are innovative tools for the detection and identification of microbial pathogens in human and veterinary medicine. The major advantages are small sample volume and a compact design. Several fluidic modules have been developed to transform analytical procedures into miniaturized scale including sampling, sample preparation, target enrichment, and detection procedures. We present evaluation data for single modules that will be integrated in a chip system for the detection of pathogens. A microfluidic chip for purification of nucleic acids was established for cell lysis using magnetic beads. This assay was evaluated with spiked environmental aerosol and swab samples. Bacillus thuringiensis was used as simulant for Bacillus anthracis, which is closely related but non-pathogenic for humans. Stationary PCR and a flow-through PCR chip module were investigated for specific detection of six highly pathogenic bacteria. The conventional PCR assays could be transferred into miniaturized scale using the same temperature/time profile. We could demonstrate that the microfluidic chip modules are suitable for the respective purposes and are promising tools for the detection of bacterial pathogens. Future developments will focus on the integration of these separate modules to an entire lab-on-a-chip system.

  3. On the trail of EHEC/EAEC--unraveling the gene regulatory networks of human pathogenic Escherichia coli bacteria.

    PubMed

    Pauling, Josch; Röttger, Richard; Neuner, Andreas; Salgado, Heladia; Collado-Vides, Julio; Kalaghatgi, Prabhav; Azevedo, Vasco; Tauch, Andreas; Pühler, Alfred; Baumbach, Jan

    2012-07-01

    Pathogenic Escherichia coli, such as Enterohemorrhagic E. coli (EHEC) and Enteroaggregative E. coli (EAEC), are globally widespread bacteria. Some may cause the hemolytic uremic syndrome (HUS). Varying strains cause epidemics all over the world. Recently, we observed an epidemic outbreak of a multi-resistant EHEC strain in Western Europe, mainly in Germany. The Robert Koch Institute reports >4300 infections and >50 deaths (July, 2011). Farmers lost several million EUR since the origin of infection was unclear. Here, we contribute to the currently ongoing research with a computer-aided study of EHEC transcriptional regulatory interactions, a network of genetic switches that control, for instance, pathogenicity, survival and reproduction of bacterial cells. Our strategy is to utilize knowledge of gene regulatory networks from the evolutionary relative E. coli K-12, a harmless strain mainly used for wet lab studies. In order to provide high-potential candidates for human pathogenic E. coli bacteria, such as EHEC, we developed the integrated online database and an analysis platform EhecRegNet. We utilize 3489 known regulations from E. coli K-12 for predictions of yet unknown gene regulatory interactions in 16 human pathogens. For these strains we predict 40,913 regulatory interactions. EhecRegNet is based on the identification of evolutionarily conserved regulatory sites within the DNA of the harmless E. coli K-12 and the pathogens. Identifying and characterizing EHEC's genetic control mechanism network on a large scale will allow for a better understanding of its survival and infection strategies. This will support the development of urgently needed new treatments. EhecRegNet is online via http://www.ehecregnet.de. PMID:22318347

  4. A simplified experimental model for clearance of some pathogenic bacteria using common bacterivorous ciliated spp. in Tigris river

    NASA Astrophysics Data System (ADS)

    Ali, Talib Hassan; Saleh, Dhuha Saad

    2014-03-01

    Bacteria-specific uptake rates of three different protozoan taxa on a pure and mixed bacterial community was studied by means of a simplified and functionally reproducible experimental model. The bacterial species Shigella flexneri, Escherichia coli and Salmonella typhi were isolated and classified from stool samples of patients suffering from diarrhea. Paramecium caudatum, Tetrahymena pyriformis and Halteria grandinella, free living ciliate Protozoans, were isolated and identified from Tigris river water. Pure and mixed ( E. coli + S. typhi), ( E. coli + Sh. flexneri) bacterial cultures were used with each ciliate genera to evaluate the following: predator duplication rate, prey reduction rate, clearance rate and net grazing rate. We used selective lactose fermentation phenomena of enteric bacteria on MacConkey medium for the quantification of bacteria cultural characteristics. The final bacteria concentration was reduced by growing protozoa of 98-99.9 % compared to protozoa-free controls. It showed that Tetrahymena pyriformis had the highest duplication rate (4.13 time/day) in both types of cultures (pure and mixed), followed by Paramecium caudatum and Halteria grandinella, respectively. Paramecium caudatum had the highest rate of ingestion in both types of cultures (26 × 103 bacteria/organism/hr) and yielded the longest time required for 90 % bacterial reduction in a pure suspension of S. typhi (166 h). Clearance rates of pathogenic bacteria by ciliates ranged between 106 nanoliter/organism/h by P. caudatum to S. typhi and 1.92 nanoliter/organism/h seen in T. pyriformis in ( E. coli + S. typhi) mixed culture. We used aquatic experimental microcosms under controlled conditions to explore bacteria-dependent ciliate growth and examined whether these ciliates could discriminate between equally sized bacterial preys in a mixture.

  5. Correlation of Metabolic Variables with the Number of ORFs in Human Pathogenic and Phylogenetically Related Non- or Less-Pathogenic Bacteria.

    PubMed

    Brambila-Tapia, Aniel Jessica Leticia; Poot-Hernández, Augusto Cesar; Garcia-Guevara, Jose Fernando; Rodríguez-Vázquez, Katya

    2016-06-01

    To date, a few works have performed a correlation of metabolic variables in bacteria; however specific correlations with these variables have not been reported. In this work, we included 36 human pathogenic bacteria and 18 non- or less-pathogenic-related bacteria and obtained all metabolic variables, including enzymes, metabolic pathways, enzymatic steps and specific metabolic pathways, and enzymatic steps of particular metabolic processes, from a reliable metabolic database (KEGG). Then, we correlated the number of the open reading frames (ORF) with these variables and with the proportions of these variables, and we observed a negative correlation with the proportion of enzymes (r = -0.506, p < 0.0001), metabolic pathways (r = -0.871, p < 00.0001), enzymatic reactions (r = -0.749, p < 00.0001), and with the proportions of central metabolism variables as well as a positive correlation with the proportions of multistep reactions (r = 0.650, p < 00.0001) and secondary metabolism variables. The proportion of multifunctional reactions (r: -0.114, p = 0.41) and the proportion of enzymatic steps (r: -0.205, p = 0.14) did not present a significant correlation. These correlations indicate that as the size of a genome (measured in the number of ORFs) increases, the proportion of genes that encode enzymes significantly diminishes (especially those related to central metabolism), suggesting that when essential metabolic pathways are complete, an increase in the number of ORFs does not require a similar increase in the metabolic pathways and enzymes, but only a slight increase is sufficient to cope with a large genome. PMID:26920870

  6. HecA, a member of a class of adhesins produced by diverse pathogenic bacteria, contributes to the attachment, aggregation, epidermal cell killing, and virulence phenotypes of Erwinia chrysanthemi EC16 on Nicotiana clevelandii seedlings

    PubMed Central

    Rojas, Clemencia M.; Ham, Jong Hyun; Deng, Wen-Ling; Doyle, Jeff J.; Collmer, Alan

    2002-01-01

    Erwinia chrysanthemi is representative of a broad class of bacterial pathogens that are capable of inducing necrosis in plants. The E. chrysanthemi EC16 hecA gene predicts a 3,850-aa member of the Bordetella pertussis filamentous hemagglutinin family of adhesins. A hecA∷Tn7 mutant was reduced in virulence on Nicotiana clevelandii seedlings after inoculation without wounding. Epifluorescence and confocal laser-scanning microscopy observations of hecA and wild-type cells expressing the green fluorescent protein revealed that the mutant is reduced in its ability to attach and then form aggregates on leaves and to cause an aggregate-associated killing of epidermal cells. Cell killing also depended on production of the major pectate lyase isozymes and the type II, but not the type III, secretion pathway in E. chrysanthemi. HecA homologs were found in bacterial pathogens of plants and animals and appear to be unique to pathogens and universal in necrogenic plant pathogens. Phylogenetic comparison of the conserved two-partner secretion domains in the proteins and the 16S rRNA sequences in respective bacteria revealed the two datasets to be fundamentally incongruent, suggesting horizontal acquisition of these genes. Furthermore, hecA and its two homologs in Yersinia pestis had a G+C content that was 10% higher than that of their genomes and similar to that of plant pathogenic Ralstonia, Xylella, and Pseudomonas spp. Our data suggest that filamentous hemagglutinin-like adhesins are broadly important virulence factors in both plant and animal pathogens. PMID:12271135

  7. Diversity and natural functions of antibiotices produced by beneficial and pathogenic soil bacteria

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil and plant-associated environments harbor numerous bacterial species that produce antibiotic metabolites. Many of these bacteria have been exploited for the discovery of clinical antibiotics and other therapeutics. In the field of plant pathology, antibiotic-producing bacteria are used as a reso...

  8. Simultaneous Concentration of Pathogenic Viruses, Bacteria and Protozoa from Water Using Sodocalcic Glass Wool Filters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: Methods for simultaneous concentration of multiple waterborne pathogens would be helpful for ensuring water quality and public health safety. The major technical issue of a reliable concentration method is the widely varied physical and chemical characteristics of pathogenic viruses, bac...

  9. Development of a DNA macroarray for simultaneous detection of multiple foodborne pathogenic bacteria in fresh chicken meat.

    PubMed

    Kupradit, Chanida; Rodtong, Sureelak; Ketudat-Cairns, Mariena

    2013-12-01

    A DNA macroarray was developed to provide the ability to detect multiple foodborne pathogens in fresh chicken meat. Probes targeted to the 16S rRNA and genus- and species-specific genes, including fimY, ipaH, prfA, and uspA, were selected for the specific detection of Salmonella spp., Shigella spp., Listeria monocytogenes, and Escherichia coli, respectively. The combination of target gene amplification by PCR and a DNA macroarray in our system was able to distinguish all target bacteria from pure cultures with a detection sensitivity of 10⁵ c.f.u. ml⁻¹. The DNA macroarray was also applied to 10 fresh chicken meat samples. The assay validation demonstrated that by combining the enrichment steps for the target bacteria and the DNA macroarray, all 4 target bacteria could be detected simultaneously from the fresh chicken samples. The sensitivity of L. monocytogenes and Shigella boydii detection in the fresh chicken samples was at least 10 and 3 c.f.u. of the initial contamination in 25 g samples, respectively. The advantages of our developed protocol are high accuracy and time reduction when compared to conventional culture. The macroarray developed in our investigation was cost effective compared to modern oligonucleotide microarray techniques because there was no expensive equipment required for the detection of multiple foodborne pathogens. PMID:23754709

  10. A recombinant horseshoe crab plasma lectin recognizes specific pathogen-associated molecular patterns of bacteria through rhamnose.

    PubMed

    Ng, Sim-Kun; Huang, Yu-Tsyr; Lee, Yuan-Chuan; Low, Ee-Ling; Chiu, Cheng-Hsun; Chen, Shiu-Ling; Mao, Liang-Chi; Chang, Margaret Dah-Tsyr

    2014-01-01

    Horseshoe crab is an ancient marine arthropod that, in the absence of a vertebrate-like immune system, relies solely on innate immune responses by defense molecules found in hemolymph plasma and granular hemocytes for host defense. A plasma lectin isolated from the hemolymph of Taiwanese Tachypleus tridentatus recognizes bacteria and lipopolysaccharides (LPSs), yet its structure and mechanism of action remain unclear, largely because of limited availability of horseshoe crabs and the lack of a heterogeneous expression system. In this study, we have successfully expressed and purified a soluble and functional recombinant horseshoe crab plasma lectin (rHPL) in an Escherichia coli system. Interestingly, rHPL bound not only to bacteria and LPSs like the native HPL but also to selective medically important pathogens isolated from clinical specimens, such as Gram-negative Pseudomonas aeruginosa and Klebsiella pneumoniae and Gram-positive Streptococcus pneumoniae serotypes. The binding was demonstrated to occur through a specific molecular interaction with rhamnose in pathogen-associated molecular patterns (PAMPs) on the bacterial surface. Additionally, rHPL inhibited the growth of P. aeruginosa PAO1 in a concentration-dependent manner. The results suggest that a specific protein-glycan interaction between rHPL and rhamnosyl residue may further facilitate development of novel diagnostic and therapeutic strategies for microbial pathogens. PMID:25541995

  11. A Recombinant Horseshoe Crab Plasma Lectin Recognizes Specific Pathogen-Associated Molecular Patterns of Bacteria through Rhamnose

    PubMed Central

    Ng, Sim-Kun; Huang, Yu-Tsyr; Lee, Yuan-Chuan; Low, Ee-Ling; Chiu, Cheng-Hsun; Chen, Shiu-Ling; Mao, Liang-Chi; Chang, Margaret Dah-Tsyr

    2014-01-01

    Horseshoe crab is an ancient marine arthropod that, in the absence of a vertebrate-like immune system, relies solely on innate immune responses by defense molecules found in hemolymph plasma and granular hemocytes for host defense. A plasma lectin isolated from the hemolymph of Taiwanese Tachypleus tridentatus recognizes bacteria and lipopolysaccharides (LPSs), yet its structure and mechanism of action remain unclear, largely because of limited availability of horseshoe crabs and the lack of a heterogeneous expression system. In this study, we have successfully expressed and purified a soluble and functional recombinant horseshoe crab plasma lectin (rHPL) in an Escherichia coli system. Interestingly, rHPL bound not only to bacteria and LPSs like the native HPL but also to selective medically important pathogens isolated from clinical specimens, such as Gram-negative Pseudomonas aeruginosa and Klebsiella pneumoniae and Gram-positive Streptococcus pneumoniae serotypes. The binding was demonstrated to occur through a specific molecular interaction with rhamnose in pathogen-associated molecular patterns (PAMPs) on the bacterial surface. Additionally, rHPL inhibited the growth of P. aeruginosa PAO1 in a concentration-dependent manner. The results suggest that a specific protein-glycan interaction between rHPL and rhamnosyl residue may further facilitate development of novel diagnostic and therapeutic strategies for microbial pathogens. PMID:25541995

  12. Recyclable Photo-Thermal Nano-Aggregates of Magnetic Nanoparticle Conjugated Gold Nanorods for Effective Pathogenic Bacteria Lysis.

    PubMed

    Ramasamy, Mohankandhasamy; Kim, Sanghyo; Lee, Su Seong; Yi, Dong Kee

    2016-01-01

    We describe the nucleophilic hybridization technique for fabricating magnetic nanoparticle (MNP) around gold nanorod (AuNR) for desired photo-thermal lysis on pathogenic bacteria. From the electromagnetic energy conversion into heat to the surrounding medium, a significant and quicker temperature rise was noted after light absorption on nanohybrids, at a controlled laser light output and optimum nanoparticle concentration. We observed a similar photo-thermal pattern for more than three times for the same material up on repeated magnetic separation. Regardless of the cell wall nature, superior pathogenic cell lysis has been observed for the bacteria suspensions of individual and mixed samples of Salmonella typhi (S.typhi) and Bacillus subtilis (B.subtilis) by the photo-heated nanoparticles. The synthesis of short gold nanorod, conjugation with magnetic nanoparticle and its subsequent laser exposure provides a rapid and reiterated photo-thermal effect with enhanced magnetic separation for efficient bactericidal application in water samples. Resultant novel properties of the nano-aggregates makes them a candidate to be used for a rapid, effective, and re-iterated photo-thermal agent against a wide variety of pathogens to attain microbe free water. PMID:27398487

  13. Intercellular and intracellular signalling systems that globally control the expression of virulence genes in plant pathogenic bacteria.

    PubMed

    Ham, Jong Hyun

    2013-04-01

    Plant pathogenic bacteria utilize complex signalling systems to control the expression of virulence genes at the cellular level and within populations. Quorum sensing (QS), an important intercellular communication mechanism, is mediated by different types of small molecules, including N-acyl homoserine lactones (AHLs), fatty acids and small proteins. AHL-mediated signalling systems dependent on the LuxI and LuxR family proteins play critical roles in the virulence of a wide range of Gram-negative plant pathogenic bacteria belonging to the Alphaproteobacteria, Betaproteobacteria and Gammaproteobacteria. Xanthomonas spp. and Xylella fastidiosa, members of the Gammaproteobacteria, however, possess QS systems that are mediated by fatty acid-type diffusible signal factors (DSFs). Recent studies have demonstrated that Ax21, a 194-amino-acid protein in Xanthomonas oryzae pv. oryzae, plays dual functions in activating a rice innate immune pathway through binding to the rice XA21 pattern recognition receptor and in regulating bacterial virulence and biofilm formation as a QS signal molecule. In xanthomonads, DSF-mediated QS systems are connected with the signalling pathways mediated by cyclic diguanosine monophosphate (c-di-GMP), which functions as a second messenger for the control of virulence gene expression in these bacterial pathogens. PMID:23186372

  14. Are pathogenic bacteria just looking for food? Metabolism and microbial pathogenesis

    PubMed Central

    Rohmer, Laurence; Hocquet, Didier; Miller, Samuel I.

    2011-01-01

    It is interesting to speculate that the evolutionary drive of microbes to develop pathogenic characteristics was to access the nutrient resources that animals provided. Environments in animals that pathogens colonize have also driven the evolution of new bacterial characteristics to maximize these new nutritional opportunities. This review focuses on genomic and functional aspects of pathogen metabolism that allow efficient utilization of nutrient resources provided by animals. Similar to genes encoding specific virulence traits, some genes encoding metabolic functions have been horizontally acquired by pathogens to provide a selective advantage in host tissues. Selective advantage in host tissues can also be gained in some circumstances by loss of function due to mutations that alter metabolic capabilities. Greater understanding of bacterial metabolism within host tissues should be important for increased understanding of host-pathogen interactions and the development of future therapeutic strategies. PMID:21600774

  15. A prebiotic effect of Ecklonia cava on the growth and mortality of olive flounder infected with pathogenic bacteria.

    PubMed

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

    2016-04-01

    Olive flounder (Paralichthys olivaceus), also known as the Japanese flounder in Japan, is one of the most important commercial marine finfish species cultured in Korea and Japan. The purpose of this study was to evaluate how a species of brown algae (Ecklonia cava, E. cava) affects the growth rate of olive flounder and its immune response to pathogenic bacteria. First, the experimental fish were divided into four groups: the control group was fed the diet containing only 1.0% Lactobacillus plantarum (L. plantarum), group I was fed 1.0% L. plantarum and 1.0% E. cava (EC), group II was fed 1.0% L. plantarum and 0.1% ethanol extract of EC (EE), and group III was fed 1.0% L. plantarum and 0.5% EE. The diets fed to the fish twice a day for 16 weeks. The results indicated that supplementation with 1.0% EC and 0.1% EE improved the growth and body weight of olive flounder, and decreased its mortality. This diet, however, did not significantly affect the biochemical profiles of the experimental flounder. The supplementation of 1.0% EC also enhanced the innate immune response of the fish, as evidenced by the high respiratory burst, and increased serum lysozyme and myeloperoxidase activity. The addition of 1.0% EC and either 0.1% or 0.5% EE also decreased the accumulative mortality of olive flounder infected by pathogenic bacteria (Edwardsiella tarda, Streptococcus iniae, and Vibrio harveyi). Overall, these results suggest that E. cava can act as a prebiotic by improving the innate immune response in fish infected with pathogenic bacteria as increased the growth of the probiotic. PMID:26921543

  16. Phylogenetic distribution of symbiotic bacteria from Panamanian amphibians that inhibit growth of the lethal fungal pathogen Batrachochytrium dendrobatidis.

    PubMed

    Becker, Matthew H; Walke, Jenifer B; Murrill, Lindsey; Woodhams, Douglas C; Reinert, Laura K; Rollins-Smith, Louise A; Burzynski, Elizabeth A; Umile, Thomas P; Minbiole, Kevin P C; Belden, Lisa K

    2015-04-01

    The introduction of next-generation sequencing has allowed for greater understanding of community composition of symbiotic microbial communities. However, determining the function of individual members of these microbial communities still largely relies on culture-based methods. Here, we present results on the phylogenetic distribution of a defensive functional trait of cultured symbiotic bacteria associated with amphibians. Amphibians are host to a diverse community of cutaneous bacteria and some of these bacteria protect their host from the lethal fungal pathogen Batrachochytrium dendrobatidis (Bd) by secreting antifungal metabolites. We cultured over 450 bacterial isolates from the skins of Panamanian amphibian species and tested their interactions with Bd using an in vitro challenge assay. For a subset of isolates, we also completed coculture experiments and found that culturing isolates with Bd had no effect on inhibitory properties of the bacteria, but it significantly decreased metabolite secretion. In challenge assays, approximately 75% of the bacterial isolates inhibited Bd to some extent and these inhibitory isolates were widely distributed among all bacterial phyla. Although there was no clear phylogenetic signal of inhibition, three genera, Stenotrophomonas, Aeromonas and Pseudomonas, had a high proportion of inhibitory isolates (100%, 77% and 73%, respectively). Overall, our results demonstrate that antifungal properties are phylogenetically widespread in symbiotic microbial communities of Panamanian amphibians and that some functional redundancy for fungal inhibition occurs in these communities. We hope that these findings contribute to the discovery and development of probiotics for amphibians that can mitigate the threat of chytridiomycosis. PMID:25737297

  17. Biological preparation of highly effective immunomagnetic beads for the separation, concentration, and detection of pathogenic bacteria in milk.

    PubMed

    Lim, Min-Cheol; Lee, Gwan-Hyung; Huynh, Duyen Thi Ngoc; Hong, Chae-Eun; Park, Soo-Yeon; Jung, Jong-Yun; Park, Cheon-Seok; Ko, Sungho; Kim, Young-Rok

    2016-09-01

    We introduce a system for the efficient separation and concentration of pathogenic bacteria using biologically prepared immunomagnetic beads. Amylose magnetic beads (AMBs) were synthesized by an enzymatic reaction of amylosucrase from Deinococcus geothermalis (DGAS). The simple and rapid conjugation of AMBs and antibodies was achieved by the MBP-SPG fusion protein. MBP (maltose binding protein) binds to the surface of an AMB owing to its intrinsic affinity to the di-glucose in the AMB. SPG (streptococcal protein G) fused to the MBP has specific affinity to the Fc region of the antibody. Anti-Escherichia coli O157 antibodies were conjugated to the AMBs through a MBP-SPG linker without any physical and chemical treatments. The efficiency of separation and concentration of the target E. coli O157:H7 by the functionalized AMBs was revealed by plating counting, conventional polymerase chain reaction (PCR), and real-time RCR analysis. The immuno-AMBs effectively separated and concentrated the target bacteria from a commercial milk sample spiked with known number of bacteria, which was then analyzed by PCR to a detection limit of 10CFU/mL. On the other hand, no PCR product was produced when milk was introduced directly to a PCR reaction. These results show that MBP-SPG is an effective linker and the resulting immuno-AMBs are capable of separating and concentrating the target bacteria from a food matrix. PMID:27315334

  18. The structure of O-polysaccharides isolated from plant pathogenic bacteria Pectobacterium wasabiae IFB5408 and IFB5427.

    PubMed

    Ossowska, Karolina; Czerwicka, Małgorzata; Sledz, Wojciech; Zoledowska, Sabina; Motyka, Agata; Szulta, Sylwia; Lojkowska, Ewa; Kaczyński, Zbigniew

    2016-05-13

    O-Polysaccharides were isolated from the lipopolysaccharides of two strains of plant pathogenic bacteria Pectobacterium wasabiae isolated in Poland in 2013 (IFB5408 and IFB5427). The purified polysaccharides were analyzed using 1D and 2D NMR spectroscopy ((1)H, DQF-COSY, TOCSY, ROESY, HSQC, HSQC-TOCSY, and HMBC) and the chemical methods. Sugar and methylation analyses of native polysaccharides, absolute configuration assignment of constituent monosaccharides together with NMR spectroscopy data revealed that the chemical structures of both O-polysaccharides are the same. PMID:27058296

  19. Point of care nucleic acid detection of viable pathogenic bacteria with isothermal RNA amplification based paper biosensor

    NASA Astrophysics Data System (ADS)

    Liu, Hongxing; Xing, Da; Zhou, Xiaoming

    2014-09-01

    Food-borne pathogens such as Listeria monocytogenes have been recognized as a major cause of human infections worldwide, leading to substantial health problems. Food-borne pathogen identification needs to be simpler, cheaper and more reliable than the current traditional methods. Here, we have constructed a low-cost paper biosensor for the detection of viable pathogenic bacteria 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 biosensor to perform a visual test, in which endpoint detection was performed using sandwich hybridization assays. When the RNA products migrated along the paper biosensor by capillary action, the gold nanoparticles accumulated at the designated Test line and Control line. Under optimized experimental conditions, as little as 0.5 pg/μL genomic RNA from Listeria monocytogenes could be detected. The whole assay process, including RNA extraction, amplification, and visualization, can be completed within several hours. The developed method is suitable for point-of-care applications to detect food-borne pathogens, as it can effectively overcome the false-positive results caused by amplifying nonviable Listeria monocytogenes.

