COMPETITION BETWEEN ANOXYGENIC PHOTOTROPHIC BACTERIA AND COLORLESS SULFUR BACTERIA IN A MICROBIAL MAT

NARCIS (Netherlands)

VISSCHER, PT; VANDENENDE, FP; SCHAUB, BEM; VANGEMERDEN, H

The populations of chemolithoautotrophic (colorless) sulfur bacteria and anoxygenic phototrophic bacteria were enumerated in a marine microbial mat. The highest population densities were found in the 0-5 mm layer of the mat: 2.0 X 10(9) cells CM-3 sediment, and 4.0 X 10(7) cells cm-3 sediment for

Effects of Ethanolic Ferolagu angulata Extract on Pathogenic Gastrointestinal Bacteria and Probiotic Bacteria in Skimmed Milk Medium

Directory of Open Access Journals (Sweden)

Reza Naghiha

2016-12-01

Full Text Available Background:    Due to excessive consumption of synthetic drugs, drug resistance rate of pathogenic bacteria is increasing and there is an ever-increasing need to find new safe compounds to tackle this problem. This study was conducted to investigate the consequences of chavill extract on the growth and viability of gastrointestinal pathogenic bacterium and probiotics bacteria. Methods:    The experiment contained three levels of the chavill extract concentrations (0, 1 and 3% which were added to the milk free fat in accompany with three probiotic bacteria (Lactobacillus acidophilus, Lactobacillus casei and lactobacillus plantaram and a pathogenic gastrointestinal bacterium (Salmonella typhimurium. Bacterial inoculums (1×107 CFU/ml with different concentrations of chavill extract were added to skimmed milk medium and bacteria growth were enumerated. Results:  The concentration of 1% chavill extract significantly increased the total count of probiotic bacteria compared to the control group, while the number of pathogenic bacteria was decreased. At 3% chavill extract the growth of Lactobacillus acidophilus and Lactobacillus plantaram were increased. On the other hand, it prevented the growth of Salmonella typhimurium Conclusion:   Chavill extracts would play as an alternative to antibiotics in pharmacological studies to decreases harmful bacteria and increase probiotic bacteria.

Use of oligodeoxynucleotide signature probes for identification of physiological groups of methylotrophic bacteria

International Nuclear Information System (INIS)

Tsien, H.C.; Bratina, B.J.; Tsuji, K.; Hanson, R.S.

1990-01-01

Oligodeoxynucleotide sequences that uniquely complemented 16S rRNAs of each group of methylotrophs were synthesized and used as hybridization probes for the identification of methylotrophic bacteria possessing the serine and ribulose monophosphate (RuMP) pathways for formaldehyde fixation. The specificity of the probes was determined by hybridizing radiolabeled probes with slot-blotted RNAs of methylotrophs and other eubacteria followed by autoradiography. The washing temperature was determined experimentally to be 50 and 52 degrees C for 9-α (serine pathway) and 10-γ (RuMP pathway) probes, respectively. RNAs isolated from serine pathway methylotrophs bound to probe 9-α, and RNAs from RuMP pathway methylotrophs bound to probe 10-γ. Nonmethylotrophic eubacterial RNAs did not bind to either probe. The probes were also labeled with fluorescent dyes. Cells fixed to microscope slides were hybridized with these probes, washed, and examined in a fluorescence microscope equipped with appropriate filter sets. Cells of methylotrophic bacteria possessing the serine or RuMP pathway specifically bind probes designed for each group. Samples with a mixture of cells of type I and II methanotrophs were detected and differentiated with single probes or mixed probes labeled with different fluorescent dyes, which enabled the detection of both types of cells in the same microscopic field

Radiosensitivity of some bacteria isolated from broiler chicken carcasses

International Nuclear Information System (INIS)

Fiszer, W.; Mroz, J.; Zabielski, J.

1981-01-01

Two groups of bacteria of Pseudomonas sp. and Bacillus sp. were isolated from poultry carcasses. The samples of a ground meat were poisoned by suspensions of these bacteria and on the next day they were irradiated. Quantitative estimation of surviving cells after irradiation was done according to TPC method. The surviving curve and dose D 10 (23 Gy) for Pseudomonas sp. group 1 is typical for this kind of bacterium. D 10 value = 2,3 kGy for Bacillus sp. is consistent with data of literature. Exceptionally high D 10 value of Pseudomonas sp. group 2 (170 Gy) seems to indicate the fact that the isolated bacteria could be the mixture often defined as Pseudomonas-Achromobacter group. Nevertheless, some scientific data show that D 10 value for Pseudomonas can reach even 120 Gy. (author)

A Study on the Measurement of the Pollution Level of Bacteria and Disinfection of Table and IP Cassette

International Nuclear Information System (INIS)

Bae, Seok Hwan; Lee, Moo Sik; Lim, Chang Seon; Kim, Gha Jung

2008-01-01

For the number of microbes and the pollution level of bacteriology of IP Cassette and Table by laboratories, after identifying the bacteria before and after using alcohol and tissue including disinfectant and statistically testing, this research was intended to provide the basic data for the prevention and the right disinfection guideline for infection management of hospitals in diagnostic radiology. The subject of this research was the general room of diagnostic radiology of a university hospital in Daejeon City. The research was conducted from Apr 5 to Apr 12, 2007. The number of microbes and the pollution level of bacteriology of IP Cassette and Table by laboratories were tested before and after using alcohol and tissue for disinfection including disinfectant. In order to collect specimens exactly, they were collected with the nurse who specialized in infection management of the hospital, and statistical processing was done with SPSS V13.0. To compare the results before and after using alcohol and tissue, T-test was implemented, and post-hoc test was conducted. Bacteria were detected in 19 cases of 24 subjects(79.2%), however, they were not detected in 5 cases(20.8%). 7 kinds of bacteria were detected as isolated bacteria, of which Methicillin Resistant coagulase-negative Staphylococci(MRCNS) were detected in 15 cases(62.5%), which was most, Methicillin Resistant Staphylococcus Aureus(MRSA) in 6 cases(16.7%), Enterococcus Faecium(EFM) in 5 cases(20.8%), Acinetobacter baumannii(ABA) in 2 cases(8.3%), and Bacillus sp, Coagulase-negative Staphylococci(CNS), and Enterococcus sp(ENT) in 1 case, respectively(4.2%). In all bacteria except ABA, Gram positive bacillia were detected in 30 cases(97%), and Gram negative bacilli were detected only in 1 case(3%). As for the kinds of bacteria and the number of groups before and after using 70% Alcohol by Groups, when the bacteria were identified after disinfecting IP Cassette and Table with 70% Alcohol, all the bacteria became

A Study on the Measurement of the Pollution Level of Bacteria and Disinfection of Table and IP Cassette

Energy Technology Data Exchange (ETDEWEB)

Bae, Seok Hwan; Lee, Moo Sik; Lim, Chang Seon; Kim, Gha Jung [Koyang University, Koyang (Korea, Republic of)

2008-09-15

For the number of microbes and the pollution level of bacteriology of IP Cassette and Table by laboratories, after identifying the bacteria before and after using alcohol and tissue including disinfectant and statistically testing, this research was intended to provide the basic data for the prevention and the right disinfection guideline for infection management of hospitals in diagnostic radiology. The subject of this research was the general room of diagnostic radiology of a university hospital in Daejeon City. The research was conducted from Apr 5 to Apr 12, 2007. The number of microbes and the pollution level of bacteriology of IP Cassette and Table by laboratories were tested before and after using alcohol and tissue for disinfection including disinfectant. In order to collect specimens exactly, they were collected with the nurse who specialized in infection management of the hospital, and statistical processing was done with SPSS V13.0. To compare the results before and after using alcohol and tissue, T-test was implemented, and post-hoc test was conducted. Bacteria were detected in 19 cases of 24 subjects(79.2%), however, they were not detected in 5 cases(20.8%). 7 kinds of bacteria were detected as isolated bacteria, of which Methicillin Resistant coagulase-negative Staphylococci(MRCNS) were detected in 15 cases(62.5%), which was most, Methicillin Resistant Staphylococcus Aureus(MRSA) in 6 cases(16.7%), Enterococcus Faecium(EFM) in 5 cases(20.8%), Acinetobacter baumannii(ABA) in 2 cases(8.3%), and Bacillus sp, Coagulase-negative Staphylococci(CNS), and Enterococcus sp(ENT) in 1 case, respectively(4.2%). In all bacteria except ABA, Gram positive bacillia were detected in 30 cases(97%), and Gram negative bacilli were detected only in 1 case(3%). As for the kinds of bacteria and the number of groups before and after using 70% Alcohol by Groups, when the bacteria were identified after disinfecting IP Cassette and Table with 70% Alcohol, all the bacteria became

Bacteria-Mineral Interactions on the Surfaces of Metal-Resistant Bacteria

International Nuclear Information System (INIS)

Malkin, A.J.

2010-01-01

The extraordinary ability of indigenous microorganisms, like metal-resistant bacteria, for biotransformation of toxic compounds is of considerable interest for the emerging area of environmental bioremediation. However, the underlying mechanisms by which metal-resistant bacteria transform toxic compounds are currently unknown and await elucidation. The project's objective was to study stress-induced responses of metal-resistant bacteria to environmental changes and chemical stimulants. This project involved a multi-institutional collaboration of our LLNL group with the group of Dr. H.-Y. Holman (Lawrence Berkeley National Laboratory). In this project, we have utilized metal-resistant bacteria Arthrobacter oxydans as a model bacterial system. We have utilized atomic force microscopy (AFM) to visualize for the first time at the nanometer scale formation of stress-induced structures on bacterial surfaces in response to Cr (VI) exposure. We have demonstrated that structure, assembly, and composition of these stress-induced structures are dependent on Cr (VI) concentrations. Our AFM observations of the appearance and development of stress-induced layers on the surfaces of Arthrobacter oxydans bacteria exposed to Cr (VI) were confirmed by Dr. Holman's biochemical, electron microscopy, and synchrotron infrared spectromicroscopy studies. In general, in vitro imaging of live microbial and cellular systems represents one of the most challenging issues in application of AFM. Various approaches for immobilization of bacteria on the substrate for in vitro imaging were tested in this project. Imaging of live bacteria was achieved, however further optimization of experimental methods are needed for high-resolution visualization of the cellular environmental structural dynamics by AFM. This project enhanced the current insight into molecular architecture, structural and environmental variability of bacterial systems. The project partially funded research for two book chapters (1

Development and validation of an automated, microscopy-based method for enumeration of groups of intestinal bacteria

NARCIS (Netherlands)

Jansen, GJ; Wildeboer-Veloo, ACM; Tonk, RHJ; Franks, AH; Welling, G

An automated microscopy-based method using fluorescently labelled 16S rRNA-targeted oligonucleotide probes directed against the predominant groups of intestinal bacteria was developed and validated. The method makes use of the Leica 600HR. image analysis system, a Kodak MegaPlus camera model 1.4 and

Light controlled 3D micromotors powered by bacteria

Science.gov (United States)

Vizsnyiczai, Gaszton; Frangipane, Giacomo; Maggi, Claudio; Saglimbeni, Filippo; Bianchi, Silvio; Di Leonardo, Roberto

2017-01-01

Self-propelled bacteria can be integrated into synthetic micromachines and act as biological propellers. So far, proposed designs suffer from low reproducibility, large noise levels or lack of tunability. Here we demonstrate that fast, reliable and tunable bio-hybrid micromotors can be obtained by the self-assembly of synthetic structures with genetically engineered biological propellers. The synthetic components consist of 3D interconnected structures having a rotating unit that can capture individual bacteria into an array of microchambers so that cells contribute maximally to the applied torque. Bacterial cells are smooth swimmers expressing a light-driven proton pump that allows to optically control their swimming speed. Using a spatial light modulator, we can address individual motors with tunable light intensities allowing the dynamic control of their rotational speeds. Applying a real-time feedback control loop, we can also command a set of micromotors to rotate in unison with a prescribed angular speed. PMID:28656975

Light controlled 3D micromotors powered by bacteria

Science.gov (United States)

Vizsnyiczai, Gaszton; Frangipane, Giacomo; Maggi, Claudio; Saglimbeni, Filippo; Bianchi, Silvio; di Leonardo, Roberto

2017-06-01

Self-propelled bacteria can be integrated into synthetic micromachines and act as biological propellers. So far, proposed designs suffer from low reproducibility, large noise levels or lack of tunability. Here we demonstrate that fast, reliable and tunable bio-hybrid micromotors can be obtained by the self-assembly of synthetic structures with genetically engineered biological propellers. The synthetic components consist of 3D interconnected structures having a rotating unit that can capture individual bacteria into an array of microchambers so that cells contribute maximally to the applied torque. Bacterial cells are smooth swimmers expressing a light-driven proton pump that allows to optically control their swimming speed. Using a spatial light modulator, we can address individual motors with tunable light intensities allowing the dynamic control of their rotational speeds. Applying a real-time feedback control loop, we can also command a set of micromotors to rotate in unison with a prescribed angular speed.

Group II intron inhibits conjugative relaxase expression in bacteria by mRNA targeting

Science.gov (United States)

Piazza, Carol Lyn; Smith, Dorie

2018-01-01

Group II introns are mobile ribozymes that are rare in bacterial genomes, often cohabiting with various mobile elements, and seldom interrupting housekeeping genes. What accounts for this distribution has not been well understood. Here, we demonstrate that Ll.LtrB, the group II intron residing in a relaxase gene on a conjugative plasmid from Lactococcus lactis, inhibits its host gene expression and restrains the naturally cohabiting mobile element from conjugative horizontal transfer. We show that reduction in gene expression is mainly at the mRNA level, and results from the interaction between exon-binding sequences (EBSs) in the intron and intron-binding sequences (IBSs) in the mRNA. The spliced intron targets the relaxase mRNA and reopens ligated exons, causing major mRNA loss. Taken together, this study provides an explanation for the distribution and paucity of group II introns in bacteria, and suggests a potential force for those introns to evolve into spliceosomal introns. PMID:29905149

Molecular diversity, cultivation, and improved detection by fluorescent in situ hybridization of a dominant group of human gut bacteria related to Roseburia spp. or Eubacterium rectale.

Science.gov (United States)

Aminov, Rustam I; Walker, Alan W; Duncan, Sylvia H; Harmsen, Hermie J M; Welling, Gjalt W; Flint, Harry J

2006-09-01

Phylogenetic analysis was used to compare 16S rRNA sequences from 19 cultured human gut strains of Roseburia and Eubacterium rectale with 356 related sequences derived from clone libraries. The cultured strains were found to represent five of the six phylotypes identified. A new oligonucleotide probe, Rrec584, and the previous group probe Rint623, when used in conjunction with a new helper oligonucleotide, each recognized an average of 7% of bacteria detected by the eubacterial probe Eub338 in feces from 10 healthy volunteers. Most of the diversity within this important group of butyrate-producing gut bacteria can apparently be retrieved through cultivation.

[Transformation and expression of specific insecticide gene Bt cry3A in resident endogenetic bacteria isolated from Apriona germari (Hope) larvae intestines].

Science.gov (United States)

Zhongkang, Wang; Wei, He; Guoxiong, Peng; Yuxian, Xia; Qiang, Li; Youping, Yin

2008-09-01

Transforming the specific insecticidal gene Bt cry3A into the dominant resident endogenetic bacteria in intestines of Apriona germari (Hope) larvae to construct transgenic bacteria that can colonize and express the insecticidal gene Bt cry3A perfectly in intestines of Apriona germari (Hope) larvae. We isolated and identified the dominant resident endogenetic bacteria by traditional methods and molecular method based of 16S rDNA analysis. Two Escherichia coli--Bacillus thuringiensis shuttle plasmid pHT305a and pHT7911 which contained specific insecticidal gene Bt cry3A were transformed into two resident endogenetic bacteria Brevibacillus brevis Ag12 and Bacillus thuringiensis Ag13 isolated from A. germari larvae intestines respectively by electro-transformation. Eighteen species of bacteria have isolated and identified from Apriona germari larvae intestines and two of them (Brevibacillus brevis Ag12 and Bacillus thuringiensis Ag13) were selected as starting bacteria to recieve the Bt cry3A. The 4 transgenic engineering strains Ag12-7911, Ag12-305a, Ag13-7911 and Ag13-305a were obtained successfully and validated by testing the plasmid stability in recombinants, transformants vegetal properties, crystal poisonous protein observation, expressional protein SDS-PAGE. The Bt cry3A gene had been transformed into Brevibacillus brevis and Bacillus thuringiensis. Both bioassay and examination of the engineering strains in intestines after feeding them to larvae showed that all these transformant strains (Brevibacillus brevis Ag12-305a, Bacillus thurigiensis Ag13-305a, Brevibacillus brevis Ag12-7911 and Bacillus thurigiensis Ag13-7911) could colonize and express 65 kDa protoxin in intestines of A. germari larvae and had insecticidal activity. We obtained four transgenic bacteria that can colonize and express the target insecticide gene Bt cry3A in A. germari larvae. They may be developed as a new insecticide.

A 3-hydroxy β-end group in xanthophylls is preferentially oxidized to a 3-oxo ε-end group in mammals.

Science.gov (United States)

Nagao, Akihiko; Maoka, Takashi; Ono, Hiroshi; Kotake-Nara, Eiichi; Kobayashi, Miyuki; Tomita, Mie

2015-02-01

We previously found that mice fed lutein accumulated its oxidative metabolites (3'-hydroxy-ε,ε-caroten-3-one and ε,ε-carotene-3,3'-dione) as major carotenoids, suggesting that mammals can convert xanthophylls to keto-carotenoids by the oxidation of hydroxyl groups. Here we elucidated the metabolic activities of mouse liver for several xanthophylls. When lutein was incubated with liver postmitochondrial fraction in the presence of NAD(+), (3'R,6'R)-3'-hydroxy-β,ε-caroten-3-one and (6RS,3'R,6'R)-3'-hydroxy-ε,ε-caroten-3-one were produced as major oxidation products. The former accumulated only at the early stage and was assumed to be an intermediate, followed by isomerization to the latter. The configuration at the C3' and C6' of the ε-end group in lutein was retained in the two oxidation products. These results indicate that the 3-hydroxy β-end group in lutein was preferentially oxidized to a 3-oxo ε-end group via a 3-oxo β-end group. Other xanthophylls such as β-cryptoxanthin and zeaxanthin, which have a 3-hydroxy β-end group, were also oxidized in the same manner as lutein. These keto-carotenoids, derived from dietary xanthophylls, were confirmed to be present in plasma of normal human subjects, and β,ε-caroten-3'-one was significantly increased by the ingestion of β-cryptoxanthin. Thus, humans as well as mice have oxidative activity to convert the 3-hydroxy β-end group of xanthophylls to a 3-oxo ε-end group. Copyright © 2015 by the American Society for Biochemistry and Molecular Biology, Inc.

The fecal bacteria

Science.gov (United States)

Sadowsky, Michael J.; Whitman, Richard L.

2011-01-01

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

Quantitative evaluation of apical extrusion of intracanal bacteria using rotary ProTaper, K3XF, twisted and hand K-file system: An ex vivo study

Directory of Open Access Journals (Sweden)

Priyanka Ghogre

2015-01-01

Conclusions: Both the rotary and hand instrumentation systems extruded intracanal bacteria through the apical foramen. K3XF file system showed least bacterial extrusion amongst all instrumentation groups.

Effects of supplementing lactic acid bacteria on fecal microbiota ...

African Journals Online (AJOL)

Results: The results indicated that Lactobacillus plantarum strain L.p X3-2B increased fecal lactic acid bacteria(LAB) and Bifidobacterium while resisting the growth of harmful bacteria. Viable counts of LAB and Bifidobacterium reached 8 log cfu/mL after feeding for 14 days. Fecal pH in the control group was high in ...

Isolation, Identification, Prevalence, and Genetic Diversity of Bacillus cereus Group Bacteria From Different Foodstuffs in Tunisia.

Science.gov (United States)

Gdoura-Ben Amor, Maroua; Siala, Mariam; Zayani, Mariem; Grosset, Noël; Smaoui, Salma; Messadi-Akrout, Feriele; Baron, Florence; Jan, Sophie; Gautier, Michel; Gdoura, Radhouane

2018-01-01

Bacillus cereus group is widespread in nature and foods. Several members of this group are recognized as causing food spoilage and/or health issues. This study was designed to determine the prevalence and genetic diversity of the B. cereus group strains isolated in Tunisia from different foods (cereals, spices, cooked food, fresh-cut vegetables, raw and cooked poultry meats, seafood, canned, pastry, and dairy products). In total, 687 different samples were collected and searched for the presence of the B. cereus group after selective plating on MYP agar and enumeration of each sample. The typical pink-orange uniform colonies surrounded by a zone of precipitate were assumed to belong to the B. cereus group. One typical colony from each sample was subcultured and preserved as cryoculture. Overall, 191 (27.8%) food samples were found positive, giving rise to a collection of 191 B. cereus -like isolates. The concentration of B. cereus -like bacteria were below 10 3 cfu/g or ml in 77.5% of the tested samples. Higher counts (>10 4 cfu/g or ml) were found in 6.8% of samples including fresh-cut vegetables, cooked foods, cereals, and pastry products. To verify whether B. cereus -like isolates belonged to the B. cereus group, a PCR test targeting the sspE gene sequence specific of the group was carried out. Therefore, 174 isolates were found to be positive. Food samples were contaminated as follows: cereals (67.6%), pastry products (46.2%), cooked food (40.8%), cooked poultry meat (32.7%), seafood products (32.3%), spices (28.8%), canned products (16.7%), raw poultry meat (9.4%), fresh-cut vegetables (5.0%), and dairy products (4.8%). The 174 B. cereus isolates were characterized by partial sequencing of the panC gene, using a Sym'Previous software tool to assign them to different phylogenetic groups. Strains were distributed as follows: 61.3, 29.5, 7.5, and 1.7% in the group III, IV, II, and V, respectively. The genetic diversity was further assessed by ERIC-PCR and PFGE

In vitro activity of daptomycin against clinical isolates of Gram-positive bacteria.

Science.gov (United States)

Piper, Kerryl E; Steckelberg, James M; Patel, Robin

2005-08-01

We determined the activity of daptomycin, a recently FDA-approved antimicrobial agent, against clinical isolates of Gram-positive bacteria, including viridans group streptococci (16 Streptococcus mitis species group, 12 S. mutans species group, 9 S. anginosus species group, 8 S. sanguinis species group, 5 S. salivarius species group) from patients with infective endocarditis, 32 methicillin-resistant Staphylococcus aureus, 32 high-level penicillin-resistant Streptococcus pneumoniae, 38 vancomycin-resistant enterococci (including 1 linezolid-resistant isolate), and the following unusual Gram-positive bacteria: 3 Listeria monocytogenes, 4 Erysipelothrix rhusiopathiae, 9 Corynebacterium species, 10 Abiotrophia/Granulicatella species, 2 Rothia (Stomatococcus) mucilaginosus, and 4 Gemella morbillorum. Daptomycin minimum inhibitory concentration (MIC)(90) values for the viridans group streptococci, methicillin-resistant S. aureus, penicillin-resistant S. pneumoniae, and Enterococcus species were 0.5, 0.5, endocarditis as well as against several types of unusual Gram-positive bacteria that can cause endocarditis.

Distribution and activity of petroleum hydrocarbon degrading bacteria in the North Sea and Baltic Sea

International Nuclear Information System (INIS)

Bruns, K.; Dahlmann, G.; Gunkel, W.

1993-01-01

Data were collected in 1988 and 1989 on the distribution and activity of petroleum hydrocarbon degrading bacteria in the North Sea and Baltic Sea. Crude oil degrading bacteria and the number of bacteria which in particular degrade naphthalene were quantified using a modified dilution method (MPN). Crude oil degrading bacteria were present in all of about 100 water samples, with as many as 10 3 ml -1 in some samples. Numbers of naphthalene degrading bacteria were at least tenfold lower. There is obviously a greater connection between this bacteria group and petroleum hydrocarbon (PHC) contamination than between the more nonspecific group of crude oil degrading bacteria and PHC contamination. Data from the North Sea show an extremely high abundance of hydrocarbon degrading bacteria, even in winter, while in the southern Baltic Sea low numbers of bacteria were found and slower crude oil degradation was observed. (orig.)

A 3-hydroxy β-end group in xanthophylls is preferentially oxidized to a 3-oxo ε-end group in mammals[S

Science.gov (United States)

Nagao, Akihiko; Maoka, Takashi; Ono, Hiroshi; Kotake-Nara, Eiichi; Kobayashi, Miyuki; Tomita, Mie

2015-01-01

We previously found that mice fed lutein accumulated its oxidative metabolites (3′-hydroxy-ε,ε-caroten-3-one and ε,ε-carotene-3,3′-dione) as major carotenoids, suggesting that mammals can convert xanthophylls to keto-carotenoids by the oxidation of hydroxyl groups. Here we elucidated the metabolic activities of mouse liver for several xanthophylls. When lutein was incubated with liver postmitochondrial fraction in the presence of NAD+, (3′R,6′R)-3′-hydroxy-β,ε-caroten-3-one and (6RS,3′R,6′R)-3′-hydroxy-ε,ε-caroten-3-one were produced as major oxidation products. The former accumulated only at the early stage and was assumed to be an intermediate, followed by isomerization to the latter. The configuration at the C3′ and C6′ of the ε-end group in lutein was retained in the two oxidation products. These results indicate that the 3-hydroxy β-end group in lutein was preferentially oxidized to a 3-oxo ε-end group via a 3-oxo β-end group. Other xanthophylls such as β-cryptoxanthin and zeaxanthin, which have a 3-hydroxy β-end group, were also oxidized in the same manner as lutein. These keto-carotenoids, derived from dietary xanthophylls, were confirmed to be present in plasma of normal human subjects, and β,ε-caroten-3′-one was significantly increased by the ingestion of β-cryptoxanthin. Thus, humans as well as mice have oxidative activity to convert the 3-hydroxy β-end group of xanthophylls to a 3-oxo ε-end group. PMID:25502844

Use of endophytic diazotrophic bacteria as a vector to express the cry3A gene from Bacillus thuringiensis

Directory of Open Access Journals (Sweden)

Salles Joana Falcão

2000-01-01

Full Text Available The goal of this study was to evaluate the potential of endophytic diazotrophic bacteria as a vector to express a cry gene from Bacillus thuringiensis, envisaging the control of pests that attack sugarcane plants. The endophytic nitrogen-fixing bacteria Gluconacetobacter diazotrophicus strain BR11281 and Herbaspirillum seropedicae strain BR11335 were used as models. The cry3A gene was transferred by conjugation using a suicide plasmid and the recombinant strains were selected by their ability to fix nitrogen in semi-solid N-free medium. The presence of the cry gene was detected by Southern-blot using an internal fragment of 1.0 kb as a probe. The production of delta-endotoxin by the recombinant H. seropedicae strain was detected by dot blot while for G. diazotrophicus the Western-blot technique was used. In both cases, a specific antibody raised against the B. thuringiensis toxin was applied. The delta-endotoxin production showed by the G. diazotrophicus recombinant strain was dependent on the nitrogen fixing conditions since the cry3A gene was fused to a nif promoter. In the case of H. seropedicae the delta-endotoxin expression was not affected by the promoter (rhi used. These results suggest that endophytic diazotrophic bacteria can be used as vectors to express entomopathogenic genes envisaging control of sugarcane pests.

[Which are the most frequently occurring enteropathogenic bacteria in clinical practice?].

Science.gov (United States)

Rohrbach, M; Gualzata, M D; Hollfelder, R; Viollier, A F; Viollier, M; Viollier, E H

1988-12-10

Diarrhea is an increasingly frequent clinical finding in Swiss medical practice. One reason is the volume of tourism in countries with different climatic and social circumstances. To obtain an overview of the enteropathogenic bacteria spectrum as a cause of diarrhea, we analyzed 11,163 stool specimens from a representative group of patients throughout Switzerland. Enteropathogenic bacteria were found in 15.2% of all specimens; 50% were Campylobacter jejuni/coli, 35% Salmonella spp., 8% Aeromonas hydrophila group, 4% Shigella spp. and 3% Yersinia enterocolitica. This distribution is taken for all age groups and for both sexes. In the infant age there was a maximum evidence of enteropathogenic bacteria of the female sex. In childhood this maximum concerned to the male sex. Patients older than fifty had no positive stool specimens. As expected the most frequent positive stool specimens were in summer.

Genomics of Probiotic Bacteria

Science.gov (United States)

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

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

MINERALIZATION OF THE HERBICIDE 2,3,6-TRICHLOROBENZOIC ACID BY A COCULTURE OF ANAEROBIC AND AEROBIC-BACTERIA

NARCIS (Netherlands)

GERRITSE, J; GOTTSCHAL, JC

1992-01-01

Bacteria from an anaerobic enrichment reductively removed chlorine from the ortho- position of 2,3,6-trichlorobenzoic acid (2,3,6-TBA) producing 2,5-dichlorobenzoate (2,5-DBA). The strictly aerobic bacterium Pseudomonas aeruginosa JB2 subsequently used 2,5-DBA as a growth substrate in the presence

Antagonistic activity of isolated lactic acid bacteria from Pliek U against gram-negative bacteria Escherichia coli ATCC 25922

Science.gov (United States)

Kiti, A. A.; Jamilah, I.; Rusmarilin, H.

2017-09-01

Lactic acid bacteria (LAB) is one group of microbes that has many benefits, notably in food and health industries sector. LAB plays an important role in food fermentation and it has bacteriostatic effect against the growth of pathogenic microorganisms. The research related LAB continued to be done to increase the diversity of potential isolates derived from nature which is indigenous bacteria for biotechnological purposes. This study was aimed to isolate and characterize LAB derived from pliek u sample and to examine the potency to inhibits Escherichia coli ATCC 25922 bacteria growth. A total of 5 isolates were isolated and based on morphological and physiological characteristics of the fifth bacteria, they are allegedly belonging to the genus Bacillus. Result of antagonistic test showed that the five isolates could inhibits the growth of E. coli ATCC 25922. The highest inhibition zone is 8.5 mm was shown by isolates NQ2, while the lowest inhibition is 1.5 mm was shown by isolates NQ3.

On-chip concentration of bacteria using a 3D dielectrophoretic chip and subsequent laser-based DNA extraction in the same chip

International Nuclear Information System (INIS)

Cho, Yoon-Kyoung; Kim, Tae-hyeong; Lee, Jeong-Gun

2010-01-01

We report the on-chip concentration of bacteria using a dielectrophoretic (DEP) chip with 3D electrodes and subsequent laser-based DNA extraction in the same chip. The DEP chip has a set of interdigitated Au post electrodes with 50 µm height to generate a network of non-uniform electric fields for the efficient trapping by DEP. The metal post array was fabricated by photolithography and subsequent Ni and Au electroplating. Three model bacteria samples (Escherichia coli, Staphylococcus epidermidis, Streptococcus mutans) were tested and over 80-fold concentrations were achieved within 2 min. Subsequently, on-chip DNA extraction from the concentrated bacteria in the 3D DEP chip was performed by laser irradiation using the laser-irradiated magnetic bead system (LIMBS) in the same chip. The extracted DNA was analyzed with silicon chip-based real-time polymerase chain reaction (PCR). The total process of on-chip bacteria concentration and the subsequent DNA extraction can be completed within 10 min including the manual operation time.