  20. A comparison of rapid and conventional measures of indicator bacteria as predictors of waterborne protozoan pathogen presence and density.

    PubMed

    Dorevitch, Samuel; Doi, Mary; Hsu, Fu-Chih; Lin, King-Teh; Roberts, Jennifer D; Liu, Li C; Gladding, Ross; Vannoy, Ember; Li, Hong; Javor, Margit; Scheff, Peter A

    2011-09-01

    E. coli and enterococci in recreational waters are monitored as indicators of fecal contamination, pathogen presence, and health risk. Quantitative polymerase chain reaction (qPCR) tests for fecal indicator bacteria can provide beach managers with same-day information about water quality, unlike culture methods which provide that information the following day. The abilities of qPCR measurements of indicator bacteria, as compared to culture measurements of indicator bacteria, as predictors of pathogen presence or density in surface waters are not well understood. The purpose of this study was to make such comparisons between water samples collected from Chicago area surface waters, including rivers, inland lakes, Lake Michigan, and the Chicago Area Waterways System, which is dominated by wastewater effluent. A total of 294 twenty-litre samples were collected and analyzed for Giardia and Cryptosporidium. qPCR and membrane filtration methods were used to quantify E. coli and enterococci. Correlation, logistic regression, and zero-inflated Poisson modeling were utilized to evaluate associations between indicators and parasites. qPCR and culture measures of the indicator bacteria were similar in their ability to predict parasite presence and density. Correlations between parasites and indicators were generally stronger at waters not dominated by effluent. Associations between indicator density and Giarida presence were observed more consistently than between indicator density and Cryptosporidium presence. Associations between enterococci and parasites were generally stronger than associations between E. coli and parasites. The use of qPCR monitoring in our setting would generate more timely results without compromising the ability to predict parasite presence or density. PMID:21826357

  1. Plant pathogenic bacteria target the actin microfilament network involved in the trafficking of disease defense components

    PubMed Central

    Jelenska, Joanna; Kang, Yongsung; Greenberg, Jean T

    2014-01-01

    Cells of infected organisms transport disease defense-related molecules along actin filaments to deliver them to their sites of action to combat the pathogen. To accommodate higher demand for intracellular traffic, plant F-actin density increases transiently during infection or treatment of Arabidopsis with pathogen-associated molecules. Many animal and plant pathogens interfere with actin polymerization and depolymerization to avoid immune responses. Pseudomonas syringae, a plant extracellular pathogen, injects HopW1 effector into host cells to disrupt the actin cytoskeleton and reduce vesicle movement in order to elude defense responses. In some Arabidopsis accessions, however, HopW1 is recognized and causes resistance via an actin-independent mechanism. HopW1 targets isoform 7 of vegetative actin (ACT7) that is regulated by phytohormones and environmental factors. We hypothesize that dynamic changes of ACT7 filaments are involved in plant immunity. PMID:25551177

  2. Inactivation of Pathogenic Bacteria on Seeds by Active Oxygen Species Generated in Low-Pressure Plasma

    NASA Astrophysics Data System (ADS)

    Ono, Reoto; Uchida, Shohei; Hayashi, Nobuya; Kosaka, Rina; Soeda, Yasutaka

    2015-09-01

    The inactivation of bacteria on seeds by active oxygen species generated by a low-pressure oxygen plasma is investigated. Species of active oxygen contributing to the inactivation of bacteria are attempted to be identified. Cylindrical stainless chamber with the internal volume of 17 L is used and RF antenna is set inside the chamber. The oxygen gas pressure is 20-100 Pa. RF power of 13.56 MHz is supplied to RF antenna and CCP is generated. After irradiation, bacteria are extracted from seeds and cultivated on nutrient agars. The number of colonies on these agars is counted after 48 h incubation. The number of bacteria on seeds decreases to less than 10-3 after plasma irradiation for 45 min comparing with that of control. The tendency of the reduction rate of bacteria on seeds has positive correlation with that of the light emission intensity of the singlet excited oxygen molecule as the oxygen gas pressure is varied. It is supposed that the singlet excited oxygen molecule would be one of the major factors for the inactivation of bacteria on seeds.

  3. Genetic Diversity and Pathogenic Variation of Common Blight Bacteria (Xanthomonas campestris pv. phaseoli and X. campestris pv. phaseoli var. fuscans) Suggests Pathogen Coevolution with the Common Bean.

    PubMed

    Mkandawire, Alexander B C; Mabagala, Robert B; Guzmán, Pablo; Gepts, Paul; Gilbertson, Robert L

    2004-06-01

    ABSTRACT Common bacterial blight (CBB), caused by Xanthomonas campestris pv. phaseoli and X. campestris pv. phaseoli var. fuscans, is one of the most important diseases of common bean (Phaseolus vulgaris) in East Africa and other bean-growing regions. Xanthomonad-like bacteria associated with CBB in Malawi and Tanzania, East Africa, and in Wisconsin, U.S., were characterized based on brown pigment production, pathogenicity on common bean, detection with an X. campestris pv. phaseoli- or X. campestris pv. phaseoli var. fuscans-specific PCR primer pair, and repetitive element polymerase chain reaction (rep-PCR) and restriction fragment length polymorphism (RFLP) analyses. The common bean gene pool (Andean or Middle American) from which each strain was isolated also was determined. In Malawi, X. campestris pv. phaseoli and X. campestris pv. phaseoli var. fuscans were isolated predominantly from Andean or Middle American beans, respectively. In Tanzania, X. campestris pv. phaseoli var. fuscans was most commonly isolated, irrespective of gene pool; whereas, in Wisconsin, only X. campestris pv. phaseoli was isolated from Andean red kidney beans. Three rep-PCR fingerprints were obtained for X. campestris pv. phaseoli strains; two were unique to East African strains, whereas the other was associated with strains collected from all other (mostly New World) locations. RFLP analyses with repetitive DNA probes revealed the same genetic diversity among X. campestris pv. phaseoli strains as did rep-PCR. These probes hybridized with only one or two fragments in the East African strains, but with multiple fragments in the other X. campestris pv. phaseoli strains. East African X. campestris pv. phaseoli strains were highly pathogenic on Andean beans, but were significantly less pathogenic on Middle American beans. In contrast, X. campestris pv. phaseoli strains from New World locations were highly pathogenic on beans of both gene pools. Together, these results indicate the

  4. In vitro activity of glucosinolates and their degradation products against brassica-pathogenic bacteria and fungi.

    PubMed

    Sotelo, T; Lema, M; Soengas, P; Cartea, M E; Velasco, P

    2015-01-01

    Glucosinolates (GSLs) are secondary metabolites found in Brassica vegetables that confer on them resistance against pests and diseases. Both GSLs and glucosinolate hydrolysis products (GHPs) have shown positive effects in reducing soil pathogens. Information about their in vitro biocide effects is scarce, but previous studies have shown sinigrin GSLs and their associated allyl isothiocyanate (AITC) to be soil biocides. The objective of this work was to evaluate the biocide effects of 17 GSLs and GHPs and of leaf methanolic extracts of different GSL-enriched Brassica crops on suppressing in vitro growth of two bacterial (Xanthomonas campestris pv. campestris and Pseudomonas syringae pv. maculicola) and two fungal (Alternaria brassicae and Sclerotinia scletoriorum) Brassica pathogens. GSLs, GHPs, and methanolic leaf extracts inhibited the development of the pathogens tested compared to the control, and the effect was dose dependent. Furthermore, the biocide effects of the different compounds studied were dependent on the species and race of the pathogen. These results indicate that GSLs and their GHPs, as well as extracts of different Brassica species, have potential to inhibit pathogen growth and offer new opportunities to study the use of Brassica crops in biofumigation for the control of multiple diseases. PMID:25362058

  5. In Vitro Activity of Glucosinolates and Their Degradation Products against Brassica-Pathogenic Bacteria and Fungi

    PubMed Central

    Sotelo, T.; Lema, M.; Soengas, P.; Cartea, M. E.

    2014-01-01

    Glucosinolates (GSLs) are secondary metabolites found in Brassica vegetables that confer on them resistance against pests and diseases. Both GSLs and glucosinolate hydrolysis products (GHPs) have shown positive effects in reducing soil pathogens. Information about their in vitro biocide effects is scarce, but previous studies have shown sinigrin GSLs and their associated allyl isothiocyanate (AITC) to be soil biocides. The objective of this work was to evaluate the biocide effects of 17 GSLs and GHPs and of leaf methanolic extracts of different GSL-enriched Brassica crops on suppressing in vitro growth of two bacterial (Xanthomonas campestris pv. campestris and Pseudomonas syringae pv. maculicola) and two fungal (Alternaria brassicae and Sclerotinia scletoriorum) Brassica pathogens. GSLs, GHPs, and methanolic leaf extracts inhibited the development of the pathogens tested compared to the control, and the effect was dose dependent. Furthermore, the biocide effects of the different compounds studied were dependent on the species and race of the pathogen. These results indicate that GSLs and their GHPs, as well as extracts of different Brassica species, have potential to inhibit pathogen growth and offer new opportunities to study the use of Brassica crops in biofumigation for the control of multiple diseases. PMID:25362058

  6. Mycoplasma gallisepticum in the commercial egg-laying hen: an historical perspective considering effects of pathogen strain, age of bird at inoculation, and diet on performance and physiology

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mycoplasma gallisepticum (MG), a pathogenic organism, primarily causes respiratory distress, but can also spread systemically to subsequently reduce egg production and egg quality in laying hens. However, the effects of MG on the performance and physiology of the commercial laying hen have been sho...

  7. Experimental inoculation of specific pathogen free broiler chickens with a thyroid homogenate, containing chicken astrovirus, which was collected from broiler chickens with runting-stunting syndrome

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Thyroid glands were collected from field broiler chickens with clinical signs and lesions of Runting-Stunting Syndrome (RSS), submitted for histopathology and processed for polymerase chain reaction (PCR) testing using chicken Astrovirus primers. One-day-old White Rock specific pathogen free (SPF) ...

  8. Comparison of inoculation methods for characterizing relative aggressiveness of two soybean sudden-death syndrome pathogens, Fusarium virguliforme and F. tucumaniae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium tucumaniae and F. virguliforme are the primary etiological agents of sudden-death syndrome (SDS) of soybean in Argentina and the United States, respectively. Five isolates of F. tucumaniae and four of F. virguliforme were tested for pathogenicity to soybeans, by comparing a toothpick method...

  9. First report of Oregon grape (Mahonia aquifolium) as an alternate host for the wheat stripe rust pathogen (Puccinia striiformis f. sp. tritici) under artificial inoculation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cereal rusts are heteroecious fungi requiring cereal crops and other unrelated host species to complete their life cycle. Puccinia striiformis Westend. f. sp. tritici Erikss. (Pst), the wheat stripe rust pathogen, has five distinct spore types. Although wheat has been recognized as the primary host...

  10. Alendronate augments interleukin-1{beta} release from macrophages infected with periodontal pathogenic bacteria through activation of caspase-1

    SciTech Connect

    Deng Xue; Tamai, Riyoko; Endo, Yasuo; Kiyoura, Yusuke

    2009-02-15

    Nitrogen-containing bisphosphonates (NBPs) are anti-bone-resorptive drugs with inflammatory side effects that include osteomyelitis and osteonecrosis of the jaw. Oral bacteria have been considered to be a trigger for these NBP-associated jaw bone diseases. The present study examined the effects of alendronate (a typical NBP) and clodronate (a non-NBP) on the production of proinflammatory cytokines by macrophages infected with Porphyromonas gingivalis and Tannerella forsythia, which are important pathogens of periodontal diseases. Pretreatment with alendronate augmented IL-1{beta}, but not TNF{alpha}, production by macrophages infected with P. gingivalis or T. forsythia. This augmentation of IL-1{beta} production was inhibited by clodronate. Furthermore, caspase-1, a promoter of IL-1{beta} production, was activated by treatment with alendronate, and caspase-1 inhibitor reduced the production of IL-1{beta} induced by alendronate and P. gingivalis. These results suggest that NBPs augment periodontal pathogenic bacteria-induced IL-1{beta} release via caspase-1 activation, and this phenomenon may contribute to the development of NBP-associated inflammatory side effects including jaw osteomyelitis. Co-treatment with clodronate may prevent and/or reduce these inflammatory effects induced by NBPs.

  11. Recent Advancements in Nanobioassays and Nanobiosensors for Foodborne Pathogenic Bacteria Detection.

    PubMed

    Chen, Jing; Park, Bosoon

    2016-06-01

    Bacterial pathogens are one of the leading causes of food safety incidents and product recalls worldwide. Timely detection and identification of microbial contamination in agricultural and food products is crucial for disease prevention and outbreak investigation. In efforts to improve and/or replace time-consuming and laborious "gold standards" for pathogen detection, numerous alternative rapid methods have been proposed in the past 15 years, with a trend toward incorporating nanotechnology and nanomaterials in food pathogen detection. This article is a review of the use of nanotechnology in various detection and sample preparation techniques and advancements in nanotechnology applications in food matrices. Some practical considerations in nanobioassay design are discussed, and the gaps between research status quo and market demands are identified. PMID:27296612

  12. Catecholamines and in vitro growth of pathogenic bacteria: enhancement of growth varies greatly among bacterial species

    NASA Technical Reports Server (NTRS)

    Belay, Tesfaye; Aviles, Hernan; Vance, Monique; Fountain, Kimberly; Sonnenfeld, Gerald

    2003-01-01

    The purpose of this study was to examine the effects of catecholamines on in vitro growth of a range of bacterial species, including anaerobes. Bacteria tested included: Porphyromonas gingivalis, Bacteriodes fragilis, Shigella boydii, Shigella sonnie, Enterobacter Sp, and Salmonella choleraesuis. The results of the current study indicated that supplementation of bacterial cultures in minimal medium with norepinephrine or epinephrine did not result in increased growth of bacteria. Positive controls involving treatment of Escherichia coli with catecholamines did result in increased growth of that bacterial species. The results of the present study extend previous observations that showed differential capability of catecholamines to enhance bacterial growth in vitro.

  13. Survival of pathogenic bacteria under nutrient starvation conditions. [aboard orbiting space stations

    NASA Technical Reports Server (NTRS)

    Boyle, Michael; Ford, Tim; Mitchell, Ralph; Maki, James

    1990-01-01

    The survival of opportunistic pathogenic microorganisms in water, under nutrient-limiting conditions, has been investigated in order to ascertain whether human pathogens can survive within a water-distribution system of the kind proposed for the NASA Space Station. Cultures of a strain of pseudomonas aeruginosa and two strains of staphylococcus aureus were incubated at 10, 25, or 37 C, and samples at 1 day, 1 week, 1 month, and six weeks. While neither of the staphylococcus strains tested were detected after 1 week of starvation, the pseudomonas strain can survive in deionized water at all three temperatures.

  14. Antibacterial activity of guava (Psidium guajava L.) and Neem (Azadirachta indica A. Juss.) extracts against foodborne pathogens and spoilage bacteria.

    PubMed

    Mahfuzul Hoque, M D; Bari, M L; Inatsu, Y; Juneja, Vijay K; Kawamoto, S

    2007-01-01

    The antibacterial activity of guava (Psidium guajava) and neem (Azadirachta indica) extracts against 21 strains of foodborne pathogens were determined--Listeria monocytogenes (five strains), Staphylococcus aureus (four strains), Escherichia coli O157:H7 (six strains), Salmonella Enteritidis (four strains), Vibrio parahaemolyticus, and Bacillus cereus, and five food spoilage bacteria: Pseudomonas aeroginosa, P. putida, Alcaligenes faecalis, and Aeromonas hydrophila (two strains). Guava and neem extracts showed higher antimicrobial activity against Gram-positive bacteria compared to Gram-negative bacteria except for V. parahaemolyticus, P. aeroginosa, and A. hydrophila. None of the extracts showed antimicrobial activity against E. coli O157:H7 and Salmonella Enteritidis. The minimum inhibitory concentration (MIC) of ethanol extracts of guava showed the highest inhibition for L. monocytogenes JCM 7676 (0.1 mg/mL), S. aureus JCM 2151 (0.1 mg/mL), S. aureus JCM 2179 (0.1 mg/mL), and V. parahaemolyticus IFO 12711 (0.1 mg/mL) and the lowest inhibition for Alcaligenes faecalis IFO 12669, Aeromonas hydrophila NFRI 8282 (4.0 mg/mL), and A. hydrophila NFRI 8283 (4.0 mg/mL). The MIC of chloroform extracts of neem showed similar inhibition for L. monocytogenes ATCC 43256 (4.0 mg/mL) and L. monocytogenes ATCC 49594 (5.0 mg/mL). However, ethanol extracts of neem showed higher inhibition for S. aureus JCM 2151 (4.5 mg/mL) and S. aureus IFO 13276 (4.5 mg/mL) and the lower inhibition for other microorganisms (6.5 mg/mL). No significant effects of temperature and pH were found on guava and neem extracts against cocktails of L. monocytogenes and S. aureus. The results of the present study suggest that guava and neem extracts possess compounds containing antibacterial properties that can potentially be useful to control foodborne pathogens and spoilage organisms. PMID:18041957

  15. Immune competence of the mammary gland as affected by somatic cell and pathogenic bacteria in ewes with subclinical mastitis.

    PubMed

    Albenzio, M; Santillo, A; Caroprese, M; Ruggieri, D; Ciliberti, M; Sevi, A

    2012-07-01

    Immune competence of the ewe mammary gland was investigated by monitoring the leukocyte differential count, cytokine pattern, and endogenous proteolytic enzymes in milk samples with different somatic cell counts (SCC) and pathogenic bacteria. Furthermore, the leukocyte differential count and T-lymphocyte populations were evaluated in ewe blood. A total of 1,500 individual milk samples were randomly selected from the pool of the samples collected during sampling and grouped into 5 classes of 300 samples each, on the basis of SCC. Classes were <300,000 cells/mL, from 300,000 to 500,000 cells/mL, from 501,000 to 1,000,000 cells/mL, from 1,001,000 to 2,000,000 cells/mL, and >2,000,000 cells/mL. Microbiological analyses of ewe milk were conducted to detect mastitis-related pathogens. Sheep whose udders were without clinical abnormalities, and whose milk was apparently normal but with at least 10(3)cfu/mL of the same pathogen were considered to have subclinical mastitis and therefore defined as infected. Polymorphonuclear neutrophilic leukocytes (PMNL) and macrophages increased with SCC, whereas lymphocytes decreased. Milk samples with SCC >1,000,000 cells/mL showed differences in leukocyte populations between uninfected and infected ewes, with higher percentages of PMNL and macrophages and lower percentages of lymphocytes in infected animals. Nonviable PMNL levels were the highest in ewe milk samples with SCC <300,000 cells/mL; starting from SCC >500,000 cells/mL, nonviable PMNL were higher in uninfected ewes than in infected ones. In infected animals giving milk with SCC >1,000,000 cells/mL, a higher CD4(+)/CD8(+) ratio was observed, suggesting that the presence of pathogens induced an activation of both CD4(+) and CD8(+). The levels of tumor necrosis factor-α and IL-12 were higher in infected than uninfected ewes, irrespective of SCC. Plasmin activity increased along with SCC and was always higher in infected than uninfected animals; cathepsin D increased starting

  16. Antibacterial activities of metabolites from Platanus occidentalis (American sycamore) against fish pathogenic bacteria

    Technology Transfer Automated Retrieval System (TEKTRAN)

    One approach to the management of common fish diseases in aquaculture is the use of antibiotic-laden feed. However, there are public concerns about the use of antibiotics in agriculture and the potential development of antibiotic resistant bacteria. Therefore, the discovery of other environmentall...

  17. Antibacterial activities of metabolites from Platanus occidenatalis (American sycamore) against fish pathogenic bacteria

    Technology Transfer Automated Retrieval System (TEKTRAN)

    One approach to the management of common fish diseases in aquaculture is the use of antibiotic-laden feed. However, there are public concerns about the use of antibiotics in agriculture and the potential development of antibiotic resistant bacteria. Therefore, the discovery of other environmentall...

  18. Potential of predatory bacteria as biocontrol agents for foodborne and plant pathogens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Foodborne pathogens such as Escherichia coli O157:H7, Salmonella spp., Listeria monocytogenes, Shigella are responsible for frequent occurrences of illnesses and mortality in humans and produce losses. Pre-harvest yield losses and post-harvest decay on minimally processed produce (fruits, vegetables...

  19. Recent Advancements in Nanobioassays and Nanobiosensors for Foodborne Pathogenic Bacteria Detection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacterial pathogens are one of the leading causes of food safety incidents and product recalls worldwide. Timely detection and identification of microbial contamination in agricultural and food products is crucial for disease prevention and outbreak investigation. Current gold standards are specific...

  20. Diarrhea-associated pathogens, lactobacilli and cellulolytic bacteria in equine feces: responses to antibiotic challenge

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Antibiotics are important to equine medicine, but antibiotic-associated diarrhea (AAD) can lead to poor performance and even mortality. AAD is attributed to disruption of the hindgut microbiota, which permits proliferation of pathogenic microbes. The goal of this study was to evaluate the effects o...

  1. Chemical Composition and In Vitro Antibacterial Activity of Mentha spicata Essential Oil against Common Food-Borne Pathogenic Bacteria

    PubMed Central

    Shahbazi, Yasser

    2015-01-01

    The aim of the present study was to investigate chemical composition and antibacterial activity of essential oil from the leaf of Mentha spicata plant against common food-borne pathogenic bacteria (Staphylococcus aureus, Bacillus subtilis, Bacillus cereus, Listeria monocytogenes, Salmonella typhimurium, and Escherichia coli O157:H7). Chemical composition of the essential oil was identified by gas chromatography coupled with mass spectrometer detector (GC-MS). The antibacterial activity of the essential oil was evaluated by broth microdilution method and agar disk diffusion assay. According to the result of GC-MS analysis, 18 components were identified, accounting for 99.89% of the whole essential oil. The main components were carvone (78.76%), limonene (11.50%), β-bourbonene (11.23%), cis-dihydrocarveol (1.43%), trans-caryophyllene (1.04%), menthone (1.01%), menthol (1%), and terpinen-4-ol (0.99). The essential oil exhibited moderate level of antibacterial activity against all test microorganisms. In general, Gram-positive bacteria were more susceptible to M. spicata essential oil than Gram-negative bacteria. L. monocytogenes was the most sensitive of the microorganisms to the antibacterial activity of M. spicata essential oil (inhibition zone = 22 mm and MIC and MBC = 2.5 µL/mL). Based on our results, the essential oil of M. spicata plant collected from Kermanshah province, west of Iran, has a potential to be applied as antibacterial agent. PMID:26351584

  2. Chemical Composition and In Vitro Antibacterial Activity of Mentha spicata Essential Oil against Common Food-Borne Pathogenic Bacteria.

    PubMed

    Shahbazi, Yasser

    2015-01-01

    The aim of the present study was to investigate chemical composition and antibacterial activity of essential oil from the leaf of Mentha spicata plant against common food-borne pathogenic bacteria (Staphylococcus aureus, Bacillus subtilis, Bacillus cereus, Listeria monocytogenes, Salmonella typhimurium, and Escherichia coli O157:H7). Chemical composition of the essential oil was identified by gas chromatography coupled with mass spectrometer detector (GC-MS). The antibacterial activity of the essential oil was evaluated by broth microdilution method and agar disk diffusion assay. According to the result of GC-MS analysis, 18 components were identified, accounting for 99.89% of the whole essential oil. The main components were carvone (78.76%), limonene (11.50%), β-bourbonene (11.23%), cis-dihydrocarveol (1.43%), trans-caryophyllene (1.04%), menthone (1.01%), menthol (1%), and terpinen-4-ol (0.99). The essential oil exhibited moderate level of antibacterial activity against all test microorganisms. In general, Gram-positive bacteria were more susceptible to M. spicata essential oil than Gram-negative bacteria. L. monocytogenes was the most sensitive of the microorganisms to the antibacterial activity of M. spicata essential oil (inhibition zone = 22 mm and MIC and MBC = 2.5 µL/mL). Based on our results, the essential oil of M. spicata plant collected from Kermanshah province, west of Iran, has a potential to be applied as antibacterial agent. PMID:26351584

  3. Glycan:glycan interactions: High affinity biomolecular interactions that can mediate binding of pathogenic bacteria to host cells

    PubMed Central

    Day, Christopher J.; Tran, Elizabeth N.; Semchenko, Evgeny A.; Tram, Greg; Hartley-Tassell, Lauren E.; Ng, Preston S. K.; King, Rebecca M.; Ulanovsky, Rachel; McAtamney, Sarah; Apicella, Michael A.; Tiralongo, Joe; Morona, Renato; Korolik, Victoria; Jennings, Michael P.