Screening, Isolation and Identification of Lactic Acid Bacteria From a Traditional Dairy Product of Sabzevar, Iran

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Sara Rashid

2014-11-01

Full Text Available Background: Lactic acid bacteria (LAB are a major group of probiotics. Isolation of these bacteria is difficult, because they have a complex ecosystem in fermented dairy products. Objectives: The aim of this study was to detect Lactobacillus and Lactococcus in a conventional dairy product (Khameh and study their probiotic characteristics. Materials and Methods: To isolateLAB, samples were collected from four different villages. Afterwards, screening was performed in pH = 2.5. The selected strains were examined for their tolerance to acidic pH (3 and 0.3% bile salt. Moreover, the antimicrobial activity of the isolated strains against two pathogenic bacteria, Salmonella typhimurium and Staphylococcus aureus, was assessed using the disc plate method. Finally, the selected strains were identified by polymerase chain reaction (PCR screening and sequencing. Results: Among the isolated samples, two strains (Lactobacillus and Lactococcus were highly resistant to unfavorable conditions and the L1 strain showed the highest antimicrobial activity. Conclusions: This study showed that the conventional dairy product (Khameh contained probiotic bacteria, which are capable of fighting against pathogenic bacteria and living in the digestive tract.

Fourier transform-infrared spectroscopic methods for microbial ecology: analysis of bacteria, bacteria-polymer mixtures and biofilms

Science.gov (United States)

Nichols, P. D.; Henson, J. M.; Guckert, J. B.; Nivens, D. E.; White, D. C.

1985-01-01

Fourier transform-infrared (FT-IR) spectroscopy has been used to rapidly and nondestructively analyze bacteria, bacteria-polymer mixtures, digester samples and microbial biofilms. Diffuse reflectance FT-IR (DRIFT) analysis of freeze-dried, powdered samples offered a means of obtaining structural information. The bacteria examined were divided into two groups. The first group was characterized by a dominant amide I band and the second group of organisms displayed an additional strong carbonyl stretch at approximately 1740 cm-1. The differences illustrated by the subtraction spectra obtained for microbes of the two groups suggest that FT-IR spectroscopy can be utilized to recognize differences in microbial community structure. Calculation of specific band ratios has enabled the composition of bacteria and extracellular or intracellular storage product polymer mixtures to be determined for bacteria-gum arabic (amide I/carbohydrate C-O approximately 1150 cm-1) and bacteria-poly-beta-hydroxybutyrate (amide I/carbonyl approximately 1740 cm-1). The key band ratios correlate with the compositions of the material and provide useful information for the application of FT-IR spectroscopy to environmental biofilm samples and for distinguishing bacteria grown under differing nutrient conditions. DRIFT spectra have been obtained for biofilms produced by Vibrio natriegens on stainless steel disks. Between 48 and 144 h, an increase in bands at approximately 1440 and 1090 cm-1 was seen in FT-IR spectra of the V. natriegens biofilm. DRIFT spectra of mixed culture effluents of anaerobic digesters show differences induced by shifts in input feedstocks. The use of flow-through attenuated total reflectance has permitted in situ real-time changes in biofilm formation to be monitored and provides a powerful tool for understanding the interactions within adherent microbial consortia.

Clinical trial: the effects of a fermented milk containing three probiotic bacteria in patients with irritable bowel syndrome - a randomized, double-blind, controlled study.

Science.gov (United States)

Simrén, M; Ohman, L; Olsson, J; Svensson, U; Ohlson, K; Posserud, I; Strid, H

2010-01-15

The effects of probiotic bacteria in IBS remain controversial. To study the effects of a probiotic product on IBS symptoms. We randomized 74 IBS patients to receive 8 weeks of daily treatment with 400 mL milk fermented with the yoghurt bacteria and containing Lactobacillus paracasei, ssp. paracasei F19, Lactobacillus acidophilus La5 and Bifidobacterium lactis Bb12 (Cultura; active) or acidified milk without these bacteria (control). The primary endpoint was the proportion of subjects reporting adequate relief of their IBS symptoms at least 50% of the weeks. IBS symptom severity, psychological symptoms and quality of life were assessed. The proportion of responders was 38% (14/37 patients) in the active group and 27% (10/37 patients) in the control group (P = 0.3). IBS symptom severity improved significantly in both groups during the treatment period. This change was greater in the active group during the first 2 weeks, but thereafter, no significant group differences were seen. We could not detect a clearly positive effect of fermented milk containing three probiotic bacteria on GI symptoms in IBS patients compared with the control treatment. However, a trend towards a more favourable effect during the first weeks was seen in the active group.

Increased number of anaerobic bacteria in the infected root canal in type 2 diabetic rats.

Science.gov (United States)

Iwama, Akihiro; Morimoto, Taisuke; Tsuji, Masahito; Nakamura, Koki; Higuchi, Naoya; Imaizumi, Ichiro; Shibata, Naoki; Yamasaki, Masahiro; Nakamura, Hiroshi

2006-05-01

The purpose of this study was to investigate the relationship between type 2 diabetes mellitus and anaerobic bacteria detected in infected root canals. Normal Wistar rats (control) received a standard laboratory diet with water (group A), and GK rats (type 2 diabetes mellitus rats) a normal laboratory diet with water (group B) or a 30% sucrose solution (group C). Chemotaxis assay was conducted on polymorphonuclear leukocytes from the 3 groups, and the numbers of anaerobic bacteria in infected root canals were determined. In the chemotaxis assay on the polymorphonuclear leukocytes, the chemotactic response of cells in group C was lower than that for groups A and B (P obligate anaerobic bacteria which stained gram negative, were significantly more numerous in group C (P < .01) than in groups A and B. The metabolic condition produced by type 2 diabetes mellitus in rats might lower the general host resistance against bacterial infection.

A portable 3D printer system for the diagnosis and treatment of multidrug-resistant bacteria

OpenAIRE

Glatzel, Stefan; Hezwani, Mohammed; Kitson, Philip J.; Gromski, Piotr S.; Schürer, Sophie; Cronin, Leroy

2016-01-01

Summary: Multidrug-resistant bacteria are a major threat to human health, but broad-spectrum\\ud antibiotics are losing efficacy. There is a need to screen a given drug against\\ud a bacterial infection outside of the laboratory. To address this need, we have designed\\ud and built an inexpensive and easy-to-use 3D-printer-based system that\\ud allows easily readable quantitative tests for the performance of antibacterial\\ud drugs. The platform creates a sterile diagnostic device by using 3D prin...

Isolation, Identification, Prevalence, and Genetic Diversity of Bacillus cereus Group Bacteria From Different Foodstuffs in Tunisia

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Maroua Gdoura-Ben Amor

2018-03-01

Full Text Available Bacillus cereus group is widespread in nature and foods. Several members of this group are recognized as causing food spoilage and/or health issues. This study was designed to determine the prevalence and genetic diversity of the B. cereus group strains isolated in Tunisia from different foods (cereals, spices, cooked food, fresh-cut vegetables, raw and cooked poultry meats, seafood, canned, pastry, and dairy products. In total, 687 different samples were collected and searched for the presence of the B. cereus group after selective plating on MYP agar and enumeration of each sample. The typical pink-orange uniform colonies surrounded by a zone of precipitate were assumed to belong to the B. cereus group. One typical colony from each sample was subcultured and preserved as cryoculture. Overall, 191 (27.8% food samples were found positive, giving rise to a collection of 191 B. cereus-like isolates. The concentration of B. cereus-like bacteria were below 103 cfu/g or ml in 77.5% of the tested samples. Higher counts (>104 cfu/g or ml were found in 6.8% of samples including fresh-cut vegetables, cooked foods, cereals, and pastry products. To verify whether B. cereus-like isolates belonged to the B. cereus group, a PCR test targeting the sspE gene sequence specific of the group was carried out. Therefore, 174 isolates were found to be positive. Food samples were contaminated as follows: cereals (67.6%, pastry products (46.2%, cooked food (40.8%, cooked poultry meat (32.7%, seafood products (32.3%, spices (28.8%, canned products (16.7%, raw poultry meat (9.4%, fresh-cut vegetables (5.0%, and dairy products (4.8%. The 174 B. cereus isolates were characterized by partial sequencing of the panC gene, using a Sym'Previous software tool to assign them to different phylogenetic groups. Strains were distributed as follows: 61.3, 29.5, 7.5, and 1.7% in the group III, IV, II, and V, respectively. The genetic diversity was further assessed by ERIC-PCR and PFGE

Reducing gas content of coal deposits by means of bacteria

Energy Technology Data Exchange (ETDEWEB)

Godlewska-Lipowa, A A; Kozlowski, B

1981-07-01

This paper discusses the results of experiments carried out in Poland under laboratory conditions on efficiency of methane control using bacteria from Methanosarcina and Methanomonas groups. Malashenko and Whittenburry culture mediums were used. Bacteria growth in an atmosphere of air and methane (48.2%, 8.6% and 5.21%) was observed. Temperature ranged from 19 to 20 C. Investigations show that the bacteria are characterized by high oxidation activity. Depending on methane concentration in the air the bacteria consume from 75% to 100% of methane during biosynthesis. The bacteria reduce methane and oxygen content and increase carbon dioxide content in the air. Using bacteria methane concentration in the air was reduced from 48.2% to 12.3%, from 8.6% to 0.0% and from 5.21% to 0.01%. (7 refs.) (In Polish)

Molecular identification of bacteria associated with canine periodontal disease.

Science.gov (United States)

Riggio, Marcello P; Lennon, Alan; Taylor, David J; Bennett, David

2011-06-02

Periodontal disease is one of the most common diseases of adult dogs, with up to 80% of animals affected. The aetiology of the disease is poorly studied, although bacteria are known to play a major role. The purpose of this study was to identify the bacteria associated with canine gingivitis and periodontitis and to compare this with the normal oral flora. Swabs were obtained from the gingival margin of three dogs with gingivitis and three orally healthy controls, and subgingival plaque was collected from three dogs with periodontitis. Samples were subjected to routine bacterial culture. The prevalent species identified in the normal, gingivitis and periodontitis groups were uncultured bacterium (12.5% of isolates), Bacteroides heparinolyticus/Pasteurella dagmatis (10.0%) and Actinomyces canis (19.4%), respectively. Bacteria were also identified using culture-independent methods (16S rRNA gene sequencing) and the predominant species identified were Pseudomonas sp. (30.9% of clones analysed), Porphyromonas cangingivalis (16.1%) and Desulfomicrobium orale (12.0%) in the normal, gingivitis and periodontitis groups, respectively. Uncultured species accounted for 13.2%, 2.0% and 10.5%, and potentially novel species for 38.2%, 38.3% and 35.3%, of clones in the normal, gingivitis and periodontitis groups, respectively. This is the first study to use utilise culture-independent methods for the identification of bacteria associated with this disease. It is concluded that the canine oral flora in health and disease is highly diverse and also contains a high proportion of uncultured and, in particular, potentially novel species. Copyright © 2011 Elsevier B.V. All rights reserved.

Bacteria Culture Test: MedlinePlus Lab Test Information

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... this page: https://medlineplus.gov/labtests/bacteriaculturetest.html Bacteria Culture Test To use the sharing features on this page, please enable JavaScript. What is a Bacteria Culture Test? Bacteria are a large group of ...

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

OpenAIRE

Nabakishore Nayak; Rajesh K. Lenka; Rabindra N. Padhy

2014-01-01

Objective: To examine antibiograms of a cohort of suppurative bacteria isolated from wound-swabs from hospitalized patients of all economic groups of a typical Indian teaching hospital. Methods: In surveillance, antibiotic resistance patterns of 10 species of suppurative bacteria isolated from wound-swabs over a period of 24 months were recorded. Those were subjected to antibiotic sensitivity test, using 16 prescribed antibiotics of 5 different groups (3 aminoglycosides, 4 beta-lactams, 3 ...

Biochanin A improves fiber fermentation by cellulolytic bacteria

Science.gov (United States)

The objective was to determine the effect of the isoflavone biochanin A (BCA) on rumen cellulolytic bacteria and consequent fermentative activity. When bovine microbial rumen cell suspensions (n = 3) were incubated (24 h, 39 °C) with ground hay, cellulolytic bacteria proliferated, short chain fatty...

The prevalence of periodontopathogenic bacteria in saliva is linked to periodontal health status and oral malodour.

Science.gov (United States)

Kurata, Hiroshi; Awano, Shuji; Yoshida, Akihiro; Ansai, Toshihiro; Takehara, Tadamichi

2008-05-01

This study investigated whether an improvement in periodontal health resulted in changes in the prevalence of periodontopathogenic bacteria in saliva and tongue coatings and a reduction in volatile sulfur compounds (VSCs: H(2)S and CH(3)SH) linked to oral malodour. The subjects were 35 patients who visited the breath odour clinic of Kyushu Dental College, Japan. Their mean age was 51.2+/-18.3 years (mean+/-sd). A clinical examination performed at baseline and 2 months after periodontal treatment assessed VSCs in mouth air using gas chromatography, periodontal probing depth and bleeding on probing (BOP) in all subjects; saliva and tongue coatings were also collected. Genomic DNA was isolated from the samples, and the proportions of five periodontopathogenic bacteria (Porphyromonas gingivalis, Tannerella forsythensis, Treponema denticola, Prevotella intermedia and Prevotella nigrescens) were investigated using quantitative real-time PCR. The subjects were classified into four groups based on the presence of a periodontal pocket of more than 4 mm (PD) and VSCs above the organoleptic threshold level (VSCT) as follows: -PD/-VSCT group, subjects without PD or VSCT; -PD/+VSCT group, those without PD but with VSCT; +PD/-VSCT group, those with PD but without VSCT; and +PD/+VSCT group, those with PD and VSCT. Although the mean PD values in the +PD/-VSCT and +PD/+VSCT groups, BOP in the +PD/+VSCT group, and H(2)S and CH(3)SH concentrations in the -PD/+VSCT and +PD/+VSCT groups were greater than in the other groups at baseline, we found no significant difference among the four groups after periodontal treatment. The proportion of periodontopathogenic bacteria in saliva was higher in the +PD/-VSCT and +PD/+VSCT groups than in the -PD/-VSCT and -PD/+VSCT groups at baseline and after treatment, but the proportions of bacteria in saliva after treatment were reduced compared to the baseline. Furthermore, the differences in the proportions of the five target bacteria in the tongue

The determination and arrangement of a combination of enzyme lactate dehydrogenase of bacteria Acinetobacter sp. as a device the identity important bacteria agent composts

Science.gov (United States)

Sukmawati, D.; Puspitaningrum, R.; Muzajjanah

2017-07-01

The number of garbage generated by the industry or society is a usual problem encountered by almost all urban centers, especially large cities such as Jakarta. Waste prevention strategy required quickly and accurately. One strategy for tackling the Junk was getting lactic acid-producing bacteria. It has been shown that lactic acid can increase the acceleration of organic matter such as an overhaul of lignin and cellulose as well as out causing toxic compounds arising from decay. This research will be conducted on the determination and characterization of the enzyme-producing compost bacteria LDH lactate dehydrogenase LDH - which in isolation from the garbage Landfill Rawasari. Methodology: Research carried out consists: isolation of lactic acid-producing bacteria; identification of microscopic, macroscopic and staining Gram; cellulose assay, and optimization of PCR conditions LDH enzymes producing bacteria. Isolation is performed by dilution method and the direct method. As many as 5-point sampling. Each stage is conducted from 10 grams of soil from the top surface of the compost. Isolation results obtained 100 isolate the bacteria. Base on the characteristic of macroscopic and microscopic observations retrieved 14 isolates of bacteria have shaped rods and brought forth a negative kind of Gram positive staining. Bacterial isolates with codes (BK1; BK3; BK4; BK5; BK6; BK7; BK8; BK9; BK10; BK11: BK12; BK 13). The potential bacteria with ability produce lactate dehydrogenase was BK1 and BK3. Base for analysis phylogenetic there was identification bacteria bak1 and bak3 where Acinetobacter sp.

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

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Richardson Anthony J

2013-01-01

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

Antibiotics from predatory bacteria

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Juliane Korp

2016-03-01

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

Increased production of outer membrane vesicles by cultured freshwater bacteria in response to ultraviolet radiation.

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Gamalier, Juliana P; Silva, Thiago P; Zarantonello, Victor; Dias, Felipe F; Melo, Rossana C N

2017-01-01

Secretion of membrane vesicles is an important biological process of both eukaryotic and prokaryotic cells. This process has been characterized in pathogenic bacteria, but is less clear in non-pathogenic bacteria from aquatic ecosystems. Here, we investigated, for the first time, the process of formation of outer membranes vesicles (OMVs), nanoscale vesicles extruded from the outer membrane (OM) of gram-negative bacteria, in cultures of freshwater bacteria after exposure or not to ultraviolet radiation (UVR) as an environmental stressor. Non-axenic cultures of freshwater bacteria isolated from a Brazilian aquatic ecosystem (Funil reservoir) were exposed or not to UVR (UVA+UVB) over a 3h period, during which cell density, viability and ultrastructure were analyzed. First, we showed that UVR induce bacterial death. UVR triggered significant negative effect on cell density after 3h of UVR treatment. This decrease was directly associated with cell death as revealed by a cell viability fluorescent probe that enables the distinction of live/dead bacteria. Transmission electron microscopy (TEM) revealed changes indicative of cell death after 3h of UVR exposure, with significant increase of damaged cells compared to the control group. Second, we demonstrated that gram-negative bacteria release OMVs during normal growth and after UVR exposure. OMVs were clearly identified as round, membrane-bound vesicles budding off from the bacterial OM as isolated or clustered vesicles or free in the extracellular medium. Remarkably, quantitative TEM analyses showed that bacteria respond to UVR with increased formation of OMVs. Moreover, while OMVs numbers per intact or damaged cell did not differ in the untreated group, UVR led to a higher vesiculation by bacteria in process of death. This means that degenerating bacteria release OMVs before lysis and that this secretion might be an adaptive/protective response to rapid changes in environmental conditions such as UV radiation. Copyright

Soil microbial activity, mycelial lengths and physiological groups of bacteria in a heavy metal polluted area

Energy Technology Data Exchange (ETDEWEB)

Nordgren, A; Kauri, T; Baeaeth, E; Soederstroem, B

1986-01-01

The biological effects of heavy metal contamination of coniferous forest soils were studied in the A/sub 01//A/sub 02/ layer around a primary smelter in Northern Sweden. Soil concentrations of 17 elements were determined. Smelter-emitted heavy metals were 5 to 75 times higher in the plot closest to the smelter compared with background levels. Despite emission of sulfur no decrease in pH was found. Bacteria producing acid from maltose, cellobiose, arabinose or xylose and bacteria hydrolyzing starch, pectin, xyland or cellulose decreased 8- to 11-fold due to the soil contamination. Chitin hydrolyzers were 5 times less abundant at the most polluted site compared with background levels. Soil respiration rate and urease activity decreased by about a factor of 4, but phosphatase activity and mycelial lengths were unaffected by the soil contamination. Soil bacteria showed a sigmoidal response to the log of metal concentration in the soil and were affected at a lower pollution level than the other biological variables in the study. A multivariate analysis (partial least squares) showed that soil metal contamination and soil pH were the two environmental factors influencing the soil microorganisms.

Cellulase Production by Bacteria: A Review

OpenAIRE

Sadhu Sangrila; Maiti Tushar Kanti

2013-01-01

Cellulose is an abundant natural biopolymer on earth and most dominating Agricultural waste. This cellulosic biomass is a renewable and abundant resource with great potential for bioconversion to value-added bioproducts. It can be degraded by cellulase produced by cellulolytic bacteria. This enzyme has various industrial applications and now considered as major group of industrial enzyme. The review discusses application of cellulase, classification of cellulase, quantification...

Quantification and characterization of putative diazotrophic bacteria from forage palm under saline water irrigation

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Gabiane dos Reis Antunes

2017-09-01

Full Text Available The aim of this study was to evaluate the density and phenotypical diversity of diazotrophic endophytic bacteria from the forage palm irrigated with different saline water depths. Opuntia stricta (IPA-200016 received five depths of saline water (L1: 80%. ETo; L2: 60%.ETo; L3: 40%; ETo; L4: 20%; ETo and, L5: 0% ETo, where ETo is the reference evapotranspiration. The roots were collected in the field, disinfected, grounded and serial diluted from 10-1 to 10-4. The total concentration of diazotrophic bacteria was determined by the most probable number method (MPN and the isolated bacteria were characterized phenotipically. The concentration of bacteria found in forage palm roots ranged from 0.36 x 104 to 109.89 104 cells per gram of root, with highest occurrence on the 60 and 80% ETo. In the dendrogram of similarity it was possible to observe the formation of 24 phenotypic groups with 100% similarity. All bacteria presented similarity superior to 40%. Among these groups, 14 are rare groups, formed by only a single bacterial isolate. In the Semi-Arid conditions, the forage palm that receives the highest amount of saline water, presents a higher density of putative nitrogen-fixing endophytic bacteria with high phenotypic diversity.

[Unique properties of highly radioresistant bacteria].

Science.gov (United States)

Romanovskaia, V A; Rokitko, P V; Malashenko, Iu R

2000-01-01

In connection with the Chernobyl Nuclear Power Plant (ChNPP) accident and the negative ecological after-effects for biota in this zone the interest has arisen to radioresistant bacteria, as to the most dynamic model of the given ecosystem, and to mechanisms which provide resistance of bacteria to ionizing radiation. The analysis of published data has shown that the radioresistant bacteria are not interrelated taxonomically and phylogenetically. The extreme radioresistant bacteria are represented by the Deinococcus species, which form a group phylogenetically close to the line Thermus-Meiothermus. Other radioresistant bacteria are the representatives of the genera Rubrobacter, Methylobacterium, Kocuria, Bacillus and some archebacteria. Data on natural habitats, of radioresistant bacteria are not numerous. In a number of cases it is difficult to distinguish their natural habitats, as they were isolated from the samples which were previously exposed to X-ray or gamma-irradiation, or from the ecosystems with the naturally raised radioactivity. To understand the strategy of survival of radioresistant bacteria, we briefly reviewed the mechanism of action of various species of radiation on cells and macromolecules; physiological signs of the cell damage caused by radiation; mechanisms eliminating (repairing) these damages. More details on mechanisms of the DNA repair in D. radiodurans are described. The extreme resistance of D. radiodurans to the DNA damaging factors is defined by 1) repair mechanisms which fundamentally differ from those in other procaryotes; 2) ability to increase the efficiency of a standard set of the DNA repairing proteins. Literary and own data on the effect of radiation on survival of various groups of bacteria in natural ecosystems are summarized. The ecological consequences of the ChNPP accident for soil bacteria in this region were estimated. The reduction of the number of soil bacteria and recession of microbial diversity under the effect of

A preliminary study on the pathogenicity of Bacillus licheniformis bacteria in immunodepressed mice

DEFF Research Database (Denmark)

Agerholm, J.S.; Jensen, N.E.; Giese, Steen Bjørck

1997-01-01

The pathogenicity of 13 strains of Bacillus licheniformis was studied in immunodepressed mice. The strains had been isolated from cases of bovine abortions (n=5), bovine feedstuffs (n=3), soil (n=l), and grain products (n=2). The origin of two strains was unknown. Groups of 10 mice were inoculated...... intravenously with B. licheniformis bacteria at doses from...

Distinction of Gram-positive and -negative bacteria using a colorimetric microbial viability assay based on the reduction of water-soluble tetrazolium salts with a selection medium.

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Tsukatani, Tadayuki; Suenaga, Hikaru; Higuchi, Tomoko; Shiga, Masanobu; Noguchi, Katsuya; Matsumoto, Kiyoshi

2011-01-01

Bacteria are fundamentally divided into two groups: Gram-positive and Gram-negative. Although the Gram stain and other techniques can be used to differentiate these groups, some issues exist with traditional approaches. In this study, we developed a method for differentiating Gram-positive and -negative bacteria using a colorimetric microbial viability assay based on the reduction of the tetrazolium salt {2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium, monosodium salt} (WST-8) via 2-methyl-1,4-napthoquinone with a selection medium. We optimized the composition of the selection medium to allow the growth of Gram-negative bacteria while inhibiting the growth of Gram-positive bacteria. When the colorimetric viability assay was carried out in a selection medium containing 0.5µg/ml crystal violet, 5.0 µg/ml daptomycin, and 5.0µg/ml vancomycin, the reduction in WST-8 by Gram-positive bacteria was inhibited. On the other hand, Gram-negative bacteria produced WST-8-formazan in the selection medium. The proposed method was also applied to determine the Gram staining characteristics of bacteria isolated from various foodstuffs. There was good agreement between the results obtained using the present method and those obtained using a conventional staining method. These results suggest that the WST-8 colorimetric assay with selection medium is a useful technique for accurately differentiating Gram-positive and -negative bacteria.

More, smaller bacteria in response to ocean's warming?

KAUST Repository

Moran, Xose Anxelu G.

2015-06-10

Heterotrophic bacteria play a major role in organic matter cycling in the ocean. Although the high abundances and relatively fast growth rates of coastal surface bacterioplankton make them suitable sentinels of global change, past analyses have largely overlooked this functional group. Here, time series analysis of a decade of monthly observations in temperate Atlantic coastal waters revealed strong seasonal patterns in the abundance, size and biomass of the ubiquitous flow-cytometric groups of low (LNA) and high nucleic acid (HNA) content bacteria. Over this relatively short period, we also found that bacterioplankton cells were significantly smaller, a trend that is consistent with the hypothesized temperature-driven decrease in body size. Although decadal cell shrinking was observed for both groups, it was only LNA cells that were strongly coherent, with ecological theories linking temperature, abundance and individual size on both the seasonal and interannual scale. We explain this finding because, relative to their HNA counterparts, marine LNA bacteria are less diverse, dominated by members of the SAR11 clade. Temperature manipulation experiments in 2012 confirmed a direct effect of warming on bacterial size. Concurrent with rising temperatures in spring, significant decadal trends of increasing standing stocks (3% per year) accompanied by decreasing mean cell size (-1% per year) suggest a major shift in community structure, with a larger contribution of LNA bacteria to total biomass. The increasing prevalence of these typically oligotrophic taxa may severely impact marine foodwebs and carbon fluxes by an overall decrease in the efficiency of the biological pump. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

Efficacy of 4 Irrigation Protocols in Killing Bacteria Colonized in Dentinal Tubules Examined by a Novel Confocal Laser Scanning Microscope Analysis.

Science.gov (United States)

Azim, Adham A; Aksel, Hacer; Zhuang, Tingting; Mashtare, Terry; Babu, Jegdish P; Huang, George T-J

2016-06-01

The aim of this study was to determine the efficiency of 4 irrigation systems in eliminating bacteria in root canals, particularly in dentinal tubules. Roots of human teeth were prepared to 25/04, autoclaved, and inoculated with Enterococcus faecalis for 3 weeks. Canals were then disinfected by (1) standard needle irrigation, (2) sonically agitating with EndoActivator, (3) XP Endo finisher, or (4) erbium:yttrium aluminum garnet laser (PIPS) (15 roots/group). The bacterial reduction in the canal was determined by MTT assays. For measuring live versus dead bacteria in the dentinal tubules (4 teeth/group), teeth were split open and stained with LIVE/DEAD BackLight. Coronal, middle, and apical thirds of the canal dentin were scanned by using a confocal laser scanning microscope (CLSM) to determine the ratio of dead/total bacteria in the dentinal tubules at various depths. All 4 irrigation protocols significantly eliminated bacteria in the canal, ranging from 89.6% to 98.2% reduction (P bacteria in the coronal, middle, and apical segments at 50-μm depth. On the other hand, PIPS had the greatest bacterial killing efficiency at the 150-μm depth in all 3 root segments. XP Endo appears to be more efficient than other 3 techniques in disinfecting the main canal space and up to 50 μm deep into the dentinal tubules. PIPS appears to be most effective in killing the bacteria deep in the dentinal tubules. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Co-existence of Anaerobic Ammonium Oxidation Bacteria and Denitrifying Anaerobic Methane Oxidation Bacteria in Sewage Sludge: Community Diversity and Seasonal Dynamics.

Science.gov (United States)

Xu, Sai; Lu, Wenjing; Mustafa, Muhammad Farooq; Caicedo, Luis Miguel; Guo, Hanwen; Fu, Xindi; Wang, Hongtao

2017-11-01

Anaerobic ammonium oxidation (ANAMMOX) and denitrifying anaerobic methane oxidation (DAMO) have been recently discovered as relevant processes in the carbon and nitrogen cycles of wastewater treatment plants. In this study, the seasonal dynamics of ANAMMOX and DAMO bacterial community structures and their abundance in sewage sludge collected from wastewater treatment plants were analysed. Results indicated that ANAMMOX and DAMO bacteria co-existed in sewage sludge in different seasons and their abundance was positively correlated (P bacteria in autumn and winter indicated that these seasons were the preferred time to favour the growth of ANAMMOX and DAMO bacteria. The community structure of ANNAMOX and DAMO bacteria could also shift with seasonal changes. The "Candidatus Brocadia" genus of ANAMMOX bacteria was mainly recovered in spring and summer, and an unknown cluster was primarily detected in autumn and winter. Similar patterns of seasonal variation in the community structure of DAMO bacteria were also observed. Group B was the dominant in spring and summer, whereas in autumn and winter, group A and group B presented almost the same proportion. The redundancy analysis revealed that pH and nitrate were the most significant factors affecting community structures of these two groups (P < 0.01). This study reported the diversity of ANAMMOX and DAMO in wastewater treatment plants that may be the basis for new nitrogen removal technologies.

Evaluation of a fluorescent lectin-based staining technique for some acidophilic mining bacteria

International Nuclear Information System (INIS)

Fife, D.J.; Bruhn, D.F.; Miller, K.S.; Stoner, D.L.

2000-01-01

A fluorescence-labeled wheat germ agglutinin staining technique was modified and found to be effective for staining gram-positive, acidophilic mining bacteria. Bacteria identified by others as being gram positive through 16S rRNA sequence analyses, yet clustering near the divergence of that group, stained weakly. Gram-negative bacteria did not stain. Background staining of environmental samples was negligible, and pyrite and soil particles in the samples did not interfere with the staining procedure

Electron microscopic examination of uncultured soil-dwelling bacteria.

Science.gov (United States)

Amako, Kazunobu; Takade, Akemi; Taniai, Hiroaki; Yoshida, Shin-ichi

2008-05-01

Bacteria living in soil collected from a rice paddy in Fukuoka, Japan, were examined by electron microscopy using a freeze-substitution fixation method. Most of the observed bacteria could be categorized, based on the structure of the cell envelope and overall morphology, into one of five groups: (i) bacterial spore; (ii) Gram-positive type; (iii) Gram-negative type; (iv) Mycobacterium like; and (v) Archaea like. However, a few of the bacteria could not be readily categorized into one of these groups because they had unique cell wall structures, basically resembling those of Gram-negative bacteria, but with the layer corresponding to the peptidoglycan layer in Gram-negative bacteria being extremely thick, like that of the cortex of a bacterial spore. The characteristic morphological features found in many of these uncultured, soil-dwelling cells were the nucleoid being in a condensed state and the cytoplasm being shrunken. We were able to produce similar morphologies in vitro using a Salmonella sp. by culturing under low-temperature, low-nutrient conditions, similar to those found in some natural environments. These unusual morphologies are therefore hypothesized to be characteristic of bacteria in resting or dormant stages.

Isolation and Partial Characterization of Bacteria in an Anaerobic Consortium That Mineralizes 3-Chlorobenzoic Acid †

OpenAIRE

Shelton, Daniel R.; Tiedje, James M.