    2015-01-01

    Cells from all domains of life express glycan structures attached to lipids and proteins on their surface, called glycoconjugates. Cell-to-cell contact mediated by glycan:glycan interactions have been considered to be low-affinity interactions that precede high-affinity protein–glycan or protein–protein interactions. In several pathogenic bacteria, truncation of surface glycans, lipooligosaccharide (LOS), or lipopolysaccharide (LPS) have been reported to significantly reduce bacterial adherence to host cells. Here, we show that the saccharide component of LOS/LPS have direct, high-affinity interactions with host glycans. Glycan microarrays reveal that LOS/LPS of four distinct bacterial pathogens bind to numerous host glycan structures. Surface plasmon resonance was used to determine the affinity of these interactions and revealed 66 high-affinity host–glycan:bacterial–glycan pairs with equilibrium dissociation constants (KD) ranging between 100 nM and 50 µM. These glycan:glycan affinity values are similar to those reported for lectins or antibodies with glycans. Cell assays demonstrated that glycan:glycan interaction-mediated bacterial adherence could be competitively inhibited by either host cell or bacterial glycans. This is the first report to our knowledge of high affinity glycan:glycan interactions between bacterial pathogens and the host. The discovery of large numbers of glycan:glycan interactions between a diverse range of structures suggests that these interactions may be important in all biological systems. PMID:26676578

  4. Glycan:glycan interactions: High affinity biomolecular interactions that can mediate binding of pathogenic bacteria to host cells.

    PubMed

    Day, Christopher J; Tran, Elizabeth N; Semchenko, Evgeny A; Tram, Greg; Hartley-Tassell, Lauren E; Ng, Preston S K; King, Rebecca M; Ulanovsky, Rachel; McAtamney, Sarah; Apicella, Michael A; Tiralongo, Joe; Morona, Renato; Korolik, Victoria; Jennings, Michael P

    2015-12-29

    Cells from all domains of life express glycan structures attached to lipids and proteins on their surface, called glycoconjugates. Cell-to-cell contact mediated by glycan:glycan interactions have been considered to be low-affinity interactions that precede high-affinity protein-glycan or protein-protein interactions. In several pathogenic bacteria, truncation of surface glycans, lipooligosaccharide (LOS), or lipopolysaccharide (LPS) have been reported to significantly reduce bacterial adherence to host cells. Here, we show that the saccharide component of LOS/LPS have direct, high-affinity interactions with host glycans. Glycan microarrays reveal that LOS/LPS of four distinct bacterial pathogens bind to numerous host glycan structures. Surface plasmon resonance was used to determine the affinity of these interactions and revealed 66 high-affinity host-glycan:bacterial-glycan pairs with equilibrium dissociation constants (K(D)) ranging between 100 nM and 50 µM. These glycan:glycan affinity values are similar to those reported for lectins or antibodies with glycans. Cell assays demonstrated that glycan:glycan interaction-mediated bacterial adherence could be competitively inhibited by either host cell or bacterial glycans. This is the first report to our knowledge of high affinity glycan:glycan interactions between bacterial pathogens and the host. The discovery of large numbers of glycan:glycan interactions between a diverse range of structures suggests that these interactions may be important in all biological systems. PMID:26676578

  5. The role of wood-inhabiting bacteria in pine wilt disease

    PubMed Central

    Zhao, Bo Guang; Tao, Jian; Ju, Yun Wei; Wang, Peng Kai; Ye, Jian Ling

    2011-01-01

    The pathogenicity of the pine wood nematode (PWN), Bursaphelenchus xylophilus together with the bacteria isolated from black pine (Pinus thunbergii) bark inoculated to axenic black pine seedlings, significantly exceeded that of the axenic PWNs alone, demonstrating that the bacteria play an important role in pine wilt disease. Inoculation of seedlings with bacteria-free culture filtrates of the seven isolates from the dead seedlings from the above experiment showed that all isolate filtrates killed the seedlings within 8 days. Identification of the bacteria using 16S rDNA sequencing showed that the isolates belonged to strains By253Ydz-fq, S209, 210-50 and 210-50 in Bacillus and the DN1.1 strain of Stenotrophomonas maltophilia, respectively. Completing Koch’s postulates using the seven bacterial isolates to inoculate pine seedlings showed that all the seedlings that received aseptic PWNs mixed with the seven bacterial isolates died within 18 days post inoculation, while those inoculated with ‘wild’ PWNs died 16 days post inoculation. No disease symptoms developed on seedlings that received sterile water or aseptic PWNs. The horizontal transfer of the pathogenic bacteria may explain differences in bacterial species carried by PWN in different geographic areas. PMID:23430766

  6. Evaluation of marine bacteriocinogenic enterococci strains with inhibitory activity against fish-pathogenic Gram-negative bacteria.

    PubMed

    Ghomrassi, Hamdi; ben Braiek, Olfa; Choiset, Yvan; Haertlé, Thomas; Hani, Khaled; Chobert, Jean-Marc; Ghrairi, Taoufik

    2016-02-11

    Use of lactic acid bacteria (LAB) as probiotics may provide an alternative to the use of antibiotics in aquaculture. LAB strains isolated from wild fish viscera and skin were evaluated for bacteriocin production and safety aspects (lack of antibiotic resistance, production of virulence factors). 16S rRNA gene sequences revealed the presence of Enterococcus faecium (13 isolates) and Lactococcus lactis (3 isolates) from fish samples. Pulsed-field gel electrophoresis analyses of the 13 enterococci isolates showed that they were all clustered, with greater than 95% similarity. However, RAPD analysis revealed significant molecular diversity between enterococci strains. Six enterococci strains were chosen and evaluated for their antibacterial activities. These strains produced a bacteriocin-like substance and exhibited a broad spectrum of inhibition against pathogenic bacteria isolated from diseased fish, including Streptococcus parauberis, Vagococcus spp., and Carnobacterium maltaromaticum, and in particular against the Gram-negative bacteria Flavobacterium frigidarium, Vibrio pectenicida, V. penaeicida, and Photobacterium damselae. The inhibition activity towards bacterial indicator strains was at a maximum when bacteria were grown at 37°C. However, bacteriocin production was observed at 15°C after 12 h of incubation. Only structural genes of enterocins A and B were detected by PCR in the 6 enterococci strains, suggesting the production of these enterocins. In addition, these strains did not harbor any virulence factors or any significant antibiotic resistance, and they tolerated bile. Our results suggest that enterococci are an important part of the bacterial flora of fish and that some strains have the potential to be used as probiotics. PMID:26865233

  7. High-throughput detection of food-borne pathogenic bacteria using oligonucleotide microarray with quantum dots as fluorescent labels.

    PubMed

    Huang, Aihua; Qiu, Zhigang; Jin, Min; Shen, Zhiqiang; Chen, Zhaoli; Wang, Xinwei; Li, Jun-Wen

    2014-08-18

    Bacterial pathogens are mostly responsible for food-borne diseases, and there is still substantial room for improvement in the effective detection of these organisms. In the present study, we explored a new method to detect target pathogens easily and rapidly with high sensitivity and specificity. This method uses an oligonucleotide microarray combined with quantum dots as fluorescent labels. Oligonucleotide probes targeting the 16SrRNA gene were synthesized to create an oligonucleotide microarray. The PCR products labeled with biotin were subsequently hybridized using an oligonucleotide microarray. Following incubation with CdSe/ZnS quantum dots coated with streptavidin, fluorescent signals were detected with a PerkinElmer Gx Microarray Scanner. The results clearly showed specific hybridization profiles corresponding to the bacterial species assessed. Two hundred and sixteen strains of food-borne bacterial pathogens, including standard strains and isolated strains from food samples, were used to test the specificity, stability, and sensitivity of the microarray system. We found that the oligonucleotide microarray combined with quantum dots used as fluorescent labels can successfully discriminate the bacterial organisms at the genera or species level, with high specificity and stability as well as a sensitivity of 10 colony forming units (CFU)/mL of pure culture. We further tested 105 mock-contaminated food samples and achieved consistent results as those obtained from traditional biochemical methods. Together, these results indicate that the quantum dot-based oligonucleotide microarray has the potential to be a powerful tool in the detection and identification of pathogenic bacteria in foods. PMID:24927399

  8. Sensitive and rapid detection of pathogenic bacteria in small volumes using impedance spectroscopy technique.

    PubMed

    Pal, Namrata; Sharma, Shashank; Gupta, Shalini

    2016-03-15

    We illustrate a novel impedance immunosensor which rapidly and sensitively detects typhoid-causing infectious bacteria Salmonella enterica serovar (Salmonella typhi) in 10 μL of sample volume. The bacteria are tagged with gold nanoparticles (Au NPs) via high-affinity antigen-antibody interactions for enhanced signal amplification and selectivity. The cell-particle bioconjugates are then subjected to alternating current (AC) electric fields applied through interdigitated microelectrodes. The immunosensor performance is optimized with respect to electric field frequency, cell concentration, incubation times and the type of blocking agent to achieve a low limit of detection (LOD) of 100 CFU/mL. The approach is extendable to a wide spectrum of clinical diseases and offers an efficient and cost-effective solution for point-of-care diagnosis. PMID:26414023

  9. Determination of pathogenic bacteria by CZE with surface-modified capillaries.

    PubMed

    Buszewski, Bogusław; Kłodzińska, Ewa

    2008-11-01

    The importance of electromigration techniques in molecular biology and medicine is increasing rapidly, especially in systematic studies on proteomes and metabolomes. Staphylococcus aureus and Escherichia coli are bacterial species most frequently encountered in human infections, and many serious illnesses can be observed in the hospital environment. In this contribution we proposed a CE method with different modification of internal capillary surface and with monolithic beds as a selective material for determination of bacteria in clinical samples. The electrophoretic separation depends on the differential mobility of bacteria in the capillary and selective interactions between bacterial cells and stationary phases (modified surface, monolithic beads). Proposed procedures could become an effective tool for diagnosis of certain diseases caused by S. aureus and E. coli as well as Proteus vulgaris. PMID:18942676

  10. Bacteriolytic effect of membrane vesicles from Pseudomonas aeruginosa on other bacteria including pathogens: conceptually new antibiotics.

    PubMed Central

    Kadurugamuwa, J L; Beveridge, T J

    1996-01-01

    Pseudomonas aeruginosa releases membrane vesicles (MVs) filled with periplasmic components during normal growth, and the quantity of these vesicles can be increased by brief exposure to gentamicin. Natural and gentamicin-induced membrane vesicles (n-MVs and g-MVs, respectively) are subtly different from one another, but both contain several important virulence factors, including hydrolytic enzyme factors (J. L. Kadurugamuwa and T. J. Beveridge, J. Bacteriol. 177:3998-4008, 1995). Peptidoglycan hydrolases (autolysins) were detected in both MV types, especially a periplasmic 26-kDa autolysin whose expression has been related to growth phase (Z. Li, A. J. Clarke, and T. J. Beveridge, J. Bacteriol. 178:2479-2488, 1996). g-MVs possessed slightly higher autolysin activity and, at the same time, small quantities of gentamicin. Both MV types hydrolyzed isolated gram-positive and gram-negative murein sacculi and were also capable of hydrolyzing several glycyl peptides. Because the MVs were bilayered, they readily fused with the outer membrane of gram-negative bacteria. They also adhered to the cell wall of gram-positive bacteria. g-MVs were more effective in lysing other bacteria because, in addition to the autolysins, they also contained small amounts of gentamicin. The bactericidal activity was 2.5 times the MIC of gentamicin, which demonstrates the synergistic effect of the antibiotic with the autolysins. n-MVs were capable of killing cultures of P. aeruginosa with permeability resistance against gentamicin, indicating that the fusion of n-MV to the outer membrane liberated autolysins into the periplasm, where they degraded the peptidoglycan and lysed the cells. g-MVs had even greater killing power since they liberated both gentamicin and autolysins into these resistant cells. These findings may help develop a conceptually new group of antibiotics designed to be effective against hard-to-kill bacteria. PMID:8631663

  11. Autoinducer-2 of the fire blight pathogen Erwinia amylovora and other plant-associated bacteria.

    PubMed

    Mohammadi, Mojtaba; Geider, Klaus

    2007-01-01

    Autoinducers are important for cellular communication of bacteria. The luxS gene has a central role in the synthesis of autoinducer-2 (AI-2). The gene was identified in a shotgun library of Erwinia amylovora and primers designed for PCR amplification from bacterial DNA. Supernatants of several Erwinia amylovora strains were assayed for AI-2 activity with a Vibrio harveyi mutant and were positive. Many other plant-associated bacteria also showed AI-2 activity such as Erwinia pyrifoliae and Erwinia tasmaniensis. The luxS genes of several bacteria were cloned, sequenced, and complemented Escherichia coli strain DH5alpha and a Salmonella typhimurium mutant, both defective in luxS, for synthesis of AI-2. Assays to detect AI-2 activity in culture supernatants of several Pseudomonas syringae pathovars failed, which may indicate the absence of AI-2 or synthesis of another type. Several reporter strains did not detect synthesis of an acyl homoserine lactone (AHL, AI-1) by Erwinia amylovora, but confirmed AHL-synthesis for Erwinia carotovora ssp. atroseptica and Pantoea stewartii. PMID:17092294

  12. Shigella IpaH Family Effectors as a Versatile Model for Studying Pathogenic Bacteria.

    PubMed

    Ashida, Hiroshi; Sasakawa, Chihiro

    2015-01-01

    Shigella spp. are highly adapted human pathogens that cause bacillary dysentery (shigellosis). Via the type III secretion system (T3SS), Shigella deliver a subset of virulence proteins (effectors) that are responsible for pathogenesis, with functions including pyroptosis, invasion of the epithelial cells, intracellular survival, and evasion of host immune responses. Intriguingly, T3SS effector activity and strategies are not unique to Shigella, but are shared by many other bacterial pathogens, including Salmonella, Yersinia, and enteropathogenic Escherichia coli (EPEC). Therefore, studying Shigella T3SS effectors will not only improve our understanding of bacterial infection systems, but also provide a molecular basis for developing live bacterial vaccines and antibacterial drugs. One of Shigella T3SS effectors, IpaH family proteins, which have E3 ubiquitin ligase activity and are widely conserved among other bacterial pathogens, are very relevant because they promote bacterial survival by triggering cell death and modulating the host immune responses. Here, we describe selected examples of Shigella pathogenesis, with particular emphasis on the roles of IpaH family effectors, which shed new light on bacterial survival strategies and provide clues about how to overcome bacterial infections. PMID:26779450

  13. Identification of organic acids in Cichorium intybus inhibiting virulence-related properties of oral pathogenic bacteria.

    PubMed

    Papetti, Adele; Mascherpa, Dora; Carazzone, Chiara; Stauder, Monica; Spratt, David A; Wilson, Michael; Pratten, Jonathan; Ciric, Lena; Lingström, Peter; Zaura, Egija; Weiss, Ervin; Ofek, Itzak; Signoretto, Caterina; Pruzzo, Carla; Gazzani, Gabriella

    2013-06-01

    The low molecular mass (LMM) extract of Cichorium intybus var. silvestre (red chicory) has been shown to inhibit virulence-linked properties of oral pathogens including Streptococcus mutans, Actinomyces naeslundii and Prevotella intermedia. In the present study HPLC-DAD-ESI/MS(2) was used to investigate the compounds contained in this extract for their anti-virulence activity. The extract contained a number of components, including oxalic, succinic, shikimic and quinic acids, which interfere with the growth and virulence traits (i.e., biofilm formation, adherence to epithelial cells and hydroxyapatite) of oral pathogens involved in gingivitis and tooth decay. Succinic and quinic acid seem to be the most potent, mainly by interfering with the ability of oral pathogens to form biofilms (either through inhibition of their development or promotion of their disruption). Our findings suggest that one or more of these compounds may modulate plaque formation in vivo, which is a prerequisite for the development of both caries and gingivitis. PMID:23411301

  14. Shigella IpaH Family Effectors as a Versatile Model for Studying Pathogenic Bacteria

    PubMed Central

    Ashida, Hiroshi; Sasakawa, Chihiro

    2016-01-01

    Shigella spp. are highly adapted human pathogens that cause bacillary dysentery (shigellosis). Via the type III secretion system (T3SS), Shigella deliver a subset of virulence proteins (effectors) that are responsible for pathogenesis, with functions including pyroptosis, invasion of the epithelial cells, intracellular survival, and evasion of host immune responses. Intriguingly, T3SS effector activity and strategies are not unique to Shigella, but are shared by many other bacterial pathogens, including Salmonella, Yersinia, and enteropathogenic Escherichia coli (EPEC). Therefore, studying Shigella T3SS effectors will not only improve our understanding of bacterial infection systems, but also provide a molecular basis for developing live bacterial vaccines and antibacterial drugs. One of Shigella T3SS effectors, IpaH family proteins, which have E3 ubiquitin ligase activity and are widely conserved among other bacterial pathogens, are very relevant because they promote bacterial survival by triggering cell death and modulating the host immune responses. Here, we describe selected examples of Shigella pathogenesis, with particular emphasis on the roles of IpaH family effectors, which shed new light on bacterial survival strategies and provide clues about how to overcome bacterial infections. PMID:26779450

  15. Limits to compensatory adaptation and the persistence of antibiotic resistance in pathogenic bacteria

    PubMed Central

    MacLean, R. Craig; Vogwill, Tom

    2015-01-01

    Antibiotic resistance carries a fitness cost that could potentially limit the spread of resistance in bacterial pathogens. In spite of this cost, a large number of experimental evolution studies have found that resistance is stably maintained in the absence of antibiotics as a result of compensatory evolution. Clinical studies, on the other hand, have found that resistance in pathogen populations usually declines after antibiotic use is stopped, suggesting that compensatory adaptation is not effective in vivo. In this article, we argue that this disagreement arises because there are limits to compensatory adaptation in nature that are not captured by the design of current laboratory selection experiments. First, clinical treatment fails to eradicate antibiotic-sensitive strains, and competition between sensitive and resistant strains leads to the rapid loss of resistance following treatment. Second, laboratory studies overestimate the efficacy of compensatory adaptation in nature by failing to capture costs associated with compensatory mutations. Taken together, these ideas can potentially reconcile evolutionary theory with the clinical dynamics of antibiotic resistance and guide the development of strategies for containing resistance in clinical pathogens. PMID:25535278

  16. Evaluation of gamma radiation levels for reducing pathogenic bacteria and fungi in animal sewage and laboratory effluents.

    PubMed Central

    Garcia, M M; Brooks, B W; Stewart, R B; Dion, W; Trudel, J R; Ouwerkerk, T

    1987-01-01

    Sewage samples collected from animal wastes and from effluents at an animal disease laboratory were inoculated with known numbers of pathogenic organisms and subjected to various doses of gamma radiation from a 60Co source. Surviving test organisms were quantitatively determined by selective and enrichment techniques. The experiment was modeled as a quantal assay in which probit analysis was applied to obtain D10 values. The D10 value represents the irradiating dose required to reduce the population by 90%. The D10 value ranged from 13.4 krad for Campylobacter fetus to 156.6 krad for Streptococcus faecalis in animal sewage. However, the D10 value for the laboratory effluent was generally lower. Based on the estimated D10 values, the rating of the test organisms in decreasing order of radiosensitivity appeared as follows: Brucella abortus, Campylobacter fetus subsp. fetus, Campylobacter jejuni, Campylobacter coli, Campylobacter laridis, Mycobacterium fortuitum, Aspergillus fumigatus, Salmonella muenster, Candida albicans, Clostridium difficile and Streptococcus faecalis. If the D5 and D1 values were utilized, this listing would be only slightly altered. PMID:3651881

  17. Antimicrobial and Efflux Pump Inhibitory Activity of Caffeoylquinic Acids from Artemisia absinthium against Gram-Positive Pathogenic Bacteria

    PubMed Central

    Fiamegos, Yiannis C.; Kastritis, Panagiotis L.; Exarchou, Vassiliki; Han, Haley; Bonvin, Alexandre M. J. J.; Vervoort, Jacques; Lewis, Kim; Hamblin, Michael R.; Tegos, George P.

    2011-01-01

    Background Traditional antibiotics are increasingly suffering from the emergence of multidrug resistance amongst pathogenic bacteria leading to a range of novel approaches to control microbial infections being investigated as potential alternative treatments. One plausible antimicrobial alternative could be the combination of conventional antimicrobial agents/antibiotics with small molecules which block multidrug efflux systems known as efflux pump inhibitors. Bioassay-driven purification and structural determination of compounds from plant sources have yielded a number of pump inhibitors which acted against gram positive bacteria. Methodology/Principal Findings In this study we report the identification and characterization of 4′,5′-O-dicaffeoylquinic acid (4′,5′-ODCQA) from Artemisia absinthium as a pump inhibitor with a potential of targeting efflux systems in a wide panel of Gram-positive human pathogenic bacteria. Separation and identification of phenolic compounds (chlorogenic acid, 3′,5′-ODCQA, 4′,5′-ODCQA) was based on hyphenated chromatographic techniques such as liquid chromatography with post column solid-phase extraction coupled with nuclear magnetic resonance spectroscopy and mass spectroscopy. Microbial susceptibility testing and potentiation of well know pump substrates revealed at least two active compounds; chlorogenic acid with weak antimicrobial activity and 4′,5′-ODCQA with pump inhibitory activity whereas 3′,5′-ODCQA was ineffective. These intitial findings were further validated with checkerboard, berberine accumulation efflux assays using efflux-related phenotypes and clinical isolates as well as molecular modeling methodology. Conclusions/Significance These techniques facilitated the direct analysis of the active components from plant extracts, as well as dramatically reduced the time needed to analyze the compounds, without the need for prior isolation. The calculated energetics of the docking poses supported the

  18. A New Zebrafish Model of Oro-Intestinal Pathogen Colonization Reveals a Key Role for Adhesion in Protection by Probiotic Bacteria

    PubMed Central

    Bégaud, Evelyne; Herbomel, Philippe; Levraud, Jean-Pierre; Ghigo, Jean-Marc

    2012-01-01

    The beneficial contribution of commensal bacteria to host health and homeostasis led to the concept that exogenous non-pathogenic bacteria called probiotics could be used to limit disease caused by pathogens. However, despite recent progress using gnotobiotic mammal and invertebrate models, mechanisms underlying protection afforded by commensal and probiotic bacteria against pathogens remain poorly understood. Here we developed a zebrafish model of controlled co-infection in which germ-free zebrafish raised on axenic living protozoa enabled the study of interactions between host and commensal and pathogenic bacteria. We screened enteric fish pathogens and identified Edwardsiella ictaluri as a virulent strain inducing a strong inflammatory response and rapid mortality in zebrafish larvae infected by the natural oro-intestinal route. Using mortality induced by infection as a phenotypic read-out, we pre-colonized zebrafish larvae with 37 potential probiotic bacterial strains and screened for survival upon E. ictaluri infection. We identified 3 robustly protective strains, including Vibrio parahaemolyticus and 2 Escherichia coli strains. We showed that the observed protective effect of E. coli was not correlated with a reduced host inflammatory response, nor with the release of biocidal molecules by protective bacteria, but rather with the presence of specific adhesion factors such as F pili that promote the emergence of probiotic bacteria in zebrafish larvae. Our study therefore provides new insights into the molecular events underlying the probiotic effect and constitutes a potentially high-throughput in vivo approach to the study of the molecular basis of pathogen exclusion in a relevant model of vertebrate oro-intestinal infection. PMID:22911651

  19. Improving alfalfa silage quality with inoculants and silo management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two areas of silage management are addressed: silage inoculants and plastic film quality. Inoculants are the most common silage additives in the United States. These products contain lactic acid bacteria to supplement the lactic acid bacteria naturally on the crop and help insure a consistent fermen...

  20. Accessing inoculation methods of maize and wheat with Azospirillum brasilense.

    PubMed

    Fukami, Josiane; Nogueira, Marco Antonio; Araujo, Ricardo Silva; Hungria, Mariangela

    2016-03-01

    The utilization of inoculants containing Azospirillum is becoming more popular due to increasing reports of expressive gains in grain yields. However, incompatibility with pesticides used in seed treatments represents a main limitation for a successful inoculation. Therefore, in this study we searched for alternatives methods for seed inoculation of maize and wheat, aiming to avoid the direct contact of bacteria with pesticides. Different doses of inoculants containing Azospirillum brasilense were employed to perform inoculation in-furrow, via soil spray at sowing and via leaf spray after seedlings had emerged, in comparison to seed inoculation. Experiments were conducted first under greenhouse controlled conditions and then confirmed in the field at different locations in Brazil. In the greenhouse, most parameters measured responded positively to the largest inoculant dose used in foliar sprays, but benefits could also be observed from both in-furrow and soil spray inoculation. However, our results present evidence that field inoculation with plant-growth promoting bacteria must consider inoculant doses, and point to the need of fine adjustments to avoid crossing the threshold of growth stimulation and inhibition. All inoculation techniques increased the abundance of diazotrophic bacteria in plant tissues, and foliar spray improved colonization of leaves, while soil inoculations favored root and rhizosphere colonization. In field experiments, inoculation with A. brasilense allowed for a 25 % reduction in the need for N fertilizers. Our results have identified alternative methods of inoculation that were as effective as the standard seed inoculation that may represent an important strategy to avoid the incompatibility between inoculant bacteria and pesticides employed for seed treatment. PMID:26759120

  1. Bio-Conjugated CNT-Bridged 3D Porous Graphene Oxide Membrane for Highly Efficient Disinfection of Pathogenic Bacteria and Removal of Toxic Metals from Water.

    PubMed

    Nellore, Bhanu Priya Viraka; Kanchanapally, Rajashekhar; Pedraza, Francisco; Sinha, Sudarson Sekhar; Pramanik, Avijit; Hamme, Ashton T; Arslan, Zikri; Sardar, Dhiraj; Ray, Paresh Chandra

    2015-09-01

    More than a billion people lack access to safe drinking water that is free from pathogenic bacteria and toxic metals. The World Health Organization estimates several million people, mostly children, die every year due to the lack of good quality water. Driven by this need, we report the development of PGLa antimicrobial peptide and glutathione conjugated carbon nanotube (CNT) bridged three-dimensional (3D) porous graphene oxide membrane, which can be used for highly efficient disinfection of Escherichia coli O157:H7 bacteria and removal of As(III), As(V), and Pb(II) from water. Reported results demonstrate that versatile membrane has the capability to capture and completely disinfect pathogenic pathogenic E. coli O157:H7 bacteria from water. Experimentally observed disinfection data indicate that the PGLa attached membrane can dramatically enhance the possibility of destroying pathogenic E. coli bacteria via synergistic mechanism. Reported results show that glutathione attached CNT-bridged 3D graphene oxide membrane can be used to remove As(III), As(V), and Pb(II) from water sample at 10 ppm level. Our data demonstrated that PGLa and glutathione attached membrane has the capability for high efficient removal of E. coli O157:H7 bacteria, As(III), As(V), and Pb(II) simultaneously from Mississippi River water. PMID:26273843

  2. Social and Economic Aspects of the Transmission of Pathogenic Bacteria between Wildlife and Food Animals: A Thematic Analysis of Published Research Knowledge.

    PubMed

    Fournier, A; Young, I; Rajić, A; Greig, J; LeJeune, J

    2015-09-01

    Wildlife is a known reservoir of pathogenic bacteria, including Mycobacterium bovis and Brucella spp. Transmission of these pathogens between wildlife and food animals can lead to damaging impacts on the agri-food industry and public health. Several international case studies have highlighted the complex and cross-sectoral challenges involved in preventing and managing these potential transmission risks. The objective of our study was to develop a better understanding of the socio-economic aspects of the transmission of pathogenic bacteria between wildlife and food animals to support more effective and sustainable risk mitigation strategies. We conducted qualitative thematic analysis on a purposive sample of 30/141 articles identified in a complementary scoping review of the literature in this area and identified two key themes. The first related to the framing of this issue as a 'wicked problem' that depends on a complex interaction of social factors and risk perceptions, governance and public policy, and economic implications. The second theme consisted of promising approaches and strategies to prevent and mitigate the potential risks from transmission of pathogenic bacteria between wildlife and food animals. These included participatory, collaborative and multidisciplinary decision-making approaches and the proactive incorporation of credible scientific evidence and local contextual factors into solutions. The integration of these approaches to address 'wicked problems' in this field may assist stakeholders and decision-makers in improving the acceptability and sustainability of future strategies to reduce the transmission of pathogenic bacteria between wildlife and food animals. PMID:25611914

  3. Antibacterial activity of a 7,10-dihydroxy-8(E)-octadecenoic acid against plant pathogenic bacteria.

    PubMed

    Sohn, Hye-Ran; Bae, Jae-Han; Hou, Ching T; Kim, Hak-Ryul

    2013-08-15

    7,10-Dihydroxy-8(E)-octadecenoic acid (DOD), one of hydroxy fatty acids, was successfully produced from oleic acid and natural vegetable oils containing oleic acid by a bacterial strain Pseudomonas aeruginosa (PR3). However, biological properties of DOD remained unknown so far. In this study, as a trial to determine the biological properties of DOD molecule, antibacterial activities of DOD against plant pathogenic bacteria were determined qualitatively and quantitatively. DOD presented strong antibacterial activities against all the bacterial strains tested with MIC value being in the range of 125-1000μg/ml and there was no sensitivity preference detected between Gram-positive and Gram-negative strains. PMID:23830454

  4. Application of a pathogen microarray for the analysis of viruses and bacteria in clinical diagnostic samples from pigs.

    PubMed

    Jaing, Crystal J; Thissen, James B; Gardner, Shea N; McLoughlin, Kevin S; Hullinger, Pam J; Monday, Nicholas A; Niederwerder, Megan C; Rowland, Raymond R R

    2015-05-01

    Many of the disease syndromes challenging the commercial swine industry involve the analysis of complex problems caused by polymicrobial, emerging or reemerging, and transboundary pathogens. This study investigated the utility of the Lawrence Livermore Microbial Detection Array (Lawrence Livermore National Laboratory, Livermore, California), designed to detect 8,101 species of microbes, in the evaluation of known and unknown microbes in serum, oral fluid, and tonsil from pigs experimentally coinfected with Porcine reproductive and respiratory syndrome virus (PRRSV) and Porcine circovirus-2 (PCV-2). The array easily identified PRRSV and PCV-2, but at decreased sensitivities compared to standard polymerase chain reaction detection methods. The oral fluid sample was the most informative, possessing additional signatures for several swine-associated bacteria, including Streptococcus sp., Clostridium sp., and Staphylococcus sp. PMID:25855363

  5. Sequential inoculation versus co-inoculation in Cabernet Franc wine fermentation.

    PubMed

    Cañas, Pedro Miguel Izquierdo; Romero, Esteban García; Pérez-Martín, Fátima; Seseña, Susana; Palop, María Llanos

    2015-04-01

    A study has been carried out in order to determine the effect of the lactic acid bacteria inoculation time on the kinetic of vinification and on chemical and sensory characteristics of Cabernet Franc wines. Traditional vinifications, with lactic acid bacteria inoculated after completion of alcoholic fermentation were compared with vinifications where yeast and bacteria were co-inoculated at the beginning of vinification. One commercial yeast strain and an autochthonous Oenococcus oeni strain (C22L9), previously identified and selected at our laboratory, were used. Monitoring of alcoholic and malolactic fermentations was carried out by yeast and lactic acid bacteria counts and by measuring l-malic acid concentration. Wines were chemically characterized and analysed for volatile compounds content. A sensory analysis, consisting of a descriptive and a triangular test, was also carried out. Results from this study showed that the concurrent yeast/bacteria inoculation of musts at the beginning of vinification produced a reduction in duration of the process without an excessive increase in volatile acidity. Differences in volatile compounds content and the corresponding impact on the sensorial profile of wines were also displayed. These results suggest that co-inoculation is a worthwhile alternative for winemaking of Cabernet Franc wines, if compared with traditional post-alcoholic fermentation lactic acid bacteria inoculation. PMID:24583599

  6. Anti-bacterial and anti-biofilm activity of probiotic bacteria against oral pathogens.

    PubMed

    Ben Taheur, Fadia; Kouidhi, Bochra; Fdhila, Kais; Elabed, Hamouda; Ben Slama, Rihab; Mahdouani, Kacem; Bakhrouf, Amina; Chaieb, Kamel

    2016-08-01

    In this study, three lactic acid bacteria (LAB), isolated from barley, traditional dried meat and fermented olive were characterized and tested for their anti-bacterial and anti-biofilm activities against oral bacteria. Our results revealed that the tested LAB were γ-hemolytic and were susceptible to four antibiotics. All the strains were resistant to low pH, bile salt, pepsin and pancreatin. Furthermore, FB2 displayed a high aut-oaggregative phenotype (99.54%) while FF2 exhibited the best co-aggregation rate. Concerning the microbial adhesion to solvent, FB2 was the most hydrophobic strain (data obtained with chloroform and n-hexadecane). In addition Pediococcus pentosaceus FB2 and Lactobacillus brevis FF2 displayed a significant inhibitory effect against Streptococcus salivarius B468 (MIC = 10%). Moreover the selected strains were able to inhibit biofilm formation of Bacillus cereus ATCC14579 (MBIC50 = 28.16%) and S. salivarius B468 (MBIC50 = 42.28%). The selected LAB could be considered as candidate probiotics for further application in functional food and mainly in the prevention of oral diseases. PMID:27317856

  7. Gut Microbiota-Induced Immunoglobulin G Controls Systemic Infection by Symbiotic Bacteria and Pathogens.

    PubMed

    Zeng, Melody Y; Cisalpino, Daniel; Varadarajan, Saranyaraajan; Hellman, Judith; Warren, H Shaw; Cascalho, Marilia; Inohara, Naohiro; Núñez, Gabriel

    2016-03-15

    The gut microbiota is compartmentalized in the intestinal lumen and induces local immune responses, but it remains unknown whether the gut microbiota can induce systemic response and contribute to systemic immunity. We report that selective gut symbiotic gram-negative bacteria were able to disseminate systemically to induce immunoglobulin G (IgG) response, which primarily targeted gram-negative bacterial antigens and conferred protection against systemic infections by E. coli and Salmonella by directly coating bacteria to promote killing by phagocytes. T cells and Toll-like receptor 4 on B cells were important in the generation of microbiota-specific IgG. We identified murein lipoprotein (MLP), a highly conserved gram-negative outer membrane protein, as a major antigen that induced systemic IgG homeostatically in both mice and humans. Administration of anti-MLP IgG conferred crucial protection against systemic Salmonella infection. Thus, our findings reveal an important function for the gut microbiota in combating systemic infection through the induction of protective IgG. PMID:26944199

  8. Effect of gamma-irradiation on frozen shrimps for decontamination of pathogenic bacteria

    NASA Astrophysics Data System (ADS)

    Ito, Hitoshi; Rashid, Harun Or; Sangthong, Naruemon; Adulyatham, Pitaya; Rattagool, Pongpen; Ishigaki, Isao

    1993-07-01

    Twelve samples of imported frozen shrimps were used in this study. The total aerobic bacteria were at 2 × 10 4 to 6 × 10 6 per gram. A few of Vibrio parahaemolyticus, V. mimicus, V. alginolyticus, V. vulnificus, V. fluvialis and Listeria monocytogenes were isolated from many samples. However, Salmonella was not detected in any of the samples. After exposure to 4-5 kGy of gamma-rays, the total aerobic bacteria in frozen shrimps were reduced by approximately 2-3 log cycles. The dose necessary to reduce the vibrio isolates and Aeromonas hydrophila at a level of below 10 -4 per gram was about 3 kGy in frozen shrimps, whereas about 3.5 kGy was required for L. monocytogenes and Salmonella typhimurium. In this study, unpleasant off-odor was clearly detected in the non-frozen shrimps irradiated at 2.5 kGy. On the other hand, off-odor was negligible in the frozen product below 5 kGy irradiation. No remarkable changes of peroxide values were also obtained up to 9 kGy of irradiation in the frozen shrimps. However peroxide values of non-frozen shrimps were clearly increased even irradiated at 4 kGy. Trimethylamine content was not changed at doses below 10 kGy in both of frozen and non-frozen shrimps. Shelf-life of defrosted shrimps were extended ca. 2 times under non-frozen market conditions.

  9. Washing-resistant surfactant coated surface is able to inhibit pathogenic bacteria adhesion

    NASA Astrophysics Data System (ADS)

    Treter, Janine; Bonatto, Fernando; Krug, Cristiano; Soares, Gabriel Vieira; Baumvol, Israel Jacob Rabin; Macedo, Alexandre José

    2014-06-01

    Surface-active substances, which are able to organize themselves spontaneously on surfaces, triggering changes in the nature of the solid-liquid interface, are likely to influence microorganism adhesion and biofilm formation. Therefore, this study aimed to evaluate chemical non-ionic surfactants activity against pathogenic microbial biofilms and to cover biomaterial surfaces in order to obtain an anti-infective surface. After testing 11 different surfactants, Pluronic F127 was selected for further studies due to its non-biocidal properties and capability to inhibit up to 90% of biofilm formation of Gram-positive pathogen and its clinical isolates. The coating technique using direct impregnation on the surface showed important antibiofilm formation characteristics, even after extensive washes. Surface roughness and bacterial surface polarity does not influence the adhesion of Staphylococcus epidermidis, however, the material coated surface became extremely hydrophilic. The phenotype of S. epidermidis does not seem to have been affected by the contact with surfactant, reinforcing the evidence that a physical phenomenon is responsible for the activity. This paper presents a simple method of surface coating employing a synthetic surfactant to prevent S. epidermidis biofilm formation.

  10. Antimicrobial Activity of Lactic Acid Bacteria in Dairy Products and Gut: Effect on Pathogens

    PubMed Central

    Rodríguez, Eva; Landete, José María

    2015-01-01

    The food industry seeks alternatives to satisfy consumer demands of safe foods with a long shelf-life able to maintain the nutritional and organoleptic quality. The application of antimicrobial compounds-producing protective cultures may provide an additional parameter of processing in order to improve the safety and ensure food quality, keeping or enhancing its sensorial characteristics. In addition, strong evidences suggest that certain probiotic strains can confer resistance against infection with enteric pathogens. Several mechanisms have been proposed to support this phenomenon, including antimicrobial compounds secreted by the probiotics, competitive exclusion, or stimulation of the immune system. Recent research has increasingly demonstrated the role of antimicrobial compounds as protective mechanism against intestinal pathogens and therefore certain strains could have an effect on both the food and the gut. In this aspect, the effects of the combination of different strains keep unknown. The development of multistrain probiotic dairy products with good technological properties and with improved characteristics to those shown by the individual strains, able to act not only as protective cultures in foods, but also as probiotics able to exert a protective action against infections, has gained increased interest. PMID:25861634

  11. Antimicrobial activity of lactic acid bacteria in dairy products and gut: effect on pathogens.

    PubMed

    Arqués, Juan L; Rodríguez, Eva; Langa, Susana; Landete, José María; Medina, Margarita

    2015-01-01

    The food industry seeks alternatives to satisfy consumer demands of safe foods with a long shelf-life able to maintain the nutritional and organoleptic quality. The application of antimicrobial compounds-producing protective cultures may provide an additional parameter of processing in order to improve the safety and ensure food quality, keeping or enhancing its sensorial characteristics. In addition, strong evidences suggest that certain probiotic strains can confer resistance against infection with enteric pathogens. Several mechanisms have been proposed to support this phenomenon, including antimicrobial compounds secreted by the probiotics, competitive exclusion, or stimulation of the immune system. Recent research has increasingly demonstrated the role of antimicrobial compounds as protective mechanism against intestinal pathogens and therefore certain strains could have an effect on both the food and the gut. In this aspect, the effects of the combination of different strains keep unknown. The development of multistrain probiotic dairy products with good technological properties and with improved characteristics to those shown by the individual strains, able to act not only as protective cultures in foods, but also as probiotics able to exert a protective action against infections, has gained increased interest. PMID:25861634

  12. Inhibitory effect of Allium sativum and Zingiber officinale extracts on clinically important drug resistant pathogenic bacteria

    PubMed Central

    2012-01-01

    Background Herbs and spices are very important and useful as therapeutic agent against many pathological infections. Increasing multidrug resistance of pathogens forces to find alternative compounds for treatment of infectious diseases. Methods In the present study the antimicrobial potency of garlic and ginger has been investigated against eight local clinical bacterial isolates. Three types of extracts of each garlic and ginger including aqueous extract, methanol extract and ethanol extract had been assayed separately against drug resistant Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis, Staphylococcus aureus, Klebsiella pneumoniae, Shigella sonnei, Staphylococcusepidermidis and Salmonella typhi. The antibacterial activity was determined by disc diffusion method. Results All tested bacterial strains were most susceptible to the garlic aqueous extract and showed poor susceptibility to the ginger aqueous extract. The (minimum inhibitory concentration) MIC of different bacterial species varied from 0.05 mg/ml to 1.0 mg/ml. Conclusion In the light of several socioeconomic factors of Pakistan mainly poverty and poor hygienic condition, present study encourages the use of spices as alternative or supplementary medicine to reduce the burden of high cost, side effects and progressively increasing drug resistance of pathogens. PMID:22540232

  13. A novel model to assess the efficacy of steam surface pasteurization of cooked surimi gels inoculated with realistic levels of Listeria innocua.

    PubMed

    Skåra, Torstein; Valdramidis, Vasilis P; Rosnes, Jan Thomas; Noriega, Estefanía; Van Impe, Jan F M

    2014-12-01

    Steam surface pasteurization is a promising decontamination technology for reducing pathogenic bacteria in different stages of food production. The effect of the artificial inoculation type and initial microbial load, however, has not been thoroughly assessed in the context of inactivation studies. In order to optimize the efficacy of the technology, the aim of this study was to design and validate a model system for steam surface pasteurization, assessing different inoculation methods and realistic microbial levels. More specifically, the response of Listeria innocua, a surrogate organism of Listeria monocytogenes, on a model fish product, and the effect of different inoculation levels following treatments with a steam surface pasteurization system was investigated. The variation in the resulting inoculation level on the samples was too large (77%) for the contact inoculation procedure to be further considered. In contrast, the variation of a drop inoculation procedure was 17%. Inoculation with high levels showed a rapid 1-2 log decrease after 3-5 s, and then no further inactivation beyond 20 s. A low level inoculation study was performed by analysing the treated samples using a novel contact plating approach, which can be performed without sample homogenization and dilution. Using logistic regression, results from this method were used to model the binary responses of Listeria on surfaces with realistic inoculation levels. According to this model, a treatment time of 23 s will result in a 1 log reduction (for P = 0.1). PMID:25084647

  14. Associations among pathogenic bacteria, parasites, and environmental and land use factors in multiple mixed-use watersheds.

    PubMed

    Wilkes, G; Edge, T A; Gannon, V P J; Jokinen, C; Lyautey, E; Neumann, N F; Ruecker, N; Scott, A; Sunohara, M; Topp, E; Lapen, D R

    2011-11-15

    Over a five year period (2004-08), 1171 surface water samples were collected from up to 24 sampling locations representing a wide range of stream orders, in a river basin in eastern Ontario, Canada. Water was analyzed for Cryptosporidium oocysts and Giardia cyst densities, the presence of Salmonella enterica subspecies enterica, Campylobacter spp., Listeria monocytogenes, and Escherichia coli O157:H7. The study objective was to explore associations among pathogen densities/occurrence and objectively defined land use, weather, hydrologic, and water quality variables using CART (Classification and Regression Tree) and binary logistical regression techniques. E. coli O157:H7 detections were infrequent, but detections were related to upstream livestock pasture density; 20% of the detections were located where cattle have access to the watercourses. The ratio of detections:non-detections for Campylobacter spp. was relatively higher (>1) when mean air temperatures were 6% below mean study period temperature values (relatively cooler periods). Cooler water temperatures, which can promote bacteria survival and represent times when land applications of manure typically occur (spring and fall), may have promoted increased frequency of Campylobacter spp. Fifty-nine percent of all Salmonella spp. detections occurred when river discharge on a branch of the river system of Shreve stream order = 9550 was >83 percentile. Hydrological events that promote off farm/off field/in stream transport must manifest themselves in order for detection of Salmonella spp. to occur in surface water in this region. Fifty seven percent of L. monocytogenes detections occurred in spring, relative to other seasons. It was speculated that a combination of winter livestock housing, silage feeding during winter, and spring application of manure that accrued during winter, contributed to elevated occurrences of this pathogen in spring. Cryptosporidium and Giardia oocyst and cyst densities were, overall

  15. Potent antimicrobial and antibiofilm activities of bacteriogenically synthesized gold-silver nanoparticles against pathogenic bacteria and their physiochemical characterizations.

    PubMed

    Ramasamy, Mohankandhasamy; Lee, Jin-Hyung; Lee, Jintae

    2016-09-01

    The objective of this study was to develop a bimetallic nanoparticle with enhanced antibacterial activity that would improve the therapeutic efficacy against bacterial biofilms. Bimetallic gold-silver nanoparticles were bacteriogenically synthesized using γ-proteobacterium, Shewanella oneidensis MR-1. The antibacterial activities of gold-silver nanoparticles were assessed on the planktonic and biofilm phases of individual and mixed multi-cultures of pathogenic Gram negative (Escherichia coli and Pseudomonas aeruginosa) and Gram positive bacteria (Enterococcus faecalis and Staphylococcus aureus), respectively. The minimum inhibitory concentration of gold-silver nanoparticles was 30-50 µM than that of other nanoparticles (>100 µM) for the tested bacteria. Interestingly, gold-silver nanoparticles were more effective in inhibiting bacterial biofilm formation at 10 µM concentration. Both scanning and transmission electron microscopy results further accounted the impact of gold-silver nanoparticles on biocompatibility and bactericidal effect that the small size and bio-organic materials covering on gold-silver nanoparticles improves the internalization and thus caused bacterial inactivation. Thus, bacteriogenically synthesized gold-silver nanoparticles appear to be a promising nanoantibiotic for overcoming the bacterial resistance in the established bacterial biofilms. PMID:27117745

  16. The rhizosphere effect on bacteria antagonistic towards the pathogenic fungus Verticillium differs depending on plant species and site.

    PubMed

    Berg, Gabriele; Opelt, Katja; Zachow, Christin; Lottmann, Jana; Götz, Monika; Costa, Rodrigo; Smalla, Kornelia

    2006-05-01

    Rhizobacteria with antagonistic activity towards plant pathogens play an essential role in root growth and plant health and are influenced by plant species in their abundance and composition. To determine the extent of the effect of the plant species and of the site on the abundance and composition of bacteria with antagonistic activity towards Verticillium dahliae, bacteria isolated from the rhizosphere of two Verticillium host plants, oilseed rape and strawberry, and from bulk soil were analysed at three different locations in Germany over two growing seasons. A total of 6732 bacterial isolates screened for in vitro antagonism towards Verticillium resulted in 560 active isolates, among which Pseudomonas (77%) and Serratia (6%) were the most dominant genera. The rhizosphere effect on the antagonistic bacterial community was shown by an enhanced proportion of antagonistic isolates, by enrichment of specific amplified ribosomal DNA restriction analysis types, species and genotypes, and by a reduced diversity in the rhizosphere in comparison to bulk soil. Such an effect was influenced by the plant species and by the site of its cultivation. Altogether, 16S rRNA gene sequencing of 66 isolates resulted in the identification of 22 different species. Antagonists of the genus Serratia were preferentially isolated from oilseed rape rhizosphere, with the exception of one site. For isolates of Pseudomonas and Serratia, plant-specific and site-specific genotypes were found. PMID:16629754

  17. Antibacterial Activity and Action Mechanism of the Essential Oil from Enteromorpha linza L. against Foodborne Pathogenic Bacteria.