1984-01-01

A methanogenic consortium able to use 3-chlorobenzoic acid as its sole energy and carbon source was enriched from anaerobic sewage sludge. Seven bacteria were isolated from the consortium in mono- or coculture. They included: one dechlorinating bacterium (strain DCB-1), one benzoate-oxidizing bacterium (strain BZ-2), two butyrate-oxidizing bacteria (strains SF-1 and NSF-2), two H2-consuming methanogens (Methanospirillum hungatei PM-1 and Methanobacterium sp. strain PM-2), and a sulfate-reduci...

Influence of a passive sonic irrigation system on the elimination of bacteria from root canal systems: a clinical study.

Science.gov (United States)

Huffaker, S Kirk; Safavi, Kamran; Spangberg, Larz S W; Kaufman, Blythe

2010-08-01

The present investigation evaluated the ability of a new passive sonic irrigation (sonic group) system (EndoActivator) to eliminate cultivable bacteria from root canals in vivo and compared it with that of standard syringe irrigation (control group). Data were obtained by using bacteriologic sampling of root canals treated by endodontic residents. Sampling results from 1 session of treatment were then compared with results obtained after intervisit calcium hydroxide disinfection and a second session of treatment. There was no significant difference in the ability of sonic group and control group to eliminate cultivable bacteria from root canals (P > .05). A second session and intervisit calcium hydroxide disinfection were able to eliminate cultivable bacteria from significantly more teeth than a single session of treatment (P treatment of apical periodontitis. Copyright 2010 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Behavior of variable V3 region from 16S rDNA of lactic acid bacteria in denaturing gradient gel electrophoresis.

Science.gov (United States)

Ercolini, D; Moschetti, G; Blaiotta, G; Coppola, S

2001-03-01

Separation of amplified V3 region from 16S rDNA by denaturing gradient gel electrophoresis (DGGE) was tested as a tool for differentiation of lactic acid bacteria commonly isolated from food. Variable V3 regions of 21 reference strains and 34 wild strains referred to species belonging to the genera Pediococcus, Enterococcus, Lactococcus, Lactobacillus, Leuconostoc, Weissella, and Streptococcus were analyzed. DGGE profiles obtained were species-specific for most of the cultures tested. Moreover, it was possible to group the remaining LAB reference strains according to the migration of their 16S V3 region in the denaturing gel. The results are discussed with reference to their potential in the analysis of LAB communities in food, besides shedding light on taxonomic aspects.

Rationalizing and advancing the 3-MPBA SERS sandwich assay for rapid detection of bacteria in environmental and food matrices.

Science.gov (United States)

Pearson, Brooke; Mills, Alexander; Tucker, Madeline; Gao, Siyue; McLandsborough, Lynne; He, Lili

2018-06-01

Bacterial foodborne illness continues to be a pressing issue in our food supply. Rapid detection methods are needed for perishable foods due to their short shelf lives and significant contribution to foodborne illness. Previously, a sensitive and reliable surface-enhanced Raman spectroscopy (SERS) sandwich assay based on 3-mercaptophenylboronic acid (3-MBPA) as a capturer and indicator molecule was developed for rapid bacteria detection. In this study, we explored the advantages and constraints of this assay over the conventional aerobic plate count (APC) method and further developed methods for detection in real environmental and food matrices. The SERS sandwich assay was able to detect environmental bacteria in pond water and on spinach leaves at higher levels than the APC method. In addition, the SERS assay appeared to have higher sensitivity to quantify bacteria in the stationary phase. On the other hand, the APC method was more sensitive to cell viability. Finally, a method to detect bacteria in a challenging high-sugar juice matrix was developed to enhance bacteria capture. This study advanced the SERS technique for real applications in environment and food matrices. Copyright © 2017 Elsevier Ltd. All rights reserved.

AS3MT-mediated tolerance to arsenic evolved by multiple independent horizontal gene transfers from bacteria to eukaryotes

DEFF Research Database (Denmark)

Palmgren, Michael; Engström, Karin; Hallström, Björn M.

2017-01-01

the evolutionary origin of AS3MT and assessed the ability of different genotypes to produce methylated arsenic metabolites. Phylogenetic analysis suggests that multiple, independent horizontal gene transfers between different bacteria, and from bacteria to eukaryotes, increased tolerance to environmental arsenic...

Diversity of ionizing radiation-resistant bacteria obtained from the Taklimakan Desert.

Science.gov (United States)

Yu, Li Zhi-Han; Luo, Xue-Song; Liu, Ming; Huang, Qiaoyun

2015-01-01

So far, little is known about the diversity of the radiation-resistant microbes of the hyperarid Taklimakan Desert. In this study, ionizing radiation (IR)-resistant bacteria from two sites in Xinjiang were investigated. After exposing the arid (water content of 0.8 ± 0.3%) and non-arid (water content of 21.3 ± 0.9%) sediment samples to IR of 3000 Gy using a (60)Co source, a total of 52 γ-radiation-resistant bacteria were isolated from the desert sample. The 16S rRNA genes of all isolates were sequenced. The phylogenetic tree places these isolates into five groups: Cytophaga-Flavobacterium-Bacteroides, Proteobacteria, Deinococcus-Thermus, Firmicutes, and Actinobacteria. Interestingly, this is the first report of radiation-resistant bacteria belonging to the genera Knoellia, Lysobacter, Nocardioides, Paracoccus, Pontibacter, Rufibacter and Microvirga. The 16s rRNA genes of four isolates showed low sequence similarities to those of the published species. Phenotypic analysis showed that all bacteria in this study are able to produce catalase, suggesting that these bacteria possess reactive oxygen species (ROS)-scavenging enzymes. These radiation-resistant bacteria also displayed diverse metabolic properties. Moreover, their radiation resistances were found to differ. The diversity of the radiation-resistant bacteria in the desert provides further ecological support for the hypothesis that the ionizing-radiation resistance phenotype is a consequence of the evolution of ROS-scavenging systems that protect cells against oxidative damage caused by desiccation. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Culturable Facultative Methylotrophic Bacteria from the Cactus Neobuxbaumia macrocephala Possess the Locus xoxF and Consume Methanol in the Presence of Ce3+ and Ca2.

Science.gov (United States)

Del Rocío Bustillos-Cristales, María; Corona-Gutierrez, Ivan; Castañeda-Lucio, Miguel; Águila-Zempoaltécatl, Carolina; Seynos-García, Eduardo; Hernández-Lucas, Ismael; Muñoz-Rojas, Jesús; Medina-Aparicio, Liliana; Fuentes-Ramírez, Luis Ernesto

2017-09-27

Methanol-consuming culturable bacteria were isolated from the plant surface, rhizosphere, and inside the stem of Neobuxbaumia macrocephala. All 38 isolates were facultative methylotrophic microorganisms. Their classification included the Classes Actinobacteria, Sphingobacteriia, Alpha-, Beta-, and Gammaproteobacteria. The deduced amino acid sequences of methanol dehydrogenase obtained by PCR belonging to Actinobacteria, Alpha-, Beta-, and Gammaproteobacteria showed high similarity to rare-earth element (REE)-dependent XoxF methanol dehydrogenases, particularly the group XoxF5. The sequences included Asp 301 , the REE-coordinating amino acid, present in all known XoxF dehydrogenases and absent in MxaF methanol dehydrogenases. The quantity of the isolates showed positive hybridization with a xoxF probe, but not with a mxaF probe. Isolates of all taxonomic groups showed methylotrophic growth in the presence of Ce 3+ or Ca 2+ . The presence of xoxF-like sequences in methylotrophic bacteria from N. macrocephala and its potential relationship with their adaptability to xerophytic plants are discussed.

Putative periodontopathic bacteria and herpesviruses in pregnant women: a case-control study.

Science.gov (United States)

Lu, Haixia; Zhu, Ce; Li, Fei; Xu, Wei; Tao, Danying; Feng, Xiping

2016-06-15

Little is known about herpesvirus and putative periodontopathic bacteria in maternal chronic periodontitis. The present case-control study aimed to explore the potential relationship between putative periodontopathic bacteria and herpesviruses in maternal chronic periodontitis.Saliva samples were collected from 36 pregnant women with chronic periodontitis (cases) and 36 pregnant women with healthy periodontal status (controls). Six putative periodontopathic bacteria (Porphyromonas gingivalis [Pg], Aggregatibacer actinomycetemcomitans [Aa], Fusobacterium nucleatum [Fn], Prevotella intermedia [Pi], Tannerella forsythia [Tf], and Treponema denticola [Td]) and three herpesviruses (Epstein-Barr virus [EBV], human cytomegalovirus [HCMV], and herpes simplex virus [HSV]) were detected. Socio-demographic data and oral health related behaviors, and salivary estradiol and progesterone levels were also collected. The results showed no significant differences in socio-demographic background, oral health related behaviors, and salivary estradiol and progesterone levels between the two groups (all P > 0.05). The detection rates of included periodontopathic microorganisms were not significantly different between the two groups (all P > 0.05), but the coinfection rate of EBV and Pg was significantly higher in the case group than in the control group (P = 0.028). EBV and Pg coinfection may promote the development of chronic periodontitis among pregnant women.

MAGNETIC BACTERIA AND THEIR POTENTIAL APPLICATIONS: A REVIEW ARTICLE

Directory of Open Access Journals (Sweden)

Sara Rajab Eljmeli

2017-03-01

Full Text Available Introduction: This outline explores the scientific discovery concerning the magnetotactic bacteria (MTB. The results of the discovery are used in microbiology, mineralogy, limnology, physics, biophysics, chemistry, biochemistry, geology, crystallography, and astrobiology. Magnetosomes of the MTB are organized in linear chains and orient the cell body along geomagnetic field lines while flagella actively propel the cells, resulting in so-called magnetotaxis. Materials and Methods: The review article about the magnetotactic bacteria is a collection of many research papers from different institutes. The emerging important points about this review lie in: (1 any biological system is capable of producing magnetic biomaterials such as magnetite (Fe3O4 and gregite (Fe3S4; (2 the navigation of these nano-crystals in the biological system is interconnected with the Earth’s magnetic field. Results: The researchers involved in the study have shown that the magnetotactic bacteria do respond to a magnetic field. This makes them attractive for biomedical and industrial applications because of the availability of superior electromagnets, superconducting magnets and permanent magnet. Magnetic bacteria can also be used as a diagnostic tool in the detection of imperfections even at the nanoscale. Discussion and Conclusions: Although the importance of this issue is still limitedly used in medical area, more performance is necessary to explore the world of these bacteria that are candidate for new industry and new therapy strategies in biotechnology and medical fields.

Effect of ultrasonic activation on the reduction of bacteria and endotoxins in root canals: a randomized clinical trial.

Science.gov (United States)

Nakamura, V C; Pinheiro, E T; Prado, L C; Silveira, A C; Carvalho, A P L; Mayer, M P A; Gavini, G

2018-01-01

This randomized clinical trial aimed to compare the effectiveness of ultrasonic activation with that of nonactivated irrigation on the removal of bacteria and endotoxin from root canals. Fifty patients with necrotic pulps and asymptomatic apical periodontitis were randomly allocated into two groups according to the final irrigation protocol after root canal preparation: Group UI - ultrasonic irrigation (n = 25) and Group NI - needle irrigation (n = 25). The root canals were medicated with calcium hydroxide for 14 days. Microbiological sampling was performed before (S1) and after the root canal preparation (S2), after the irrigation protocols (S3) and after the removal of the intracanal medication (S4). Total bacteria counts were determined by qPCR and the endotoxin levels by the limulus amebocyte lysate assay. Intragroup analyses were performed using the Wilcoxon test for related samples, whereas intergroup analyses were performed using the Mann-Whitney U-test (P  0.05). Ultrasonic activation was more effective than nonactivated irrigation for reducing the number of bacteria but not the endotoxin levels in root canals of teeth with apical periodontitis. © 2017 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Trends of 9,416 multidrug-resistant Gram-negative bacteria

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Viviane Decicera Colombo Oliveira

2015-06-01

Full Text Available Summary Objective: a resistance of hospital-acquired bacteria to multiple antibiotics is a major concern worldwide. The objective of this study was to investigate multidrugresistant (MDR bacteria, clinical specimens, origin of specimen and trends, and correlate these with bacterial sensitivity and consumption of antimicrobials. Methods: 9,416 bacteria of nosocomial origin were evaluated in a tertiary hospital, from 1999 to 2008. MDR was defined for Gram-negative bacteria (GNB as resistance to two or more classes/groups of antibiotics. Results: GNB MDR increased by 3.7 times over the study period (p<0.001. Acinetobacter baumannii was the most prevalent (36.2%. Over the study period, there were significant 4.8-fold and 14.6-fold increases for A. baumannii and K. pneumoniae (p<0.001, respectively. Sixty-seven percent of isolates of MDR GNB were isolated in intensive care units. The resistance of A. baumannii to carbapenems increased from 7.4 to 57.5% during the study period and concomitant with an increased consumption. Conclusion: that decade showed prevalence of GNB and a gradual increase in MDR GNB. There was an increase in carbapenem resistance of 50.1% during the study.

Cadmium resistance of endophytic bacteria and rizosféricas bacteria isolated from Oriza sativa in Colombia

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Nataly Ayubb T

2017-12-01

Full Text Available The present study had as objective to evaluate in vitro the resistance of endophytic bacteria and rizospheric bacteria to different concentrations of Cadmium.This bacteria were isolated fron different tissues of commercial rice varieties and from bacteria isolated from the rhizosphere in rice plantations of the Nechí (Antioquía and Achí (Bolivar.  Plant growth promotion was evaluated in vitro by nitrogen fixation, phosphate solubilization and siderophores production of endophytic bacteria. Of each tissue isolated from rice plants was carried out isolation in culture medium for endophytic bacteria, and the soil samples were serially diluted in peptone water. Each sample was determined the population density by counting in CFU / g of tissue and morphotypes were separated by shape, color, size and appearance in culture media. Significant differences were observed for density population of bacteria with respect to tissue, with higher values in root (4x1011 g/root, followed of the stem (3x1010g/etem, leaf (5x109 g/ leaf, flag leaf (3x109 g/ flag leaf and with less density in panicle (4x108 g/panicle. The results of the identification with kit API were confirmed the presence of endophytic bacteria Burkholderia cepaceae and rizospheric bacteria Pseudomona fluorescens With the ability to tolerate different concentrations of Cd, fix nitrogen, solubilize phosphates and produce siderophores.

Exposure to biohazards in wood dust: bacteria, fungi, endotoxins, and (1-->3)-beta-D-glucans.

Science.gov (United States)

Alwis, K U; Mandryk, J; Hocking, A D

1999-09-01

Personal exposure to fungi, bacteria, endotoxin, and (1-->3)-beta-D-glucan was determined at different woodworking sites--logging sites, sawmills, woodchipping sites, and joineries. Exposure levels to fungi at logging sites and sawmills were in the range of 10(3)-10(4) cfu/m3, at the woodchipping mill, 10(3)-10(5) cfu/m3, and at joineries, 10(2)-10(4) cfu/m3. Although mean endotoxin levels were lower than the suggested threshold value of 20 ng/m3, some personal exposures at sawmills and a joinery exceeded the standard. The geometric mean personal (1-->3)-beta-D-glucan exposure level at the woodchipping mill was 2.32 ng/m3, at sawmills, 1.37 ng/m3, at logging sites, 2.02 ng/m3, and at joineries, 0.43 ng/m3. Highly significant associations were found between mean personal inhalable endotoxin exposures and Gram-negative bacteria levels (p 3)-beta-D-glucan exposures and fungi levels (p = 0.0003). The prevalence of cough, phlegm, chronic bronchitis, nasal symptoms, frequent headaches, and eye and throat irritations was significantly higher among woodworkers than controls. Dose-response relationships were found between personal exposures and work-related symptoms among joinery workers and sawmill and chip mill workers.

Evolution of the Kdo2-lipid A Biosynthesis in Bacteria

Energy Technology Data Exchange (ETDEWEB)

S Opiyo; R Pardy; H Moriyama; E Moriyama

2011-12-31

BACKGROUND: Lipid A is the highly immunoreactive endotoxic center of lipopolysaccharide (LPS). It anchors the LPS into the outer membrane of most Gram-negative bacteria. Lipid A can be recognized by animal cells, triggers defense-related responses, and causes Gram-negative sepsis. The biosynthesis of Kdo2-lipid A, the LPS substructure, involves with nine enzymatic steps. RESULTS: In order to elucidate the evolutionary pathway of Kdo2-lipid A biosynthesis, we examined the distribution of genes encoding the nine enzymes across bacteria. We found that not all Gram-negative bacteria have all nine enzymes. Some Gram-negative bacteria have no genes encoding these enzymes and others have genes only for the first four enzymes (LpxA, LpxC, LpxD, and LpxB). Among the nine enzymes, five appeared to have arisen from three independent gene duplication events. Two of such events happened within the Proteobacteria lineage, followed by functional specialization of the duplicated genes and pathway optimization in these bacteria. CONCLUSIONS: The nine-enzyme pathway, which was established based on the studies mainly in Escherichia coli K12, appears to be the most derived and optimized form. It is found only in E. coli and related Proteobacteria. Simpler and probably less efficient pathways are found in other bacterial groups, with Kdo2-lipid A variants as the likely end products. The Kdo2-lipid A biosynthetic pathway exemplifies extremely plastic evolution of bacterial genomes, especially those of Proteobacteria, and how these mainly pathogenic bacteria have adapted to their environment.

Salt and alkali stresses reduction in wheat by plant growth promoting haloalkaliphilic bacteria

OpenAIRE

Torbaghan, Mehrnoush Eskandari; Lakzian, Amir; Astaraei, Ali Reza; Fotovat, Amir; Besharati, Hossein

2017-01-01

Haloalkaliphilic bacteria have plant growth promoting characteristics that can be used to deal with different environmental stresses. To study the effect of haloalkaliphilic bacteria to reduce salinity and alkalinity stress in wheat, 48 isolates were isolated and grouped into halophiles, alkaliphiles and haloalkaliphiles based on growth characteristics. The ammonia, 3-indole acetic acid and ACC (1-aminocyclopropane-1-carboxylate) deaminase production were studied. Wheat yield was evaluated in...

Polyacrylamide+Al2(SO4)3 and polyacrylamide+CaO remove coliform bacteria and nutrients from swine wastewater

International Nuclear Information System (INIS)

Entry, J.A.; Phillips, Ian; Stratton, Helen; Sojka, R.E.

2003-01-01

Polyacrylamide mixture may be able to reduce run-off of enteric bacteria from animal wastes. - Animal wastes are a major contributor of nutrients and enteric microorganisms to surface water and ground water. Polyacrylamide (PAM) mixtures are an effective flocculent, and we hypothesized that they would reduce transport of microorganisms in flowing water. After waste water running at 60.0 l min -1 flowed over PAM+Al 2 (SO 4 ) 3 , or PAM+CaO in furrows, total coliform bacteria (TC) and fecal coliform bacteria (FC) were reduced by 30-50% at 1 and 50 m downstream of the treatments compared to the control. In a column study, PAM+Al 2 (SO 4 ) 3 , and PAM+CaO applied to sandy, sandy loam, loam, and clay soils reduced NH 4 + and ortho-P concentrations in leachate compared to the source waste water and the control. PAM+Al 2 (SO 4 ) 3 and PAM+CaO applied to sandy, sandy loam and loam soils reduced both total and ortho-P, concentrations in leachate compared to the source wastewater and control treatment. In a field study, PAM+Al 2 (SO 4 ) 3 , or PAM+CaO treatments did not consistently reduce NH 4 + , NO 3 - , ortho-P, and total P concentrations in wastewater flowing over any soil compared to inflow wastewater or the control treatment. With proper application PAM+ Al 2 (SO 4 ) 3 and PAM+CaO may be able to reduce the numbers of enteric bacteria in slowly flowing wastewater running off animal confinement areas, reducing the amount of pollutants entering surface water and groundwater

Effectiveness of siwak Salvadora Persica extract to Aggregatibacter Actinomycetemcomitans as one of pathogenic bacteria causing periodontal disease

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Arni Irawaty Djais

2017-04-01

Full Text Available Objective : Periodontal disease is one of oral and dental diseases which most commonly found in humans caused by several factors, one of them due to the accumulation of bacterial plaque. Aggregatibacter actinomycetemcomitans is a bacterial pathogen that frequently causes periodontal disease. Material and Methods : To inhibit the growth of these bacteria can be done by using natural ingredients that contain anti-bacterial agent. One of the natural ingredients that contain antibacterial substances is Siwak. To determine the effect of siwak extract against bacteria Aggregatibacter actinobaciluscomnitans as one of the pathogenic bacteria causing periodontal diseases. The study was laboratory experimental with posttest only control group design. Results : This study used sample of Aggregatibacter actinomycetemcomitans colonies in MHA medium. Twenty four samples were divided into six treatment groups, they were 5 groups given the extract siwak with concentration of 3.125%, 6:25%, 12.5%, 25%, 50% and 1 group treated with control DMSO 5%. Inhibition zone was measured after 48 hours incubation at 37°C and measured using caliper. Data analysis was performed using Kruskal Wallis test. The mean diameter of inhibition zone at concentrations of 3.125%, 6:25%, 12.5%, 25%, and 50% were 6.4 mm, 7.0 mm, 7.2 mm, 7.9 mm and 8.6 mm. Conclusion : Siwak extract can inhibit the growth of Aggregatibacter actinomycetemcomitans as one of the pathogenic bacteria causing periodontal diseases with the largest concentration is a concentration of 50% and the smallest concentration that is 3.125%.

Thymidine kinase diversity in bacteria

DEFF Research Database (Denmark)

Sandrini, Michael; Clausen, A.R.; Munch-Petersen, B.

2006-01-01

Thymidine kinases (TKs) appear to be almost ubiquitous and are found in nearly all prokaryotes, eukaryotes, and several viruses. They are the key enzymes in thymidine salvage and activation of several anti-cancer and antiviral drugs. We show that bacterial TKs can be subdivided into 2 groups. The....... The TKs from Gram-positive bacteria are more closely related to the eukaryotic TK1 enzymes than are TKs from Gram-negative bacteria....

A simple and efficient method for poly-3-hydroxybutyrate quantification in diazotrophic bacteria within 5 minutes using flow cytometry

Directory of Open Access Journals (Sweden)

L.P.S. Alves

Full Text Available The conventional method for quantification of polyhydroxyalkanoates based on whole-cell methanolysis and gas chromatography (GC is laborious and time-consuming. In this work, a method based on flow cytometry of Nile red stained bacterial cells was established to quantify poly-3-hydroxybutyrate (PHB production by the diazotrophic and plant-associated bacteria, Herbaspirillum seropedicae and Azospirillum brasilense. The method consists of three steps: i cell permeabilization, ii Nile red staining, and iii analysis by flow cytometry. The method was optimized step-by-step and can be carried out in less than 5 min. The final results indicated a high correlation coefficient (R2=0.99 compared to a standard method based on methanolysis and GC. This method was successfully applied to the quantification of PHB in epiphytic bacteria isolated from rice roots.

A simple and efficient method for poly-3-hydroxybutyrate quantification in diazotrophic bacteria within 5 minutes using flow cytometry.

Science.gov (United States)

Alves, L P S; Almeida, A T; Cruz, L M; Pedrosa, F O; de Souza, E M; Chubatsu, L S; Müller-Santos, M; Valdameri, G

2017-01-16

The conventional method for quantification of polyhydroxyalkanoates based on whole-cell methanolysis and gas chromatography (GC) is laborious and time-consuming. In this work, a method based on flow cytometry of Nile red stained bacterial cells was established to quantify poly-3-hydroxybutyrate (PHB) production by the diazotrophic and plant-associated bacteria, Herbaspirillum seropedicae and Azospirillum brasilense. The method consists of three steps: i) cell permeabilization, ii) Nile red staining, and iii) analysis by flow cytometry. The method was optimized step-by-step and can be carried out in less than 5 min. The final results indicated a high correlation coefficient (R2=0.99) compared to a standard method based on methanolysis and GC. This method was successfully applied to the quantification of PHB in epiphytic bacteria isolated from rice roots.

A simple and efficient method for poly-3-hydroxybutyrate quantification in diazotrophic bacteria within 5 minutes using flow cytometry

Science.gov (United States)

Alves, L.P.S.; Almeida, A.T.; Cruz, L.M.; Pedrosa, F.O.; de Souza, E.M.; Chubatsu, L.S.; Müller-Santos, M.; Valdameri, G.

2017-01-01

The conventional method for quantification of polyhydroxyalkanoates based on whole-cell methanolysis and gas chromatography (GC) is laborious and time-consuming. In this work, a method based on flow cytometry of Nile red stained bacterial cells was established to quantify poly-3-hydroxybutyrate (PHB) production by the diazotrophic and plant-associated bacteria, Herbaspirillum seropedicae and Azospirillum brasilense. The method consists of three steps: i) cell permeabilization, ii) Nile red staining, and iii) analysis by flow cytometry. The method was optimized step-by-step and can be carried out in less than 5 min. The final results indicated a high correlation coefficient (R2=0.99) compared to a standard method based on methanolysis and GC. This method was successfully applied to the quantification of PHB in epiphytic bacteria isolated from rice roots. PMID:28099582

Wastewater nutrient removal in a mixed microalgae-bacteria culture: effect of light and temperature on the microalgae-bacteria competition.

Science.gov (United States)

González-Camejo, J; Barat, R; Pachés, M; Murgui, M; Seco, A; Ferrer, J

2018-02-01

The aim of this study was to evaluate the effect of light intensity and temperature on nutrient removal and biomass productivity in a microalgae-bacteria culture and their effects on the microalgae-bacteria competition. Three experiments were carried out at constant temperature and various light intensities: 40, 85 and 125 µE m -2  s -1 . Other two experiments were carried out at variable temperatures: 23 ± 2°C and 28 ± 2°C at light intensity of 85 and 125 µE m -2  s -1 , respectively. The photobioreactor was fed by the effluent from an anaerobic membrane bioreactor. High nitrogen and phosphorus removal efficiencies (about 99%) were achieved under the following operating conditions: 85-125 µE m -2  s -1 and 22 ± 1°C. In the microalgae-bacteria culture studied, increasing light intensity favoured microalgae growth and limited the nitrification process. However, a non-graduated temperature increase (up to 32°C) under the light intensities studied caused the proliferation of nitrifying bacteria and the nitrite and nitrate accumulation. Hence, light intensity and temperature are key parameters in the control of the microalgae-bacteria competition. Biomass productivity significantly increased with light intensity, reaching 50.5 ± 9.6, 80.3 ± 6.5 and 94.3 ± 7.9 mgVSS L -1  d -1 for a light intensity of 40, 85 and 125 µE m -2  s -1 , respectively.

Enumeration and characterization of arsenic-tolerant diazotrophic bacteria in a long-term heavy-metal-contaminated soil

OpenAIRE

Oliveira, A.; Pampulha, M.E.; Neto, M.M.; Almeida, A.C.

2009-01-01

The abundance of arsenic-tolerant diazotrophic bacteria was compared in a long-term contaminated soil versus a non-contaminated one. In addition, the characterization of tolerant diazotrophic bacteria was carried out. Differences in the number of heterotrophic N2 fixers were found between soils. Contaminated soil showed a decrease in the microbial population size of about 80%, confirming the great sensitivity of this group of soil bacteria to metals. However, quantitat...

Comparative genomics of the lactic acid bacteria

Energy Technology Data Exchange (ETDEWEB)

Makarova, K.; Slesarev, A.; Wolf, Y.; Sorokin, A.; Mirkin, B.; Koonin, E.; Pavlov, A.; Pavlova, N.; Karamychev, V.; Polouchine, N.; Shakhova, V.; Grigoriev, I.; Lou, Y.; Rokhsar, D.; Lucas, S.; Huang, K.; Goodstein, D. M.; Hawkins, T.; Plengvidhya, V.; Welker, D.; Hughes, J.; Goh, Y.; Benson, A.; Baldwin, K.; Lee, J. -H.; Diaz-Muniz, I.; Dosti, B.; Smeianov, V; Wechter, W.; Barabote, R.; Lorca, G.; Altermann, E.; Barrangou, R.; Ganesan, B.; Xie, Y.; Rawsthorne, H.; Tamir, D.; Parker, C.; Breidt, F.; Broadbent, J.; Hutkins, R.; O' Sullivan, D.; Steele, J.; Unlu, G.; Saier, M.; Klaenhammer, T.; Richardson, P.; Kozyavkin, S.; Weimer, B.; Mills, D.

2006-06-01

Lactic acid-producing bacteria are associated with various plant and animal niches and play a key role in the production of fermented foods and beverages. We report nine genome sequences representing the phylogenetic and functional diversity of these bacteria. The small genomes of lactic acid bacteria encode a broad repertoire of transporters for efficient carbon and nitrogen acquisition from the nutritionally rich environments they inhabit and reflect a limited range of biosynthetic capabilities that indicate both prototrophic and auxotrophic strains. Phylogenetic analyses, comparison of gene content across the group, and reconstruction of ancestral gene sets indicate a combination of extensive gene loss and key gene acquisitions via horizontal gene transfer during the coevolution of lactic acid bacteria with their habitats.

Identification of a novel acetate-utilizing bacterium belonging to Synergistes group 4 in anaerobic digester sludge.

Science.gov (United States)

Ito, Tsukasa; Yoshiguchi, Kazumi; Ariesyady, Herto Dwi; Okabe, Satoshi

2011-12-01

Major acetate-utilizing bacterial and archaeal populations in methanogenic anaerobic digester sludge were identified and quantified by radioisotope- and stable-isotope-based functional analyses, microautoradiography-fluorescence in situ hybridization (MAR-FISH) and stable-isotope probing of 16S rRNA (RNA-SIP) that can directly link 16S rRNA phylogeny with in situ metabolic function. First, MAR-FISH with (14)C-acetate indicated the significant utilization of acetate by only two major groups, unidentified bacterial cells and Methanosaeta-like filamentous archaeal cells, in the digester sludge. To identify the acetate-utilizing unidentified bacteria, RNA-SIP was conducted with (13)C(6)-glucose and (13)C(3)-propionate as sole carbon source, which were followed by phylogenetic analysis of 16S rRNA. We found that bacteria belonging to Synergistes group 4 were commonly detected in both 16S rRNA clone libraries derived from the sludge incubated with (13)C-glucose and (13)C-propionate. To confirm that this bacterial group can utilize acetate, specific FISH probe targeting for Synergistes group 4 was newly designed and applied to the sludge incubated with (14)C-acetate for MAR-FISH. The MAR-FISH result showed that bacteria belonging to Synergistes group 4 significantly took up acetate and their active population size was comparable to that of Methanosaeta in this sludge. In addition, as bacteria belonging to Synergistes group 4 had high K(m) for acetate and maximum utilization rate, they are more competitive for acetate over Methanosaeta at high acetate concentrations (2.5-10  mM). To our knowledge, it is the first time to report the acetate-utilizing activity of uncultured bacteria belonging to Synergistes group 4 and its competitive significance to acetoclastic methanogen, Methanosaeta.