    PubMed

    Patra, Jayanta Kumar; Baek, Kwang-Hyun

    2016-01-01

    Foodborne illness and disease caused by foodborne pathogenic bacteria is continuing to increase day by day and it has become an important topic of concern among various food industries. Many types of synthetic antibacterial agents have been used in food processing and food preservation; however, they are not safe and have resulted in various health-related issues. Therefore, in the present study, essential oil from an edible seaweed, Enteromorpha linza (AEO), was evaluated for its antibacterial activity against foodborne pathogens, along with the mechanism of its antibacterial action. AEO at 25 mg/disc was highly active against Bacillus cereus (12.3-12.7 mm inhibition zone) and Staphylococcus aureus (12.7-13.3 mm inhibition zone). The minimum inhibitory concentration and minimum bactericidal concentration values of AEO ranged from 12.5-25 mg/mL. Further investigation of the mechanism of action of AEO revealed its strong impairing effect on the viability of bacterial cells and membrane permeability, as indicated by a significant increase in leakage of 260 nm absorbing materials and K⁺ ions from the cell membrane and loss of high salt tolerance. Taken together, these data suggest that AEO has the potential for use as an effective antibacterial agent that functions by impairing cell membrane permeability via morphological alternations, resulting in cellular lysis and cell death. PMID:27007365

  18. Gluconobacter as Well as Asaia Species, Newly Emerging Opportunistic Human Pathogens among Acetic Acid Bacteria ▿ †

    PubMed Central

    Alauzet, Corentine; Teyssier, Corinne; Jumas-Bilak, Estelle; Gouby, Anne; Chiron, Raphael; Rabaud, Christian; Counil, François; Lozniewski, Alain; Marchandin, Hélène

    2010-01-01

    Acetic acid bacteria (AAB) are broadly used in industrial food processing. Among them, members of the genera Asaia, Acetobacter, and Granulibacter were recently reported to be human opportunistic pathogens. We isolated AAB from clinical samples from three patients and describe here the clinical and bacteriological features of these cases. We report for the first time (i) the isolation of a Gluconobacter sp. from human clinical samples; (ii) the successive isolation of different AAB, i.e., an Asaia sp. and two unrelated Gluconobacter spp., from a cystic fibrosis patient; and (iii) persistent colonization of the respiratory tract by a Gluconobacter sp. in this patient. We reviewed the main clinical features associated with AAB isolation identified in the 10 documented reports currently available in the literature. Albeit rare, infections as well as colonization with AAB are increasingly reported in patients with underlying chronic diseases and/or indwelling devices. Clinicians as well as medical microbiologists should be aware of these unusual opportunistic pathogens, which are difficult to detect during standard medical microbiological investigations and which are multiresistant to antimicrobial agents. Molecular methods are required for identification of genera of AAB, but the results may remain inconclusive for identification to the species level. PMID:20826638

  19. Antibacterial activity of commercially available plant-derived essential oils against oral pathogenic bacteria.

    PubMed

    Bardají, D K R; Reis, E B; Medeiros, T C T; Lucarini, R; Crotti, A E M; Martins, C H G

    2016-01-01

    This work investigated the antibacterial activity of 15 commercially available plant-derived essential oils (EOs) against a panel of oral pathogens. The broth microdilution method afforded the minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of the assayed EOs. The EO obtained from Cinnamomum zeylanicum (Lauraceae) (CZ-EO) displayed moderate activity against Fusobacterium nucleatum (MIC and MBC = 125 μg/mL), Actinomyces naeslundii (MIC and MBC = 125 μg/mL), Prevotella nigrescens (MIC and MBC = 125 μg/mL) and Streptococcus mutans (MIC = 200 μg/mL; MBC = 400 μg/mL). (Z)-isosafrole (85.3%) was the main chemical component of this oil. We did not detect cinnamaldehyde, previously described as the major constituent of CZ-EO, in specimens collected in other countries. PMID:26165725

  20. Effects of mutation and some environmental factors on the physiology and pathogenicity of selected bacteria

    NASA Technical Reports Server (NTRS)

    Decicco, B. T.

    1974-01-01

    Studies with mutants of Staphylococcus aureus lacking some virulence factors suggest that the presence of deoxyribonuclease correlates with mouse pathogenicity of S. aureus, while the ability to ferment mannitol or the possession of coagulases are not required for virulence. Autotrophy investigations on mycobacteria demonstrate a complete correlation between the ability to grow with hydrogen and the species of scotochromogenic mycobacterium tested. All tested strains of M. gordonae, a saprophyte, could grow autotrophically while none of the tested strains of M. scrofulaceum, a clinically important species, possessed this ability. A series of heat tolerant mutants of Pseudomonas fluorescences were obtained which can grow at temperatures up to 54 C, in contrast to a maximum growth temperature of 37 C for the wild type.

  1. Bacteria Murmur: Application of an Acoustic Biosensor for Plant Pathogen Detection

    PubMed Central

    Dimopoulou, Anastasia; Glynos, Paraskevas; Gizeli, Electra

    2015-01-01

    A multi-targeting protocol for the detection of three of the most important bacterial phytopathogens, based on their scientific and economic importance, was developed using an acoustic biosensor (the Quartz Crystal Microbalance) for DNA detection. Acoustic detection was based on a novel approach where DNA amplicons were monitored and discriminated based on their length rather than mass. Experiments were performed during real time monitoring of analyte binding and in a direct manner, i.e. without the use of labels for enhancing signal transduction. The proposed protocol improves time processing by circumventing gel electrophoresis and can be incorporated as a routine detection method in a diagnostic lab or an automated lab-on-a-chip system for plant pathogen diagnostics. PMID:26177507

  2. Identification of lactobacilli with inhibitory effect on biofilm formation by pathogenic bacteria on stainless steel surfaces.

    PubMed

    Ait Ouali, Fatma; Al Kassaa, Imad; Cudennec, Benoit; Abdallah, Marwan; Bendali, Farida; Sadoun, Djamila; Chihib, Nour-Eddine; Drider, Djamel

    2014-11-17

    Two hundred and thirty individual clones of microorganisms were recovered from milk tanks and milking machine surfaces at two distinct farms (Bejaja City, Algeria). Of these clones, 130 were identified as lactic acid bacteria (LAB). In addition Escherichia coli, Salmonella, Staphylococcus aureus and Pseudomonas aeruginosa species were identified in the remaining 100 isolates-spoilage isolate. These isolates were assayed for ability to form biofilms. S. aureus, Lactobacillus brevis strains LB1F2, LB14F1 and LB15F1, and Lactobacillus pentosus strains LB2F2 and LB3F2 were identified as the best biofilm formers. Besides, these LAB isolates were able to produce proteinaceous substances with antagonism against the aforementioned spoilage isolates, when grown in MRS or TSB-YE media. During the screening, L. pentosus LB3F2 exhibited the highest antibacterial activity when grown in TSB-YE medium at 30 °C. Additionally, L. pentosus LB3F2 was able to strongly hamper the adhesion of S. aureus SA3 on abiotic surfaces as polystyrene and stainless steel slides. LAB isolates did not show any hemolytic activity and all of them were sensitive to different families of antibiotic tested. It should be pointed out that LB3F2 isolate was not cytotoxic on the intestinal cells but could stimulate their metabolic activity. This report unveiled the potential of LB1F2, LB14F1, LB15F1, LB2F2, and LB3F2 isolates to be used as natural barrier or competitive exclusion organism in the food processing sector as well as a positive biofilm forming bacteria. PMID:25261829

  3. Influence of pathogenic bacteria species present in the postpartum bovine uterus on proteome profiles.

    PubMed

    Ledgard, A M; Smolenski, G A; Henderson, H; Lee, R S F

    2015-01-01

    In the first 2-3 weeks after parturition >90% of dairy cows will have some form of uterine infection. Uterine contamination with pathogens, such as Trueperella (formerly Arcanobacterium) pyogenes increases the risk of developing more severe endometritis, which can reduce conception rates. In this study, we compared the uterine proteome of cows infected with Trueperella pyogenes with that of uninfected cows, using 2D gel electrophoresis, and identified annexins A1 and A2 (ANXA1 and ANXA2), apolipoprotein A-1, calprotectin (S100A9), cathelicidin, enolase 1 (ENO1), peptidoglycan recognition protein 1 (PGLYRP1), phosphoglycerate mutase 1 (PGAM1), serine dehydratase (SDS) and serine protease inhibitors (SERPIN) B1, B3 and B4 proteins as differing in abundance in endometritis. Subsequently, levels of ten of these proteins were monitored in uterine samples collected from a herd of lactating, dairy cows at 15 and 42 days post-partum (DPP). The levels were compared with the cytology scores of the samples and the bacterial species isolated from the uterus. Cathelicidin, PGLYRP1, SERPINB1 and S100A9 levels at 15DPP showed strong positive correlations (r=0.78, 0.80, 0.79, and 0.68 respectively; P<0.001) with % of polymorphonuclear neutrophils (PMN). When compared with other bacterial pathogens identified, Streptococcus agalactiae and Truperella pyogenes induced increased expression of the indicator proteins, suggesting that these organisms may adversely affect the subsequent ability of the cow to conceive. Interestingly, there was no difference in the proportion of cows pregnant at 6 and 17 weeks after start of mating between the cows with high or low %PMN. PMID:24331367

  4. Tropism and Induction of Cytokines in Human Embryonic-Stem Cells-Derived Neural Progenitors upon Inoculation with Highly- Pathogenic Avian H5N1 Influenza Virus

    PubMed Central

    Pringproa, Kidsadagon; Rungsiwiwut, Ruttachuk; Tantilertcharoen, Rachod; Praphet, Reunkeaw; Pruksananonda, Kamthorn; Baumgärtner, Wolfgang; Thanawongnuwech, Roongroje

    2015-01-01

    Central nervous system (CNS) dysfunction caused by neurovirulent influenza viruses is a dreaded complication of infection, and may play a role in some neurodegenerative conditions, such as Parkinson-like diseases and encephalitis lethargica. Although CNS infection by highly pathogenic H5N1 virus has been demonstrated, it is unknown whether H5N1 infects neural progenitor cells, nor whether such infection plays a role in the neuroinflammation and neurodegeneration. To pursue this question, we infected human neural progenitor cells (hNPCs) differentiated from human embryonic stem cells in vitro with H5N1 virus, and studied the resulting cytopathology, cytokine expression, and genes involved in the differentiation. Human embryonic stem cells (BG01) were maintained and differentiated into the neural progenitors, and then infected by H5N1 virus (A/Chicken/Thailand/CUK2/04) at a multiplicity of infection of 1. At 6, 24, 48, and 72 hours post-infection (hpi), cytopathic effects were observed. Then cells were characterized by immunofluorescence and electron microscopy, supernatants quantified for virus titers, and sampled cells studied for candidate genes.The hNPCs were susceptible to H5N1 virus infection as determined by morphological observation and immunofluorescence. The infection was characterized by a significant up-regulation of TNF-α gene expression, while expressions of IFN-α2, IFN-β1, IFN-γ and IL-6 remained unchanged compared to mock-infected controls. Moreover, H5N1 infection did not appear to alter expression of neuronal and astrocytic markers of hNPCs, such as β-III tubulin and GFAP, respectively. The results indicate that hNPCs support H5N1 virus infection and may play a role in the neuroinflammation during acute viral encephalitis. PMID:26274828

  5. Deep characterization of the microbiomes of Calophya spp. (Hemiptera: Calophyidae) gall-inducing psyllids reveals the absence of plant pathogenic bacteria and three dominant endosymbionts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacteria associated with sap-feeding insect herbivores include not only symbionts that may increase their hosts’ fitness, but also harmful plant pathogens. Calophya spp., gall-inducing psyllids (Hemiptera: Calophyidae), are being investigated for their potential as biological control agents of the n...

  6. Characterizing relationships among fecal indicator bacteria, microbial source tracking markers, and associated waterborne pathogen occurrence in stream water and sediments in a mixed land use watershed

    EPA Science Inventory

    Bed sediments of streams and rivers may store high concentrations of fecal indicator bacteria (FIB) and pathogens. Due to resuspension events, these contaminants can be mobilized into the water column and affect overall water quality. Other bacterial indicators such as microbial ...

  7. ANTIBACTERIAL ACTIVITY OF GUAVA (PSIDIUM GUAJAVA L.) AND NEEM (AZADIRACHTA INDICA A. JUSS.)EXTRACTS AGAINST FOOD BORNE PATHOGENS AND SPOILAGE BACTERIA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this study was to investigate the antibacterial properties of guava (Psidium guajava) and neem (Azadirachta indica) extracts against a number of common food borne pathogens and spoilage bacteria. Screening for antibacterial activity was determined by disc diffusion assay against 21...

  8. Characterizing Relationships Among Fecal Indicator Bacteria, Microbial Source Tracking Markers, and Associated Waterborne Pathogen Occurrence in Stream Water and Sediments in a Mixed Land Use Watershed

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bed sediments of streams and rivers may store high concentrations of fecal indicator bacteria (FIB) and pathogens. These contaminants can be mobilized into the water column due to resuspension events, thus affecting overall water quality. Along with the contaminants, other markers such as microbia...

  9. Suppression of pecan and peach pathogens using metabolites or broths of from symbiotic bacteria obtained from the guts of entomopathogenic nematodes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Concentrated metabolites from the bacteria Xenorhabdus spp. and Photorhabdus spp. have previously been shown to suppress growth of peach and pecan pathogens in vitro, and reduce disease on detached leaves or terminals. The objectives of this study were 1) determine if bacterial broths (in addition t...

  10. Comparative Evaluation of the Antimicrobial Activity of Different Antimicrobial Peptides against a Range of Pathogenic Bacteria

    PubMed Central

    Ebbensgaard, Anna; Mordhorst, Hanne; Overgaard, Michael Toft; Nielsen, Claus Gyrup; Aarestrup, Frank Møller; Hansen, Egon Bech

    2015-01-01

    Analysis of a Selected Set of Antimicrobial Peptides The rapid emergence of resistance to classical antibiotics has increased the interest in novel antimicrobial compounds. Antimicrobial peptides (AMPs) represent an attractive alternative to classical antibiotics and a number of different studies have reported antimicrobial activity data of various AMPs, but there is only limited comparative data available. The mode of action for many AMPs is largely unknown even though several models have suggested that the lipopolysaccharides (LPS) play a crucial role in the attraction and attachment of the AMP to the bacterial membrane in Gram-negative bacteria. We compared the potency of Cap18, Cap11, Cap11-1-18m2, Cecropin P1, Cecropin B, Bac2A, Bac2A-NH2, Sub5-NH2, Indolicidin, Melittin, Myxinidin, Myxinidin-NH2, Pyrrhocoricin, Apidaecin and Metalnikowin I towards Staphylococcus aureus, Enterococcus faecalis, Pseudomonas aeruginosa, Escherichia coli, Aeromonas salmonicida, Listeria monocytogenes, Campylobacter jejuni, Flavobacterium psychrophilum, Salmonella typhimurium and Yersinia ruckeri by minimal inhibitory concentration (MIC) determinations. Additional characteristics such as cytotoxicity, thermo and protease stability were measured and compared among the different peptides. Further, the antimicrobial activity of a selection of cationic AMPs was investigated in various E. coli LPS mutants. Cap18 Shows a High Broad Spectrum Antimicrobial Activity Of all the tested AMPs, Cap18 showed the most efficient antimicrobial activity, in particular against Gram-negative bacteria. In addition, Cap18 is highly thermostable and showed no cytotoxic effect in a hemolytic assay, measured at the concentration used. However, Cap18 is, as most of the tested AMPs, sensitive to proteolytic digestion in vitro. Thus, Cap18 is an excellent candidate for further development into practical use; however, modifications that should reduce the protease sensitivity would be needed. In addition, our

  11. Structural characterization and comparison of three acyl-carrier-protein synthases from pathogenic bacteria

    SciTech Connect

    Halavaty, Andrei S.; Kim, Youngchang; Minasov, George; Shuvalova, Ludmilla; Dubrovska, Ievgeniia; Winsor, James; Zhou, Min; Onopriyenko, Olena; Skarina, Tatiana; Papazisi, Leka; Kwon, Keehwan; Peterson, Scott N.; Joachimiak, Andrzej; Savchenko, Alexei; Anderson, Wayne F.

    2012-10-01

    The structural characterization of acyl-carrier-protein synthase (AcpS) from three different pathogenic microorganisms is reported. One interesting finding of the present work is a crystal artifact related to the activity of the enzyme, which fortuitously represents an opportunity for a strategy to design a potential inhibitor of a pathogenic AcpS. Some bacterial type II fatty-acid synthesis (FAS II) enzymes have been shown to be important candidates for drug discovery. The scientific and medical quest for new FAS II protein targets continues to stimulate research in this field. One of the possible additional candidates is the acyl-carrier-protein synthase (AcpS) enzyme. Its holo form post-translationally modifies the apo form of an acyl carrier protein (ACP), which assures the constant delivery of thioester intermediates to the discrete enzymes of FAS II. At the Center for Structural Genomics of Infectious Diseases (CSGID), AcpSs from Staphylococcus aureus (AcpS{sub SA}), Vibrio cholerae (AcpS{sub VC}) and Bacillus anthracis (AcpS{sub BA}) have been structurally characterized in their apo, holo and product-bound forms, respectively. The structure of AcpS{sub BA} is emphasized because of the two 3′, 5′-adenosine diphosphate (3′, 5′-ADP) product molecules that are found in each of the three coenzyme A (CoA) binding sites of the trimeric protein. One 3′, 5′-ADP is bound as the 3′, 5′-ADP part of CoA in the known structures of the CoA–AcpS and 3′, 5′-ADP–AcpS binary complexes. The position of the second 3′, 5′-ADP has never been described before. It is in close proximity to the first 3′, 5′-ADP and the ACP-binding site. The coordination of two ADPs in AcpS{sub BA} may possibly be exploited for the design of AcpS inhibitors that can block binding of both CoA and ACP.

  12. Jenner-predict server: prediction of protein vaccine candidates (PVCs) in bacteria based on host-pathogen interactions

    PubMed Central

    2013-01-01

    Background Subunit vaccines based on recombinant proteins have been effective in preventing infectious diseases and are expected to meet the demands of future vaccine development. Computational approach, especially reverse vaccinology (RV) method has enormous potential for identification of protein vaccine candidates (PVCs) from a proteome. The existing protective antigen prediction software and web servers have low prediction accuracy leading to limited applications for vaccine development. Besides machine learning techniques, those software and web servers have considered only protein’s adhesin-likeliness as criterion for identification of PVCs. Several non-adhesin functional classes of proteins involved in host-pathogen interactions and pathogenesis are known to provide protection against bacterial infections. Therefore, knowledge of bacterial pathogenesis has potential to identify PVCs. Results A web server, Jenner-Predict, has been developed for prediction of PVCs from proteomes of bacterial pathogens. The web server targets host-pathogen interactions and pathogenesis by considering known functional domains from protein classes such as adhesin, virulence, invasin, porin, flagellin, colonization, toxin, choline-binding, penicillin-binding, transferring-binding, fibronectin-binding and solute-binding. It predicts non-cytosolic proteins containing above domains as PVCs. It also provides vaccine potential of PVCs in terms of their possible immunogenicity by comparing with experimentally known IEDB epitopes, absence of autoimmunity and conservation in different strains. Predicted PVCs are prioritized so that only few prospective PVCs could be validated experimentally. The performance of web server was evaluated against known protective antigens from diverse classes of bacteria reported in Protegen database and datasets used for VaxiJen server development. The web server efficiently predicted known vaccine candidates reported from Streptococcus pneumoniae and

  13. The Effect of Lactic Acid Bacteria Isolates on the Urinary Tract Pathogens to Infants In Vitro

    PubMed Central

    Lee, Ho Seok; Kim, Won Yong

    2009-01-01

    Urinary tract infections are common clinical problems in children, even though lots of treatment strategies have been tried. Many studies of the application of probiotics for urinary tract infection in female adults exist, but there is a lack of studies in children. The aims of this study were to screen probiotic strains for inhibiting the uropathogens in vitro, to find candidates for in vivo study. Nine strains of E. coli were isolated from children with urinary tract infection and six uropathogens were obtained from Korean Colletion for Type Cultures and American Type Culture Collection. Also 135 lactic acid bacteria (LAB) strains were isolated from healthy children, and were identified through physiologic, biochemical methods, 16S rDNA PCR, and data analysis. And with agar disk diffusion assay technique the antimicrobial activities of these LAB strains against those uropathogens were examined. Three strains of separated LAB strains demonstrated major antimicrobial activity against all the uropathogens. In the agar disk diffusion assay technique, antimicrobial activities increased most in the 4th day culture broth with separated Lactobacillus. In summary, some LAB can be used as candidates to develop the probiotic microorganisms that inhibit uropathogens in children, and are expected to be applied to treatment and prevention of pediatric urinary tract infection. PMID:19194563

  14. Application of capillary zone electrophoresis (CZE) to the determination of pathogenic bacteria for medical diagnosis.

    PubMed

    Jackowski, Marek; Szeliga, Jacek; Kłodzińska, Ewa; Buszewski, Bogusław

    2008-07-01

    Microorganisms like bacteria, viruses, fungi, etc. have a major impact on human, animal, and plant life. Several decades ago it was observed that intact cells suspended in an isotonic salt solution moved toward the anode and the mobility was proportional to the density of the charge located on the cell surfaces. Since then, efforts have been made to make electrophoresis a useful tool in cell studies. Microorganisms are no exception. In the present work we applied the capillary zone electrophoresis (CZE) with dynamical modification of the capillary surface for separation of E. coli and P. vulgaris. The same method was used for identification of E. coli in infected urine (direct injection--UTIs) and also for identification of Helicobacter pylori which is a gram-negative bacillus responsible for one of the most common infections found in humans worldwide. Using spectrophotometric measurements at lambda = 214 nm we proved that it is possible to measure the concentration of bacterial cells up to 5 x 10(8) cells/mL. Recent studies have demonstrated very practical uses for electrophoretic techniques, especially in the field of medical diagnosis. PMID:18373084

  15. Deep-sea hydrothermal vent bacteria related to human pathogenic Vibrio species

    PubMed Central

    Hasan, Nur A.; Grim, Christopher J.; Lipp, Erin K.; Rivera, Irma N. G.; Chun, Jongsik; Haley, Bradd J.; Taviani, Elisa; Choi, Seon Young; Hoq, Mozammel; Munk, A. Christine; Brettin, Thomas S.; Bruce, David; Challacombe, Jean F.; Detter, J. Chris; Han, Cliff S.; Eisen, Jonathan A.; Huq, Anwar; Colwell, Rita R.