Toxicity of laser irradiated photoactive fluoride PrF3 nanoparticles toward bacteria

International Nuclear Information System (INIS)

Pudovkin, M S; Korableva, S L; Krasheninnicova, A O; Nizamutdinov, A S; Semashko, V V; Zelenihin, P V; Alakshin, E M; Nevzorova, T A

2014-01-01

The article is devoted to exploration of biological effects of crystalline PrF 3 nanoparticles toward Salmonella typhimurium TA 98 bacteria under the laser irradiation. Obtained results show bactericidal activity of PrF 3 nanoparticles and optimal parameters of laser irradiation (power of laser irradiation, wavelength, diameter of the laser spoil, and exposure time) have been found under which the effects of bactericidal activity become the most significant. Survival of bacterial cells under laser irradiation with wavelength 532 nm in colloidal solution of PrF 3 nanoparticles was 39%, 34%, 20% for exposure times 5 minutes, 15 minutes and 30 minutes, correspondingly

"DRUG RESISTANCE PATTERN IN ISOLATED BACTERIA FROM BLOOD CULTURES"

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A. Sobhani

2004-05-01

Full Text Available Bacteremia is an important infectious disease which may lead to death. Common bacteria and pattern of antibiotic resistance in different communities are different and understanding these differences is important. In the present study, relative frequency and pattern of drug resistance have been examined in bacteria isolated from blood cultures in Razi Hospital laboratory. The method of the study was descriptive. Data collection was carried out retrospectively. Total sample consisted of 311 positive blood cultures from 1999 to 2001. Variables under study were bacterial strains, antibiotics examined in antibiogram, microbial resistance, and patients' age and sex. The most common isolated bacteria were Salmonella typhi (22.2% and the least common ones were Citrobacter (1.6%. The highest antibiotic resistance was seen against amoxicillin (88.4%. The proportion of males to females was1: 1/1 and the most common age group was 15-44 (47.3%. Common bacteria and pattern of antibiotic resistance were different in some areas and this subject requires further studies in the future.

Heavy metals detoxification in soil performed by sulfate - reducing bacteria

International Nuclear Information System (INIS)

Pado, R.; Pawlowska-Cwiek, L.; Szwagrzyk, J.

1994-01-01

The process of sulfate reduction carried out by mixed bacteria cultures in the presence of heavy cations (Fe 2+ , Pb 2+ , Cd 2+ , Zn 2+ , Cu 2+ ) was investigated. The range of harmful metals concentrations responded to the acceptable levels in soil and their multiplications (10-100 times) in contaminated soil. The results show the possibility of detoxicating these metals, especially lead. In the highest lead concentrations (3950 and 7500 ppm), only after one month of activities conducted by bacteria dissimilating hydrogen sulfide, between about 73 and 81 per cent of lead was converted into practically insoluble PbS. It was found that detoxication process with the presence of bacteria from this group prolonged with the increase of metal concentration (Zn 2+ and Cd 2+ in particular. (author). 30 refs, 5 figs, 3 tabs

An efficient method for qualitative screening of phosphate-solubilizing bacteria.

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Mehta, S; Nautiyal, C S

2001-07-01

An efficient protocol was developed for qualitative screening of phosphate-solubilizing bacteria, based upon visual observation. Our results indicate that, by using our formulation containing bromophenol blue, it is possible to quickly screen on a qualitative basis the phosphate-solubilizing bacteria. Qualitative analysis of the phosphate solubilized by various groups correlated well with grouping based upon quantitative analysis of bacteria isolated from soil, effect of carbon, nitrogen, salts, and phosphate solubilization-defective transposon mutants. However, unlike quantitative analysis methods that involve time-consuming biochemical procedures, the time for screening phosphate-solubilizing bacteria is significantly reduced by using our simple protocol. Therefore, it is envisaged that usage of this formulation based upon qualitative analysis will be salutary for the quick screening of phosphate-solubilizing bacteria. Our results indicate that the formulation can also be used as a quality control test for expeditiously screening the commercial bioinoculant preparations, based on phosphate solubilizers.

Biochemistry, physiology and biotechnology of sulfate-reducing bacteria.

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Barton, Larry L; Fauque, Guy D

2009-01-01

Chemolithotrophic bacteria that use sulfate as terminal electron acceptor (sulfate-reducing bacteria) constitute a unique physiological group of microorganisms that couple anaerobic electron transport to ATP synthesis. These bacteria (220 species of 60 genera) can use a large variety of compounds as electron donors and to mediate electron flow they have a vast array of proteins with redox active metal groups. This chapter deals with the distribution in the environment and the major physiological and metabolic characteristics of sulfate-reducing bacteria (SRB). This chapter presents our current knowledge of soluble electron transfer proteins and transmembrane redox complexes that are playing an essential role in the dissimilatory sulfate reduction pathway of SRB of the genus Desulfovibrio. Environmentally important activities displayed by SRB are a consequence of the unique electron transport components or the production of high levels of H(2)S. The capability of SRB to utilize hydrocarbons in pure cultures and consortia has resulted in using these bacteria for bioremediation of BTEX (benzene, toluene, ethylbenzene and xylene) compounds in contaminated soils. Specific strains of SRB are capable of reducing 3-chlorobenzoate, chloroethenes, or nitroaromatic compounds and this has resulted in proposals to use SRB for bioremediation of environments containing trinitrotoluene and polychloroethenes. Since SRB have displayed dissimilatory reduction of U(VI) and Cr(VI), several biotechnology procedures have been proposed for using SRB in bioremediation of toxic metals. Additional non-specific metal reductase activity has resulted in using SRB for recovery of precious metals (e.g. platinum, palladium and gold) from waste streams. Since bacterially produced sulfide contributes to the souring of oil fields, corrosion of concrete, and discoloration of stonework is a serious problem, there is considerable interest in controlling the sulfidogenic activity of the SRB. The

Halolactibacillus halophilus gen. nov., sp. nov. and Halolactibacillus miurensis sp. nov., halophilic and alkaliphilic marine lactic acid bacteria constituting a phylogenetic lineage in Bacillus rRNA group 1.

Science.gov (United States)

Ishikawa, Morio; Nakajima, Kazuyuki; Itamiya, Yuko; Furukawa, Sayumi; Yamamoto, Yasushi; Yamasato, Kazuhide

2005-11-01

Eleven novel strains of marine-inhabiting lactic acid bacteria that were isolated from living and decaying marine organisms collected from a temperate area of Japan are described. The isolates were motile with peritrichous flagella and non-sporulating. They lacked catalase, quinones and cytochromes. Fermentation products from glucose were lactate, formate, acetate and ethanol. Lactate yield as percentage conversion from glucose was affected by the pH of the fermentation medium: approximately 55 % at the optimal growth pH of 8.0, greater than approximately 70 % at pH 7.0 and less than approximately 30 % at pH 9.0. The molar ratio of the other three products was the same at each cultivation pH, approximately 2 : 1 : 1. Carbohydrates and related compounds were aerobically metabolized to acetate and pyruvate as well as lactate. The isolates were slightly halophilic, highly halotolerant and alkaliphilic. The optimum NaCl concentration for growth was 2.0-3.0 % (w/v), with a range of 0-25.5 %. The optimum pH for growth was 8.0-9.5, with a range of 6.0-10.0. The G+C content of the DNA was 38.5-40.7 mol%. The isolates constituted two genomic species (DNA-DNA relatedness of less than 41 %) each characterized by sugar fermentation profiles. The cell-wall peptidoglycan of both phenotypes contained meso-diaminopimelic acid. The major cellular fatty acids were C(16 : 0) and a-C(13 : 0). Comparative sequence analysis of the 16S rRNA genes revealed that these isolates represent novel species constituting a phylogenetic unit outside the radiation of typical lactic acid bacteria and an independent line of descent within the group composed of the halophilic/halotolerant/alkaliphilic and/or alkalitolerant species in Bacillus rRNA group 1, with 94.8-95.1 % similarity to the genus Paraliobacillus, 93.7-94.1 % to the genus Gracilibacillus and 93.8-94.2 % to Virgibacillus marismortui. On the basis of possession of physiological and biochemical characteristics common to typical lactic acid

Motility of electric cable bacteria

DEFF Research Database (Denmark)

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

2016-01-01

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

Uranium association with halophilic and non-halophilic bacteria and archaea

International Nuclear Information System (INIS)

Francis, A.J.; Gillow, J.B.; Dodge, C.J.; Harris, R.; Beveridge, T.J.; Papenguth, H.W.

2004-01-01

We determined the association of uranium with bacteria isolated from the Waste Isolation Pilot Plant (WIPP), Carlsbad, New Mexico, and compared this with known strains of halophilic and non-halophilic bacteria and archaea. Examination of the cultures by transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDS) showed uranium accumulation extracellularly and/or intracellularly to a varying degree. In Pseudomonas fluorescens and Bacillus subtilis uranium was associated with the cell surface and in the latter it was present as irregularly shaped grains. In Halobacterium halobium, the only archeon studied here, uranium was present as dense deposits and with Haloanaerobium praevalens as spikey deposits. Halomonas sp. isolated from the WIPP site accumulated uranium both extracellularly on the cell surface and intracellularly as electron-dense discrete granules. Extended X-ray absorption fine structure (EXAFS) analysis of uranium with the halophilic and non-halophilic bacteria and archaea showed that the uranium present in whole cells was bonded to an average of 2.4 ± 0.7 phosphoryl groups at a distance of 3.65 ± 0.03 Aa. Comparison of whole cells of Halomonas sp. with the cell wall fragments of lysed cells showed the presence of a uranium bidentate complex at 2.91 ± 0.03 Aa with the carboxylate group on the cell wall, and uranyl hydroxide with U-U interaction at 3.71 ± 0.03 Aa due to adsorption or precipitation reactions; no U-P interaction was observed. Addition of uranium to the cell lysate of Halomonas sp. resulted in the precipitation of uranium due to the inorganic phosphate produced by the cells. These results show that the phosphates released from bacteria bind a significant amount of uranium. However, the bacterially immobilized uranium was readily solubilized by bicarbonate with concurrent release of phosphate into solution. (orig.)

Differential responses of soil bacteria, fungi, archaea and protists to plant species richness and plant functional group identity.

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Dassen, Sigrid; Cortois, Roeland; Martens, Henk; de Hollander, Mattias; Kowalchuk, George A; van der Putten, Wim H; De Deyn, Gerlinde B

2017-08-01

Plants are known to influence belowground microbial community structure along their roots, but the impacts of plant species richness and plant functional group (FG) identity on microbial communities in the bulk soil are still not well understood. Here, we used 454-pyrosequencing to analyse the soil microbial community composition in a long-term biodiversity experiment at Jena, Germany. We examined responses of bacteria, fungi, archaea, and protists to plant species richness (communities varying from 1 to 60 sown species) and plant FG identity (grasses, legumes, small herbs, tall herbs) in bulk soil. We hypothesized that plant species richness and FG identity would alter microbial community composition and have a positive impact on microbial species richness. Plant species richness had a marginal positive effect on the richness of fungi, but we observed no such effect on bacteria, archaea and protists. Plant species richness also did not have a large impact on microbial community composition. Rather, abiotic soil properties partially explained the community composition of bacteria, fungi, arbuscular mycorrhizal fungi (AMF), archaea and protists. Plant FG richness did not impact microbial community composition; however, plant FG identity was more effective. Bacterial richness was highest in legume plots and lowest in small herb plots, and AMF and archaeal community composition in legume plant communities was distinct from that in communities composed of other plant FGs. We conclude that soil microbial community composition in bulk soil is influenced more by changes in plant FG composition and abiotic soil properties, than by changes in plant species richness per se. © 2017 The Authors. Molecular Ecology Published by John Wiley & Sons Ltd.

Lactic acid bacteria as a cell factory for riboflavin production.

Science.gov (United States)

Thakur, Kiran; Tomar, Sudhir Kumar; De, Sachinandan

2016-07-01

Consumers are increasingly becoming aware of their health and nutritional requirements, and in this context, vitamins produced in situ by microbes may suit their needs and expectations. B groups vitamins are essential components of cellular metabolism and among them riboflavin is one of the vital vitamins required by bacteria, plants, animals and humans. Here, we focus on the importance of microbial production of riboflavin over chemical synthesis. In addition, genetic abilities for riboflavin biosynthesis by lactic acid bacteria are discussed. Genetically modified strains by employing genetic engineering and chemical analogues have been developed to enhance riboflavin production. The present review attempts to collect the currently available information on riboflavin production by microbes in general, while placing greater emphasis on food grade lactic acid bacteria and human gut commensals. For designing riboflavin-enriched functional foods, proper selection and exploitation of riboflavin-producing lactic acid bacteria is essential. Moreover, eliminating the in situ vitamin fortification step will decrease the cost of food production. © 2015 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

The in Vitro Antimicrobial Efficacy of PDT against Periodontopathogenic Bacteria

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Philippe A. Haag

2015-11-01

Full Text Available Periodontitis, an inflammatory disease, is caused by biofilms with a mixed microbial etiology and involves the progressive destruction of the tooth-supporting tissues. A rising number of studies investigate the clinical potential of photodynamic therapy (PDT as an adjunct during active therapy. The aim of the present review was to evaluate the available literature for the in vitro antimicrobial efficacy of photodynamic therapy focusing on the periodontopathogenic bacteria Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis and Fusobacterium nucleatum. The focused question was: “Is it possible to decrease (at least 3 log steps or 99.9% or even eliminate bacterial growth by photodynamic therapy in vitro when compared to untreated control groups or control groups treated by placebo?” In general, PDT resulted in a substantial reduction of surviving bacteria. However, not all studies showed the desired reduction or elimination. The ranges of log10-reduction were 0.38 (58% to a complete eradication (100% for P. gingivalis, 0.21 (39% to 100% for A. actinomycetemcomitans and 0.3 (50% to 100% for F. nucleatum. In conclusion, further and particularly more comparable studies are needed to evaluate if PDT can be clinically successful as an adjuvant in periodontal therapy.

Analysis of molecular interactions between yoghurt bacteria by an integrated genomics approach

NARCIS (Netherlands)

Sieuwerts, S.

2009-01-01

The lactic acid bacteria (LAB) are a group of Gram-positive bacteria that ferment sugars such as lactose to produce mainly lactic acid. LAB are a group of industrially important microorganisms that are applied for the production of many fermented foods. These include foods produced with substrates

Cultivable Bacteria from Milk from Slovenian Breastfeeding Mothers

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Bojana Bogovič Matijašić

2014-01-01

Full Text Available The human milk microbiota plays an important role in the development of infant´s intestinal microbiota and in the protection of infants against pathogenic microorganisms. The aim of this study is to investigate the microbial composition of human milk from 47 breastfeeding mothers, sampled separately from the left (L and the right (R breast, on the 30th day after giving birth. We quantified some major bacterial groups in human milk, compared the cultivable bacteria from the left and the right breast and identified strain diversity of lactobacilli. The results revealed that human milk contains lactic acid bacteria, bifidobacteria and mesophilic aerobic bacteria, of which the last were the most abundant group. Although the microbial composition of human milk in L and R breast samples was comparable, the concentration of bacteria in the two samples from the same mother might vary, therefore milk sample taken from one breast only does not reflect the average microbial composition. Using random amplified polymorphic DNA (RAPD, 86 presumptive isolates of lactobacilli from representative samples of human milk from 11 mothers were classified into 11 groups. Moreover, representatives of different RAPD groups were identified using 16S rDNA sequencing. Out of 11 RAPD groups, 4 groups (21 % of all isolates belonged to the species Lactobacillus gasseri. The most representative RAPD profile (48 % of isolates was found to belong to the species Lactobacillus fermentum. Other RAPD groups were associated with L. salivarius, L. reuteri, Enterococcus faecium, Staphylococcus epidermidis and Bifidobacterium breve species.

Antibiotic-resistant bacteria in drinking water.

Science.gov (United States)

Armstrong, J L; Shigeno, D S; Calomiris, J J; Seidler, R J

1981-08-01

We analyzed drinking water from seven communities for multiply antibiotic-resistant (MAR) bacteria (bacteria resistant to two or more antibiotics) and screened the MAR bacterial isolates obtained against five antibiotics by replica plating. Overall, 33.9% of 2,653 standard plate count bacteria from treated drinking waters were MAR. Two different raw water supplies for two communities carried MAR standard plate count bacteria at frequencies of 20.4 and 18.6%, whereas 36.7 and 67.8% of the standard plate count populations from sites within the respective distribution systems were MAR. Isolate identification revealed that MAR gram-positive cocci (Staphylococcus) and MAR gram-negative, nonfermentative rods (Pseudomonas, Alcaligenes, Moraxella-like group M, and Acinetobacter) were more common in drinking waters than in untreated source waters. Site-to-site variations in generic types and differences in the incidences of MAR organisms indicated that shedding of MAR bacteria living in pipelines may have contributed to the MAR populations in tap water. We conclude that the treatment of raw water and its subsequent distribution select for standard plate count bacteria exhibiting the MAR phenotype.

Conservation of the 2-keto-3-deoxymanno-octulosonic acid (Kdo) biosynthesis pathway between plants and bacteria.

Science.gov (United States)

Smyth, Kevin M; Marchant, Alan

2013-10-18

The increasing prevalence of multi-drug resistant bacteria is driving efforts in the development of new antibacterial agents. This includes a resurgence of interest in the Gram-negative bacteria lipopolysaccharide (LPS) biosynthesis enzymes as drug targets. The six carbon acidic sugar 2-keto-3-deoxymanno-octulosonic acid (Kdo) is a component of the lipid A moiety of the LPS in Gram-negative bacteria. In most cases the lipid A substituted by Kdo is the minimum requirement for cell growth, thus presenting the possibility of targeting either the synthesis or incorporation of Kdo for the development of antibacterial agents. Indeed, potent in vitro inhibitors of Kdo biosynthesis enzymes have been reported but have so far failed to show sufficient in vivo action against Gram-negative bacteria. As part of an effort to design more potent antibacterial agents targeting Kdo biosynthesis, the crystal structures of the key Kdo biosynthesis enzymes from Escherichia coli have been solved and their structure based mechanisms characterized. In eukaryotes, Kdo is found as a component of the pectic polysaccharide rhamnogalacturonan II in the plant primary cell wall. Interestingly, despite incorporating Kdo into very different macromolecules the Kdo biosynthesis and activation pathway is almost completely conserved between plants and bacteria. This raises the possibility for plant research to exploit the increasingly detailed knowledge and resources being generated by the microbiology community. Likewise, insights into Kdo biosynthesis in plants will be potentially useful in efforts to produce new antimicrobial compounds. Copyright © 2013 Elsevier Ltd. All rights reserved.

ATR-FTIR Spectroscopic Evidence for Biomolecular Phosphorus and Carboxyl Groups Facilitating Bacterial Adhesion to Iron Oxides

Science.gov (United States)

Parikh, Sanjai J.; Mukome, Fungai N.D.; Zhang, Xiaoming

2014-01-01

Attenuated total reflectance (ATR) Fourier transform infrared (FTIR) spectroscopy has been used to probe the binding of bacteria to hematite (α-Fe2O3) and goethite (α-FeOOH). In situ ATR-FTIR experiments with bacteria (Pseudomonas putida, P. aeruginosa, Escherichia coli), mixed amino acids, polypeptide extracts, deoxyribonucleic acid (DNA), and a suite of model compounds were conducted. These compounds represent carboxyl, catecholate, amide, and phosphate groups present in siderophores, amino acids, polysaccharides, phospholipids, and DNA. Due in part to the ubiquitous presence of carboxyl groups in biomolecules, numerous IR peaks corresponding to outer-sphere or unbound (1400 cm−1) and inner-sphere (1310-1320 cm−1) coordinated carboxyl groups are noted following reaction of bacteria and biomolecules with α-Fe2O3 and α-FeOOH. However, the data also reveal that the presence of low-level amounts (i.e., 0.45-0.79%) of biomolecular phosphorous groups result in strong IR bands at ~1043 cm−1, corresponding to inner-sphere Fe-O-P bonds, underscoring the importance of bacteria associated P-containing groups in biomolecule and cell adhesion. Spectral comparisons also reveal slightly greater P-O-Fe contributions for bacteria (Pseudomonad, E. coli) deposited on α-FeOOH, as compared to α-Fe2O3. This data demonstrates that slight differences in bacterial adhesion to Fe oxides can be attributed to bacterial species and Fe-oxide minerals. However, more importantly, the strong binding affinity of phosphate in all bacteria samples to both Fe-oxides results in the formation of inner-sphere Fe-O-P bonds, signifying the critical role of biomolecular P in the initiation of bacterial adhesion. PMID:24859052

High motility reduces grazing mortality of planktonic bacteria

DEFF Research Database (Denmark)

Matz, Carsten; Jurgens, K.

2005-01-01

We tested the impact of bacterial swimming speed on the survival of planktonic bacteria in the presence of protozoan grazers. Grazing experiments with three common bacterivorous nanoflagellates revealed low clearance rates for highly motile bacteria. High-resolution video microscopy demonstrated...... size revealed highest grazing losses for moderately motile bacteria with a cell size between 0.2 and 0.4 mum(3). Grazing mortality was lowest for cells of >0.5 mum(3) and small, highly motile bacteria. Survival efficiencies of >95% for the ultramicrobacterial isolate CP-1 (less than or equal to0.1 mum......(3), >50 mum s(-1)) illustrated the combined protective action of small cell size and high motility. Our findings suggest that motility has an important adaptive function in the survival of planktonic bacteria during protozoan grazing....

Antimicrobial-resistant bacteria in wild game in Slovenia

Science.gov (United States)

Križman, M.; Kirbiš, A.; Jamnikar-Ciglenečki, U.

2017-09-01

Wildlife is usually not exposed to clinically-used antimicrobial agents but can acquire antimicrobial resistance throughout contact with humans, domesticated animals and environments. Samples of faeces from intestines (80 in total) were collected from roe deer (52), wild boars (11), chamois (10) red deer (6) and moufflon (1). After culture on ChromID extended spectrum β-lactamase (ESBL) plates to select for growth of ESBL-producing bacteria, 25 samples produced bacterial colonies for further study. Six species of bacteria were identified from the 25 samples: Stenotrophomonas maltophilia, Serratia fonticola, Stenotrophomonas nitritireducens, Enterococcus faecium, Enterococcus faecalis and Escherichia coli. Two ESBL enzymes were amplified from group TEM and three from group CTX-M-1. Undercooked game meat and salami can be a source of resistant bacteria when animals are not eviscerated properly.

Marine Pseudomonas putida: a potential source of antimicrobial substances against antibiotic-resistant bacteria

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Palloma Rodrigues Marinho

2009-08-01

Full Text Available Bacteria isolated from marine sponges found off the coast of Rio de Janeiro, Brazil, were screened for the production of antimicrobial substances. We report a new Pseudomonas putida strain (designated P. putida Mm3 isolated from the sponge Mycale microsigmatosa that produces a powerful antimicrobial substance active against multidrug-resistant bacteria. P. putida Mm3 was identified on the basis of 16S rRNA gene sequencing and phenotypic tests. Molecular typing for Mm3 was performed by RAPD-PCR and comparison of the results to other Pseudomonas strains. Our results contribute to the search for new antimicrobial agents, an important strategy for developing alternative therapies to treat infections caused by multidrug-resistant bacteria.

Marine Pseudomonas putida: a potential source of antimicrobial substances against antibiotic-resistant bacteria.

Science.gov (United States)

Marinho, Palloma Rodrigues; Moreira, Ana Paula Barbosa; Pellegrino, Flávia Lúcia Piffano Costa; Muricy, Guilherme; Bastos, Maria do Carmo de Freire; Santos, Kátia Regina Netto dos; Giambiagi-deMarval, Marcia; Laport, Marinella Silva

2009-08-01

Bacteria isolated from marine sponges found off the coast of Rio de Janeiro, Brazil, were screened for the production of antimicrobial substances. We report a new Pseudomonas putida strain (designated P. putida Mm3) isolated from the sponge Mycale microsigmatosa that produces a powerful antimicrobial substance active against multidrug-resistant bacteria. P. putida Mm3 was identified on the basis of 16S rRNA gene sequencing and phenotypic tests. Molecular typing for Mm3 was performed by RAPD-PCR and comparison of the results to other Pseudomonas strains. Our results contribute to the search for new antimicrobial agents, an important strategy for developing alternative therapies to treat infections caused by multidrug-resistant bacteria.

Identification of marine methanol-utilizing bacteria

Energy Technology Data Exchange (ETDEWEB)

Yamamoto, M; Iwaki, H; Kouno, K; Inui, T

1980-01-01

A taxonomical study of 65 marine methanol-utilizing bacteria is described. They were Gram-negative, non-spore-forming rods with a polar flagellum and had marine bacterial properties and required vitamin B/sub 12/ for growth. All of them assimilated fructose in addition to C/sub 1/-compounds and produced acid oxidatively from fructose. Twenty-four strains assimilated only C/sub 1/-compounds. They were resistant to penicillin, oxytetracycline and 0/129 substance (Vibrio stat), and tolerant to 12% NaCl. Guanine-cytosine contents of deoxyribonucleic acid in typical strains fell in the range of 43.8 to 47.6%. Other morphological and physiological properties were almost the same as those of terrestrial methanol-utilizers. Bacteria in the first group (41 strains) were facultative methylotrophs and were divided into three subgroups by the assimilation of methylated amines, that is, subgroup I (30 strains) assimilated mono-, di- and tri-methylamine, subgroup II (9 strains) assimilated only mono-methylamine, the bacteria of subgroups I and II were named Alteromonas thalassomethanolica sp. nov. and subgroup III (2 strains) did not assimilate methylated amines, and was tentatively assigned as Alteromonas sp. The second group of bacteria (24 strains) was obligate methylotrophs, named Methylomonas thalassica sp. nov. and was divided into subgroup IV (15 strains) which assimilated mono-, di and tri-methylamine and subgroup V (9 strains) which assimilated mono-methylamine.

Childhood urinary tract infection caused by extended-spectrum β-lactamase-producing bacteria: Risk factors and empiric therapy.

Science.gov (United States)

Uyar Aksu, Nihal; Ekinci, Zelal; Dündar, Devrim; Baydemir, Canan

2017-02-01

This study investigated risk factors of childhood urinary tract infection (UTI) associated with extended-spectrum β-lactamase (ESBL)-producing bacteria (ESBL-positive UTI) and evaluated antimicrobial resistance as well as empiric treatment of childhood UTI. The records of children with positive urine culture between 1 January 2008 and 31 December 2012 were evaluated. Patients with positive urine culture for ESBL-producing bacteria were defined as the ESBL-positive group, whereas patients of the same gender and similar age with positive urine culture for non-ESBL-producing bacteria were defined as the ESBL-negative group. Each ESBL-positive patient was matched with two ESBL-negative patients. The ESBL-positive and negative groups consisted of 154 and 308 patients, respectively. Potential risk factors for ESBL-positive UTI were identified as presence of underlying disease, clean intermittent catheterization (CIC), hospitalization, use of any antibiotic and history of infection in the last 3 months (P infection in the last 3 months were identified as independent risk factors. In the present study, 324 of 462 patients had empiric therapy. Empiric therapy was inappropriate in 90.3% of the ESBL-positive group and in 4.5% of the ESBL-negative group. Resistance to nitrofurantoin was similar between groups (5.1% vs 1.2%, P = 0.072); resistance to amikacin was low in the ESBL-positive group (2.6%) and there was no resistance in the ESBL-negative group. Clean intermittent catheterization, hospitalization and history of infection in the last 3 months should be considered as risk factors for ESBL-positive UTI. The combination of ampicillin plus amikacin should be taken into consideration for empiric therapy in patients with acute pyelonephritis who have the risk factors for ESBL-positive UTI. Nitrofurantoin seems to be a logical choice for the empiric therapy of cystitis. © 2016 Japan Pediatric Society.

32 CFR 1624.3 - Age selection groups.

Science.gov (United States)

2010-07-01

... 32 National Defense 6 2010-07-01 2010-07-01 false Age selection groups. 1624.3 Section 1624.3....3 Age selection groups. Age selection groups are established as follows: (a) The age 20 selection group for each calendar year consists of registrants who have attained or will attain the age of 20 in...

Poincare group, SU(3) and V-A in leptonic decay

International Nuclear Information System (INIS)

Boehm, A.

1975-07-01

From as few assumptions as possible about the relations between the Poincare group, the particle classifying SU(3) and V-A we derive properties of the K/sub l 3 / and K/sub L 2 / decays. From the assumed relation between SU(3) and the Poincare group and the first class condition it follows that the formfactor ratio Xi of K/sub l 3 / decay is Xi = --0.57, and that a value of Xi = 0 is in disagreement with very general and well accepted theoretical assumptions. Assuming universality of V-A, the Cabibbo suppression is derived from the relations between SU(3) and V-A as a consequence of the brokenness of SU(3). (U.S.)

Genome-wide Studies of Mycolic Acid Bacteria: Computational Identification and Analysis of a Minimal Genome

KAUST Repository

Kamanu, Frederick Kinyua

2012-12-01

The mycolic acid bacteria are a distinct suprageneric group of asporogenous Grampositive, high GC-content bacteria, distinguished by the presence of mycolic acids in their cell envelope. They exhibit great diversity in their cell and morphology; although primarily non-pathogens, this group contains three major pathogens Mycobacterium leprae, Mycobacterium tuberculosis complex, and Corynebacterium diphtheria. Although the mycolic acid bacteria are a clearly defined group of bacteria, the taxonomic relationships between its constituent genera and species are less well defined. Two approaches were tested for their suitability in describing the taxonomy of the group. First, a Multilocus Sequence Typing (MLST) experiment was assessed and found to be superior to monophyletic (16S small ribosomal subunit) in delineating a total of 52 mycolic acid bacterial species. Phylogenetic inference was performed using the neighbor-joining method. To further refine phylogenetic analysis and to take advantage of the widespread availability of bacterial genome data, a computational framework that simulates DNA-DNA hybridisation was developed and validated using multiscale bootstrap resampling. The tool classifies microbial genomes based on whole genome DNA, and was deployed as a web-application using PHP and Javascript. It is accessible online at http://cbrc.kaust.edu.sa/dna_hybridization/ A third study was a computational and statistical methods in the identification and analysis of a putative minimal mycolic acid bacterial genome so as to better understand (1) the genomic requirements to encode a mycolic acid bacterial cell and (2) the role and type of genes and genetic elements that lead to the massive increase in genome size in environmental mycolic acid bacteria. Using a reciprocal comparison approach, a total of 690 orthologous gene clusters forming a putative minimal genome were identified across 24 mycolic acid bacterial species. In order to identify new potential drug

Molecular Diversity, Cultivation, and Improved Detection by Fluorescent In Situ Hybridization of a Dominant Group of Human Gut Bacteria Related to Roseburia spp. or Eubacterium rectale

OpenAIRE

Aminov, Rustam I.; Walker, Alan W.; Duncan, Sylvia H.; Harmsen, Hermie J. M.; Welling, Gjalt W.; Flint, Harry J.

2006-01-01

Phylogenetic analysis was used to compare 16S rRNA sequences from 19 cultured human gut strains of Roseburia and Eubacterium rectale with 356 related sequences derived from clone libraries. The cultured strains were found to represent five of the six phylotypes identified. A new oligonucleotide probe, Rrec584, and the previous group probe Rint623, when used in conjunction with a new helper oligonucleotide, each recognized an average of 7% of bacteria detected by the eubacterial probe Eub338 i...