    2015-01-01

    Vibrio species are both ubiquitous and abundant in marine coastal waters, estuaries, ocean sediment, and aquaculture settings worldwide. We report here the isolation, characterization, and genome sequence of a novel Vibrio species, Vibrio antiquarius, isolated from a mesophilic bacterial community associated with hydrothermal vents located along the East Pacific Rise, near the southwest coast of Mexico. Genomic and phenotypic analysis revealed V. antiquarius is closely related to pathogenic Vibrio species, namely Vibrio alginolyticus, Vibrio parahaemolyticus, Vibrio harveyi, and Vibrio vulnificus, but sufficiently divergent to warrant a separate species status. The V. antiquarius genome encodes genes and operons with ecological functions relevant to the environment conditions of the deep sea and also harbors factors known to be involved in human disease caused by freshwater, coastal, and brackish water vibrios. The presence of virulence factors in this deep-sea Vibrio species suggests a far more fundamental role of these factors for their bacterial host. Comparative genomics revealed a variety of genomic events that may have provided an important driving force in V. antiquarius evolution, facilitating response to environmental conditions of the deep sea. PMID:25964331

  16. Deep-sea hydrothermal vent bacteria related to human pathogenic Vibrio species.

    PubMed

    Hasan, Nur A; Grim, Christopher J; Lipp, Erin K; Rivera, Irma N G; Chun, Jongsik; Haley, Bradd J; Taviani, Elisa; Choi, Seon Young; Hoq, Mozammel; Munk, A Christine; Brettin, Thomas S; Bruce, David; Challacombe, Jean F; Detter, J Chris; Han, Cliff S; Eisen, Jonathan A; Huq, Anwar; Colwell, Rita R

    2015-05-26

    Vibrio species are both ubiquitous and abundant in marine coastal waters, estuaries, ocean sediment, and aquaculture settings worldwide. We report here the isolation, characterization, and genome sequence of a novel Vibrio species, Vibrio antiquarius, isolated from a mesophilic bacterial community associated with hydrothermal vents located along the East Pacific Rise, near the southwest coast of Mexico. Genomic and phenotypic analysis revealed V. antiquarius is closely related to pathogenic Vibrio species, namely Vibrio alginolyticus, Vibrio parahaemolyticus, Vibrio harveyi, and Vibrio vulnificus, but sufficiently divergent to warrant a separate species status. The V. antiquarius genome encodes genes and operons with ecological functions relevant to the environment conditions of the deep sea and also harbors factors known to be involved in human disease caused by freshwater, coastal, and brackish water vibrios. The presence of virulence factors in this deep-sea Vibrio species suggests a far more fundamental role of these factors for their bacterial host. Comparative genomics revealed a variety of genomic events that may have provided an important driving force in V. antiquarius evolution, facilitating response to environmental conditions of the deep sea. PMID:25964331

  17. The Role of CRISPR-Cas Systems in Virulence of Pathogenic Bacteria

    PubMed Central

    Staals, Raymond H. J.; Endtz, Hubert P.; van Baarlen, Peter; van der Oost, John

    2014-01-01

    SUMMARY Clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated (Cas) genes are present in many bacterial and archaeal genomes. Since the discovery of the typical CRISPR loci in the 1980s, well before their physiological role was revealed, their variable sequences have been used as a complementary typing tool in diagnostic, epidemiologic, and evolutionary analyses of prokaryotic strains. The discovery that CRISPR spacers are often identical to sequence fragments of mobile genetic elements was a major breakthrough that eventually led to the elucidation of CRISPR-Cas as an adaptive immunity system. Key elements of this unique prokaryotic defense system are small CRISPR RNAs that guide nucleases to complementary target nucleic acids of invading viruses and plasmids, generally followed by the degradation of the invader. In addition, several recent studies have pointed at direct links of CRISPR-Cas to regulation of a range of stress-related phenomena. An interesting example concerns a pathogenic bacterium that possesses a CRISPR-associated ribonucleoprotein complex that may play a dual role in defense and/or virulence. In this review, we describe recently reported cases of potential involvement of CRISPR-Cas systems in bacterial stress responses in general and bacterial virulence in particular. PMID:24600041

  18. Synergistic effects of ethanol and UV radiation to reduce levels of selected foodborne pathogenic bacteria.

    PubMed

    Ha, Ji-Hyoung; Ha, Sang-Do

    2010-03-01

    The purpose of this study was to determine whether combined treatments would produce synergistic disinfection effects on food products during food processing compared with single treatments. We investigated the bactericidal effects of a commercial chemical disinfectant (ethanol) and of UV radiation on Bacillus cereus F4810/72, Cronobacter sakazakii KCTC 2949, Staphylococcus aureus ATCC 35556, Escherichia coli ATCC 10536, and Salmonella enterica Typhimurium NO/NA in vitro. Various concentrations of ethanol (10, 30, 40, and 50%) were tested with various exposure doses of UV radiation (6, 96, 216, 360, and 504 mWs/cm(2)) with a UV lamp. The combined ethanol-UV treatments resulted in greater reductions in bacterial counts than did either treatment alone. The synergistic effect values for B. cereus, C. sakazakii, S. aureus, S. enterica Typhimurium NO/NA, and E. coli were 0.40 to 1.52, 0.52 to 1.74, 0.20 to 2.32, 0.07 to 1.14, and 0.02 to 1.75 log CFU/ml, respectively. The results of this study suggest that a significant synergistic benefit results from combining ethanol and UV treatments against foodborne pathogens in vitro. PMID:20202345

  19. Transcriptome analysis of wheat inoculated with Fusarium graminearum.

    PubMed

    Erayman, Mustafa; Turktas, Mine; Akdogan, Guray; Gurkok, Tugba; Inal, Behcet; Ishakoglu, Emre; Ilhan, Emre; Unver, Turgay

    2015-01-01

    Plants are frequently exposed to microorganisms like fungi, bacteria, and viruses that cause biotic stresses. Fusarium head blight (FHB) is an economically risky wheat disease, which occurs upon Fusarium graminearum (Fg) infection. Moderately susceptible (cv. "Mizrak 98") and susceptible (cv. "Gun 91") winter type bread wheat cultivars were subjected to transcriptional profiling after exposure to Fg infection. To examine the early response to the pathogen in wheat, we measured gene expression alterations in mock and pathogen inoculated root crown of moderately susceptible (MS) and susceptible cultivars at 12 hours after inoculation (hai) using 12X135K microarray chip. The transcriptome analyses revealed that out of 39,179 transcripts, 3668 genes in microarray were significantly regulated at least in one time comparison. The majority of differentially regulated transcripts were associated with disease response and the gene expression mechanism. When the cultivars were compared, a number of transcripts and expression alterations varied within the cultivars. Especially membrane related transcripts were detected as differentially expressed. Moreover, diverse transcription factors showed significant fold change values among the cultivars. This study presented new insights to understand the early response of selected cultivars to the Fg at 12 hai. Through the KEGG analysis, we observed that the most altered transcripts were associated with starch and sucrose metabolism and gluconeogenesis pathways. PMID:26539199

  20. Association between commensal bacteria and opportunistic pathogens in the dental plaque of elderly individuals.

    PubMed

    Tada, A; Senpuku, H; Motozawa, Y; Yoshihara, A; Hanada, N; Tanzawa, H

    2006-08-01

    Opportunistic infections in the oral cavity of the elderly may increase the incidence of systemic disease. The objective of this study was to investigate the differences in the oral bacterial flora between dependent elderly (inpatients) and independent elderly (community-dwelling residents). After multiple variables were taken into account, inpatients had significantly lower detection rates than community-dwelling residents for alpha-streptococci (p < 0.001) and Neisseria (p 0.004), and higher detection rates for Pseudomonas aeruginosa (p 0.024), methicillin-resistant Staphylococcus aureus (MRSA) (p 0.011) and Actinomyces spp. (p 0.005). Among inpatients, the requirement for a high degree of care was related negatively to detection of alpha-streptococci, but was related significantly to detection of P. aeruginosa (p 0.018) or MRSA (p 0.004). Tube-fed inpatients had a significantly lower detection rate for alpha-streptococci (p 0.041) and a higher detection rate for P. aeruginosa (p 0.004) than those who did not require tube feeding. Inpatients with a history of antibiotic use had a significantly lower detection rate for alpha-streptococci (p 0.049) and a higher detection rate for MRSA (p 0.007) than those without a history of antibiotic use. The detection rates for P. aeruginosa or MRSA in inpatients without alpha-streptococci were higher than in inpatients with alpha-streptococci after controlling for age and gender (P. aeruginosa, p 0.006; MRSA, p 0.001). Overall, detection of alpha-streptococci had an inverse correlation with the detection of P. aeruginosa and MRSA in the oral cavity and is likely to be an indicator of pathogenic bacterial infection. PMID:16842573

  1. The effects of citrus extract (Citrox©) on the naturally occurring microflora and inoculated pathogens, Bacillus cereus and Salmonella enterica, in a model food system and the traditional Greek yogurt-based salad Tzatziki.

    PubMed

    Tsiraki, Maria I; Savvaidis, Ioannis N

    2016-02-01

    The antimicrobial effect of citrus extract (at 1 mL/kg [TC1] and 2 mL/kg [TC2]) on the naturally occurring microflora and inoculated pathogens (Bacillus cereus and Salmonella enterica, at ca. 6 log cfu/g) in the traditional Greek yogurt-based salad Tzatziki during storage under vacuum at 4 or 10 °C was examined. We also examined the effect of citrus extract (Citrox(©)) against the two aforementioned pathogens in tryptic soy broth (TSB). Of the two treatments, TC2 yielded the lowest yeast counts, irrespective of temperature, resulting in approximately 2 (4 °C) and 3 (10 °C) log reductions on the final day of storage (70 and 30 days, respectively). Although panelists preferred the TC1-treated salad, the TC2-treated product was sensorily acceptable. Therefore, at the concentrations used, Citrox had no negative sensorial effect on the Tzatziki. During storage, the Bacillus populations in the Citrox-treated Tzatziki samples progressively decreased, showing major declines from days 12 and 28 (at 10 and 4 °C, respectively). Citrox, especially at 2 mL/kg, had a significant effect on the survival of B. cereus. S. enterica showed major declines in all untreated Tzatziki samples from day 0-70 (4 °C) and from day 0-30 (10 °C), with averages of 2.5 and 2.8 log cfu/g, respectively. The results indicate that Citrox (at 1 and 2 mL/kg) is effective, from a safety standpoint, for reducing Bacillus and Salmonella spp. in Tzatziki. In addition, 2% citrus extract also showed a higher inhibitory effect against B. cereus and S. enterica grown in TSB than 1% citrus extract. PMID:26678142

  2. Sediment composition influences spatial variation in the abundance of human pathogen indicator bacteria within an estuarine environment.

    PubMed

    Perkins, Tracy L; Clements, Katie; Baas, Jaco H; Jago, Colin F; Jones, Davey L; Malham, Shelagh K; McDonald, James E

    2014-01-01

    Faecal contamination of estuarine and coastal waters can pose a risk to human health, particularly in areas used for shellfish production or recreation. Routine microbiological water quality testing highlights areas of faecal indicator bacteria (FIB) contamination within the water column, but fails to consider the abundance of FIB in sediments, which under certain hydrodynamic conditions can become resuspended. Sediments can enhance the survival of FIB in estuarine environments, but the influence of sediment composition on the ecology and abundance of FIB is poorly understood. To determine the relationship between sediment composition (grain size and organic matter) and the abundance of pathogen indicator bacteria (PIB), sediments were collected from four transverse transects of the Conwy estuary, UK. The abundance of culturable Escherichia coli, total coliforms, enterococci, Campylobacter, Salmonella and Vibrio spp. in sediments was determined in relation to sediment grain size, organic matter content, salinity, depth and temperature. Sediments that contained higher proportions of silt and/or clay and associated organic matter content showed significant positive correlations with the abundance of PIB. Furthermore, the abundance of each bacterial group was positively correlated with the presence of all other groups enumerated. Campylobacter spp. were not isolated from estuarine sediments. Comparisons of the number of culturable E. coli, total coliforms and Vibrio spp. in sediments and the water column revealed that their abundance was 281, 433 and 58-fold greater in sediments (colony forming units (CFU)/100g) when compared with the water column (CFU/100ml), respectively. These data provide important insights into sediment compositions that promote the abundance of PIB in estuarine environments, with important implications for the modelling and prediction of public health risk based on sediment resuspension and transport. PMID:25397595

  3. Sediment Composition Influences Spatial Variation in the Abundance of Human Pathogen Indicator Bacteria within an Estuarine Environment

    PubMed Central

    Perkins, Tracy L.; Clements, Katie; Baas, Jaco H.; Jago, Colin F.; Jones, Davey L.; Malham, Shelagh K.; McDonald, James E.

    2014-01-01

    Faecal contamination of estuarine and coastal waters can pose a risk to human health, particularly in areas used for shellfish production or recreation. Routine microbiological water quality testing highlights areas of faecal indicator bacteria (FIB) contamination within the water column, but fails to consider the abundance of FIB in sediments, which under certain hydrodynamic conditions can become resuspended. Sediments can enhance the survival of FIB in estuarine environments, but the influence of sediment composition on the ecology and abundance of FIB is poorly understood. To determine the relationship between sediment composition (grain size and organic matter) and the abundance of pathogen indicator bacteria (PIB), sediments were collected from four transverse transects of the Conwy estuary, UK. The abundance of culturable Escherichia coli, total coliforms, enterococci, Campylobacter, Salmonella and Vibrio spp. in sediments was determined in relation to sediment grain size, organic matter content, salinity, depth and temperature. Sediments that contained higher proportions of silt and/or clay and associated organic matter content showed significant positive correlations with the abundance of PIB. Furthermore, the abundance of each bacterial group was positively correlated with the presence of all other groups enumerated. Campylobacter spp. were not isolated from estuarine sediments. Comparisons of the number of culturable E. coli, total coliforms and Vibrio spp. in sediments and the water column revealed that their abundance was 281, 433 and 58-fold greater in sediments (colony forming units (CFU)/100g) when compared with the water column (CFU/100ml), respectively. These data provide important insights into sediment compositions that promote the abundance of PIB in estuarine environments, with important implications for the modelling and prediction of public health risk based on sediment resuspension and transport. PMID:25397595

  4. Pathogen prevalence and influence of composted dairy manure application on antimicrobial resistance profiles of commensal soil bacteria.

    PubMed

    Edrington, Tom S; Fox, William E; Callaway, Todd R; Anderson, Robin C; Hoffman, Dennis W; Nisbet, David J

    2009-03-01

    Composting manure, if done properly, should kill pathogenic bacteria such as Salmonella and Escherichia coli O157:H7, providing for an environmentally safe product. Over a 3-year period, samples of composted dairy manure, representing 11 composting operations (two to six samples per producer; 100 total samples), were screened for Salmonella and E. coli O157:H7 and were all culture negative. Nonpathogenic bacteria were cultured from these compost samples that could theoretically facilitate the spread of antimicrobial resistance from the dairy to compost application sites. Therefore, we collected soil samples (three samples per plot; 10 plots/treatment; 90 total samples) from rangeland that received either composted dairy manure (CP), commercial fertilizer (F), or no treatment (control, CON). Two collections were made appoximately 2 and 7 months following treatment application. Soil samples were cultured for Pseudomonas and Enterobacter and confirmed isolates subjected to antimicrobial susceptibility testing. Three species of Enterobacter (cloacae, 27 isolates; aeroginosa, two isolates; sakazakii, one isolate) and two species of Pseudomonas (aeruginosa, 11 isolates; putida, seven isolates) were identified. Five Enterobacter isolates were resistant to ampicillin and one isolate was resistant to spectinomycin. All Pseudomonas isolates were resistant to ampicillin, ceftiofur, florfenicol, sulphachloropyridazine, sulphadimethoxine, and trimethoprim/sulfamethoxazole and most isolates were resistant to chlortetracycline and spectinomycin. Pseudomonas isolates were resistant to an average of 8.6, 7.9, and 8 antibiotics for CON, CP, and F treatments, respectively. No treatment differences were observed in antimicrobial resistance patterns in any of the soil isolates examined. Results reported herein support the use of composted dairy manure as an environmentally friendly soil amendment. PMID:19105635

  5. Identification and molecular characterization of pathogenic bacteria in foods confiscated from non-EU flights passengers at one Spanish airport.

    PubMed

    Rodríguez-Lázaro, David; Ariza-Miguel, Jaime; Diez-Valcarce, Marta; Stessl, Beatrix; Beutlich, Janine; Fernández-Natal, Isabel; Hernández, Marta; Wagner, Martin; Rovira, Jordi

    2015-09-16

    Two hundred food samples of animal origin confiscated from passengers arriving on flights from non-European countries at the International Airport of Bilbao (Spain) were tested for the presence of four main bacterial foodborne pathogens (Campylobacter spp., Escherichia coli O157:H7, Listeria monocytogenes and Salmonella spp.) during 2012 and 2013. Overall, 20 samples were positive for L. monocytogenes (10%) and 11 for Salmonella spp. (5.5%), whereas Campylobacter spp. and E. coli O157:H7 were not detected in any sample. The positive isolates were widely clustered: 14 and 7 different pulsotypes for L. monocytogenes and Salmonella spp. isolates, respectively. Nine sequence types (ST) were detected for L. monocytogenes: ST2 (45%), ST9 (15% isolates), ST8 and ST87 (10%), and ST308, ST37, ST155 and ST378 (5%). The Salmonella spp. isolates belonged to seven serovars: monophasic serovar 4,12:d:- (3; 27.3%), Rauform (2; 18.2%), Anatum (2; 18.2%), Oranienburg, Enteritidis, Newport and Typhimurium (1; 9.1% each). Antibiotic resistance among L. monocytogenes isolates was high, especially for clindamycin and daptomycin (more than 95% of the isolates). These results indicate that food samples imported by travelers in their personal luggage may harbor the most prevalent L. monocytogenes genotypes and Salmonella spp. serovars responsible for foodborne outbreaks worldwide. Consequently, international travel can play an important role in the prevalence and dissemination of successful clones of foodborne pathogenic bacteria, and continuous monitoring of international movements is of importance to better understand clonal evolution and emergence and dissemination of successful lineages. PMID:25454793

  6. Bacteria in the Leaf Ecosystem with Emphasis on Pseudomonas syringae—a Pathogen, Ice Nucleus, and Epiphyte

    PubMed Central

    Hirano, Susan S.; Upper, Christen D.

    2000-01-01

    The extremely large number of leaves produced by terrestrial and aquatic plants provide habitats for colonization by a diversity of microorganisms. This review focuses on the bacterial component of leaf microbial communities, with emphasis on Pseudomonas syringae—a species that participates in leaf ecosystems as a pathogen, ice nucleus, and epiphyte. Among the diversity of bacteria that colonize leaves, none has received wider attention than P. syringae, as it gained notoriety for being the first recombinant organism (Ice− P. syringae) to be deliberately introduced into the environment. We focus on P. syringae to illustrate the attractiveness and somewhat unique opportunities provided by leaf ecosystems for addressing fundamental questions of microbial population dynamics and mechanisms of plant-bacterium interactions. Leaf ecosystems are dynamic and ephemeral. The physical environment surrounding phyllosphere microbes changes continuously with daily cycles in temperature, radiation, relative humidity, wind velocity, and leaf wetness. Slightly longer-term changes occur as weather systems pass. Seasonal climatic changes impose still a longer cycle. The physical and physiological characteristics of leaves change as they expand, mature, and senesce and as host phenology changes. Many of these factors influence the development of populations of P. syringae upon populations of leaves. P. syringae was first studied for its ability to cause disease on plants. However, disease causation is but one aspect of its life strategy. The bacterium can be found in association with healthy leaves, growing and surviving for many generations on the surfaces of leaves as an epiphyte. A number of genes and traits have been identified that contribute to the fitness of P. syringae in the phyllosphere. While still in their infancy, such research efforts demonstrate that the P. syringae-leaf ecosystem is a particularly attractive system with which to bridge the gap between what is known

  7. Antimicrobial properties of black grape (Vitis vinifera L.) peel extracts against antibiotic-resistant pathogenic bacteria and toxin producing molds

    PubMed Central

    Yadav, Devbrat; Kumar, Arvind; Kumar, Pramod; Mishra, Diwaker

    2015-01-01

    Aim: Black grape peel possesses a substantial amount of polyphenolic antimicrobial compounds that can be used for controlling the growth of pathogenic microorganisms. The purpose of this study was to assess antibacterial and antifungal activity of black grape peel extracts against antibiotic-resistant pathogenic bacteria and toxin producing molds, respectively. Materials and Methods: Peel of grape was subjected to polyphenolic extraction using different solvents viz., water, ethanol, acetone, and methanol. Antibiotic-resistant strains of Staphylococcus aureus, Enterococcus faecalis, Enterobacter aerogenes, Salmonella typhimurium, and Escherichia coli were screened for the antibacterial activity of different grape extracts. Antibacterial activity was analyzed using agar well diffusion method. Penicillium chrysogenum, Penicillium expansum, Aspergillus niger and Aspergillus versicolor were screened for the antifungal activity. Antifungal activity was determined by counting nongerminated spores in the presence of peel extracts. Results: As compared to other solvent extracts, methanol extracts possessed high antibacterial and antifungal activity. S. typhimurium and E. coli showed complete resistance against antibacterial action at screened concentrations of grape peel extracts. Maximum zone of inhibition was found in case of S. aureus, i.e., 22 mm followed by E. faecalis and E. aerogenes, i.e., 18 and 21 mm, respectively, at 1080 mg tannic acid equivalent (TAE)/ml. The maximum and minimum percent of growth inhibition was shown by P. expansum and A. niger as 73% and 15% at 1080 TAE/ml concentration of grape peel extract, respectively. Conclusions: Except S. typhimurium and E. coli, growth of all bacterial and mold species were found to be significantly (P < 0.05) inhibited by all the solvent extracts. PMID:26729960

  8. Experimental murine chronic hepatitis: results following intrahepatic inoculation of human uveitis mycoplasma-like organisms.

    PubMed Central

    Johnson, L. A.; Wirostko, E.; Wirostko, B. M.

    1993-01-01

    Mycoplasma-like organisms (MLO) are non-cultivated intracellular cell-wall deficient pathogenic bacteria with a distinctive ultrastructural appearance. Diagnosis of MLO disease depends on finding the organisms in parasitized cells using a transmission electron microscope. MLO are a well studied cause of transmissible chronic plant disease responsive to antibiotics. MLO have recently been found to cause human chronic uveitis, orbital, and retinal disease with autoimmune features. Ophthalmic leucocytes in these patients display MLO parasitization. Inoculation of human uveitis MLO into mouse eyelids produced chronic uveitis. MLO also disseminated to produce randomly distributed lethal systemic disease including chronic hepatitis. MLO parasitized leucocytes were present in all disease sites. Direct intrahepatic inoculation of human hepatic pathogens is a simple and efficient technique to produce murine hepatitis. This report describes the delayed onset widespread inflammatory liver disease produced by direct intrahepatic inoculation of human chronic uveitis MLO in 12 of 20 mice versus 0 in 40 controls (P < 0.05). The liver disease was accompanied by elevated serum SGOT levels, splenomegaly, and accelerated mortality. All 12 inflamed livers displayed MLO parasitized leucocytes versus 0 of 10 control livers. The resemblance of human chronic active hepatitis, massive hepatic necrosis, and post-necrotic cirrhosis to the MLO induced murine liver disease, the role of molecular biologic techniques in the detection and classification of those bacteria, and in therapy of MLO disease are discussed. Images Figure 1 Figure 2 Figure 3 Figure 4 PMID:8398804

  9. Metabolic Environments and Genomic Features Associated with Pathogenic and Mutualistic Interactions between Bacteria and Plants is accepted for publication in MPMI

    SciTech Connect

    Karpinets, Tatiana V; Park, Byung H; Syed, Mustafa H; Klotz, Martin G; Uberbacher, Edward C

    2014-01-01

    Most bacterial symbionts of plants are phenotypically characterized by their parasitic or matualistic relationship with the host; however, the genomic characteristics that likely discriminate mutualistic symbionts from pathogens of plants are poorly understood. This study comparatively analyzed the genomes of 54 plant-symbiontic bacteria, 27 mutualists and 27 pathogens, to discover genomic determinants of their parasitic and mutualistic nature in terms of protein family domains, KEGG orthologous groups, metabolic pathways and families of carbohydrate-active enzymes (CAZymes). We further used all bacteria with sequenced genomesl, published microarrays and transcriptomics experimental datasets, and literature to validate and to explore results of the comparison. The analysis revealed that genomes of mutualists are larger in size and higher in GC content and encode greater molecular, functional and metabolic diversity than the investigated genomes of pathogens. This enriched molecular and functional enzyme diversity included constructive biosynthetic signatures of CAZymes and metabolic pathways in genomes of mutualists compared with catabolic signatures dominant in the genomes of pathogens. Another discriminative characteristic of mutualists is the co-occurence of gene clusters required for the expression and function of nitrogenase and RuBisCO. Analysis of previously published experimental data indicate that nitrogen-fixing mutualists may employ Rubisco to fix CO2 not in the canonical Calvin-Benson-Basham cycle but in a novel metabolic pathway, here called Rubisco-based glycolysis , to increase efficiency of sugar utilization during the symbiosis with plants. An important discriminative characteristic of plant pathogenic bacteria is two groups of genes likely encoding effector proteins involved in host invasion and a genomic locus encoding a putative secretion system that includes a DUF1525 domain protein conserved in pathogens of plants and of other organisms. The

  10. Characterization of bacteria associated with pinewood nematode Bursaphelenchus xylophilus.

    PubMed

    Vicente, Claudia S L; Nascimento, Francisco; Espada, Margarida; Barbosa, Pedro; Mota, Manuel; Glick, Bernard R; Oliveira, Solange

    2012-01-01

    Pine Wilt Disease (PWD) is a complex disease integrating three major agents: the pathogenic agent, the pinewood nematode Bursaphelenchus xylophilus; the insect-vector Monochamus spp.; and the host pine tree, Pinus sp. Since the early 80's, the notion that another pathogenic agent, namely bacteria, may play a role in PWD has been gaining traction, however the role of bacteria in PWD is still unknown. The present work supports the possibility that some B. xylophilus-associated bacteria may play a significant role in the development of this disease. This is inferred as a consequence of: (i) the phenotypic characterization of a collection of 35 isolates of B. xylophilus-associated bacteria, in different tests broadly used to test plant pathogenic and plant growth promoting bacteria, and (ii) greenhouse experiments that infer the pathogenicity of these bacteria in maritime pine, Pinus pinaster. The results illustrate the presence of a heterogeneous microbial community associated with B. xylophilus and the traits exhibited by at least, some of these bacteria, appear to be related to PWD symptoms. The inoculation of four specific B. xylophilus-associated bacteria isolates in P. pinaster seedlings resulted in the development of some PWD symptoms suggesting that these bacteria likely play an active role with B. xylophilus in PWD. PMID:23091599

  11. A novel challenge test incorporating irradiation (60Co) of compost sub-samples to validate thermal lethality towards pathogenic bacteria.

    PubMed

    Moore, John E; Watabe, Miyuki; Stewart, Andrew; Cherie Millar, B; Rao, Juluri R

    2009-01-01

    Maturing compost heaps normally attaining temperatures ranging from 55 to 65 degrees C is generally regarded to conform to recommended biological risks and sanitation standards for composts stipulated by either EU or US-EPA. Composted products derived from animal sources are further required by EU biohazard safety regulatory legislation that such composts either attain 70 degrees C for over 3h during maturation or via treatment at 70 degrees C for 1h before being considered for dispensation on land. The setting of the upper limit of thermal lethality at 70 degrees C/1h for achieving biosecurity of the animal waste composted products (e.g. pelleted fertilizer formulations) is not properly substantiated by specific validation tests, comprising a 'wipe-out' step (usually via autoclaving) followed by inoculation of a prescribed bacterium, exposure to 70 degrees C/1h and the lethality determined. Pelleted formulations of composts are not amenable for wet methods (autoclaving) for wipe-out sterilization step as this is detrimental to the pellet and compromises sample integrity. This study describes a laboratory method involving the employment of ((60)Co) irradiation 'wipe-out' step to: (a) compost sub-samples drawn from compost formulation heaps and (b) pelleted products derived from composted animal products while determining the thermal lethality of a given time/temperature (70 degrees C/1h) treatment process and by challenging the irradiated sample (not just with one bacterium but), out with 10 potential food-poisoning organisms from the bacterial genera (Campylobacter, Escherichia, Listeria, Salmonella, Yersinia) frequently detected in pig and poultry farm wastes. This challenge test on compost sub-samples can be a useful intervention ploy for 'inspection and validation' technique for composters during the compost maturity process, whose attainment of temperatures of 55-65 degrees C is presumed sufficient for attainment of sanitation. Stringent measures are further

  12. Back To Bacteria.

    ERIC Educational Resources Information Center

    Flannery, Maura C.

    1997-01-01

    Explores new research about bacteria. Discusses bacterial genomes, archaea, unusual environments, evolution, pathogens, bacterial movement, biofilms, bacteria in the body, and a bacterial obsession. Contains 29 references. (JRH)

  13. Screening and Scoring of Antimicrobial and Biological Activities of Italian Vulnerary Plants against Major Oral Pathogenic Bacteria

    PubMed Central

    Ferrazzano, Gianmaria F.; Roberto, Lia; Catania, Maria Rosaria; Chiaviello, Angela; De Natale, Antonino; Roscetto, Emanuela; Pinto, Gabriele; Pollio, Antonino; Ingenito, Aniello; Palumbo, Giuseppe

    2013-01-01

    This study aims to evaluate the activity of Italian vulnerary plants against the most important oral pathogenic bacteria. This estimate was accomplished through a fivefold process: (a) a review of ethnobotanical and microbiological data concerning the Italian vulnerary plants; (b) the development of a scoring system to rank the plants; (c) the comparative assessment of microbiological properties; (d) the assessment of potential cytotoxic effects on keratinocyte-like cells and gingival fibroblasts in culture by XTT cell viability assay; (e) clinical evaluation of the most suitable plant extract as antibacterial agent in a home-made mouthwash. The study assays hexane (H), ethanol (E), and water (W) extracts from 72 plants. The agar diffusion method was used to evaluate the activity against Streptococcus mutans, Streptococcus sobrinus, Lactobacillus casei, and Actinomyces viscosus. Twenty-two plants showed appreciable activity. The extracts showing the strongest antibacterial power were those from Cotinus coggygria Scop., Equisetum hyemale L., Helichrysum litoreum Guss, Juniperus communis L., and Phyllitis scolopendrium (L.) Newman subsp. scolopendrium. The potential cytotoxic effect of these extracts was assessed. On the basis of these observations, a mouth-rinse containing the ethanolic extract of H. litoreum has been tested in vivo, resulting in reduction of the salivary concentration of S. mutans. PMID:24302963

  14. Screening and Scoring of Antimicrobial and Biological Activities of Italian Vulnerary Plants against Major Oral Pathogenic Bacteria.

    PubMed

    Ferrazzano, Gianmaria F; Roberto, Lia; Catania, Maria Rosaria; Chiaviello, Angela; De Natale, Antonino; Roscetto, Emanuela; Pinto, Gabriele; Pollio, Antonino; Ingenito, Aniello; Palumbo, Giuseppe

    2013-01-01

    This study aims to evaluate the activity of Italian vulnerary plants against the most important oral pathogenic bacteria. This estimate was accomplished through a fivefold process: (a) a review of ethnobotanical and microbiological data concerning the Italian vulnerary plants; (b) the development of a scoring system to rank the plants; (c) the comparative assessment of microbiological properties; (d) the assessment of potential cytotoxic effects on keratinocyte-like cells and gingival fibroblasts in culture by XTT cell viability assay; (e) clinical evaluation of the most suitable plant extract as antibacterial agent in a home-made mouthwash. The study assays hexane (H), ethanol (E), and water (W) extracts from 72 plants. The agar diffusion method was used to evaluate the activity against Streptococcus mutans, Streptococcus sobrinus, Lactobacillus casei, and Actinomyces viscosus. Twenty-two plants showed appreciable activity. The extracts showing the strongest antibacterial power were those from Cotinus coggygria Scop., Equisetum hyemale L., Helichrysum litoreum Guss, Juniperus communis L., and Phyllitis scolopendrium (L.) Newman subsp. scolopendrium. The potential cytotoxic effect of these extracts was assessed. On the basis of these observations, a mouth-rinse containing the ethanolic extract of H. litoreum has been tested in vivo, resulting in reduction of the salivary concentration of S. mutans. PMID:24302963

  15. Fecal Indicator and Pathogenic Bacteria and Their Antibiotic Resistance in Alluvial Groundwater of an Irrigated Agricultural Region with Dairies.

    PubMed

    Li, Xunde; Atwill, Edward R; Antaki, Elizabeth; Applegate, Olin; Bergamaschi, Brian; Bond, Ronald F; Chase, Jennifer; Ransom, Katherine M; Samuels, William; Watanabe, Naoko; Harter, Thomas

    2015-09-01

    Surveys of microbiological groundwater quality were conducted in a region with intensive animal agriculture in California, USA. The survey included monitoring and domestic wells in eight concentrated animal feeding operations (CAFOs) and 200 small (domestic and community supply district) supply wells across the region. was not detected in groundwater, whereas O157:H7 and were each detected in 2 of 190 CAFO monitoring well samples. Nonpathogenic generic and spp. were detected in 24.2% (46/190) and 97.4% (185/190) groundwater samples from CAFO monitoring wells and in 4.2% (1/24) and 87.5% (21/24) of CAFO domestic wells, respectively. Concentrations of both generic and spp. were significantly associated with well depth, season, and the type of adjacent land use in the CAFO. No pathogenic bacteria were detected in groundwater from 200 small supply wells in the extended survey. However, 4.5 to 10.3% groundwater samples were positive for generic and . Concentrations of generic were not significantly associated with any factors, but concentrations of were significantly associated with proximity to CAFOs, seasons, and concentrations of potassium in water. Among a subset of and isolates from both surveys, the majority of (63.6%) and (86.1%) isolates exhibited resistance to multiple (≥3) antibiotics. Findings confirm significant microbial and antibiotic resistance loading to CAFO groundwater. Results also demonstrate significant attenuative capacity of the unconfined alluvial aquifer system with respect to microbial transport. PMID:26436261

  16. Gold nanoparticles synthesized by Brassica oleracea (Broccoli) acting as antimicrobial agents against human pathogenic bacteria and fungi

    NASA Astrophysics Data System (ADS)

    Piruthiviraj, Prakash; Margret, Anita; Krishnamurthy, Poornima Priyadharsani

    2016-04-01

    Production of antimicrobial agents through the synthesis of gold nanoparticles using green technology has been extensively made consistent by various researchers; yet, this study uses the flower bud's aqueous extracts of Brassica oleracea (Broccoli) as a reducing agent for chloroauric acid (1 mM). After 30 min of incubation, synthesis of gold nanoparticles (AuNps) was observed by a change in extract color from pale yellow to purple color. Synthesis of AuNps was confirmed in UV-visible spectroscopy at the range of approximately 560 nm. The SEM analysis showed the average nanoparticles size of 12-22 nm. The antimicrobial activity of AuNps was analyzed by subjecting it to human pathogenic bacteria (Gram-positive Staphylococcus aureus and Gram-negative Klebsiella pneumonia) and fungi (Aspergillus flavus, Aspergillus niger and Candida albicans) using disc diffusion method. The broccoli-synthesized AuNps showed the efficient antibacterial and antifungal activity of above-mentioned microbes. It was confirmed that AuNps have the best antimicrobial agent compared to the standard antibiotics (Gentamicin and Fluconazole). When the concentrations of AuNps were increased (10, 25, and 50 µg/ml), the sensitivity zone also increased for all the tested microbes. The synthesized AuNps are capable of rendering high antimicrobial efficacy and, hence, have a great potential in the preparation of drugs used against major bacterial and fungal diseases in humans.

  17. Multiplex detection and genotyping of pathogenic bacteria on paper-based biosensor with a novel universal primer mediated asymmetric PCR.

    PubMed

    Liu, Fang; Liu, Hongxing; Liao, Yuhui; Wei, Jitao; Zhou, Xiaoming; Xing, Da

    2015-12-15

    Traditionary multiplex asymmetric polymerase chain reaction (PCR) can be applied to detect multiplex target organisms simultaneously, but complex optimizations of primer concentrations and staggered additions of primers are required to achieve equal amplification of multiplex genes. To overcome this shortcoming, we propose a novel method based on multiplex asymmetric PCR and paper-based nucleic acid diagnostics (PBNAD). In the asymmetric PCR, a universal primer was introduced to break the bottlenecks of low sensitivity and self-inhibition among different sets of primers. Amplification using the novel multiplex asymmetric PCR boosted the quantity of single-stranded amplicons, and the amplified products contained the same sequence at the 5' end. Therefore, only one gold nanoparticle-based signal probe was needed for the simultaneous detection of three genes using the PBNAD platform, and the detection signals could be observed with the naked eye. With this highly efficient, novel multiplex asymmetric PCR, as little as 1 pg/μL genomic DNA can be detected. This method can also be applied to genotyping for reliable epidemiological investigations. This proof-of-concept study highlights the potential of the PBNAD platform for cost- and labor-effective applications in the detection of pathogenic bacteria. PMID:26226347

  18. DESIGN NOTE: Development of an integrated solid-state generator for light inactivation of food-related pathogenic bacteria

    NASA Astrophysics Data System (ADS)

    Ghasemi, Z.; Macgregor, S.; Anderson, J.; Lamont, Y.

    2003-06-01

    This paper is concerned with the design and performance of a fully integrated solid-state Marx generator, which has been developed to drive a UV flashlamp for use in microbiological inactivation. The generator has an output voltage rating of 3 kV and a peak current rating of 2 kA, although the modular approach taken allows for a number of voltage and current ratings to be achieved. The generator is constructed using a number of series- and parallel-connected 1.2 kV insulated-gate-bipolar-transistor (IGBT) switched capacitors. Switching of the IGBT modules is controlled by an optical signal. Details are given of how the optimum IGBT gate-drive circuit is achieved using optical components and a pass-through wire to provide the required energies for individual IGBT modules. The generator is demonstrated as the driver of a UV flashlamp used for inactivation of food-related pathogenic bacteria such as E. coli and Salmonella. The performance of the Marx generator over a period of 106 pulses is examined, along with the changes that occur in the spectrum of the UV flashlamp during the same period.

  19. Synergistic effects of sodium hypochlorite and ultraviolet radiation in reducing the levels of selected foodborne pathogenic bacteria.

    PubMed

    Ha, Ji-Hyoung; Ha, Sang-Do

    2011-05-01

    The purpose of this study was to determine whether combined treatment would produce synergistic effects to facilitate the sterilization of food products during production relative to single treatment. To assess this hypothesis, we investigated the bactericidal effects of ultraviolet (UV) irradiation and a commercial chemical disinfectant, sodium hypochlorite (NaClO), on Bacillus cereus F4810/72, Cronobacter sakazakii KCTC 2949, Staphylococcus aureus ATCC 35556, Escherichia coli ATCC 10536, and Salmonella Typhimurium novobiocin/nalidixic acid in vitro. Various concentrations of NaClO (20, 60, 100, and 200 ppm NaClO) were tested along with exposure to UV radiation at various doses (6, 96, 216, 360, and 504 mW s/cm(2)). The combined NaClO/UV treatments resulted in greater reductions in bacterial counts than either treatment alone. The synergy values against B. cereus, C. sakazakii, S. aureus, Salmonella Typhimurium, and E. coli were 0.25-1.17, 0.33-1.97, 0.42-1.72, 0.02-1.44, and 0.01-0.85 log(10) CFU/mL, respectively. The results of this study suggest that a significant synergistic benefit results from combined NaClO/UV processing against food-borne pathogenic bacteria in vitro. PMID:21204702

  20. Characterization of the microbial community in a lotic environment to assess the effect of pollution on nitrifying and potentially pathogenic bacteria.

    PubMed

    Medeiros, J D; Araújo, L X; da Silva, V L; Diniz, C G; Cesar, D E; Del'Duca, A; Coelho, C M

    2014-08-01

    This study aimed to investigate microbes involved in the nitrogen cycle and potentially pathogenic bacteria from urban and rural sites of the São Pedro stream. Water samples were collected from two sites. A seasonal survey of bacterial abundance was conducted. The dissolved nutrient content was analysed. PCR and FISH analysis were performed to identify and quantify microbes involved in the nitrogen cycle and potentially pathogenic bacteria. The seasonal survey revealed that the bacterial abundance was similar along the year on the rural area but varied on the urban site. Higher concentration of dissolved nutrients in the urban area indicated a eutrophic system. Considering the nitrifying microbes, the genus Nitrobacter was found, especially in the urban area, and may act as the principal bacteria in converting nitrite into nitrate at this site. The molecular markers napA, amoA, and nfrA were more accumulated at the urban site, justifying the higher content of nutrients metabolised by these enzymes. Finally, high intensity of amplicons from Enterococcus, Streptococcus, Bacteroides/Prevotella/Porphyromonas, Salmonella, S. aureus, P. aeruginosa and the diarrheagenic lineages of E. coli were observed at the urban site. These results indicate a change in the structure of the microbial community imposed by anthrophic actions. The incidence of pathogenic bacteria in aquatic environments is of particular importance to public health, emphasising the need for sewage treatment to minimise the environmental impacts associated with urbanisation. PMID:25296210

  1. Autofluorescence imaging device for real-time detection and tracking of pathogenic bacteria in a mouse skin wound model: preclinical feasibility studies.

    PubMed

    Wu, Yichao Charlie; Kulbatski, Iris; Medeiros, Philip J; Maeda, Azusa; Bu, Jiachuan; Xu, Lizhen; Chen, Yonghong; DaCosta, Ralph S

    2014-08-01

    Bacterial infection significantly impedes wound healing. Clinical diagnosis of wound infections is subjective and suboptimal, in part because bacteria are invisible to the naked eye during clinical examination. Moreover, bacterial infection can be present in asymptomatic patients, leading to missed opportunities for diagnosis and treatment. We developed a prototype handheld autofluorescence (AF) imaging device (Portable Real-time Optical Detection, Identification and Guidance for Intervention - PRODIGI) to noninvasively visualize and measure bacterial load in wounds in real time. We conducted preclinical pilot studies in an established nude mouse skin wound model inoculated with bioluminescent Staphylococcus aureus bacteria. We tested the feasibility of longitudinal AF imaging for in vivo visualization of bacterial load in skin wounds, validated by bioluminescence imaging. We showed that bacteria (S. aureus), occult to standard examination, can be visualized in wounds using PRODIGI. We also detected quantitative changes in wound bacterial load over time based on the antibiotic treatment and the correlation of bacterial AF intensity with bacterial load. AF imaging of wounds offers a safe, noninvasive method for visualizing the presence, location, and extent of bacteria as well as measuring relative changes in bacterial load in wounds in real time. PMID:25089944

  2. Autofluorescence imaging device for real-time detection and tracking of pathogenic bacteria in a mouse skin wound model: preclinical feasibility studies

    NASA Astrophysics Data System (ADS)

    Wu, Yichao Charlie; Kulbatski, Iris; Medeiros, Philip J.; Maeda, Azusa; Bu, Jiachuan; Xu, Lizhen; Chen, Yonghong; DaCosta, Ralph S.

    2014-08-01

    Bacterial infection significantly impedes wound healing. Clinical diagnosis of wound infections is subjective and suboptimal, in part because bacteria are invisible to the naked eye during clinical examination. Moreover, bacterial infection can be present in asymptomatic patients, leading to missed opportunities for diagnosis and treatment. We developed a prototype handheld autofluorescence (AF) imaging device (Portable Real-time Optical Detection, Identification and Guidance for Intervention-PRODIGI) to noninvasively visualize and measure bacterial load in wounds in real time. We conducted preclinical pilot studies in an established nude mouse skin wound model inoculated with bioluminescent Staphylococcus aureus bacteria. We tested the feasibility of longitudinal AF imaging for in vivo visualization of bacterial load in skin wounds, validated by bioluminescence imaging. We showed that bacteria (S. aureus), occult to standard examination, can be visualized in wounds using PRODIGI. We also detected quantitative changes in wound bacterial load over time based on the antibiotic treatment and the correlation of bacterial AF intensity with bacterial load. AF imaging of wounds offers a safe, noninvasive method for visualizing the presence, location, and extent of bacteria as well as measuring relative changes in bacterial load in wounds in real time.

  3. Detection of genes encoding multidrug resistance and biofilm virulence factor in uterine pathogenic bacteria in postpartum dairy cows.

    PubMed

    Kasimanickam, V R; Owen, K; Kasimanickam, R K

    2016-01-15

    Reckless use of antibiotics and/or development of biofilm are the rationale for the development of multidrug resistance (MDR) of pathogenic bacteria. The objective of the present study was to detect MDR genes in Trueperella pyogenes and to detect biofilm virulence factor (VF) genes in Escherichia coli isolated from the uterus of postpartum dairy cows. Uterine secretions from different parity postpartum Holstein cows (n = 40) were collected using cytobrush technique after a sterile procedure from cows with varying degree of uterine inflammatory conditions. The cytobrush was stored in a specimen collector, placed in a cooler with ice, and transported to the laboratory within 2 hours. The pathogens were isolated and were identified initially by their colony morphology and biochemical characteristics. To further identify and classify the single species, and to determine the presence of MDR and VF genes, the genes fragments were amplified using the respective primers by either singleplex or multiplex polymerase chain reaction protocol, and amplicons were detected by electrophoresis method. T pyogenes was isolated in 17 of 40 (42.5%) cows in the study population as recognized by the 16S rRNA gene. Of the positive T pyogenes samples, 8 of 17 (42.1%) were positive for integron type 1 (intI I), and none were positive for integron type 2 (intI II). Of those 8 positive for intI I, six of eight (66.7%) were positive for amplicons aadA5 and aadA24-ORF1 at 1048 and 1608 bp, respectively, associated with specific drug resistance. Presence of addA5 indicated resistance to sulfadiazine, bacitracin, florfenicol, and ceftiofur. Presence of addA24-ORF1 indicated resistant to sulfadiazine, bacitracin, penicillin, clindamycin, and erythromycin. E coli was isolated in 18 of 40 (45.0%) cows in the study population. The genes for VF, Agn43a, and Agn43 b, associated with biofilm production, were found in 6 of 18 (33.3%) of the positive isolates. Both T pyogenes MDR gene and E coli

  4. Service Learning Course in Which Undergraduates and Middle School Students Investigate Levels of Pathogen Indicating Bacteria in Beach Sand

    NASA Astrophysics Data System (ADS)

    Imamura, G.; Mika, K.; Lin, T.; Lee, C.; Lin, C.; Jay, J.

    2007-12-01

    Service-learning is a pedagogy that combines academic rigor with activities that address human and community needs. Over the past three years, we have developed a service-learning course that involves UCLA students working with 6th graders in an economically disadvantaged neighborhood to address issues of environmental science and health. This past year UCLA students conducted a research project in collaboration with a middle school class to investigate levels of pathogen-indicating organisms in beach sand near the Santa Monica pier. All students were taught necessary methods in class by the UCLA professor, and then met at the field site. Fieldwork involved collection of water and sand samples from various locations, extraction of bacteria from sand by shaking with buffer and decanting, and addition of sample to growth media that allow quantification of two organisms, Escherichia coli and enterococci. These organisms are typically used to indicate fecal contamination of water. Methods were straightforward and were accomplished by the 6th graders with only modest supervision by the UCLA students. Results showed extremely high levels of pathogen indicating organisms in the vicinity of a diverted stormdrain, indicating a continuing problem with the diversion. Levels decreased with distance away from the stormdrain, indicating migration of the organisms from the site of the diversion. UCLA students then visited the sixth grade classroom to help the sixth graders create Powerpoint posters including statement of hypotheses, graphs of the results, pictures of the entire process, and conclusions. Middle school students then visited UCLA to tour the campus and present their posters at a poster session hosted by the Center for Embedded Networked Sensing at UCLA. Desired outcomes at the 6th grade level included: 1) increased interest in science; 2) greater knowledge of and interest in attending college; and 3) enhanced knowledge of and feeling of political empowerment

  5. Application of loop-mediated isothermal amplification (LAMP) assay for the rapid diagnosis of pathogenic bacteria in clinical sputum specimens of acute exacerbation of COPD (AECOPD)

    PubMed Central

    Zhang, Wei; Chen, Chuanhui; Cui, Jian; Bai, Wei; Zhou, Jing

    2015-01-01

    The present study explores the application of LAMP for rapid diagnosis of pathogenic bacteria in clinical sputum specimens of AECOPD as compared with conventional sputum culturing method. 120 sputum specimens of AECOPD patients, 46 sputum specimens of healthy controls, as well as 166 serum specimens as negative controls, were evaluated by LAMP assay using primers of eight typical respiratory pathogens. No cross-reactivity was observed in these negative control species using LAMP assay. The lower detection limit of LAMP assay was approximately 103 copies. 25 cases (20.8%) were detected at least one positive bacteria species by conventional sputum culturing method, while 73 cases (60.8%) were tested positive in LAMP assay. Moreover, compared with sputum culture, bacterial titers results of LAMP assay were more consistent with FEV1/FVC value of AECOPD patients. These results indicated that the sensitivity of LAMP assay was significantly higher than that of sputum culturing method. PMID:26221344

  6. Adhesion to brown trout skin mucus, antagonism against cyst adhesion and pathogenicity to rainbow trout of some inhibitory bacteria against Saprolegnia parasitica .