Effects of Gram-negative Bacteria, E.coli and Cold Exposure on Free Radicals Production, Lactate Dehydrogenase and Glutathione Peroxidase Activity in the Lungs of Rats, Rattus norvigicus

International Nuclear Information System (INIS)

AlSaid, A Haffor

2007-01-01

The purpose of this study was to explore the effects of LPS-gram negative bacteria and low ambient temperature on free radicals (FR) production, the activities of lactate dehydrogenase (LDH) and glutathione peroxidase (GPx) in the lungs of rats, Rattus norvigisu. Twenty four male rats, matched with age and weigh, were divided randomly into four groups namely control (C), Bacteria (B), cold temperature (T), and bacteria plus cold (BT). The T group was exposed to 10-12degree C ambient temperature for 3 days. Animals of the BT was injected LPS bacteria (IP, 500 micron g/kg) during the last five hour of cold exposure to 10-12 degree C for 3 days. In comparison with C group FR increased significantly (p<0.05) in the experimental groups, indicating high rate of reactive oxygen species (ROS) accumulation. The activity of LDH increased significantly (p<0.05) in the T and BT groups, which demonstrated that bacteria and exposure to cold are causes for cellular injury in the lungs. The synergetic effect of both bacteria and cold on LDH was more intense, as compared with the single effect. The activity of GPx increased significantly (p<0.05) in the B and BT, as compared with the C group. The results of the present study is the first worldwide report to demonstrate that both cold exposure and bacteria infection are mediated by elevation in FR generation. (author)

Inhibition of fish bacteria pathogen in tilapia using a concoction three of Borneo plant extracts

Science.gov (United States)

Hardi, EH; Saptiani, G.; Kusuma, IW; Suwinarti, W.; Sudaryono, A.

2018-04-01

This study was conducted to evaluate the antibacterial activity of concoction Solanum ferox, Boesenbergia pandurata and Zingimber zerumbetextract (SF, BP, and ZZ) to inhibit pathogenic bacteria in tilapia with the each concentrations 600 ppm BP, 900 ppm SF and 200 ppm ZZ. Antibacterial activity was measured by testing the concoction of three plants extract against single isolate Aeromonas hydrophila and Pseudomonas sp. and combined both bacteria (105 colony-forming units per milliliter). In this research, oxytetracycline was used as a control. Clear zone inhibition was observed at 6, 12, 18 and 24 hours after incubation at 30 °C. The results showed that the different concoction of BP: SF: ZZ have inhibitory zones against both single and joint isolate bacteria. The ratio of3:3:4 and 1:8:1 had higher antibacterial activity towards Pseudomonas sp. and 1:1:3 ratios both inhibit joint bacteria. The ZI% higher of concoction extracts against A.hydrophila is 1:1:8; 1:3:1; 3:4:3. The ZI% concoction extracts against Pseudomonas sp. ware 3:3:4 and 1:8:1 ratio. While the two bacteria combined, just 1:1:3 ratio had higher Z%. The conclusion is that a concoction of SF:BP:ZZ is effective to inhibit the growth of A.hydrophila and Pseudomonas sp., even its antibacterial ability is similar to the effectiveness of antibiotic oxytetracycline.

Vitreous System Ag2O –ZnO–B2O3 Action Against Gram Negative Bacteria

Directory of Open Access Journals (Sweden)

Razvan Stefan

2010-05-01

Full Text Available In this work the ability of the system xAg2O  (100-x [45ZnO55B2O3] oxide glasses to inhibit the growth of bacteria Eschierchia coli, Pseudomonas and Salmonella was investigated. Using the diffusimetric method there were measured the diameters of inhibition, in order to classify the sensitivity of gram negative bacteria to oxide compounds containing silver, for their use as filters. Vitreous samples were processed as powders with grain between 45 and 75 m and less than 45 m for a large of contact area with the microorgansms and to make possible the study of biological effect of grain addiction. Action of the investigated oxide system against the gram negative bacteria is strictly related to the presence of silver oxide in glass composition.

Direct immobilization of antibodies on Zn-doped Fe_3O_4 nanoclusters for detection of pathogenic bacteria

International Nuclear Information System (INIS)

Pal, Monalisa; Lee, Sanghee; Kwon, Donghoon; Hwang, Jeongin; Lee, Hyeonjeong; Hwang, Seokyung; Jeon, Sangmin

2017-01-01

Zinc-doped magnetic nanoclusters (Zn-MNCs) were synthesized and used to detect pathogenic bacteria in milk. Hydrothermally synthesized Zn-MNCs exhibited stronger magnetic properties than pure MNCs, which facilitated the magnetic separation from the sample using a permanent magnet. The presence of accessible Zn sites allows the direct immobilization of half-fragmented antibodies over Zn-MNCs through strong Zn−S bonds and prevents the tedious multiple steps of molecular functionalization or coating with costly noble metals prior to conjugation with an antibody. After the capture and magnetic separation of Salmonella in milk using the antibody-functionalized Zn-MNCs, the concentration of bacteria was determined with a portable ATP luminometer and the detection limit was found to be 10 CFU/mL. - Highlights: • Zn-doped Fe_3O_4 nanoclusters (Zn-MNCs) were synthesized by hydrothermal method. • Antibodies were directly immobilized over Zn-MNCs through strong Zn–S_t_h_i_o_l bonds. • Higher magnetization of Zn-MNCs than pure MNCs facilitates the magnetic separation. • Detection limit of pathogenic bacteria in milk was found to be 10 cfu/mL. • Cost effective, sensitive and selective detection of bacteria.

Bacteria-mediated bisphenol A degradation.

Science.gov (United States)

Zhang, Weiwei; Yin, Kun; Chen, Lingxin

2013-07-01

Bisphenol A (BPA) is an important monomer in the manufacture of polycarbonate plastics, food cans, and other daily used chemicals. Daily and worldwide usage of BPA and BPA-contained products led to its ubiquitous distribution in water, sediment/soil, and atmosphere. Moreover, BPA has been identified as an environmental endocrine disruptor for its estrogenic and genotoxic activity. Thus, BPA contamination in the environment is an increasingly worldwide concern, and methods to efficiently remove BPA from the environment are urgently recommended. Although many factors affect the fate of BPA in the environment, BPA degradation is mainly depended on the metabolism of bacteria. Many BPA-degrading bacteria have been identified from water, sediment/soil, and wastewater treatment plants. Metabolic pathways of BPA degradation in specific bacterial strains were proposed, based on the metabolic intermediates detected during the degradation process. In this review, the BPA-degrading bacteria were summarized, and the (proposed) BPA degradation pathway mediated by bacteria were referred.

A photometric high-throughput method for identification of electrochemically active bacteria using a WO3 nanocluster probe.

Science.gov (United States)

Yuan, Shi-Jie; He, Hui; Sheng, Guo-Ping; Chen, Jie-Jie; Tong, Zhong-Hua; Cheng, Yuan-Yuan; Li, Wen-Wei; Lin, Zhi-Qi; Zhang, Feng; Yu, Han-Qing

2013-01-01

Electrochemically active bacteria (EAB) are ubiquitous in environment and have important application in the fields of biogeochemistry, environment, microbiology and bioenergy. However, rapid and sensitive methods for EAB identification and evaluation of their extracellular electron transfer ability are still lacking. Herein we report a novel photometric method for visual detection of EAB by using an electrochromic material, WO(3) nanoclusters, as the probe. This method allowed a rapid identification of EAB within 5 min and a quantitative evaluation of their extracellular electron transfer abilities. In addition, it was also successfully applied for isolation of EAB from environmental samples. Attributed to its rapidness, high reliability, easy operation and low cost, this method has high potential for practical implementation of EAB detection and investigations.

In vitro ciprofloxacin resistance patterns of gram positive bacteria isolated from clinical specimens in a teaching hospital in Saudi Arabia

International Nuclear Information System (INIS)

Akhtar, N.; Alzahrani, A.; Obeid, O.El-Treify; Dassal, D.

2009-01-01

Over the last few decades the ever-increasing level of bacterial resistance to antimicrobials has been a cause of worldwide concern. Fluoroquinolones, particularly ciprofloxacin has been used indiscriminately for both gram-positive and gram-negative bacterial infections. The increased use of ciprofloxacin has led to a progressive loss of bacterial susceptibility to this antibiotic. Therefore it is necessary to have update knowledge of resistance pattern of bacteria to this antibiotic so that alternate appropriate antibiotics can be used for ciprofloxacin-resistant bacterial infections. Objective: To evaluate the trends of ciprofloxacin resistance pattern in commonly isolated gram positive bacteria over time in a Saudi Arabian teaching hospital. Methods: A retrospective analysis was carried out for ciprofloxacin susceptibility patterns of 5534 isolates of gram-positive bacteria isolated from clinical specimens submitted to microbiology laboratories at King Fahd Hospital of the University (KFHU), Al-Khobar, Saudi Arabia during the period from January 2002 to August 2005. Results: Increase in ciprofloxacin resistance rates with some fluctuations, among these isolates, were observed. For Staphylococcus aureus, it varied from 4.62, 1.83, 7.01 and 3.98%, methicillin resistant Staphylococcus aureus (MRSA) 97.92, 97.75, 87.01 and 88.26%, Streptococcus pyogenes 5.35, 4.47, 14.44 and 3.53% during the years 2002, 2003, 2004 and 2005 respectively. Cirprofloxacin resistance during the years 2002, 2004 and 2005 for other isolates was as follows: Streptococcus pneumoniae, 30.23, 23.02 and 26.47%; enterococcus group D, 43.05, 20.68 and 57.03% and non-enterococcus group D, 62.96, 76.92 and 87.50% respectively. Conclusion: Ciprofloxacin resistance in gram positive bacterial clinical isolates particularly Staphylococcus aureus, methicillin resistant Staphylococcus aureus (MRSA) enterococcus group D, and non-enterococcus group D, has greatly increased and ciprofloxacin no more remains

Automorphism group of nonabelian groups of order p{sup 3}

Energy Technology Data Exchange (ETDEWEB)

Sarmin, Nor Haniza [Department of Mathematical Sciences, Faculty of Science, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru (Malaysia); Barakat, Yasamin [Department of Mathematical Sciences, Faculty of Science, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru, Malaysia and Islamic Azad University-Ahvaz Branch, Ahvaz (Iran, Islamic Republic of)

2014-06-19

Let G be a nonabelian group of order p{sup 3}, where p is a prime number. Then G is a two generated group that its commutator, centre and Frattini subgroup coincide and are of order p. Hence, the quotient group of G over its centre and also Frattini quotient group of G, both are of order p{sup 2}. However, the first mentioned quotient is isomorphic to the inner group of G, which is a normal subgroup of automorphism group of G. Whereas, Frattini quotient group of G is an abelian elementary group that can be considered as a vector space of dimension two over Z{sub p}, the field of integers modulo p. In this paper, we consider to apply these properties of G to characterize the automorphism group of G.

Effects of doe-litter separation on intestinal bacteria, immune response and morphology of suckling rabbits

Directory of Open Access Journals (Sweden)

Yukun Zhang

2018-03-01

Full Text Available Gut development is stimulated by exposure to microorganisms, especially early-life microbial exposure. This study aimed to investigate whether doe-litter separation, which is performed in many rabbit farms, affects this exposure and therefore inhibits the development of intestinal system in suckling rabbits. Immediately after parturition, Rex rabbit does (n=16 were adjusted to 8 kits per litter and divided into doe-litter separation (DLS group and doe-litter together (DLT group based on the conditions of the does. One healthy kit per litter was selected and sacrificed at 7 d, 14 d, 21 d and 28 d of age, and the number of total bacteria, Escherichia coli and Bacteroides-Prevotella, expression of interleukin 6 (IL-6 and interleukin 10 (IL-10 in duodenum and caecum were investigated by real-time polymerase chain reaction. The morphological parameters of duodenum and vermiform appendix were also measured. Our results showed that doe-litter separation affected the number of intestinal bacteria. At 7 d of age, except for caecal Escherichia coli, the number of the investigated bacteria was decreased by doe-litter separation (P<0.05. But 1 wk later, only the number of total bacteria and Bacteroides-Prevotella in caecal content (P<0.05 and Escherichia coli in duodenal content from DLS kits (P<0.05 were still lower than those from DLT kits. After being provided with supplementary food for 7 d, DLS kits had fewer total bacteria in caecal content (P<0.05 and fewer E. coli in duodenal content (P<0.01 than DLT kits. After growing to 28 d of age, kits in DLS group still tended to have fewer total bacteria in caecal content, and expression of IL-10 and secretion of secretory IgA (sIgA in vermiform appendix in DLS group was obviously lower than kits in DLT group (P<0.05. The villus height:crypt depth ratio in duodenum at 3rd wk and 4th wk was decreased by DLS (P<0.05. Kits in DLS group had shorter villus height (P<0.05, higher crypt depth (P<0.05 and shorter

Coexistence of nitrifying, anammox and denitrifying bacteria in a sequencing batch reactor

Directory of Open Access Journals (Sweden)

Michela eLangone

2014-02-01

Full Text Available Elevated nitrogen removal efficiencies from ammonium-rich wastewaters have been demonstrated by several applications, that combine nitritation and anammox processes. Denitrification will occur simultaneously when organic carbon is also present. In this study, the activity of aerobic ammonia oxidizing, anammox and denitrifying bacteria in a full scale Sequencing Batch Reactor, treating digester supernatants, was studied by means of batch-assays. AOB and anammox activities were maximum at pH of 8.0 and 7.8-8.0, rispectively. Short term effect of nitrite on anammox activity was studied, showing nitrite up to 42 mg/L did not result in inhibition. Both denitrification via nitrate and nitrite were measured. To reduce nitrite-oxidizing activity, high of NH3 – N (1.9-10 mg N-NH3/L and low nitrite (3-8 mg TNN/L are required conditions during the whole SBR cycle.Molecular analysis showed the nitritation-anammox sludge harbored a high microbial diversity, where each microorganism has a specific role. Using ammonia monooxygenase α –subunit (amoA gene as a marker, our analyses suggested different macro- and micro-environments in the reactor strongly affect the AOB community, allowing the development of different AOB species, such as N. europaea/eutropha and N. oligotropha groups, which improve the stability of nitritation process. A specific PCR primer set, used to target the 16S rRNA gene of anammox bacteria, confirmed the presence of the Ca. Brocadia fulgida type, able to grow in precence of organic matter and to tolerate high nitrite concentrations. The diversity of denitrifiers was assessed by using dissimilatory nitrite reductase (nirS gene-based analyses, who showed denitifiers were related to different betaproteobacterial genera, such as Thauera, Pseudomonas, Dechloromonas and Aromatoleum, able to assist in forming microbial aggregates. Concerning possible secondary processes, no n-damo bacteria were found while NOB from the genus of Nitrobacter

Influence of extracellular polymeric substances (EPS) on Cd adsorption by bacteria

Energy Technology Data Exchange (ETDEWEB)

Wei Xing [State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070 (China); Fang Linchuan [Key Laboratory of Subtropical Agricultural Resources and Environment, Ministry of Agriculture, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070 (China); Cai Peng, E-mail: cp@mail.hzau.edu.cn [State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070 (China); Key Laboratory of Subtropical Agricultural Resources and Environment, Ministry of Agriculture, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070 (China); Huang Qiaoyun [State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070 (China); Key Laboratory of Subtropical Agricultural Resources and Environment, Ministry of Agriculture, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070 (China); Chen Hao [College of Science, Huazhong Agricultural University, Wuhan 430070 (China); Liang Wei; Rong, Xinming [Key Laboratory of Subtropical Agricultural Resources and Environment, Ministry of Agriculture, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070 (China)

2011-05-15

The role of extracellular polymeric substances (EPS) in Cd adsorption by Bacillus subtilis and Pseudomonas putida was investigated using a combination of batch adsorption experiments, potentiometric titrations, Fourier transform infrared spectroscopy (FTIR). An increased adsorption capacity of Cd was observed for untreated bacteria relative to that for EPS-free bacteria. Surface complexation modeling of titration data showed the similar pK{sub a} values of functional groups (carboxyl, phosphate and hydroxyl) between untreated and EPS-free bacteria. However, site concentrations on the untreated bacteria were found to be higher than those on the EPS-free bacteria. FTIR spectra also showed that no significant difference in peak positions was observed between untreated and EPS-free bacteria and carboxyl and phosphate groups were responsible for Cd adsorption on bacterial cells. The information obtained in this study is of fundamental significance for understanding the interaction mechanisms between heavy metals and biofilms in natural environments. - Highlights: > The presence of EPS on bacterial surfaces facilitates the adsorption of Cd. > The promoting effects on Cd adsorption are more remarkable on Gram-positive B. subtilis cells than that on Gram-negative P. putida cells. > Carboxyl and phosphate groups are mostly responsible for Cd binding on untreated and EPS-free cells. > Intact bacterial cells and EPS-free cells have similar binding mechanisms for Cd. - Intact bacterial cells and EPS-free cells have similar binding mechanisms for Cd.

Differential staining of bacteria: gram stain.

Science.gov (United States)

Moyes, Rita B; Reynolds, Jackie; Breakwell, Donald P

2009-11-01

In 1884, Hans Christian Gram, a Danish doctor, developed a differential staining technique that is still the cornerstone of bacterial identification and taxonomic division. This multistep, sequential staining protocol separates bacteria into four groups based on cell morphology and cell wall structure: Gram-positive cocci, Gram-negative cocci, Gram-positive rods, and Gram-negative rods. The Gram stain is useful for assessing bacterial contamination of tissue culture samples or for examining the Gram stain status and morphological features of bacteria isolated from mixed or isolated bacterial cultures. (c) 2009 by John Wiley & Sons, Inc.

Bacterial production and growth rate estimation from [3H]thymidine incorporation for attached and free-living bacteria in aquatic systems

International Nuclear Information System (INIS)

Iriberri, J.; Unanue, M.; Ayo, B.; Barcina, I.; Egea, L.

1990-01-01

Production and specific growth rates of attached and free-living bacteria were estimated in an oligotrophic marine system, La Salvaje Beach, Vizcaya, Spain, and in a freshwater system having a higher nutrient concentration, Butron River, Vizcaya, Spain. Production was calculated from [methyl- 3 H]thymidine incorporation by estimating specific conversion factors (cells or micrograms of C produced per mole of thymidine incorporated) for attached and free-living bacteria, respectively, in each system. Conversion factors were not statistically different between attached and free-living bacteria: 6.812 x 10 11 and 8.678 x 10 11 μg of C mol -1 for free-living and attached bacteria in the freshwater system, and 1.276 x 10 11 and 1.354 x 10 11 μg of C mol -1 for free-living and attached bacteria in the marine system. Therefore, use of a unique conversion factor for the mixed bacterial population is well founded. However, conversion factors were higher in the freshwater system than in the marine system. This could be due to the different tropic conditions of the two systems. Free-living bacteria contributed the most to production in the two systems (85% in the marine system and 67% in the freshwater system) because of their greater contribution to total biomass. Specific growth rates calculated from production data and biomass data were similar for attached and free-living bacteria

Nucleotide sequence alignment of hdcA from Gram-positive bacteria.

Science.gov (United States)

Diaz, Maria; Ladero, Victor; Redruello, Begoña; Sanchez-Llana, Esther; Del Rio, Beatriz; Fernandez, Maria; Martin, Maria Cruz; Alvarez, Miguel A

2016-03-01

The decarboxylation of histidine -carried out mainly by some gram-positive bacteria- yields the toxic dietary biogenic amine histamine (Ladero et al. 2010 〈10.2174/157340110791233256〉 [1], Linares et al. 2016 〈http://dx.doi.org/10.1016/j.foodchem.2015.11.013〉〉 [2]). The reaction is catalyzed by a pyruvoyl-dependent histidine decarboxylase (Linares et al. 2011 〈10.1080/10408398.2011.582813〉 [3]), which is encoded by the gene hdcA. In order to locate conserved regions in the hdcA gene of Gram-positive bacteria, this article provides a nucleotide sequence alignment of all the hdcA sequences from Gram-positive bacteria present in databases. For further utility and discussion, see 〈http://dx.doi.org/ 10.1016/j.foodcont.2015.11.035〉〉 [4].

A flow-cytometric gram-staining technique for milk-associated bacteria.

Science.gov (United States)

Holm, Claus; Jespersen, Lene

2003-05-01

A Gram-staining technique combining staining with two fluorescent stains, Oregon Green-conjugated wheat germ agglutinin (WGA) and hexidium iodide (HI) followed by flow-cytometric detection is described. WGA stains gram-positive bacteria while HI binds to the DNA of all bacteria after permeabilization by EDTA and incubation at 50 degrees C for 15 min. For WGA to bind to gram-positive bacteria, a 3 M potassium chloride solution was found to give the highest fluorescence intensity. A total of 12 strains representing some of the predominant bacterial species in bulk tank milk and mixtures of these were stained and analyzed by flow cytometry. Overall, the staining method showed a clear differentiation between gram-positive and gram-negative bacterial populations. For stationary-stage cultures of seven gram-positive bacteria and five gram-negative bacteria, an average of 99% of the cells were correctly interpreted. The method was only slightly influenced by the growth phase of the bacteria or conditions such as freezing at -18 degrees C for 24 h. For any of these conditions, an average of at least 95% of the cells were correctly interpreted. When stationary-stage cultures were stored at 5 degrees C for 14 days, an average of 86% of the cells were correctly interpreted. The Gram-staining technique was applied to the flow cytometry analysis of bulk tank milk inoculated with Staphylococcus aureus and Escherichia coli. These results demonstrate that the technique is suitable for analyzing milk samples without precultivation.

The diversity of PAH-degrading bacteria in a deep-sea water column above the Southwest Indian Ridge

Science.gov (United States)

Yuan, Jun; Lai, Qiliang; Sun, Fengqin; Zheng, Tianling; Shao, Zongze

2015-01-01

The bacteria involved in organic pollutant degradation in pelagic deep-sea environments are largely unknown. In this report, the diversity of polycyclic aromatic hydrocarbon (PAH)-degrading bacteria was analyzed in deep-sea water on the Southwest Indian Ridge (SWIR). After enrichment with a PAH mixture (phenanthrene, anthracene, fluoranthene, and pyrene), nine bacterial consortia were obtained from depths of 3946–4746 m. While the consortia degraded all four PAHs when supplied in a mixture, when PAHs were tested individually, only phenanthrene supported growth. Thus, degradation of the PAH mixture reflected a cometabolism of anthracene, fluoranthene, and pyrene with phenanthrene. Further, both culture-dependent and independent methods revealed many new bacteria involved in PAH degradation. Specifically, the alpha and gamma subclasses of Proteobacteria were confirmed as the major groups within the communities. Additionally, Actinobacteria, the CFB group and Firmicutes were detected. Denaturing Gradient Gel Electrophoresis (DGGE) analysis showed that bacteria closely affiliated with Alcanivorax, Novosphingobium, and Rhodovulum occurred most frequently in different PAH-degrading consortia. By using general heterotrophic media, 51 bacteria were isolated from the consortia and of these 34 grew with the PAH mixture as a sole carbon source. Of these, isolates most closely related to Alterierythrobacter, Citricella, Erythrobacter, Idiomarina, Lutibacterium, Maricaulis, Marinobacter, Martelella, Pseudidiomarina, Rhodobacter, Roseovarius, Salipiger, Sphingopyxis, and Stappia were found to be PAH degraders. To the best of our knowledge, this is the first time these bacteria have been identified in this context. In summary, this report revealed significant diversity among the PAH-degrading bacteria in the deep-sea water column. These bacteria may play a role in PAH removal in deep-sea environments. PMID:26379634

The diversity of PAH-degrading bacteria in a deep-sea water column above the Southwest Indian Ridge.

Science.gov (United States)

Yuan, Jun; Lai, Qiliang; Sun, Fengqin; Zheng, Tianling; Shao, Zongze

2015-01-01

The bacteria involved in organic pollutant degradation in pelagic deep-sea environments are largely unknown. In this report, the diversity of polycyclic aromatic hydrocarbon (PAH)-degrading bacteria was analyzed in deep-sea water on the Southwest Indian Ridge (SWIR). After enrichment with a PAH mixture (phenanthrene, anthracene, fluoranthene, and pyrene), nine bacterial consortia were obtained from depths of 3946-4746 m. While the consortia degraded all four PAHs when supplied in a mixture, when PAHs were tested individually, only phenanthrene supported growth. Thus, degradation of the PAH mixture reflected a cometabolism of anthracene, fluoranthene, and pyrene with phenanthrene. Further, both culture-dependent and independent methods revealed many new bacteria involved in PAH degradation. Specifically, the alpha and gamma subclasses of Proteobacteria were confirmed as the major groups within the communities. Additionally, Actinobacteria, the CFB group and Firmicutes were detected. Denaturing Gradient Gel Electrophoresis (DGGE) analysis showed that bacteria closely affiliated with Alcanivorax, Novosphingobium, and Rhodovulum occurred most frequently in different PAH-degrading consortia. By using general heterotrophic media, 51 bacteria were isolated from the consortia and of these 34 grew with the PAH mixture as a sole carbon source. Of these, isolates most closely related to Alterierythrobacter, Citricella, Erythrobacter, Idiomarina, Lutibacterium, Maricaulis, Marinobacter, Martelella, Pseudidiomarina, Rhodobacter, Roseovarius, Salipiger, Sphingopyxis, and Stappia were found to be PAH degraders. To the best of our knowledge, this is the first time these bacteria have been identified in this context. In summary, this report revealed significant diversity among the PAH-degrading bacteria in the deep-sea water column. These bacteria may play a role in PAH removal in deep-sea environments.

[3H]Leucine incorporation method as a tool to measure secondary production by periphytic bacteria associated to the roots of floating aquatic macrophyte.

Science.gov (United States)

Miranda, M R; Guimarães, J R D; Coelho-Souza, A S

2007-10-01

The present study assessed the application of [(3)H]Leucine incorporation into protein by periphytic bacteria associated with the roots of the floating aquatic macrophyte Eichornia crassipes. Basic assumptions underlying the method, such as linearity of leucine incorporation, saturation level of incorporation rates, incorporation into other macromolecules, specificity of incorporation for bacterial assemblages and [(3)H]Leucine degradation during samples storage were tested, and two procedures for extracting the incorporated leucine were compared. Both methods gave the same results, however, the hot TCA extraction method was less time consuming than the alkaline extraction method. Incorporation of [(3)H]Leucine was linear for up to 40 min. Saturation concentration of [(3)H]Leucine incorporation into protein was 1500 nM. An experiment with prokaryotic and eukaryotic inhibitors showed no significant [(3)H]Leucine incorporation into eukaryotes even in high leucine concentrations. No significant amounts of radiolabel were incorporated into other macromolecules. The maximum time of sample storage after the incubation is 15 days. The leucine incorporation method can be a reliable tool to measure bacterial production in the periphyton root-associated bacteria.

A flow cytometric technique for quantification and differentiation of bacteria in bulk tank milk

DEFF Research Database (Denmark)

Holm, C.; Mathiasen, T.; Jespersen, Lene

2004-01-01

were defined: region 1 includes bacteria mainly associated with poor hygiene, region 2 includes psychrotrophic hygiene bacteria and region 3 includes bacteria mainly related to mastitis. The ability of the flow cytometric technique to predict the main cause of elevated bacterial counts on routine...

Survival and detection of coliforms, Enterobacteriaceae, and gram-negative bacteria in Greek yogurt.

Science.gov (United States)

Hervert, C J; Martin, N H; Boor, K J; Wiedmann, M

2017-02-01

Despite the widespread use of coliforms as indicator bacteria, increasing evidence suggests that the Enterobacteriaceae (EB) and total gram-negative groups more accurately reflect the hygienic status of high-temperature, short-time pasteurized milk and processing environments. If introduced into milk as postpasteurization contamination, these bacteria may grow to high levels and produce a wide range of sensory-related defects. However, limited information is available on the use and survival of bacterial hygiene indicators in dairy products outside of pasteurized fluid milk and cheese. The goal of this study was to (1) provide information on the survival of a diverse set of bacterial hygiene indicators in the low pH environment of Greek yogurt, (2) compare traditional and alternative detection methods for their ability to detect bacterial hygiene indicators in Greek yogurt, and (3) offer insight into optimal hygiene indicator groups for use in low-pH fermented dairy products. To this end, we screened 64 bacterial isolates, representing 24 dairy-relevant genera, for survival and detection in Greek yogurt using 5 testing methods. Before testing, isolates were inoculated into plain, 0% fat Greek yogurt (pH 4.35 to 4.65), followed by a 12-h hold period at 4 ± 1°C. Yogurts were subsequently tested using Coliform Petrifilm (3M, St. Paul, MN) to detect coliforms; Enterobacteriaceae Petrifilm (3M), violet red bile glucose agar and the D-Count (bioMérieux, Marcy-l'Étoile, France) to detect EB; and crystal violet tetrazolium agar (CVTA) to detect total gram-negative bacteria. Overall, the non-EB gram-negative isolates showed significantly larger log reductions 12 h after inoculation into Greek yogurt (based on bacterial numbers recovered on CVTA) compared with the coliform and noncoliform EB isolates tested. The methods evaluated varied in their ability to detect different microbial hygiene indicators in Greek yogurt. Crystal violet tetrazolium agar detected the highest

Anaerobic bacteria

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Anaerobic bacteria are bacteria that do not live or grow when oxygen is present. In humans, these bacteria ... Brook I. Diseases caused by non-spore-forming anaerobic bacteria. In: Goldman L, Schafer AI, eds. Goldman-Cecil ...

Ocean acidification impacts bacteria-phytoplankton coupling at low-nutrient conditions

Science.gov (United States)

Hornick, Thomas; Bach, Lennart T.; Crawfurd, Katharine J.; Spilling, Kristian; Achterberg, Eric P.; Woodhouse, Jason N.; Schulz, Kai G.; Brussaard, Corina P. D.; Riebesell, Ulf; Grossart, Hans-Peter

2017-01-01

The oceans absorb about a quarter of the annually produced anthropogenic atmospheric carbon dioxide (CO2), resulting in a decrease in surface water pH, a process termed ocean acidification (OA). Surprisingly little is known about how OA affects the physiology of heterotrophic bacteria or the coupling of heterotrophic bacteria to phytoplankton when nutrients are limited. Previous experiments were, for the most part, undertaken during productive phases or following nutrient additions designed to stimulate algal blooms. Therefore, we performed an in situ large-volume mesocosm ( ˜ 55 m3) experiment in the Baltic Sea by simulating different fugacities of CO2 (fCO2) extending from present to future conditions. The study was conducted in July-August after the nominal spring bloom, in order to maintain low-nutrient conditions throughout the experiment. This resulted in phytoplankton communities dominated by small-sized functional groups (picophytoplankton). There was no consistent fCO2-induced effect on bacterial protein production (BPP), cell-specific BPP (csBPP) or biovolumes (BVs) of either free-living (FL) or particle-associated (PA) heterotrophic bacteria, when considered as individual components (univariate analyses). Permutational Multivariate Analysis of Variance (PERMANOVA) revealed a significant effect of the fCO2 treatment on entire assemblages of dissolved and particulate nutrients, metabolic parameters and the bacteria-phytoplankton community. However, distance-based linear modelling only identified fCO2 as a factor explaining the variability observed amongst the microbial community composition, but not for explaining variability within the metabolic parameters. This suggests that fCO2 impacts on microbial metabolic parameters occurred indirectly through varying physicochemical parameters and microbial species composition. Cluster analyses examining the co-occurrence of different functional groups of bacteria and phytoplankton further revealed a separation of

Helicobacter bilis Infection Alters Mucosal Bacteria and Modulates Colitis Development in Defined Microbiota Mice.

Science.gov (United States)

Atherly, Todd; Mosher, Curtis; Wang, Chong; Hostetter, Jesse; Proctor, Alexandra; Brand, Meghan W; Phillips, Gregory J; Wannemuehler, Michael; Jergens, Albert E

2016-11-01

Helicobacter bilis infection of C3H/HeN mice harboring the altered Schaedler flora (ASF) triggers progressive immune responsiveness and the development of colitis. We sought to investigate temporal alterations in community structure of a defined (ASF-colonized) microbiota in normal and inflamed murine intestines and to correlate microbiota changes to histopathologic lesions. The colonic mucosal microbiota of healthy mice and ASF mice colonized with H. bilis for 3, 6, or 12 weeks were investigated by fluorescence in situ hybridization targeting the 16S ribosomal RNA genes of total bacteria, group-specific organisms, and individual ASF bacterial species. Microbial profiling of ASF and H. bilis abundance was performed on cecal contents. Helicobacter bilis-colonized mice developed colitis associated with temporal changes in composition and spatial distribution of the mucosal microbiota. The number of total bacteria, ASF519, and helicobacter-positive bacteria were increased (P attachment, or by invasion, and this interaction is differentially expressed over time.