    PubMed

    Carbajal-González, M T; Fregeneda-Grandes, J M; González-Palacios, C; Aller-Gancedo, J M

    2013-04-29

    Biological control of saprolegniosis with bacteria might be an alternative to the use of chemical compounds. Among criteria for the selection of such bacteria are their absence of pathogenicity to fish and their ability to prevent adhesion of the pathogen to the skin mucus. The pathogenicity to rainbow trout of 21 bacterial isolates with in vitro inhibitory activity against Saprolegnia parasitica was studied. Fifteen of the isolates, identified as Aeromonas sobria, Pantoea agglomerans, Pseudomonas fluorescens, Serratia fonticola, Xanthomonas retroflexus and Yersinia kristensenii, were non-pathogenic when injected into rainbow trout. Their capacity to adhere to the skin mucus of male and female brown trout and to reduce the adhesion of S. parasitica cysts under exclusion, competition and displacement conditions was tested. The 15 bacterial isolates showed a low adhesion rate, ranging between 1.7% (for an A. sobria isolate) and 15.3% (a P. fluorescens isolate). This adhesion was greater in the case of mucus from male brown trout than from females. Similarities in the adhesion to male mucus and other substrates and correlation to that observed to polystyrene suggest that adhesion to skin mucus does not depend on the substrate. A high percentage (88.9%) of the S. parasitica cysts adhered to the skin mucus of male brown trout. Almost all of the bacteria reduced this adhesion ratio significantly under exclusion and competition conditions. However, only half of the isolates displaced cysts from skin mucus, and more bacterial cells were necessary for this effect. A novel method to study the adhesion of S. parasitica cysts to skin mucus of trout and their interactions with inhibitory bacteria is described. PMID:23670078

  7. Surface expression of protein A on magnetosomes and capture of pathogenic bacteria by magnetosome/antibody complexes

    PubMed Central

    Xu, Jun; Hu, Junying; Liu, Lingzi; Li, Li; Wang, Xu; Zhang, Huiyuan; Jiang, Wei; Tian, Jiesheng; Li, Ying; Li, Jilun

    2014-01-01

    Magnetosomes are membrane-enclosed magnetite nanocrystals synthesized by magnetotactic bacteria (MTB). They display chemical purity, narrow size ranges, and species-specific crystal morphologies. Specific transmembrane proteins are sorted to the magnetosome membrane (MM). MamC is the most abundant MM protein of Magnetospirillum gryphiswaldense strain MSR-1. MamF is the second most abundant MM protein of MSR-1 and forms stable oligomers. We expressed staphylococcal protein A (SPA), an immunoglobulin-binding protein from the cell wall of Staphylococcus aureus, on MSR-1 magnetosomes by fusion with MamC or MamF. The resulting recombinant magnetosomes were capable of self-assembly with the Fc region of mammalian antibodies (Abs) and were therefore useful for functionalization of magnetosomes. Recombinant plasmids pBBR-mamC-spa and pBBR-mamF-spa were constructed by fusing spa (the gene that encodes SPA) with mamC and mamF, respectively. Recombinant magnetosomes with surface expression of SPA were generated by introduction of these fusion genes into wild-type MSR-1 or a mamF mutant strain. Studies with a Zeta Potential Analyzer showed that the recombinant magnetosomes had hydrated radii significantly smaller than those of WT magnetosomes and zeta potentials less than −30 mV, indicating that the magnetosome colloids were relatively stable. Observed conjugation efficiencies were as high as 71.24 μg Ab per mg recombinant magnetosomes, and the conjugated Abs retained most of their activity. Numbers of Vibrio parahaemolyticus (a common pathogenic bacterium in seafood) captured by recombinant magnetosome/Ab complexes were measured by real-time fluorescence-based quantitative PCR. One mg of complex was capable of capturing as many as 1.74 × 107 Vibrio cells. The surface expression system described here will be useful for design of functionalized magnetosomes from MSR-1 and other MTB. PMID:24765089

  8. Growth performance and shedding of some pathogenic bacteria in feedlot cattle treated with different growth-promoting agents.

    PubMed

    Lefebvre, Brigitte; Malouin, François; Roy, Gabriel; Giguère, Karine; Diarra, Moussa S

    2006-06-01

    Eighty steers with a mean body weight of 319 kg were used in a study to evaluate the effect of a growth-promoting implant (trenbolone acetate plus estradiol benzoate), monensin, and oxytetracycline on the steer performance and shedding of some foodborne pathogens. The steers were allotted to one of eight treatment combinations according to a randomized complete block design with 16 pens of five animals. Rectal fecal samples were collected before treatment commenced and over a period of more than 24 weeks to study the influence of treatments on the intestinal microbiology of the animals. Results supported the beneficial effect of the hormonal implant on the performance of feedlot steers (average daily gain, feed efficiency, and fat thickness), on carcass characteristics (hot carcass weight, lean yield), and economic value of the carcasses (P < 0.01). The levels of Escherichia coli in feces were not affected by treatments but remained high throughout the study period. Antibiotic-resistant isolates of E. coli were more frequently found as the study progressed but were not associated with any specific treatment. Also independently of treatment, we observed a reduction over time in the shedding of Campylobacter and Yersinia during the feeding period, whereas the shedding of Enterococcus was increased. The results of this study confirmed the beneficial economic effect of growth-promoting agents in beef production and showed that the agents tested did not specifically affect the overall microbial evolution of the animal gut. However, the study also showed, independently of the growth promoter used, the shedding of Campylobacter, Yersinia, and antibiotic-resistant E. coli in the feedlot environment. These bacteria also may be found in the colonic tissue of steers at slaughter and might be a source of carcasses contamination. PMID:16786843

  9. Electrochemical Genosensor To Detect Pathogenic Bacteria (Escherichia coli O157:H7) As Applied in Real Food Samples (Fresh Beef) To Improve Food Safety and Quality Control.

    PubMed

    Abdalhai, Mandour H; Fernandes, António Maximiano; Xia, Xiaofeng; Musa, Abubakr; Ji, Jian; Sun, Xiulan

    2015-05-27

    The electrochemical genosensor is one of the most promising methods for the rapid and reliable detection of pathogenic bacteria. In a previous work, we performed an efficient electrochemical genosensor detection of Staphylococcus aureus by using lead sulfide nanoparticles (PbSNPs). As a continuation of this study, in the present work, the electrochemical genosensor was used to detect Escherichia coli O157:H7. The primer and probes were designed using NCBI database and Sigma-Aldrich primer and probe software. The capture and signalizing probes were modified by thiol (SH) and amine (NH2), respectively. Then, the signalizing probe was connected using cadmium sulfide nanoparticles (CdSNPs), which showed well-defined peaks after electrochemical detection. The genosensor was prepared by immobilization of complementary DNA on the gold electrode surface, which hybridizes with a specific fragment gene from pathogenic to make a sandwich structure. The conductivity and sensitivity of the sensor were increased by using multiwalled carbon nanotubes (MWCNT) that had been modified using chitosan deposited as a thin layer on the glass carbon electrode (GCE) surface, followed by a deposit of bismuth. The peak currents of E. coli O157:H7 correlated in a linear fashion with the concentration of tDNA. The detection limit was 1.97 × 10(-14) M, and the correlation coefficient was 0.989. A poorly defined current response was observed as the negative control and baseline. Our results showed high sensitivity and selectivity of the electrochemical DNA biosensor to the pathogenic bacteria E. coli O157:H7. The biosensor was also used to evaluate the detection of pathogen in real beef samples contaminated artificially. Compared with other electrochemical DNA biosensors, we conclude that this genosensor provides for very efficient detection of pathogenic bacteria. Therefore, this method may have potential application in food safety and related fields. PMID:25965077

  10. 3D-Printed Microfluidic Device for the Detection of Pathogenic Bacteria Using Size-based Separation in Helical Channel with Trapezoid Cross-Section

    PubMed Central

    Lee, Wonjae; Kwon, Donghoon; Choi, Woong; Jung, Gyoo Yeol; Jeon, Sangmin

    2015-01-01

    A facile method has been developed to detect pathogenic bacteria using magnetic nanoparticle clusters (MNCs) and a 3D-printed helical microchannel. Antibody-functionalized MNCs were used to capture E. coli (EC) bacteria in milk, and the free MNCs and MNC-EC complexes were separated from the milk using a permanent magnet. The free MNCs and MNC-EC complexes were dispersed in a buffer solution, then the solution was injected into a helical microchannel device with or without a sheath flow. The MNC-EC complexes were separated from the free MNCs via the Dean drag force and lift force, and the separation was facilitated in the presence of a sheath flow. The concentration of the E. coli bacteria was determined using a light absorption spectrometer, and the limit of detection was found to be 10 cfu/mL in buffer solution and 100 cfu/mL in milk. PMID:25578942

  11. 3D-printed microfluidic device for the detection of pathogenic bacteria using size-based separation in helical channel with trapezoid cross-section.

    PubMed

    Lee, Wonjae; Kwon, Donghoon; Choi, Woong; Jung, Gyoo Yeol; Jeon, Sangmin

    2015-01-01

    A facile method has been developed to detect pathogenic bacteria using magnetic nanoparticle clusters (MNCs) and a 3D-printed helical microchannel. Antibody-functionalized MNCs were used to capture E. coli (EC) bacteria in milk, and the free MNCs and MNC-EC complexes were separated from the milk using a permanent magnet. The free MNCs and MNC-EC complexes were dispersed in a buffer solution, then the solution was injected into a helical microchannel device with or without a sheath flow. The MNC-EC complexes were separated from the free MNCs via the Dean drag force and lift force, and the separation was facilitated in the presence of a sheath flow. The concentration of the E. coli bacteria was determined using a light absorption spectrometer, and the limit of detection was found to be 10 cfu/mL in buffer solution and 100 cfu/mL in milk. PMID:25578942

  12. Fecal-Indicator Bacteria and Escherichia coli Pathogen Data Collected Near a Novel Sub-Irrigation Water-Treatment System in Lenawee County, Michigan, June-November 2007

    USGS Publications Warehouse

    Duris, Joseph W.; Beeler, Stephanie

    2008-01-01

    The U.S. Geological Survey, in cooperation with the Lenawee County Conservation District in Lenawee County, Mich., conducted a sampling effort over a single growing season (June to November 2007) to evaluate the microbiological water quality around a novel livestock reservoir wetland sub-irrigation system. Samples were collected and analyzed for fecal coliform bacteria, Escherichia coli (E. coli) bacteria, and six genes from pathogenic strains of E. coli. A total of 73 water-quality samples were collected on nine occasions from June to November 2007. These samples were collected within the surface water, shallow ground water, and the manure-treatment system near Bakerlads Farm near Clayton in Lenawee County, Mich. Fecal coliform bacteria concentrations ranged from 10 to 1.26 million colony forming units per 100 milliliters (CFU/100 mL). E. coli bacteria concentrations ranged from 8 to 540,000 CFU/100 mL. Data from the E. coli pathogen analysis showed that 73 percent of samples contained the eaeA gene, 1 percent of samples contained the stx2 gene, 37 percent of samples contained the stx1 gene, 21 percent of samples contained the rfbO157 gene, and 64 percent of samples contained the LTIIa gene.

  13. Deep Characterization of the Microbiomes of Calophya spp. (Hemiptera: Calophyidae) Gall-Inducing Psyllids Reveals the Absence of Plant Pathogenic Bacteria and Three Dominant Endosymbionts

    PubMed Central

    2015-01-01

    Bacteria associated with sap-feeding insect herbivores include not only symbionts that may increase their hosts’ fitness but also harmful plant pathogens. Calophya spp. gall-inducing psyllids (Hemiptera: Calophyidae) are being investigated for their potential as biological control agents of the noxious weed, Brazilian peppertree (Schinus terebinthifolia), in Florida. Although there are no examples of plant pathogen transmission by members of the family Calophyidae, several insects in the superfamily Psylloidea are known to transmit pathogenic bacteria in the genera Candidatus Liberibacter and Candidatus Phytoplasma. To determine whether Calophya spp. harbor potentially harmful plant pathogenic bacteria, we sequenced small subunit (SSU) ribosomal RNA (rRNA) gene amplicons generated from individuals from four Calophya spp. populations. All microbial SSU gene sequences fell into the bacterial domain, with 98-99% belonging to the Proteobacteria. The Calophya microbiomes contained a relatively simple community, with 49-79 operational taxonomic units (OTUs; 97%) detected, and only 5-8 OTUs with greater than 1% abundance. Candidatus Carsonella showed the highest relative abundance, with OTUs from this candidate genus representing between 51 – 65% of all recovered sequences. The next most abundant clade observed was an unclassified Enterobacteriacae group closely related to bacteria from the genera Buchnera and Blochmannia that ranged from 20-31% in relative abundance. Wolbachia populations were the third most abundant group and represented 7-27% of the diversity in microbial OTUs. No SSU rRNA gene sequences from putative pathogenic bacteria from the genera Ca. Liberibacter or Ca. Phytoplasma were detected in the microbiomes of the four Calophya populations. The probability that infected psyllids were present in our colonies, but were not sampled, was extremley low (1.39 x 10-10). As far as we are aware, our study is the first to characterize the microbiome of a

  14. Deep Characterization of the Microbiomes of Calophya spp. (Hemiptera: Calophyidae) Gall-Inducing Psyllids Reveals the Absence of Plant Pathogenic Bacteria and Three Dominant Endosymbionts.

    PubMed

    Overholt, Will A; Diaz, Rodrigo; Rosskopf, Erin; Green, Stefan J; Overholt, William A

    2015-01-01

    Bacteria associated with sap-feeding insect herbivores include not only symbionts that may increase their hosts' fitness but also harmful plant pathogens. Calophya spp. gall-inducing psyllids (Hemiptera: Calophyidae) are being investigated for their potential as biological control agents of the noxious weed, Brazilian peppertree (Schinus terebinthifolia), in Florida. Although there are no examples of plant pathogen transmission by members of the family Calophyidae, several insects in the superfamily Psylloidea are known to transmit pathogenic bacteria in the genera Candidatus Liberibacter and Candidatus Phytoplasma. To determine whether Calophya spp. harbor potentially harmful plant pathogenic bacteria, we sequenced small subunit (SSU) ribosomal RNA (rRNA) gene amplicons generated from individuals from four Calophya spp. populations: All microbial SSU gene sequences fell into the bacterial domain, with 98-99% belonging to the Proteobacteria. The Calophya microbiomes contained a relatively simple community, with 49-79 operational taxonomic units (OTUs; 97%) detected, and only 5-8 OTUs with greater than 1% abundance. Candidatus Carsonella showed the highest relative abundance, with OTUs from this candidate genus representing between 51-65% of all recovered sequences. The next most abundant clade observed was an unclassified Enterobacteriacae group closely related to bacteria from the genera Buchnera and Blochmannia that ranged from 20-31% in relative abundance. Wolbachia populations were the third most abundant group and represented 7-27% of the diversity in microbial OTUs. No SSU rRNA gene sequences from putative pathogenic bacteria from the genera Ca. Liberibacter or Ca. Phytoplasma were detected in the microbiomes of the four Calophya populations. The probability that infected psyllids were present in our colonies, but were not sampled, was extremley low (1.39 x 10(-10)). As far as we are aware, our study is the first to characterize the microbiome of a candidate

  15. Dual metabolomics: a novel approach to understanding plant-pathogen interactions.

    PubMed

    Allwood, J William; Clarke, Andrew; Goodacre, Royston; Mur, Luis A J

    2010-04-01

    One of the most well-characterised plant pathogenic interactions involves Arabidopsis thaliana and the bacteria Pseudomonas syringae pathovar tomato (Pst). The standard Pst inoculation procedure involves infiltration of large populations of bacteria into plant leaves which means that metabolite changes cannot be readily assigned to the host or pathogen. A plant cell-pathogen co-culture based approach has been developed where the plant and pathogen cells are separated after 12h of co-culture via differential filtering and centrifugation. Fourier transform infrared (FT-IR) spectroscopy was employed to assess the intracellular metabolomes (metabolic fingerprints) of both host and pathogen and their extruded (extracellular) metabolites (metabolic footprints) under conditions relevant to disease and resistance. We propose that this system will enable the metabolomic profiling of the separated host and pathogen (i.e. 'dual metabolomics') and will facilitate the modelling of reciprocal responses. PMID:20138320

  16. A novel, multiplex, real-time PCR–based approach for the detection of the commonly occurring pathogenic fungi and bacteria

    PubMed Central

    2013-01-01

    Background Polymerase chain reaction (PCR)-based techniques are widely used to identify fungal and bacterial infections. There have been numerous reports of different, new, real-time PCR-based pathogen identification methods although the clinical practicability of such techniques is not yet fully clarified. The present study focuses on a novel, multiplex, real-time PCR-based pathogen identification system developed for rapid differentiation of the commonly occurring bacterial and fungal causative pathogens of bloodstream infections. Results A multiplex, real-time PCR approach is introduced for the detection and differentiation of fungi, Gram-positive (G+) and Gram-negative (G-) bacteria. The Gram classification is performed with the specific fluorescence resonance energy transfer (FRET) probes recommended for LightCycler capillary real-time PCR. The novelty of our system is the use of a non-specific SYBR Green dye instead of labelled anchor probes or primers, to excite the acceptor dyes on the FRET probes. In conjunction with this, the use of an intercalating dye allows the detection of fungal amplicons. With the novel pathogen detection system, fungi, G + and G- bacteria in the same reaction tube can be differentiated within an hour after the DNA preparation via the melting temperatures of the amplicons and probes in the same tube. Conclusions This modified FRET technique is specific and more rapid than the gold-standard culture-based methods. The fact that fungi, G + and G- bacteria were successfully identified in the same tube within an hour after the DNA preparation permits rapid and early evidence-based management of bloodstream infections in clinical practice. PMID:24364823

  17. Isolation of some pathogenic bacteria from the great spruce bark beetle, Dendroctonus micans and its specific predator, Rhizophagus grandis.

    PubMed

    Yaman, M; Ertürk, O; Aslan, I

    2010-01-01

    Some bacteria were isolated from Dendroctonus micans and its specific predator, Rhizophagus grandis. Six bacteria from D. micans were identified as Bacillus pumilus, Enterobacter intermedius, Citrobacter freundii, Cellulomonas flavigena, Microbacterium liquefaciens and Enterobacter amnigenus, three bacteria from R. grandis as Klebsiella pneumoniae, Pantoea agglomerans and Serratia grimesii, on the basis of fatty acid methyl ester analysis and carbon utilization profile by using Microbial Identification and Biolog Microplate Systems. Their insecticidal effects were tested on larvae and adults of D. micans. PMID:20336502

  18. Efficacy of plant essential oils against foodborne pathogens and spoilage bacteria associated with ready-to-eat vegetables: antimicrobial and sensory screening.

    PubMed

    Gutierrez, Jorge; Rodriguez, Gabriel; Barry-Ryan, Catherine; Bourke, Paula

    2008-09-01

    The objectives of this study were to evaluate the antimicrobial activity of plant essential oils (EOs) against foodborne pathogens and key spoilage bacteria pertinent to ready-to-eat vegetables and to screen the selected EOs for sensory acceptability. The EOs basil, caraway, fennel, lemon balm, marjoram, nutmeg, oregano, parsley, rosemary, sage, and thyme were evaluated. The bacteria evaluated were Listeria spp., Staphylococcus aureus, Lactobacillus spp., Bacillus cereus, Salmonella, Enterobacter spp., Escherichia coli, and Pseudomonas spp. Quantitative antimicrobial analyses were performed using an absorbance-based microplate assay. Efficacy was compared using MIC, the half maximum inhibitory concentration, and the increase in lag phase. Generally, gram-positive bacteria were more sensitive to EOs than were gram-negative bacteria, and Listeria monocytogenes strains were among the most sensitive. Of the spoilage organisms, Pseudomonas spp. were the most resistant. Oregano and thyme EOs had the highest activity against all the tested bacteria. Marjoram and basil EOs had selectively high activity against B. cereus, Enterobacter aerogenes, E. coli, and Salmonella, and lemon balm and sage EOs had adequate activity against L. monocytogenes and S. aureus. Within bacterial species, EO efficacy was dependent on strain and in some cases the origin of the strain. On a carrot model product, basil, lemon balm, marjoram, oregano, and thyme EOs were deemed organoleptically acceptable, but only oregano and marjoram EOs were deemed acceptable for lettuce. Selected EOs may be useful as natural and safe additives for promoting the safety and quality of ready-to-eat vegetables. PMID:18810868

  19. Influence of cyanobacterial inoculation on the culturable microbiome and growth of rice.

    PubMed

    Priya, Himani; Prasanna, Radha; Ramakrishnan, Balasubramanian; Bidyarani, Ngangom; Babu, Santosh; Thapa, Shobit; Renuka, Nirmal

    2015-02-01

    Rice plants are selective with their associations with bacteria that are beneficial for growth, nutrient uptake, exhibit induced resistance or antagonism towards pathogens. Cyanobacteria as bioinoculants are known to promote the growth and health of rice plants. The present investigation was aimed at understanding whether and how cyanobacterial (Calothrix elenkinii) inoculation influenced the rice plant growth and the culturable bacterial populations and identifying the dominant culturable "microbiome" members. The plant tissue extracts were used to enumerate populations of the culturable microbiome members using selected enrichment media with different nutrient levels. About 10-fold increases in population densities of culturable microbiome members in different media were recorded, with some isolates having metabolic potential for nitrogen fixation and phosphorus solubilization. Fatty acid methyl ester (FAME) analysis and 16S rRNA sequencing of selected microbial morphotypes suggested the predominance of the members of Bacillaceae. Significant increases in plant growth attributes, nitrogenase activity and indole acetic acid production, and activities of hydrolytic and defense enzymes were recorded in the Calothrix inoculated plants. The PCR-based analysis and scanning electron microscopic (SEM) observations confirmed the presence of inoculated cyanobacterium inside the plant tissues. This investigation illustrated that cyanobacterial inoculation can play significant roles in improving growth and metabolism of rice directly and interact with the beneficial members from the endophytic microbiome of rice seedlings synergistically. PMID:25644956

  20. Diversity of indigenous endophytic bacteria associated with the roots of Chinese cabbage (Brassica campestris L.) cultivars and their antagonism towards pathogens.

    PubMed

    Haque, Md Azizul; Yun, Han Dae; Cho, Kye Man

    2016-05-01

    The study aimed to reveal the diversity of endophytic bacteria in the roots of Chinese cabbage (CC) cultivated in two areas in Korea, namely, Seosang-gun (SS) and Haenam-gun (HN), and also in a transgenic plant (TP) from the laboratory. A total of 653 colonies were isolated from the interior of CC roots, comprising 118, 302, and 233 isolates from SS, HN, and TP samples, respectively. Based on 16S rRNA gene sequence analysis, the isolates belonged to four major phylogenetic groups: high-G+C Gram-positive bacteria (HGC-GPB), low-G+C Gram-positive bacteria (LGC-GPB), Proteobacteria, and Bacteriodetes. The most dominant groups in the roots of the SS, HN, and TP cultivars were LGC-GPB (48.3%), Proteobacteria (50.2%), and HGC-GPB (38.2%), respectively. Importantly, most of the isolates that produced cell-walldegrading enzymes belonged to the genus Bacillus. Bacillus sp. (HNR03, TPR06), Bacillus pumilus (SSR07, HNR11, TPR07), and Bacillus subtilis (TPR03) showed high antagonism against the tested food-borne pathogenic bacteria. In addition, Bacillus sp. (HNR03, TPR06), Bacillus pumilus (SSR07, HNR11, HNR17, TPR11), Microbacterium oxidans (SSR09, TPR04), Bacillus cereus HNR10, Pseudomonas sp. HNR13, and Bacillus subtilis (TPR02, TPR03) showed strong antagonistic activity against the fungi Phythium ultimum, Phytophthora capsici, Fusarium oxysporum, and Rhizoctonia solani. The endophytes isolated from the TP cultivar showed the strongest antagonistic reactions against pathogens. This study is the first report on endophytic bacteria from Chinese cabbage roots. PMID:27095454

  1. Characterizing relationships among fecal indicator bacteria, microbial source tracking markers, and associated waterborne pathogen occurrence in stream water and sediments in a mixed land use watershed.

    PubMed

    Bradshaw, J Kenneth; Snyder, Blake J; Oladeinde, Adelumola; Spidle, David; Berrang, Mark E; Meinersmann, Richard J; Oakley, Brian; Sidle, Roy C; Sullivan, Kathleen; Molina, Marirosa

    2016-09-15

    Bed sediments of streams and rivers may store high concentrations of fecal indicator bacteria (FIB) and pathogens. Due to resuspension events, these contaminants can be mobilized into the water column and affect overall water quality. Other bacterial indicators such as microbial source tracking (MST) markers, developed to determine potential sources of fecal contamination, can also be resuspended from bed sediments. The primary objective of this study was to predict occurrence of waterborne path