COMPARISON OF NON-COLIFORM BACTERIA IN BALI CATTLE FAECES BASED ON LEVEL OF MATURITY AND MAINTENANCE PATTERN

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Kadek Andre Sulaksana

2017-08-01

Full Text Available This study aim was to determine the effect of maintenance type and maturity level of bali cattle to the total of non coliform bacteria in bali cattle. A total of 24 samples of bali cattle’s feces were used. This study was a Factorial 2 x 3 of group-randomised design, contained of two type maintenance (TPA Suwung and Sobangan and three levels of cattle maturity (calves, heifers, and adult. The groups were based on time sampling. The data then analyzed using Analysis of Variance Test and continued by using Least Significant Different test. The results showed that the amount of non-coliform bacteria in adult bali cattle feces were higher then heifers and calves. Total of non coliform bacteria in bali cattle in  landfill was higher then the cattle that reared in captivity in Bali Cattle Breeding Center, the Sobangan village of Mengwi Badung regency.

Adhesion of biodegradative anaerobic bacteria to solid surfaces

Energy Technology Data Exchange (ETDEWEB)

Schie, P.M. van; Fletcher, M.

1999-11-01

In order to exploit the ability of anaerobic bacteria to degrade certain contaminants for bioremediation of polluted subsurface environments, the authors need to understand the mechanisms by which such bacteria partition between aqueous and solid phases, as well as the environmental conditions that influence partitioning. They studied four strictly anaerobic bacteria, Desulfomonile tiedjei, Syntrophomonas wolfei, Syntrophobacter wolinii, and Desulfovibrio sp. strain G11, which theoretically together can constitute a tetrachloroethylene- and trichloroethylene-dechlorinating consortium. Adhesion of these organisms was evaluated by microscopic determination of the numbers of cells that attached to glass coverslips exposed to cell suspensions under anaerobic conditions. The authors studied the effects of the growth phase of the organisms on adhesion, as well as the influence of electrostatic and hydrophobic properties of the substratum. Results indicate that S. wolfei adheres in considerably higher numbers to glass surfaces than the other three organisms. Starvation greatly decreases adhesion of S. wolfei and Desulfovibrio sp. strain G11 but seems to have less of an effect on the adhesion of the other bacteria. The presence of Fe{sup 3+} on the substratum, which would be electropositive, significantly increased the adhesion of S. wolfei, whereas the presence of silicon hydrophobic groups decreased the numbers of attached cells of all species. Measurements of transport of cells through hydrophobic-interaction and electro-static-interaction columns indicated that all four species had negatively charged cell surfaces and that D. tiedjei and Desulfovibrio sp. strain G11 possessed some hydrophobic cell surface properties. These findings are an early step toward understanding the dynamic attachment of anaerobic bacteria in anoxic environments.

Bacteria within the gastrointestinal tract microbiota correlated with improved growth and feed conversion: Challenges presented for the identification of performance enhancing probiotic bacteria

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Dragana eStanley

2016-02-01

Full Text Available Identification of bacteria associated with desirable productivity outcomes in animals may offer a direct approach to the identification of probiotic bacteria for use in animal production. We performed three controlled chicken trials (n=96 to investigate caecal microbiota differences between the best and poorest performing birds using four performance measures; Feed Conversion Rate (FCR, utilisation of energy from the feed measured as Apparent Metabolisable Energy (AME, gain rate (GR and amount of feed eaten (FE. The shifts in microbiota composition associated with the performance measures were very different between the three trials. Analysis of the caecal microbiota revealed that the high and low FCR birds had significant differences in the abundance of some bacteria as demonstrated by shifts in microbiota alpha and beta diversity. Trials 1 and 2 showed significant overall community shifts, however the microbial changes driving the difference between good and poor performers were very different. Lachnospiraceae, Ruminococcaceae and Erysipelotrichaceae families and genera Ruminococcus, Faecalibacterium and multiple lineages of genus Clostridium (from families Lachnospiraceae, Ruminococcaceae and Erysipelotrichaceae were highly abundant in good FCR birds in Trial 1. Different microbiota was associated with FCR in Trial 2; Catabacteriaceae and unknown Clostridiales family members were increased in good FCR and genera Clostridium (from family Clostridiaceae and Lactobacillus were associated with poor FCR. Trial 3 had only mild microbiota differences associated with all 4 performance measures. Overall, the genus Lactobacillus was correlated with feed intake which resulted in poor FCR performance. The genus Faecalibacterium correlated with improved FCR, increased GR and reduced FE. There was overlap in phylotypes correlated with improved FCR and GR, while different microbial cohorts appeared to be correlated with FE. Even under controlled conditions

New molecular method to detect denitrifying anaerobic methane oxidation bacteria from different environmental niches.

Science.gov (United States)

Xu, Sai; Lu, Wenjing; Muhammad, Farooq Mustafa; Liu, Yanting; Guo, Hanwen; Meng, Ruihong; Wang, Hongtao

2018-03-01

The denitrifying anaerobic methane oxidation is an ecologically important process for reducing the potential methane emission into the atmosphere. The responsible bacterium for this process was Candidatus Methylomirabilis oxyfera belonging to the bacterial phylum of NC10. In this study, a new pair of primers targeting all the five groups of NC10 bacteria was designed to amplify NC10 bacteria from different environmental niches. The results showed that the group A was the dominant NC10 phylum bacteria from the sludges and food waste digestate while in paddy soil samples, group A and group B had nearly the same proportion. Our results also indicated that NC10 bacteria could exist in a high pH environment (pH9.24) from the food waste treatment facility. The Pearson relationship analysis showed that the pH had a significant positive relationship with the NC10 bacterial diversity (pbacteria. Copyright © 2017. Published by Elsevier B.V.

Halophilic and haloalkaliphilic sulfur-oxidizing bacteria

NARCIS (Netherlands)

Sorokin, D.Y.; Banciu, H.; Robertson, L.A.; Kuenen, J.G.; Muntyan, M.S.; Muyzer, G.; Rosenberg, E.; DeLong, F.; Delong, E.; Lory, S.; Stackebrandt, E.; Thompson, F.

2013-01-01

Chemotrophic sulfur-oxidizing bacteria (SOB) represent an important functional group of microorganisms responsible for the dark oxidation of reduced sulfur compounds generated by sulfidogens. Until recently, only a single genus of halophilic SOB (Halothiobacillus) has been described, and nothing was

PHOTODYNAMIC INACTIVATION OF PATHOGENIC BACTERIA IN BIOFILMS USING NEW SYNTHETIC BACTERIOCHLORIN DERIVATIVES

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I. G. Tiganova

2017-01-01

Full Text Available Bacteriochlorins as the antimicrobial photosensitizers have a promising future in the face of the unrelenting increase in antimicrobial resistance. The goal of this study was to investigate the infl uence of lipophilicity and number of positively charged  substituents in these molecules on the photodynamic inactivation  (PDI of biofi lm bacteria in vitro. Testing how bacteriochlorin  derivatives with different properties affect microbes will allow to  determine the optimal ratio of these parameters within a single  molecule. We have investigated 4 bacteriochlorin derivatives, all of  which were synthesized in Organic Intermediates and Dyes Institute. These were: hydrophobic neutral meso-tetra(3-pyridyl  bacteriochlorin (ВС1, amphyphilic tetracationic meso-tetra(1- undecyl-3-pyridylbacteriochlorin tetrabromide (ВС2, hydrophilic  tetracationic meso-tetra[1-(4'-bromobutyl-3-pyridyl]bacteriochlorin  tetrabromide (ВС3 and octacationic meso-tetra[1-(4'-pyridiniobutyl -3-pyridyl]bacteriochlorin octabromide (ВС4 . The water-soluble  cationic bacteriochlorin derivatives showed the most effective PDI of  bacteria in biofi lms. While tetracationic BC3 caused total inactivation of S. aureus 15, octacationic BC4 was bactericidal for P. aeruginosa  32 to the same degree (>99.999%. Interestingly, increasing the  number of cationic substituents from 4 to 8 in bacteriochlorin  molecules enhances bactericidal action against gram-negative  bacteria in biofi lms. The lack of charge-carrying groups and high  degree of lipophilicity of PS have negative impact on PDI of biofi lm  bacteria. Bacterial membrane damage as a result of PDI can be one of the causes of cell death.

Assessment of Photodynamic Inactivation against Periodontal Bacteria Mediated by a Chitosan Hydrogel in a 3D Gingival Model

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Po-Chun Peng

2016-11-01

Full Text Available Chitosan hydrogels containing hydroxypropyl methylcellulose (HPMC and toluidine blue O were prepared and assessed for their mucoadhesive property and antimicrobial efficacy of photodynamic inactivation (PDI. Increased HPMC content in the hydrogels resulted in increased mucoadhesiveness. Furthermore, we developed a simple In Vitro 3D gingival model resembling the oral periodontal pocket to culture the biofilms of Staphylococcus aureus (S. aureus, Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans, and Porphyromonas gingivalis (P. gingivalis. The PDI efficacy of chitosan hydrogel was examined against periodontal biofilms cultured in this 3D gingival model. We found that the PDI effectiveness was limited due to leaving some of the innermost bacteria alive at the non-illuminated site. Using this 3D gingival model, we further optimized PDI procedures with various adjustments of light energy and irradiation sites. The PDI efficacy of the chitosan hydrogel against periodontal biofilms can significantly improve via four sides of irradiation. In conclusion, this study not only showed the clinical applicability of this chitosan hydrogel but also the importance of the light irradiation pattern in performing PDI for periodontal disease.

Assessment of Photodynamic Inactivation against Periodontal Bacteria Mediated by a Chitosan Hydrogel in a 3D Gingival Model.

Science.gov (United States)

Peng, Po-Chun; Hsieh, Chien-Ming; Chen, Chueh-Pin; Tsai, Tsuimin; Chen, Chin-Tin

2016-11-01

Chitosan hydrogels containing hydroxypropyl methylcellulose (HPMC) and toluidine blue O were prepared and assessed for their mucoadhesive property and antimicrobial efficacy of photodynamic inactivation (PDI). Increased HPMC content in the hydrogels resulted in increased mucoadhesiveness. Furthermore, we developed a simple In Vitro 3D gingival model resembling the oral periodontal pocket to culture the biofilms of Staphylococcus aureus ( S. aureus ), Aggregatibacter actinomycetemcomitans ( A. actinomycetemcomitans ), and Porphyromonas gingivalis ( P. gingivalis ). The PDI efficacy of chitosan hydrogel was examined against periodontal biofilms cultured in this 3D gingival model. We found that the PDI effectiveness was limited due to leaving some of the innermost bacteria alive at the non-illuminated site. Using this 3D gingival model, we further optimized PDI procedures with various adjustments of light energy and irradiation sites. The PDI efficacy of the chitosan hydrogel against periodontal biofilms can significantly improve via four sides of irradiation. In conclusion, this study not only showed the clinical applicability of this chitosan hydrogel but also the importance of the light irradiation pattern in performing PDI for periodontal disease.

Identification of Bacteria and the Effect on Compressive Strength of Concrete

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Anneza L. H.

2016-01-01

Full Text Available This paper presents the species of bacteria used in this study as well as the effect of the bacteria on compressive strength of bioconcrete. Bioconcrete is not only more environmentally friendly but it is easy to procure. The objective of this research is to identify the ureolytic bacteria and sulphate reduction bacteria that have been isolated and further use the bacteria in concrete to determine the effect of bacteria on compressive strength. Identification of bacteria is conducted through Polymerase chain reaction (PCR method and DNA sequencing. The DNA of the bacteria was run through BLAST algorithm to determine the bacterial species.The bacteria were added into the concrete mix as a partial replacement of water. 3% of water is replaced by ureolytic bacteria and 5% of water is replaced by sulphate reduction bacteria. After running BLAST algorithm the bacteria were identified as Enterococcus faecalis (ureolytic bacteria and Bacillus sp (sulphate reduction bacteria. The result of the compressive strength for control is 36.0 Mpa. Partial replacement of 3% water by ureolytic bacteria has strength of 38.2Mpa while partial replacement of 5% of water by sulphate reduction bacteria has strength of 42.5Mpa. The significant increase of compressive strength with the addition of bacteria shows that bacteria play a significant role in the improvement of compressive strength.

Effectiveness of a pre-procedural mouthwash in reducing bacteria in dental aerosols: randomized clinical trial

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Belén RETAMAL-VALDES

2017-03-01

Full Text Available Abstract The aim of this randomized, single blinded clinical trial was to evaluate the effect of a pre-procedural mouthwash containing cetylpyridinium chloride (CPC, zinc lactate (Zn and sodium fluoride (F in the reduction of viable bacteria in oral aerosol after a dental prophylaxis with ultrasonic scaler. Sixty systemically healthy volunteers receiving dental prophylaxis were randomly assigned to one of the following experimental groups (15 per group: (i rinsing with 0.075% CPC, 0.28% Zn and 0.05% F (CPC+Zn+F, (ii water or (iii 0.12% chlorhexidine digluconate (CHX, and (iv no rinsing. Viable bacteria were collected from different locations in the dental office on enriched TSA plates and anaerobically incubated for 72 hours. The colonies were counted and species were then identified by Checkerboard DNA–DNA Hybridization. The total number of colony-forming units (CFUs detected in the aerosols from volunteers who rinsed with CPC+Zn+F or CHX was statistically significantly (p<0.05 lower than of those subjects who did not rinse or who rinsed with water. When all locations were considered together, the aerosols from the CPC+Zn+F and CHX groups showed, respectively, 70% and 77% fewer CFUs than those from the No Rinsing group and 61% and 70% than those from the Water group. The mean proportions of bacterial species from the orange complex were statistically significantly (p<0.05 lower in aerosols from the CPC+Zn+F and CHX groups compared with the others two groups. In conclusion, the mouthwash containing CPC+Zn+F, is effective in reducing viable bacteria in oral aerosol after a dental prophylaxis with ultrasonic scaler.

Multiqubit Clifford groups are unitary 3-designs

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Zhu, Huangjun

2017-12-01

Unitary t -designs are a ubiquitous tool in many research areas, including randomized benchmarking, quantum process tomography, and scrambling. Despite the intensive efforts of many researchers, little is known about unitary t -designs with t ≥3 in the literature. We show that the multiqubit Clifford group in any even prime-power dimension is not only a unitary 2-design, but also a 3-design. Moreover, it is a minimal 3-design except for dimension 4. As an immediate consequence, any orbit of pure states of the multiqubit Clifford group forms a complex projective 3-design; in particular, the set of stabilizer states forms a 3-design. In addition, our study is helpful in studying higher moments of the Clifford group, which are useful in many research areas ranging from quantum information science to signal processing. Furthermore, we reveal a surprising connection between unitary 3-designs and the physics of discrete phase spaces and thereby offer a simple explanation of why no discrete Wigner function is covariant with respect to the multiqubit Clifford group, which is of intrinsic interest in studying quantum computation.

Isolation and characterization of bacteria from wasted ionic exchange resins kept at Area de Gestion Ezeiza belonging to RA-3 Reactor

International Nuclear Information System (INIS)

Mosquera Rodriguez, Leon; Pizarro, Ramon A.

2009-01-01

A spent ionic exchange resin kept at Area de Gannet's Ezeiza (Age), belonging to RA-3 Reactor, was treated with sterile water. Microorganisms suspended in the aqueous sample were isolated by several methods, broadening as much as possible cell recovery conditions. Bacteria were subject to purity controls and re-isolation when necessary. Characterization of the strains found in the sample included morphological, physiological and biochemical tests as well as stains. Being the spent resins volume reduction at Age the main purpose, a screening experiment is proposed based on bacteria capability to take carbon from the sediment present in the liquid sample. Recovered bacteria are at least the following: Method I: Bacillus cereus, Bacillus circulans, Bacillus sp., Pseudomonas pseudoalcaligenes, Pseudomonas acidovorans, Pseudomonas sp. Method II: Bacillus cereus, Pseudomonas alcaligenes, Flavimonas sp., Agrobacterium sp. Method III: Bacillus circulans, Bacillus sphaericus, Kocuria rosea, Kytococcus sedentarius, Pseudomonas acidovorans. Microorganisms present in the sample are characteristic of those having low microbiological-contamination levels. Way III is an isolation method whose design would lead to find bacteria having the desired properties in order to diminish the volume of RA-3 Reactor spent resins. (author)

Group B streptococcus - pregnancy

Science.gov (United States)

... medlineplus.gov/ency/patientinstructions/000511.htm Group B streptococcus - pregnancy To use the sharing features on this page, please enable JavaScript. Group B streptococcus (GBS) is a type of bacteria that some ...

Ammonia production by ruminal microorganisms and enumeration, isolation, and characterization of bacteria capable of growth on peptides and amino acids from the sheep rumen.

Science.gov (United States)

Eschenlauer, S C P; McKain, N; Walker, N D; McEwan, N R; Newbold, C J; Wallace, R J

2002-10-01

Excessive NH(3) production in the rumen is a major nutritional inefficiency in ruminant animals. Experiments were undertaken to compare the rates of NH(3) production from different substrates in ruminal fluid in vitro and to assess the role of asaccharolytic bacteria in NH(3) production. Ruminal fluid was taken from four rumen-fistulated sheep receiving a mixed hay-concentrate diet. The calculated rate of NH(3) production from Trypticase varied from 1.8 to 19.7 nmol mg of protein(-1) min(-1) depending on the substrate, its concentration, and the method used. Monensin (5 micro M) inhibited NH(3) production from proteins, peptides, and amino acids by an average of 28% with substrate at 2 mg/ml, compared to 48% with substrate at 20 mg/ml (P = 0.011). Of the total bacterial population, 1.4% grew on Trypticase alone, of which 93% was eliminated by 5 micro M monensin. Many fewer bacteria (0.002% of the total) grew on amino acids alone. Nineteen isolates capable of growth on Trypticase were obtained from four sheep. 16S ribosomal DNA and traditional identification methods indicated the bacteria fell into six groups. All were sensitive to monensin, and all except one group (group III, similar to Atopobium minutum), produced NH(3) at >250 nmol min(-1) mg of protein(-1), depending on the medium, as determined by a batch culture method. All isolates had exopeptidase activity, but only group III had an apparent dipeptidyl peptidase I activity. Groups I, II, and IV were most closely related to asaccharolytic ruminal and oral Clostridium and Eubacterium spp. Group V comprised one isolate, similar to Desulfomonas piger (formerly Desulfovibrio pigra). Group VI was 95% similar to Acidaminococcus fermentans. Growth of the Atopobium- and Desulfomonas-like isolates was enhanced by sugars, while growth of groups I, II, and V was significantly depressed by sugars. This study therefore demonstrates that different methodologies and different substrate concentrations provide an explanation

Fuzzy species among recombinogenic bacteria

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Fraser Christophe

2005-03-01

Full Text Available Abstract Background It is a matter of ongoing debate whether a universal species concept is possible for bacteria. Indeed, it is not clear whether closely related isolates of bacteria typically form discrete genotypic clusters that can be assigned as species. The most challenging test of whether species can be clearly delineated is provided by analysis of large populations of closely-related, highly recombinogenic, bacteria that colonise the same body site. We have used concatenated sequences of seven house-keeping loci from 770 strains of 11 named Neisseria species, and phylogenetic trees, to investigate whether genotypic clusters can be resolved among these recombinogenic bacteria and, if so, the extent to which they correspond to named species. Results Alleles at individual loci were widely distributed among the named species but this distorting effect of recombination was largely buffered by using concatenated sequences, which resolved clusters corresponding to the three species most numerous in the sample, N. meningitidis, N. lactamica and N. gonorrhoeae. A few isolates arose from the branch that separated N. meningitidis from N. lactamica leading us to describe these species as 'fuzzy'. Conclusion A multilocus approach using large samples of closely related isolates delineates species even in the highly recombinogenic human Neisseria where individual loci are inadequate for the task. This approach should be applied by taxonomists to large samples of other groups of closely-related bacteria, and especially to those where species delineation has historically been difficult, to determine whether genotypic clusters can be delineated, and to guide the definition of species.

The unit group of group algebra $F_qSL(2;Z_3$

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Swati Maheshwari

2016-01-01

Full Text Available Let $\\F_q$ be a finite field of characteristic $p$ having $q$ elements, where $q = p^k$ and $p\\ge 5$. Let $ SL(2,\\Z_3$ be the special linear group of $2\\times2$ matrices with determinant $1$ over $\\Z_3$. In this note we establish the structure of the unit group of $\\F_q SL(2,\\Z_3$.

Multidrug-resistant Gram-negative bacteria: a product of globalization.

Science.gov (United States)

Hawkey, P M

2015-04-01

Global trade and mobility of people has increased rapidly over the last 20 years. This has had profound consequences for the evolution and the movement of antibiotic resistance genes. There is increasing exposure of populations all around the world to resistant bacteria arising in the emerging economies. Arguably the most important development of the last two decades in the field of antibiotic resistance is the emergence and spread of extended-spectrum β-lactamases (ESBLs) of the CTX-M group. A consequence of the very high rates of ESBL production among Enterobacteriaceae in Asian countries is that there is a substantial use of carbapenem antibiotics, resulting in the emergence of plasmid-mediated resistance to carbapenems. This article reviews the emergence and spread of multidrug-resistant Gram-negative bacteria, focuses on three particular carbapenemases--imipenem carbapenemases, Klebsiella pneumoniae carbapenemase, and New Delhi metallo-β-lactamase--and highlights the importance of control of antibiotic use. Copyright © 2015. Published by Elsevier Ltd.

'Rare biosphere' bacteria as key phenanthrene degraders in coastal seawaters.

Science.gov (United States)

Sauret, Caroline; Séverin, Tatiana; Vétion, Gilles; Guigue, Catherine; Goutx, Madeleine; Pujo-Pay, Mireille; Conan, Pascal; Fagervold, Sonja K; Ghiglione, Jean-François

2014-11-01

By coupling DNA-SIP and pyrosequencing approaches, we identified Cycloclasticus sp. as a keystone degrader of polycyclic aromatic hydrocarbons (PAH) despite being a member of the 'rare biosphere' in NW Mediterranean seawaters. We discovered novel PAH-degrading bacteria (Oceanibaculum sp., Sneathiella sp.) and we identified other groups already known to possess this function (Alteromonas sp., Paracoccus sp.). Together with Cycloclasticus sp., these groups contributed to potential in situ phenanthrene degradation at a rate >0.5 mg l(-1) day(-1), sufficient to account for a considerable part of PAH degradation. Further, we characterized the PAH-tolerant bacterial communities, which were much more diverse in the polluted site by comparison to unpolluted marine references. PAH-tolerant bacteria were also members of the rare biosphere, such as Glaciecola sp. Collectively, these data show the complex interactions between PAH-degraders and PAH-tolerant bacteria and provide new insights for the understanding of the functional ecology of marine bacteria in polluted waters. Copyright © 2014 Elsevier Ltd. All rights reserved.

9 CFR 3.7 - Compatible grouping.

Science.gov (United States)

2010-01-01

... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Compatible grouping. 3.7 Section 3.7... Cats 1 Animal Health and Husbandry Standards § 3.7 Compatible grouping. Dogs and cats that are housed...; (c) Puppies or kittens 4 months of age or less may not be housed in the same primary enclosure with...

Does estradiol have an impact on the dipeptidyl peptidase IV enzyme activity of the Prevotella intermedia group bacteria?

Science.gov (United States)

Fteita, Dareen; Könönen, Eija; Gürsoy, Mervi; Söderling, Eva; Gürsoy, Ulvi Kahraman

2015-12-01

Initiation and development of pregnancy-associated gingivitis is seemingly related to the microbial shift towards specific gram-negative anaerobes in subgingival biofilms. It is known that Prevotella intermedia sensu lato is able to use estradiol as an alternative source of growth instead of vitamin K. The aim of the present study was to investigate the impact of estradiol on the bacterial dipeptidyl peptidase IV (DPPIV) enzyme activity in vitro as a virulent factor of the Prevotella intermedia group bacteria, namely P. intermedia, Prevotella nigrescens, Prevotella pallens, and Prevotella aurantiaca. In all experiments, 2 strains of each Prevotella species were used. Bacteria were incubated with the concentrations of 0, 30, 90, and 120 nmol/L of estradiol and were allowed to build biofilms at an air-solid interface. DPPIV activities of biofilms were measured kinetically during 20 min using a fluorometric assay. The enzyme activity was later related to the amount of protein produced by the same biofilm, reflecting the biofilm mass. Estradiol significantly increased DPPIV activities of the 8 Prevotella strains in a strain- and dose-dependent manner. In conclusion, our in vitro experiments indicate that estradiol regulates the DPPIV enzyme activity of P. intermedia, P. nigrescens, P. pallens, and P. aurantiaca strains differently. Our results may, at least partly, explain the role of estradiol to elicit a virulent state which contributes to the pathogenesis of pregnancy-related gingivitis. Copyright © 2015 Elsevier Ltd. All rights reserved.

Isolation of previously uncultured rumen bacteria by dilution to extinction using a new liquid culture medium.

Science.gov (United States)

Kenters, Nikki; Henderson, Gemma; Jeyanathan, Jeyamalar; Kittelmann, Sandra; Janssen, Peter H

2011-01-01

A new anaerobic medium that mimics the salts composition of rumen fluid was used in conjunction with a dilution method of liquid culture to isolate fermentative bacteria from the rumen of a grass-fed sheep. The aim was to inoculate a large number of culture tubes each with a mean of 97% sequence identity to genes of uncultured bacteria detected in various gastrointestinal environments. This strategy has therefore allowed us to cultivate many novel rumen bacteria, opening the way to overcoming the lack of cultures of many of the groups detected using cultivation-independent methods. Copyright © 2010 Elsevier B.V. All rights reserved.

A novel, optical, on-line bacteria sensor for monitoring drinking water quality.

Science.gov (United States)

Højris, Bo; Christensen, Sarah Christine Boesgaard; Albrechtsen, Hans-Jørgen; Smith, Christian; Dahlqvist, Mathis

2016-04-04

Today, microbial drinking water quality is monitored through either time-consuming laboratory methods or indirect on-line measurements. Results are thus either delayed or insufficient to support proactive action. A novel, optical, on-line bacteria sensor with a 10-minute time resolution has been developed. The sensor is based on 3D image recognition, and the obtained pictures are analyzed with algorithms considering 59 quantified image parameters. The sensor counts individual suspended particles and classifies them as either bacteria or abiotic particles. The technology is capable of distinguishing and quantifying bacteria and particles in pure and mixed suspensions, and the quantification correlates with total bacterial counts. Several field applications have demonstrated that the technology can monitor changes in the concentration of bacteria, and is thus well suited for rapid detection of critical conditions such as pollution events in drinking water.

Coryneform bacteria associated with canine otitis externa

DEFF Research Database (Denmark)

Aalbæk, Bent; Bemis, David A.; Schjærff, Mette

2010-01-01

This study aims to investigate the occurrence of coryneform bacteria in canine otitis externa. A combined case series and case-control study was carried out to improve the current knowledge on frequency and clinical significance of coryneform bacteria in samples from canine otitis externa. A total...... of 16 cases of otitis externa with involvement of coryneform bacteria were recorded at two referral veterinary hospitals in Denmark and the US, respectively. Coryneform bacteria were identified by partial 16S rRNA gene sequencing. Corynebacterium auriscanis was the most common coryneform species (10...... cases). Small colony variants of this species were also observed. Other coryneform isolates were identified as Corynebacterium amycolatum (3 cases), Corynebacterium freneyi (2 cases) and an Arcanobacterium-like species (1 case). The coryneform bacteria were in all cases isolated together with other...

Mirasol PRT system inactivation efficacy evaluated in platelet concentrates by bacteria-contamination model

Directory of Open Access Journals (Sweden)

Jocić Miodrag

2011-01-01

Full Text Available Background/Aim. Bacterial contamination of blood components, primarily platelet concentrates (PCs, has been identified as one of the most frequent infectious complications in transfusion practice. PC units have a high risk for bacterial growth/multiplication due to their storage at ambient temperature (20 ± 2°C. Consequences of blood contamination could be effectively prevented or reduced by pathogen inactivation systems. The aim of this study was to determine the Mirasol pathogen reduction technology (PRT system efficacy in PCs using an artificial bacteria-contamination model. Methods. According to the ABO blood groups, PC units (n = 216 were pooled into 54 pools (PC-Ps. PC-Ps were divided into three equal groups, with 18 units in each, designed for an artificial bacteria-contamination. Briefly, PC-Ps were contaminated by Staphylococcus epidermidis, Staphylococcus aureus or Escherichia coli in concentrations 102 to 107 colony forming units (CFU per unit. Afterward, PC-Ps were underwent to inactivation by Mirasol PRT system, using UV (l = 265-370 nm activated riboflavin (RB. All PC-Ps were assayed by BacT/Alert Microbial Detection System for CFU quantification before and after the Mirasol treatment. Samples from non-inactivated PC-P units were tested after preparation and immediately following bacterial contamination. Samples from Mirasol treated units were quantified for CFUs one hour, 3 days and 5 days after inactivation. Results. A complete inactivation of all bacteria species was obtained at CFU concentrations of 102 and 103 per PC-P unit through storage/ investigation period. The most effective inactivation (105 CFU per PC-P unit was obtained in Escherichia coli setting. Contrary, inactivation of all the three tested bacteria species was unworkable in concentrations of ≥ 106 CFU per PC-P unit. Conclusion. Efficient inactivation of investigated bacteria types with a significant CFU depletion in PC-P units was obtained - 3 Log for all

Epiphytic marine pigmented bacteria: A prospective source of natural antioxidants

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Ravindra Pawar

2015-03-01

Full Text Available Awareness on antioxidants and its significance in human healthcare has increased many folds in recent time. Increased demand requisite on welcoming newer and alternative resources for natural antioxidants. Seaweed associated pigmented bacteria screened for its antioxidant potentials reveals 55.5% of the organisms were able to synthesize antioxidant compounds. DPPH assay showed 20% of the organisms to reach a antioxidant zone of 1 cm and 8.3% of the strains more than 3 cm. Pseudomonas koreensis (JX915782 a Sargassum associated yellowish brown pigmented bacteria have better activity than known commercial antioxidant butylated hydroxytoluene (BHT against DPPH scavenging. Serratia rubidaea (JX915783, an associate of Ulva sp. and Pseudomonas argentinensis (JX915781 an epiphyte of Chaetomorpha media, were also contributed significantly towards ABTS (7.2% ± 0.03 to 15.2 ± 0.09%; 1.8% ± 0.01 to 15.7 ± 0.22% and FRAP (1.81 ± 0.01 to 9.35 ± 0.98; 7.97 ± 0.12 to 18.70 ± 1.84 μg/mL of AsA Eq. respectively. 16S rRNA gene sequence analysis revealed bacteria that have higher antioxidant activity belongs to a bacterial class Gammaproteobacteria. Statistical analysis of phenolic contents in relation with other parameters like DPPH, ABTS, reducing power and FRAP are well correlated (p < 0.05. Results obtained from the current study inferred that the seaweed associated pigmented bacteria have enormous potential on antioxidant compounds and need to be extracted in a larger way for clinical applications.

Comparison of apical extrusion of intracanal bacteria by various glide-path establishing systems: an in vitro study

Directory of Open Access Journals (Sweden)

Alberto Dagna

2017-11-01

Full Text Available Objectives This study compared the amount of apically extruded bacteria during the glide-path preparation by using multi-file and single-file glide-path establishing nickel-titanium (NiTi rotary systems. Materials and Methods Sixty mandibular first molar teeth were used to prepare the test apparatus. They were decoronated, blocked into glass vials, sterilized in ethylene oxide gas, infected with a pure culture of Enterococcus faecalis, randomly assigned to 5 experimental groups, and then prepared using manual stainless-steel files (group KF and glide-path establishing NiTi rotary files (group PF with PathFiles, group GF with G-Files, group PG with ProGlider, and group OG with One G. At the end of canal preparation, 0.01 mL NaCl solution was taken from the experimental vials. The suspension was plated on brain heart infusion agar and colonies of bacteria were counted, and the results were given as number of colony-forming units (CFU. Results The manual instrumentation technique tested in group KF extruded the highest number of bacteria compared to the other 4 groups (p < 0.05. The 4 groups using rotary glide-path establishing instruments extruded similar amounts of bacteria. Conclusions All glide-path establishment instrument systems tested caused a measurable apical extrusion of bacteria. The manual glide-path preparation showed the highest number of bacteria extruded compared to the other NiTi glide-path establishing instruments.

Polyacrylamide+Al{sub 2}(SO{sub 4}){sub 3} and polyacrylamide+CaO remove coliform bacteria and nutrients from swine wastewater

Energy Technology Data Exchange (ETDEWEB)

Entry, J.A.; Phillips, Ian; Stratton, Helen; Sojka, R.E

2003-03-01

Polyacrylamide mixture may be able to reduce run-off of enteric bacteria from animal wastes. - Animal wastes are a major contributor of nutrients and enteric microorganisms to surface water and ground water. Polyacrylamide (PAM) mixtures are an effective flocculent, and we hypothesized that they would reduce transport of microorganisms in flowing water. After waste water running at 60.0 l min{sup -1} flowed over PAM+Al{sub 2}(SO{sub 4}){sub 3}, or PAM+CaO in furrows, total coliform bacteria (TC) and fecal coliform bacteria (FC) were reduced by 30-50% at 1 and 50 m downstream of the treatments compared to the control. In a column study, PAM+Al{sub 2}(SO{sub 4}){sub 3}, and PAM+CaO applied to sandy, sandy loam, loam, and clay soils reduced NH{sub 4}{sup +} and ortho-P concentrations in leachate compared to the source waste water and the control. PAM+Al{sub 2}(SO{sub 4}){sub 3} and PAM+CaO applied to sandy, sandy loam and loam soils reduced both total and ortho-P, concentrations in leachate compared to the source wastewater and control treatment. In a field study, PAM+Al{sub 2}(SO{sub 4}){sub 3}, or PAM+CaO treatments did not consistently reduce NH{sub 4}{sup +}, NO{sub 3}{sup -}, ortho-P, and total P concentrations in wastewater flowing over any soil compared to inflow wastewater or the control treatment. With proper application PAM+ Al{sub 2}(SO{sub 4}){sub 3} and PAM+CaO may be able to reduce the numbers of enteric bacteria in slowly flowing wastewater running off animal confinement areas, reducing the amount of pollutants entering surface water and groundwater.

Carotenoid β-ring hydroxylase and ketolase from marine bacteria-promiscuous enzymes for synthesizing functional xanthophylls.

Science.gov (United States)

Misawa, Norihiko

2011-01-01

Marine bacteria belonging to genera Paracoccus and Brevundimonas of the α-Proteobacteria class can produce C₄₀-type dicyclic carotenoids containing two β-end groups (β rings) that are modified with keto and hydroxyl groups. These bacteria produce astaxanthin, adonixanthin, and their derivatives, which are ketolated by carotenoid β-ring 4(4')-ketolase (4(4')-oxygenase; CrtW) and hydroxylated by carotenoid β-ring 3(3')-hydroxylase (CrtZ). In addition, the genus Brevundimonas possesses a gene for carotenoid β-ring 2(2')-hydroxylase (CrtG). This review focuses on these carotenoid β-ring-modifying enzymes that are promiscuous for carotenoid substrates, and pathway engineering for the production of xanthophylls (oxygen-containing carotenoids) in Escherichia coli, using these enzyme genes. Such pathway engineering researches are performed towards efficient production not only of commercially important xanthophylls such as astaxanthin, but also of xanthophylls minor in nature (e.g., β-ring(s)-2(2')-hydroxylated carotenoids).

A nitrous acid biosynthetic pathway for diazo group formation in bacteria.

Science.gov (United States)

Sugai, Yoshinori; Katsuyama, Yohei; Ohnishi, Yasuo

2016-02-01

Although some diazo compounds have bioactivities of medicinal interest, little is known about diazo group formation in nature. Here we describe an unprecedented nitrous acid biosynthetic pathway responsible for the formation of a diazo group in the biosynthesis of the ortho-diazoquinone secondary metabolite cremeomycin in Streptomyces cremeus. This finding provides important insights into the biosynthetic pathways not only for diazo compounds but also for other naturally occurring compounds containing nitrogen-nitrogen bonds.

PCR detection of thermophilic spore-forming bacteria involved in canned food spoilage.

Science.gov (United States)

Prevost, S; Andre, S; Remize, F

2010-12-01

Thermophilic bacteria that form highly heat-resistant spores constitute an important group of spoilage bacteria of low-acid canned food. A PCR assay was developed in order to rapidly trace these bacteria. Three PCR primer pairs were designed from rRNA gene sequences. These primers were evaluated for the specificity and the sensitivity of detection. Two primer pairs allowed detection at the species level of Geobacillus stearothermophilus and Moorella thermoacetica/thermoautrophica. The other pair allowed group-specific detection of anaerobic thermophilic bacteria of the genera Thermoanaerobacterium, Thermoanaerobacter, Caldanerobium and Caldanaerobacter. After a single enrichment step, these PCR assays allowed the detection of 28 thermophiles from 34 cans of spoiled low-acid food. In addition, 13 ingredients were screened for the presence of these bacteria. This PCR assay serves as a detection method for strains able to spoil low-acid canned food treated at 55°C. It will lead to better reactivity in the canning industry. Raw materials and ingredients might be qualified not only for quantitative spore contamination, but also for qualitative contamination by highly heat-resistant spores.

[Analysis of pathogenic bacteria and drug resistance in neonatal purulent meningitis].

Science.gov (United States)

Zhu, Minli; Hu, Qianhong; Mai, Jingyun; Lin, Zhenlang

2015-01-01

To study the clinical characteristics, pathogenic bacteria, and antibiotics resistance of neonatal purulent meningitis in order to provide the guide for early diagnosis and appropriate treatment. A retrospective review was performed and a total of 112 cases of neonatal purulent meningitis (male 64, female 58) were identified in the neonatal intensive care unit of Yuying Children's Hospital of Wenzhou Medical University seen from January 1, 2004 to December 31, 2013. The clinical information including pathogenic bacterial distribution, drug sensitivity, head imageology and therapeutic outcome were analyzed. Numeration data were shown in ratio and chi square test was applied for group comparison. Among 112 cases, 46 were admitted from 2004 to 2008 and 66 from 2009 to 2013, 23 patients were preterm and 89 were term, 20 were early onset (occurring within 3 days of life) and 92 were late onset meningitis (occurring after 3 days of life). In 62 (55.4%) cases the pathogens were Gram-positive bacteria and in 50 (44.6%) were Gram-negative bacteria. The five most frequently isolated pathogens were Escherichia coli (32 cases, 28.6%), coagulase-negative staphylococcus (CNS, 20 cases, 17.9%), Streptococcus (18 cases, 16.1%, Streptococcus agalactiae 15 cases), Enterococci (13 cases, 11.6%), Staphylococcus aureus (9 cases, 8.0%). Comparison of pathogenic bacterial distribution between 2004-2008 and 2009-2013 showed that Gram-positive bacteria accounted for more than 50% in both period. Escherichia coli was the most common bacterium, followed by Streptococcus in last five years which was higher than the first five years (22.7% (15/66) vs. 6.5% (3/46), χ(2) = 5.278, P bacteria in early onset meningitis and higher than those in late onset meningitis (35.0% (7/20) vs. 12.0% (11/92), χ(2) = 4.872, P pathogens responsible for neonatal purulent meningitis over the past ten years. There were increasing numbers of cases with Streptococcus meningitis which are more common in early onset

Direct immobilization of antibodies on Zn-doped Fe{sub 3}O{sub 4} nanoclusters for detection of pathogenic bacteria

Energy Technology Data Exchange (ETDEWEB)

Pal, Monalisa; Lee, Sanghee; Kwon, Donghoon; Hwang, Jeongin; Lee, Hyeonjeong; Hwang, Seokyung; Jeon, Sangmin, E-mail: jeons@postech.ac.kr

2017-02-01

Zinc-doped magnetic nanoclusters (Zn-MNCs) were synthesized and used to detect pathogenic bacteria in milk. Hydrothermally synthesized Zn-MNCs exhibited stronger magnetic properties than pure MNCs, which facilitated the magnetic separation from the sample using a permanent magnet. The presence of accessible Zn sites allows the direct immobilization of half-fragmented antibodies over Zn-MNCs through strong Zn−S bonds and prevents the tedious multiple steps of molecular functionalization or coating with costly noble metals prior to conjugation with an antibody. After the capture and magnetic separation of Salmonella in milk using the antibody-functionalized Zn-MNCs, the concentration of bacteria was determined with a portable ATP luminometer and the detection limit was found to be 10 CFU/mL. - Highlights: • Zn-doped Fe{sub 3}O{sub 4} nanoclusters (Zn-MNCs) were synthesized by hydrothermal method. • Antibodies were directly immobilized over Zn-MNCs through strong Zn–S{sub thiol} bonds. • Higher magnetization of Zn-MNCs than pure MNCs facilitates the magnetic separation. • Detection limit of pathogenic bacteria in milk was found to be 10 cfu/mL. • Cost effective, sensitive and selective detection of bacteria.

Identification of moderately halophilic bacteria from Thai fermented fish ( pla-ra ) and proposal of Virgibacillus siamensis sp. nov.

Science.gov (United States)

Tanasupawat, Somboon; Chamroensaksri, Nitcha; Kudo, Takuji; Itoh, Takashi

2010-10-01

Forty-one isolates of moderately halophilic bacteria were isolated from fermented fish (pla-ra) in Thailand. On the basis of their phenotypic and chemotaxonomic characteristics, DNA-DNA relatedness and 16S rRNA gene sequences analyses, they were divided into six groups. The isolates in Group I to V were Gram-positive rod-shaped bacteria. They contained meso-diaminopimelic acid in the cell-wall peptidoglycan and menaquinone with seven isoprene units (MK-7). An isolate in Group VI was a Gram-negative rod-shaped bacterium. The DNA G+C contents of tested strains ranged from 36.5-63 mol%. Ten strains (Group I) were identified as Virgibacillus dokdonensis, 13 isolates (Group II) as V. halodenitrificans, 14 isolates (Group III) as V. marismortui, 1 isolate (Group IV) as Virgibacillus sp., 2 isolates (Group V) as Bacillus vietnamnensis, and 1 isolate (Group VI) as Chromohalobacter salexigens. Isolate MS3-4 in Group IV was closely related to V. carmonensis KCTC 3819(T) (95.9%). This strain contained anteiso-C(15:0) (55.8%) and anteiso-C(17:0) (17.7%) as major cellular fatty acids and had phosphatidylglycerol, diphosphatidylglycerol and an unidentified glycolipid as polar lipids. The DNA G+C content of MS3-4 was 38.0 mol%. The strain from Group IV is proposed as Virgibacillus siamensis sp. nov. and MS3-4(T) is the type strain (JCM 15395(T) =PCU 312(T) =TISTR 1957(T)).

Apical extrusion of bacteria when using reciprocating single-file and rotary multifile instrumentation systems.

Science.gov (United States)

Tinoco, J M; De-Deus, G; Tinoco, E M B; Saavedra, F; Fidel, R A S; Sassone, L M

2014-06-01

To evaluate ex vivo, apical bacterial extrusion associated with two reciprocating single-file systems (WaveOne and Reciproc) compared with a conventional multifile rotary system (BioRace). Forty-five human single-rooted mandibular incisors were used. Endodontic access cavities were prepared, and root canals were contaminated with an Enterococcus faecalis suspension. Following incubation at 37 °C for thirty days, the contaminated teeth were divided into three groups of 15 specimens each (G1 - Reciproc, G2 - WaveOne and G3 - BioRace). Positive and negative controls consisted of 5 infected teeth and 3 uninfected incisors that were instrumented with one of the tested NiTi systems, respectively. Bacteria extruded from the apical foramen during instrumentation were collected into vials containing 0.9% NaCl. The microbiological samples were taken from the vials and incubated in brain heart agar medium for 24 h. The resulting bacterial titre, in colony-forming units (CFU) per mL, was determined, and these data were analysed by Wilcoxon matched-pairs signed rank test and Kruskal-Wallis H-test. The level of significance was set at α = 0.05. No significant difference was found in the number of CFU between the two reciprocating systems (P = 0.41). The conventional multifile rotary system group was associated with significantly higher CFU than both of the two reciprocating groups (P = 0.01). All instrumentation systems extruded bacteria beyond the foramen. However, both reciprocating single-file systems extruded fewer bacteria apically than the conventional multifile rotary system. © 2013 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Restoration using Azolla imbricata increases nitrogen functional bacterial groups and genes in soil.

Science.gov (United States)

Lu, Xiao-Ming; Lu, Peng-Zhen; Yang, Ke

2017-05-01

Microbial groups are major factors that influence soil function. Currently, there is a lack of studies on microbial functional groups. Although soil microorganisms play an important role in the nitrogen cycle, systematic studies of the effects of environmental factors on microbial populations in relation to key metabolic processes in the nitrogen cycle are seldom reported. In this study, we conducted a systematic analysis of the changes in nitrogen functional groups in mandarin orange garden soil treated with Azolla imbricata. The structures of the major functional bacterial groups and the functional gene abundances involved in key processes of the soil nitrogen cycle were analyzed using high-throughput sequencing (HTS) and quantitative real-time PCR, respectively. The results indicated that returning A. imbricata had an important influence on the composition of soil nitrogen functional bacterial communities. Treatment with A. imbricata increased the diversity of the nitrogen functional bacteria. The abundances of nitrogen functional genes were significantly higher in the treated soil compared with the control soil. Both the diversity of the major nitrogen functional bacteria (nifH bacteria, nirK bacteria, and narG bacteria) and the abundances of nitrogen functional genes in the soil showed significant positive correlations with the soil pH, the organic carbon content, available nitrogen, available phosphorus, and NH 4 + -N and NO 3 - -N contents. Treatment with 12.5 kg fresh A. imbricata per mandarin orange tree was effective to improve the quality of the mandarin orange garden soil. This study analyzed the mechanism of the changes in functional bacterial groups and genes involved in key metabolic processes of the nitrogen cycle in soil treated by A. imbricata.

Secretory phospholipase A2 in dromedary tears: a host defense against staphylococci and other gram-positive bacteria.

Science.gov (United States)

Ben Bacha, Abir; Abid, Islem

2013-03-01

The best known physiologic function of secreted phospholipase A2 (sPLA2) group IIA (sPLA2-IIA) is defense against bacterial infection through hydrolytic degradation of bacterial membrane phospholipids. In fact, sPLA2-IIA effectively kills Gram-positive bacteria and to a lesser extent Gram-negative bacteria and is considered a major component of the eye's innate immune defense system. The antibacterial properties of sPLA2 have been demonstrated in rabbit and human tears. In this report, we have analyzed the bactericidal activity of dromedary tears and the subsequently purified sPLA2 on several Gram-positive bacteria. Our results showed that the sPLA2 displays a potent bactericidal activity against all the tested bacteria particularly against the Staphylococcus strains when tested in the ionic environment of tears. There is a synergic action of the sPLA2 with lysozyme when added to the bacteria culture prior to sPLA2. Interestingly, lysozyme purified from dromedary tears showed a significant bactericidal activity against Listeria monocytogene and Staphylococcus epidermidis, whereas the one purified from human tears displayed no activity against these two strains. We have also demonstrated that Ca(2+) is crucial for the activity of dromedary tear sPLA2 and to a less extent Mg(2+) ions. Given the presence of sPLA2 in tears and intestinal secretions, this enzyme may play a substantial role in innate mucosal and systemic bactericidal defenses against Gram-positive bacteria.

Lactic Acid Bacteria : embarking on 30 more years of research

NARCIS (Netherlands)

Kok, Jan; Johansen, Eric; Kleerebezem, Michiel; Teusink, Bas

2014-01-01

The 11th International Symposium on Lactic Acid Bacteria Lactic Acid Bacteria play important roles in the pro- duction of food and feed and are increasingly used as health-promoting probiotics. The incessant scientific interest in these microorganisms by academic research groups as well as by

Manufacture of Probiotic Bacteria

Science.gov (United States)

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

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

Sensitivity of certain bacteria to antibiotics and irradiation

Energy Technology Data Exchange (ETDEWEB)

Harsojo,; Andini, L S; Siagian, E G; Lina, M R; Zuleiha, S [National Atomic Energy Agency, Jakarta (Indonesia). Pasar Djumat Research Centre

1981-07-01

An experiment has been conducted to find vegetative forms of certain bacteria in Indonesia which are resistant to irradiation, the resistance of which will be compared to that of known radioresistant bacteria micrococcus radiodurans. To inactivate the vegetative forms of resistant bacteria to irradiation high doses are needed, while for storage purposes lower doses change the physical and chemical properties of the stored commodity are preferred. For this purpose the bacteria were irradiated in aerobic condition with gamma radiation doses of 0.1, 0.2 and 0.3 kGy, or treated with antibiotics e.g. tetracycline HCl or chloramphenicol with concentrations of 0.1, 0.2 and 0.3 ..mu..g/ml respectively. The results indicated that doses of 0.2 kGy and 0.1 ..mu..g/ml reduced the ability of the bacteria for multiplication.

Detection of endocarditis bacteria in tonsillar mucosa of Afghan population.

Science.gov (United States)

Ruggiero, F; Carbone, D; Mugavero, R; Palmieri, A; Lauritano, D; Baggi, L; Nardone, M; Carinci, F; Martinelli, M

2018-01-01

Endocarditis is a cardiovascular disease caused by the inflammation of the inner tissues of the heart, the endocardium, usually of the valves. Bacteraemia is essential in the development of endocarditis, and there are some findings that the main pathogens of endocarditis are viridans group streptococci: Streptococcus oralis, Streptococcus sanguinis, and Enterococcus faecalis. There is strong evidence that endocarditis bacteria are present in the tonsillar microbiota, so that tonsillar infection is associated with an increased risk of endocarditis. The aim of this manuscript is to investigate the presence of the main pathogens of endocarditis in tonsillar microbiota of an Afghan population group. A sample of 80 tonsil swabs were analyzed by quantitative real time PCR to detect endocarditis pathogens and an estimation of the total bacterial load. The median bacterial load in PCR reaction was 1.4x106 (interquartile range 4,7x105 - 2,9x106). Three species, S. Oralis, S. Sanguinis, and E. Faecalis were found in large amounts in all specimens. On the other hand, S. Mitis was never detected. The S. Aureus was found in 3 samples with a prevalence of 0.04 (C.I. 0.01-0.10). The S. Mutans was found in 33 samples with a prevalence of 0.41 (C.I. 0.31-0.52). Endocarditis bacteria has been found into the tonsillar microbiota, so there is sufficient evidence to justify that the oral cavity is a reservoir of endocarditis bacteria that can have a significant impact on the cardiovascular function.

Initiation of translation in bacteria by a structured eukaryotic IRES RNA.

Science.gov (United States)

Colussi, Timothy M; Costantino, David A; Zhu, Jianyu; Donohue, John Paul; Korostelev, Andrei A; Jaafar, Zane A; Plank, Terra-Dawn M; Noller, Harry F; Kieft, Jeffrey S

2015-03-05

The central dogma of gene expression (DNA to RNA to protein) is universal, but in different domains of life there are fundamental mechanistic differences within this pathway. For example, the canonical molecular signals used to initiate protein synthesis in bacteria and eukaryotes are mutually exclusive. However, the core structures and conformational dynamics of ribosomes that are responsible for the translation steps that take place after initiation are ancient and conserved across the domains of life. We wanted to explore whether an undiscovered RNA-based signal might be able to use these conserved features, bypassing mechanisms specific to each domain of life, and initiate protein synthesis in both bacteria and eukaryotes. Although structured internal ribosome entry site (IRES) RNAs can manipulate ribosomes to initiate translation in eukaryotic cells, an analogous RNA structure-based mechanism has not been observed in bacteria. Here we report our discovery that a eukaryotic viral IRES can initiate translation in live bacteria. We solved the crystal structure of this IRES bound to a bacterial ribosome to 3.8 Å resolution, revealing that despite differences between bacterial and eukaryotic ribosomes this IRES binds directly to both and occupies the space normally used by transfer RNAs. Initiation in both bacteria and eukaryotes depends on the structure of the IRES RNA, but in bacteria this RNA uses a different mechanism that includes a form of ribosome repositioning after initial recruitment. This IRES RNA bridges billions of years of evolutionary divergence and provides an example of an RNA structure-based translation initiation signal capable of operating in two domains of life.

Comparative evaluation of apical extrusion of bacteria using hand and rotary systems : An in vitro study

Science.gov (United States)

Ghivari, Sheetal B; Kubasad, Girish C; Deshpande, Preethi

2012-01-01

Aim: To evaluate the bacteria extruded apically during root canal preparation using two hand and rotary instrumentation techniques. Materials and Methods: Eighty freshly extracted mandibular premolars were mounted in bacteria collection apparatus. Root canals were contaminated with the pure culture of Enterococcus fecalis (ATCC 29212) and dried at 37°C for 24 h. Bacteria extruded were collected, incubated in brain heart infusion agar for 24 h at 36°C and the colony forming units (CFU) were counted. Statistical Analysis: The mean number of colony forming units were calculated by One-way ANOVA and comparison between the groups made by multiple comparison (Dunnet D) test. Results: The step-back technique extruded highest number of bacteria in comparison to other hand and rotary Ni–Ti systems. Conclusion: Under the limitation of this study all hand and rotary instrumentation techniques extruded bacteria. Among all the instrumentation techniques step-back technique extruded more number of bacteria and K-3 system the least. Further in vivo research in this direction could provide more insight into the biologic factors associated and focus on bacterial species that essentially play a major role in post instrumentation flare-ups. PMID:22368332

Applications of Magnetosomes Synthesized by Magnetotactic Bacteria in Medicine

International Nuclear Information System (INIS)

Alphandéry, Edouard

2014-01-01

Magnetotactic bacteria belong to a group of bacteria that synthesize iron oxide nanoparticles covered by biological material that are called magnetosomes. These bacteria use the magnetosomes as a compass to navigate in the direction of the earth’s magnetic field. This compass helps the bacteria to find the optimum conditions for their growth and survival. Here, we review several medical applications of magnetosomes, such as those in magnetic resonance imaging (MRI), magnetic hyperthermia, and drug delivery. Different methods that can be used to prepare the magnetosomes for these applications are described. The toxicity and biodistribution results that have been published are summarized. They show that the magnetosomes can safely be used provided that they are prepared in specific conditions. The advantageous properties of the magnetosomes compared with those of chemically synthesized nanoparticles of similar composition are also highlighted.

Identification of entomopathogenic nematodes and symbiotic bacteria from Nam Nao National Park in Thailand and larvicidal activity of symbiotic bacteria against Aedes aegypti and Aedes albopictus.

Science.gov (United States)

Yooyangket, Temsiri; Muangpat, Paramaporn; Polseela, Raxsina; Tandhavanant, Sarunporn; Thanwisai, Aunchalee; Vitta, Apichat

2018-01-01

Entomopathogenic nematodes (EPNs) that are symbiotically associated with Xenorhabdus and Photorhabdus bacteria can kill target insects via direct infection and toxin action. There are limited reports identifying such organisms in the National Park of Thailand. Therefore, the objectives of this study were to identify EPNs and symbiotic bacteria from Nam Nao National Park, Phetchabun Province, Thailand and to evaluate the larvicidal activity of bacteria against Aedes aegypti and Ae. albopictus. A total of 12 EPN isolates belonging to Steinernema and Heterorhabditis were obtained form 940 soil samples between February 2014 and July 2016. EPNs were molecularly identified as S. websteri (10 isolates) and H. baujardi (2 isolates). Symbiotic bacteria were isolated from EPNs and molecularly identified as P. luminescens subsp. akhurstii (13 isolates), X. stockiae (11 isolates), X. vietnamensis (2 isolates) and X. japonica (1 isolate). For the bioassay, bacterial suspensions were evaluated for toxicity against third to early fourth instar larvae of Aedes spp. The larvae of both Aedes species were orally susceptible to symbiotic bacteria. The highest larval mortality of Ae. aegypti was 99% after exposure to X. stockiae (bNN112.3_TH) at 96 h, and the highest mortality of Ae. albopictus was 98% after exposure to P. luminescens subsp. akhurstii (bNN121.4_TH) at 96 h. In contrast to the control groups (Escherichia coli and distilled water), the mortality rate of both mosquito larvae ranged between 0 and 7% at 72 h. Here, we report the first observation of X. vietnamensis in Thailand. Additionally, we report the first observation of P. luminescens subsp. akhurstii associated with H. baujardi in Thailand. X. stockiae has potential to be a biocontrol agent for mosquitoes. This investigation provides a survey of the basic diversity of EPNs and symbiotic bacteria in the National Park of Thailand, and it is a bacterial resource for further studies of bioactive compounds.

Comparison of the kinetics of intestinal colonization by associating 5 probiotic bacteria assumed either in a microencapsulated or in a traditional, uncoated form.

Science.gov (United States)

Piano, Mario D; Carmagnola, Stefania; Ballarè, Marco; Balzarini, Marco; Montino, Franco; Pagliarulo, Michela; Anderloni, Andrea; Orsello, Marco; Tari, Roberto; Sforza, Filomena; Mogna, Luca; Mogna, Giovanni

2012-10-01

Beneficial findings concerning probiotics are increasing day by day. However, one of the most important parameters able to significantly affect the probiotic value of a microorganism is its survival during the transit through the stomach and the duodenum. Some techniques may be applied that aim to improve this parameter, but microencapsulation of bacterial cells remains one of the most important. A recent study assessed the kinetics of intestinal colonization by a mixture of 2 probiotic strains, given either in a microencapsulated or in a traditional, uncoated form. A comparison between the intestinal colonization by associating 5 microencapsulated bacteria and the same uncoated strains was performed by a double-blind, randomized, cross-over study. The study (December 2007 to January 2009) involved 53 healthy volunteers. In particular, subjects were divided into 2 groups: group A (27 subjects) was given a mix of probiotic strains Probiotical S.p.A. (Novara, Italy), Lactobacillus acidophilus LA02 (DSM 21717), Lactobacillus rhamnosus LR04 (DSM 16605), L. rhamnosus GG, or LGG (ATCC 53103), L. rhamnosus LR06 (DSM 21981), and Bifidobacterium lactis BS01 (LMG P-21384) in an uncoated form, whereas group B (26 subjects) received the same strains microencapsulated with a gastroprotected material. The uncoated strains were administered at 5×10⁹ cfu/strain/d (a total of 25×10⁹ cfu/d) for 21 days, whereas the microencapsulated bacteria were given at 1×10⁹ cfu/strain/d (a total of 5×10⁹ cfu/d) for 21 days. At the end of the first period of supplementation with probiotics, a 3-week wash-out phase was included in the study setting. At the end of the wash-out period, the groups crossed over their treatment regimen; that is, group A was administered the microencapsulated bacteria and group B the uncoated bacteria. The administered quantities of each strain were the same as the first treatment. A quantitative evaluation of intestinal colonization by probiotics, either

Simultaneous photocatalytic and microbial degradation of dye-containing wastewater by a novel g-C3N4-P25/photosynthetic bacteria composite.

Directory of Open Access Journals (Sweden)

Xinying Zhang

Full Text Available Azo dyes are very resistant to light-induced fading and biodegradation. Existing advanced oxidative pre-treatment methods based on the generation of non-selective radicals cannot efficiently remove these dyes from wastewater streams, and post-treatment oxidative dye removal is problematic because it may leave many byproducts with unknown toxicity profiles in the outgoing water, or cause expensive complete mineralization. These problems could potentially be overcome by combining photocatalysis and biodegradation. A novel visible-light-responsive hybrid dye removal agent featuring both photocatalysts (g-C3N4-P25 and photosynthetic bacteria encapsulated in calcium alginate beads was prepared by self-assembly. This system achieved a removal efficiency of 94% for the dye reactive brilliant red X-3b and also reduced the COD of synthetic wastewater samples by 84.7%, successfully decolorized synthetic dye-contaminated wastewater and reduced its COD, demonstrating the advantages of combining photocatalysis and biocatalysis for wastewater purification. The composite apparently degrades X-3b by initially converting the dye into aniline and phenol derivatives whose aryl moieties are then attacked by free radicals to form alkyl derivatives, preventing the accumulation of aromatic hydrocarbons that might suppress microbial activity. These alkyl intermediates are finally degraded by the photosynthetic bacteria.

Divergent pro-inflammatory profile of human dendritic cells in response to commensal and pathogenic bacteria associated with the airway microbiota

DEFF Research Database (Denmark)

Larsen, Jeppe Madura; Steen-Jensen, Daniel Bisgaard; Laursen, Janne Marie

2012-01-01

of individual bacterial species are unknown. In this study, we compared the immune stimulatory capacity on human monocyte-derived dendritic cells (DCs) of selected airway commensal and pathogenic bacteria predominantly associated with lungs of asthma or COPD patients (pathogenic Haemophillus spp. and Moraxella...... spp.), healthy lungs (commensal Prevotella spp.) or both (commensal Veillonella spp. and Actinomyces spp.). All bacteria were found to induce activation of DCs as demonstrated by similar induction of CD83, CD40 and CD86 surface expression. However, asthma and COPD-associated pathogenic bacteria...... provoked a 3-5 fold higher production of IL-23, IL-12p70 and IL-10 cytokines compared to the commensal bacteria. Based on the differential cytokine production profiles, the studied airway bacteria could be segregated into three groups (Haemophilus spp. and Moraxella spp. vs. Prevotella spp. and Veillonella...

Mortality of fecal bacteria in seawater

International Nuclear Information System (INIS)

Garcia-Lara, J.; Menon, P.; Servais, P.; Billen, G.

1991-01-01

The authors propose a method for determining the mortality rate for allochthonous bacteria released in aquatic environments without interference due to the loss of culturability in specific culture media. This method consists of following the disappearance of radioactivity from the trichloracetic acid-insoluble fraction in water samples to which [ 3 H]thymidine-prelabeled allochthonous bacteria have been added. In coastal seawater, they found that the actual rate of disappearance of fecal bacteria was 1 order of magnitude lower than the rate of loss of culturability on specific media. Minor adaptation of the procedure may facilitate assessment of the effect of protozoan grazing and bacteriophage lysis on the overall bacterial mortality rate

Low-intensity laser coupled with photosensitizer to reduce bacteria in root canals compared to chemical control

International Nuclear Information System (INIS)

Garcez Segundo, Aguinaldo Silva

2002-01-01

The photodynamic therapy is a process in which a dye is associate with an appropriate wavelength of light and this dye goes to an excited state. The excited reacts with oxygen to form the highly reactive compound singlet oxygen, and this compound can kill bacteria and tumor cells. The purpose of this study was to evaluate the bactericidal reduction in root canal contaminated with E. Faecalis. Thirty teeth with their root canals prepared were contaminated with E. faecalis. The teeth have received the chemical substance sodium hypochlorite for 30 minutes; ten teeth have received the azulene dye paste for 5 minutes and have been irradiated with a diode laser, output power 10 mW and λ= 685 nm for 3 minutes. Ten teeth have not received treatment (control group). The bacterial reduction was significantly higher for laser group when compared to chemical and control groups. These results indicate photodynamic therapy as an effective method to kill bacteria. (author)

Metabolic activity of uncultivated magnetotactic bacteria revealed by NanoSIMS

Science.gov (United States)

He, M.; Zhang, W.; Gu, L.; Pan, Y.; Lin, W.

2017-12-01

Microorganisms that exhibit magnetotaxis behavior, collectively known as the magnetotactic bacteria (MTB), are those whose motility is influenced by the Earth's magnetic field. MTB are a physiologically diverse group of bacteria with a unique feature of intracellular biomineralization of magnetosomes (Fe3O4 and/or Fe3S4) (Bazylinski et al., 2013). However, the ecophysiology of uncultivated MTB, especially those within the Nitrospirae phylum forming hundreds of bullet-shaped magnetite magnetosomes per cell, is still not well characterized (Lin et al., 2014). Nanoscale secondary ion mass spectrometry (NanoSIMS) is a powerful tool for revealing element distribution in nanometer-scale resolution, which opens exciting possibilities for the study of interactions between microorganisms and environments (Gao et al., 2016; Musat et al., 2016). Here we applied NanoSIMS to investigate the dynamics of carbon and nitrogen assimilations in two magnetotactic Nitrospirae populations at single cell level. Our NanoSIMS results confirmed the metabolic potential of Nitrospirae MTB proposed by genomic and metagenomic analysis and provided additional insights into the ecophysiology of uncultivated MTB. This study suggests that NanoSIMS-based analyses are powerful approaches for investigating and characterizing the ecological function of environmental microorganisms. References: Bazylinski D A., Lefèvre, C T., Schüler D., 2013. Magnetotactic Bacteria. 453-494.Lin W, Bazylinski DA, Xiao T, Wu L- F, Pan Y., 2014. Life with compass: diversity and biogeography of magnetotactic bacteria. Environ Microbiol, 16: 1462-2920.Gao D., Huang X., Tao Y., 2016. A critical review of NanoSIMS in analysis of microbial metabolic activities at single-cell level. Crit Rev Biotechnol, 36: 884-890.Musat N., Musat F., Weber PK., Pett-Ridge J., 2016. Tracking microbial interactions with NanoSIMS. Curr Opin Biotechnol, 41: 114-121.

Anaerobic bacteria in wastewater treatment plant.

Science.gov (United States)

Cyprowski, Marcin; Stobnicka-Kupiec, Agata; Ławniczek-Wałczyk, Anna; Bakal-Kijek, Aleksandra; Gołofit-Szymczak, Małgorzata; Górny, Rafał L

2018-03-28

The objective of this study was to assess exposure to anaerobic bacteria released into air from sewage and sludge at workplaces from a wastewater treatment plant (WWTP). Samples of both sewage and sludge were collected at six sampling points and bioaerosol samples were additionally collected (with the use of a 6-stage Andersen impactor) at ten workplaces covering different stages of the technological process. Qualitative identification of all isolated strains was performed using the biochemical API 20A test. Additionally, the determination of Clostridium pathogens was carried out using 16S rRNA gene sequence analysis. The average concentration of anaerobic bacteria in the sewage samples was 5.49 × 10 4 CFU/mL (GSD = 85.4) and in sludge-1.42 × 10 6 CFU/g (GSD = 5.1). In turn, the average airborne bacterial concentration was at the level of 50 CFU/m 3 (GSD = 5.83) and the highest bacterial contamination (4.06 × 10 3  CFU/m 3 ) was found in winter at the bar screens. In total, 16 bacterial species were determined, from which the predominant strains belonged to Actinomyces, Bifidobacterium, Clostridium, Propionibacterium and Peptostreptococcus genera. The analysis revealed that mechanical treatment processes were responsible for a substantial emission of anaerobic bacteria into the air. In both the sewage and air samples, Clostridium perfringens pathogen was identified. Anaerobic bacteria were widely present both in the sewage and in the air at workplaces from the WWTP, especially when the technological process was performed in closed spaces. Anaerobic bacteria formed small aggregates with both wastewater droplets and dust particles of sewage sludge origin and as such may be responsible for adverse health outcomes in exposed workers.

Labelling of bacteria with indium chelates

International Nuclear Information System (INIS)

Kleinert, P.; Pfister, W.; Endert, G.; Sproessig, M.

1985-01-01

The indium chelates were prepared by reaction of radioactive indiumchloride with 10 μg oxine, 15 μg tropolone and 3 mg acetylacetone, resp. The formed chelates have been incubated with 10 9 germs/ml for 5 minutes, with labelling outputs from 90 to 95%. Both gram-positive (Streptococcus, Staphylococcus) and gram-negative bacteria (Escherichia coli) can be labelled. The reproductive capacity of the bacteria was not impaired. The application of indium labelled bacteria allows to show the distribution of microorganisms within the living organism and to investigate problems of bacterial adherence. (author)

The effect of radiation on bioluminescent bacteria: possible use of luminescent bacteria as a biological dosemeter

International Nuclear Information System (INIS)

Mantel, J.; Freidin, M.; Perry, H.

1983-01-01

The purpose of the study was to investigate the response of the bioluminescent Photobacterium phosphoreum to radiation, and the possible use of the bacteria as a biological radiation dosemeter, i.e. a water-equivalent biological system that will compare beams not merely on the basis of absorbed dose, but also have intrinsic RBE values for different radiation beams. Samples were irradiated by a 12 MeV electron beam at a dose rate of 3.0 Gy min -1 , by 60 Co gamma rays at 2.85 Gy min -1 , and by 100 kVsub(p) x-rays at a dose rate of 2.13 Gy min -1 . To study dose-rate dependence, the survival fraction was obtained for a 12 MeV electron beam at 0.50 and 12 Gy min -1 for 20.0 Gy. The survival fraction proved to be independent of dose rate in this range. The results presented in this work indicate that by using bioluminescent bacteria, RBE measurements can be markedly simplified and the results interpreted unequivocally. (U.K.)

Big bacteria

DEFF Research Database (Denmark)

Schulz, HN; Jørgensen, BB

2001-01-01

A small number of prokaryotic species have a unique physiology or ecology related to their development of unusually large size. The biomass of bacteria varies over more than 10 orders of magnitude, from the 0.2 mum wide nanobacteria to the largest cells of the colorless sulfur bacteria......, Thiomargarita namibiensis, with a diameter of 750 mum. All bacteria, including those that swim around in the environment, obtain their food molecules by molecular diffusion. Only the fastest and largest swimmers known, Thiovulum majus, are able to significantly increase their food supply by motility...... and by actively creating an advective flow through the entire population. Diffusion limitation generally restricts the maximal size of prokaryotic cells and provides a selective advantage for mum-sized cells at the normally low substrate concentrations in the environment. The largest heterotrophic bacteria...

Uptake of americium-241 by algae and bacteria

Energy Technology Data Exchange (ETDEWEB)

Geisy, J P; Paine, D

1978-01-01

Algae and bacteria are important factors in the transport and mobilization of elements in the biosphere. These factors may be involved in trophic biomagnification, resulting in a potential human hazard or environmental degradation. Although americium, one of the most toxic elements known, is not required for plant growth, it may be concentrated by algae and bacteria. Therefore, the availability of americium-241 to algae and bacteria was studied to determine their role in the ultimate fate of this element released into the environment. Both algae and bacteria concentrated americium-241 to a high degree, making them important parts of the biomagnification process. The ability to concentrate americium-241 makes algae and bacteria potentially significant factors in cycling this element in the water column. (4 graphs, numerous references, 3 tables)

Emerging role of bacteria in oral carcinogenesis: a review with special reference to perio-pathogenic bacteria.

Science.gov (United States)

Perera, Manosha; Al-Hebshi, Nezar Noor; Speicher, David J; Perera, Irosha; Johnson, Newell W

2016-01-01

Oral cancer, primarily oral squamous cell carcinoma (OSCC), continues to be a major global health problem with high incidence and low survival rates. While the major risk factors for this malignancy, mostly lifestyle related, have been identified, around 15% of oral cancer cases remain unexplained. In light of evidence implicating bacteria in the aetiology of some cancer types, several epidemiological studies have been conducted in the last decade, employing methodologies ranging from traditional culture techniques to 16S rRNA metagenomics, to assess the possible role of bacteria in OSCC. While these studies have demonstrated differences in microbial composition between cancerous and healthy tissues, they have failed to agree on specific bacteria or patterns of oral microbial dysbiosis to implicate in OSCC. On the contrary, some oral taxa, particularly Porphyromonas gingivalis and Fusobacterium nucleatum, show strong oral carcinogenic potential in vitro and in animal studies. Bacteria are thought to contribute to oral carcinogenesis via inhibition of apoptosis, activation of cell proliferation, promotion of cellular invasion, induction of chronic inflammation, and production of carcinogens. This narrative review provides a critical analysis of and an update on the association between bacteria and oral carcinogenesis and the possible mechanisms underlying it.

Radionuclide sorption to a mixture of anaerobic bacteria in the repository environment

International Nuclear Information System (INIS)

Sasaki, Takayuki; Kubota, Takumi; Kudo, Akira

2002-01-01

The sorption of the radionuclides, Pu, Np, Pa, Sr and Cs, to a mixture of anaerobic bacteria activated under specific conditions of temperature, pH and depleted nutrients after a long dormant period has been investigated. For Pu, after 4 hours at neutral pH, the distribution coefficient (K d ) between bacteria and aqueous phase at 308 and 278K was around 10 3-4 (ml g -1 ). Over 5 days, however, the K d at 308K increased to over 10 5 . Sterilized (dead) and dormant anaerobic bacteria adsorbed Pu to the same extent. K d for Np at 308K after 5 days had a low value around 10 2 . After 10 days, however, K d was >100-fold higher. On the other hand, K d for Np at 278K remained low, without any significant increase over time. The interaction between Pa and bacteria was found to be stronger than that for Np, with K d for Pa about 100 times higher. For Sr and Ca, significant K d change was not seen through 120 d. The value for Sr is a few times larger than that for Cs due to the different electrostatic interaction with the bacteria based on the charge of ion. (author)

High resistance of some oligotrophic bacteria to ionizing radiation

International Nuclear Information System (INIS)

Nikitin, D.I.; Tashtemirova, M.A.; Pitryuk, I.A.; Sorokin, V.V.; Oranskaya, M.S.; Nikitin, L.E.

1994-01-01

The resistance of seven cultures of eutrophic and oligotrophic bacteria to gamma radiation (at doses up to 360 Gy) was investigated. The bacteria under study were divided into three groups according to their survival ability after irradiation. Methylobacterium organophilum and open-quotes Pedodermatophilus halotoleransclose quotes (LD 50 = 270 Gy) were highly tolerant. By their tolerance, these organisms approached Deinococcus radiodurans. Aquatic ring-shaped (toroidal) bacteria Flectobacillus major and open-quotes Arcocella aquaticaclose quotes (LD 5 = 173 and 210 Gy, respectively) were moderately tolerant. Eutrophic Pseudomonas fluorescens and Escherichia coli (LD 50 = 43 and 38 Gy, respectively) were the most sensitive. X-ray microanalysis showed that in tolerant bacteria the intracellular content of potassium increased and the content of calcium decreased after irradiation. No changes in the element composition of the eutrophic bacterium E. coli were detected. Possible mechanisms of the resistance of oligotrophic bacteria to gamma radiation are discussed

Cultivable bacteria populations associated with leaves of banana and plantain plants and their antagonistic activity against Mycosphaerella fijiensis.

Science.gov (United States)

Ceballos, Isabel; Mosquera, Sandra; Angulo, Mónica; Mira, John J; Argel, Luz Edith; Uribe-Velez, Daniel; Romero-Tabarez, Magally; Orduz-Peralta, Sergio; Villegas, Valeska

2012-10-01

Mycosphaerella fijiensis is the etiological agent of Black Sigatoka, a fungal disease that affects production of banana and plantain crops in tropical regions. The sizes of cultivable epiphytic and endophytic bacterial populations, aerobic endospore forming bacteria (AEFB), and antagonist bacteria against M. fijiensis isolated from three Musa spp. cultivars from Urabá (Colombia) were studied, in order to find a suitable screening strategy to isolate antagonistic bacteria. Most of the variability found in the epiphytic and endophytic bacterial community sizes among fruit trees was explained by the cultivar differences. We found population sizes ranging from 1.25 × 10(3) to 9.64 × 10(5) CFU/g of fresh leaf and found that 44 % of total cultivable bacteria belong to the AEFB group. We isolated 648 AEFB from three different cultivars and assessed their antagonistic activity against M. fijiensis using the cell-free supernatant obtained from bacterial liquid cultures in three different in vitro assays. Five percent of those bacteria showed higher percent inhibition than the positive control Bacillus subtilis UA321 has (percent inhibition = 84 ± 5) in the screening phase. Therefore, they were selected as antagonistic bacteria against the pathogen. The strains with the highest percentage of antagonism were found in older leaves for the three cultivars, given support to recommend this group of leaves for future samplings. Some of these isolated bacteria affected the mycelium and ascospores morphology of the fungus. They also presented in vitro characteristics related to a successful colonization of the phylloplane such as indolic compounds, surfactant production, and biofilm formation, which makes them possible, potential candidates as biological control agents.

HYDROCARBON-DEGRADING BACTERIA AND SURFACTANT ACTIVITY

Energy Technology Data Exchange (ETDEWEB)

Brigmon, R; Topher Berry, T; Grazyna A. Plaza, G; jacek Wypych, j

2006-08-15

Fate of benzene ethylbenzene toluene xylenes (BTEX) compounds through biodegradation was investigated using two different bacteria, Ralstonia picketti (BP-20) and Alcaligenes piechaudii (CZOR L-1B). These bacteria were isolated from extremely polluted petroleum hydrocarbon contaminated soils. PCR and Fatty Acid Methyl Ester (FAME) were used to identify the isolates. Biodegradation was measured using each organism individually and in combination. Both bacteria were shown to degrade each of the BTEX compounds. Alcaligenes piechaudii biodegraded BTEXs more efficiently while mixed with BP-20 and individually. Biosurfactant production was observed by culture techniques. In addition 3-hydroxy fatty acids, important in biosurfactant production, was observed by FAME analysis. In the all experiments toluene and m+p- xylenes were better growth substrates for both bacteria than the other BTEX compounds. In addition, the test results indicate that the bacteria could contribute to bioremediation of aromatic hydrocarbons (BTEX) pollution increase biodegradation through the action by biosurfactants.

Variable phosphorus uptake rates and allocation across microbial groups in the oligotrophic Gulf of Mexico.

Science.gov (United States)

Popendorf, Kimberly J; Duhamel, Solange

2015-10-01

Microbial uptake of dissolved phosphorus (P) is an important lever in controlling both microbial production and the fate and cycling of marine P. We investigated the relative role of heterotrophic bacteria and phytoplankton in P cycling by measuring the P uptake rates of individual microbial groups (heterotrophic bacteria and the phytoplankton groups Synechococcus, Prochlorococcus and picoeukaryotic phytoplankton) in the P-depleted Gulf of Mexico. Phosphorus uptake rates were measured using incubations with radiolabelled phosphate and adenosine triphosphate coupled with cell sorting flow cytometry. We found that heterotrophic bacteria were the dominant consumers of P on both a biomass basis and a population basis. Biovolume normalized heterotrophic bacteria P uptake rate per cell (amol P μm(-3) h(-1)) was roughly an order of magnitude greater than phytoplankton uptake rates, and heterotrophic bacteria were responsible for generally greater than 50% of total picoplankton P uptake. We hypothesized that this variation in uptake rates reflects variation in cellular P allocation strategies, and found that, indeed, the fraction of cellular P uptake utilized for phospholipid production was significantly higher in heterotrophic bacteria compared with cyanobacterial phytoplankton. These findings indicate that heterotrophic bacteria have a uniquely P-oriented physiology and play a dominant role in cycling dissolved P. © 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.

A method to detect metal–drug complexes and their interactions with pathogenic bacteria via graphene nanosheet assist laser desorption/ionization mass spectrometry and biosensors

International Nuclear Information System (INIS)

Abdelhamid, Hani Nasser; Wu, Hui-Fen

2012-01-01

Highlights: ► Probe transition metals-complexes based on noncovalent functionalized graphene for MALDI-MS. ► Study interaction of transition metals complexes with pathogenic bacteria. ► Propose a new biosensor for two pathogenic bacteria. - Abstract: A new method was proposed to probe the interactions between transition metals of Fe(II), Fe(III), Cu(II) with a non steroidal anti-inflammatory drug (NSAID), flufenamic acid (FF) using graphene as a matrix for Graphene assisted laser desorption ionization mass spectrometry (GALDI-MS). Metal–drug complexation was confirmed via UV absorption spectroscopy, fluorescence spectroscopy, pH meter, and change in solution conductivity. The optimal molar ratios for these complexation interactions are stoichiometry 1:2 in both Cu(II) and Fe(II) complexes, and 1:3 in Fe(III) complexes at physiological pH (7.4). Metal complexation of the drug could enhance fluorescence for 20 fold which is due to the charge transfer reaction or increase rigidity of the drug. The main interaction between graphene and flufenamic acid is the Π–Π interaction which allows us to probe the metal–drug complexation. The GALDI-MS could sensitively detect the drug at m/z 281.0 Da (protonated molecule) with detection limit 2.5 pmol (1.0 μM) and complexation at m/z 661.0, 654.0 and 933.0 Da corresponding to [Cu(II)(FF) 2 (H 2 O) 2 + H] + , [Fe(II)(FF) 2 (H 2 O) 2 + H] + and [Fe(III) (FF) 3 (H 2 O) 2 + H] + , respectively (with limit of detection (LOD) 2.0 pmol (10.0 μM). Matrix assisted laser desorption ionization mass spectrometry (MALDI-MS) spectra show change in the protein profile of intact pathogenic bacteria (Pseudomonas aeroginosa, Staphylococcus aureus). The change in the ionization ability (mainly proton affinity) of pathogenic bacteria may be due to the interactions between the bacteria with the drug (or its complexes). Shielding carboxylic group by metals and increase the hydrophilicity could enhance the biocompatibility of complexes

Big bacteria

DEFF Research Database (Denmark)

Schulz, HN; Jørgensen, BB

2001-01-01

A small number of prokaryotic species have a unique physiology or ecology related to their development of unusually large size. The biomass of bacteria varies over more than 10 orders of magnitude, from the 0.2 mum wide nanobacteria to the largest cells of the colorless sulfur bacteria...... and by actively creating an advective flow through the entire population. Diffusion limitation generally restricts the maximal size of prokaryotic cells and provides a selective advantage for mum-sized cells at the normally low substrate concentrations in the environment. The largest heterotrophic bacteria......, the 80 x 600 mum large Epulopiscium sp. from the gut of tropical fish, are presumably living in a very nutrient-rich medium. Many large bacteria contain numerous inclusions in the cells that reduce the volume of active cytoplasm. The most striking examples of competitive advantage from large cell size...

Tetrahydro-2,1,3-boraoxazines - a new group boron heterocyclics

International Nuclear Information System (INIS)

Piotrowska, H.; Serafin, B.; Urbanski, T.; Vasudeva, S.K.

1977-01-01

The synthesis of new group of compounds derivative of tetrahydro-2,1,3 boraoxazine(5) by condensation of aminoalcohols 3 with aryloboronic acids(4) was carried out. The properties of new compounds are presented. (B.C.)

A Multiplex SYBR Green Real-Time PCR Assay for the Detection of Three Colistin Resistance Genes from Cultured Bacteria, Feces, and Environment Samples

Directory of Open Access Journals (Sweden)

Jiyun Li

2017-10-01

Full Text Available The aim of the study was to develop a multiplex assay for rapid detection of mcr-1, mcr-2, and mcr-3, a group of genes of conferring resistance to colistin mediated by plasmid in Enterobacteriaceae. A SYBR Green based real-time PCR assay has been designed to detect the mcr genes, and applied to cultured bacteria, feces and soil samples. All three mcr genes could be detected with a lower limit of 102 cultured bacteria. This test was highly specific and sensitive, and generated no false-positive results. The assay was also conclusive when applied to feces and soil samples containing mcr-1-positive Escherichia coli, which could facilitate the screening of mcr genes not only in the bacteria, but also directly from the environment. This simple, rapid, sensitive, and specific multiplex assay will be useful for rapid screening of the colistin resistance in both clinical medicine and animal husbandry.

[Diversity and enzyme-producing activity of culturable halophilic bacteria in Daishan Saltern of East China].

Science.gov (United States)

Yang, Dan-Dan; Li, Qian; Huang, Jing-Jing; Chen, Min

2012-11-01

Soil and saline water samples were collected from the Daishan Saltern of East China, and the halophilic bacteria were isolated and cultured by using selective media, aimed to investigate the diversity and enzyme-producing activity of culturable halophilic bacteria in saltern environment. A total of 181 strains were isolated by culture-dependent method. Specific primers were used to amplify the 16S rRNA gene of bacteria and archaea. The operation taxonomy units (OTUs) were determined by ARDRA method, and the representative strain of each OTU was sequenced. The phylogenetic position of all the isolated strains was determined by 16S rRNA sequencing. The results showed that the isolated 181 strains displayed 21 operational taxonomic units (OTUs), of which, 12 OTUs belonged to halophilic bacteria, and the others belonged to halophilic archaea. Phylogenetic analysis indicated that there were 7 genera presented among the halophilic bacteria group, and 4 genera presented among the halophilic archaea group. The dominant halophilic strains were of Halomonas and Haloarcula, with 46.8% in halophilic bacteria and 49.1% in halophilic archaea group, respectively. Enzyme-producing analysis indicated that most strains displayed enzyme-producing activity, including the activities of producing amylase, proteinase and lipase, and the dominant strains capable of enzyme-producing were of Haloarcula. Our results showed that in the environment of Daishan Saltern, there existed a higher diversity of halophilic bacteria, being a source sink for screening enzyme-producing bacterial strains.

[Characteristics of natural strains of naphthalene-utilizing bacteria of the genus Pseudomonas].

Science.gov (United States)

Levchuk, A A; Vasilenko, S L; Bulyga, I M; Titok, M A; Thomas, K M

2005-01-01

Sixty-three strains of bacteria capable of utilizing naphthalene as the sole source of carbon and energy were isolated from 137 samples of soil taken in different sites in Belarus. All isolated bacteria contained extrachromosomal genetic elements of 45 to 150 kb in length. It was found that bacteria of 31 strains contained the IncP-9 incompatibility group plasmids, bacteria of one strain carried a plasmid containing replicons IncP-9 and IncP-7, and bacteria of 31 strains contained unidentified plasmids. Primary identification showed that the hosts of plasmids of naphthalene biodegradation are fluorescent bacteria of the genus Pseudomonas (P. putida and P. aeruginosa; a total of 47 strains) and unidentified nonfluorescent microorganisms (a total of 16 strains). In addition to the ability to utilize naphthalene, some strains exhibited the ability to stimulate the growth and development of the root system of Secale cereale.

Screening identification of aerobic denitrification bacteria with high soil desalinization capacity

Science.gov (United States)

Jin, H.; Chen, H.; Jin, H.; Qian, Y.; Zhang, K.

2017-08-01

In order to study the mechanism of bacteria used in the saline soil remediation process, the aerobic denitrification bacteria were isolated from an agricultural greenhouse soil in a farm in East China’s Zhejiang Province. The identification, nitrogen reducing characteristics and the denitrification effect of bacteria from different soils at various locations were investigated. The results showed that the NO3- removal rate was 91% with bacteria from the greenhouse soil under aerobic conditions in 52 h, and the bacteria were identified as Gram-positive Castellaniella denitrification bacteria.

Differentiation between spore-forming and asporogenic bacteria using a PCR and southern hybridization based method

Energy Technology Data Exchange (ETDEWEB)

Brill, J.A.; Wiegel, J. [Univ. of Georgia, Athens, GA (United States)

1997-12-31

A set of molecular probes was devised to develop a method for screening for the presence of sequences homologous to three representative genes exclusively involved in endosporulation. Based on known gene sequences, degenerate PCR primers were designed against spo0A and ssp. Experimental conditions were devised under which homologs of both genes were consistently detected in endospore-forming bacteria, but not in asporogenic bacteria. The PCR amplification products and dpaA/B from Bacillus subtilis were used as hybridization probes for Southern blots. Identical conditions were used with the genomic DNA from endospore-forming and asporogenic bacteria. We therefore concluded that the probes specifically detect the targeted sporulation genes and we obtained no indication that genes homologous to ssp, spo0A and dpaA/B are present in asporogenic bacteria. Thus, this assay can potentially be used to detect spore-forming bacteria in various kinds of samples and to distinguish between bacteria containing sporulation genes and those who do not regardless of whether sporulation is observed or not. 43 refs., 3 figs., 1 tab.

Relationship between luminous fish and symbiosis. I. Comparative studies of lipopolysaccharides isolated from symbiotic luminous bacteria of the luminous marine fish, Physiculus japonicus.

Science.gov (United States)

Kuwae, T; Andoh, M; Fukasawa, S; Kurata, M

1983-01-01

In order to investigate the relationship between host and symbiosis in the luminous marine fish, Physiculus japonicus, the bacterial lipopolysaccharides (LPS) of symbiotic luminous bacteria were compared serologically and electrophoretically. Five symbiotic luminous bacteria (PJ strains) were separately isolated from five individuals of this fish species caught at three points, off the coasts of Chiba, Nakaminato, and Oharai. LPS preparations were made from these bacteria by Westphal's phenol-water method and highly purified by repeated ultracentrifugation. These LPSs contained little or no 2-keto-3-deoxyoctonate and had powerful mitogenic activity. In sodium dodecylsulfate polyacrylamide gel electrophoresis, these PJ-1 to -5 LPSs were separated by their electrophoretic patterns into three groups; the first group included PJ-1 and PJ-4, the second group PJ-2 and PJ-3, and the third group PJ-5 alone. The results agreed with those of the double immunodiffusion test; precipitin lines completely coalesced within each group but not with other groups. In immunoelectrophoresis, one precipitin line was observed between anti PJ-2 LPS serum and PJ-5 LPS but the electrophoretic mobility of PJ-5 LPS was clearly different from that of the PJ-2 LPS group. Furthermore, in a 50% inhibition test with PJ-2 LPS by the passive hemolysis system, the doses of PJ-2 LPS, PJ-3 LPS, and PJ-5 LPS required for 50% inhibition (ID50) in this system were 0.25, 0.25, and 21.6 micrograms/ml for each alkali-treated LPS, respectively, and the ID50's of both PJ-1 LPS and PJ-4 LPS were above 1,000 micrograms/ml. These results indicate that PJ-5 LPS has an antigenic determinant partially in common with LPS from the PJ-2 group but not with LPS from the PJ-1 group and that the symbiotic luminous bacterium PJ-5 is more closely related to the PJ-2 group than to the PJ-1 group. These results show that the species Physiculus japonicus is symbiotically associated with at least three immunologically different

Colonization of the oral cavity by probiotic bacteria.

Science.gov (United States)

Ravn, I; Dige, I; Meyer, R L; Nyvad, B

2012-01-01

The aim of this study was to investigate if three probiotic bacteria present in the milk product Cultura Dofilus® naturell could be detected in saliva and on oral mucosal surfaces, and if they colonized dental surfaces in situ in 8 caries-inactive individuals after 8 daily exposures to the milk product for up to 3 days. Bacteria were identified by fluorescence in situ hybridization and confocal laser scanning microscopy. While probiotic bacteria were present sporadically in the oral cavity on mucosal surfaces and in saliva after 3 days of frequent use of the probiotic milk, they were not detected on dental surfaces. Probiotic bacteria may thus contribute to general oral health, but their potential role in biofilm-induced dental diseases remains unclear. Copyright © 2012 S. Karger AG, Basel.

A porous silicon optical microcavity for sensitive bacteria detection

International Nuclear Information System (INIS)

Li Sha; Huang Jianfeng; Cai Lintao

2011-01-01

A porous silicon microcavity (PSM) is highly sensitive to subtle interface changes due to its high surface area, capillary condensation ability and a narrow resonance peak (∼10 nm). Based on the well-defined optical properties of a PSM, we successfully fabricated a bacteria detection chip for molecular or subcellular analysis by surface modification using undecylenic acid (UA), and the specific recognition binding of vancomycin to the D-alanyl-D-alanine of bacteria. The red shift of the PSM resonance peak showed a good linear relationship with bacteria concentration ranging from 100 to 1000 bacteria ml -1 at the level of relative standard deviation of 0.994 and detection limit of 20 bacteria ml -1 . The resulting PSM sensors demonstrated high sensitivity, good reproducibility, fast response and low cost for biosensing.

A porous silicon optical microcavity for sensitive bacteria detection

Science.gov (United States)

Li, Sha; Huang, Jianfeng; Cai, Lintao

2011-10-01

A porous silicon microcavity (PSM) is highly sensitive to subtle interface changes due to its high surface area, capillary condensation ability and a narrow resonance peak (~10 nm). Based on the well-defined optical properties of a PSM, we successfully fabricated a bacteria detection chip for molecular or subcellular analysis by surface modification using undecylenic acid (UA), and the specific recognition binding of vancomycin to the D-alanyl-D-alanine of bacteria. The red shift of the PSM resonance peak showed a good linear relationship with bacteria concentration ranging from 100 to 1000 bacteria ml - 1 at the level of relative standard deviation of 0.994 and detection limit of 20 bacteria ml - 1. The resulting PSM sensors demonstrated high sensitivity, good reproducibility, fast response and low cost for biosensing.

A porous silicon optical microcavity for sensitive bacteria detection

Energy Technology Data Exchange (ETDEWEB)

Li Sha; Huang Jianfeng; Cai Lintao, E-mail: lt.cai@siat.ac.cn [CAS Key Lab of Health Informatics, Shenzhen Key Laboratory of Cancer Nanotechnology, Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055 (China)

2011-10-21

A porous silicon microcavity (PSM) is highly sensitive to subtle interface changes due to its high surface area, capillary condensation ability and a narrow resonance peak ({approx}10 nm). Based on the well-defined optical properties of a PSM, we successfully fabricated a bacteria detection chip for molecular or subcellular analysis by surface modification using undecylenic acid (UA), and the specific recognition binding of vancomycin to the D-alanyl-D-alanine of bacteria. The red shift of the PSM resonance peak showed a good linear relationship with bacteria concentration ranging from 100 to 1000 bacteria ml{sup -1} at the level of relative standard deviation of 0.994 and detection limit of 20 bacteria ml{sup -1}. The resulting PSM sensors demonstrated high sensitivity, good reproducibility, fast response and low cost for biosensing.

Oh What a Tangled Biofilm Web Bacteria Weave

Science.gov (United States)

... Home Page Oh What a Tangled Biofilm Web Bacteria Weave By Elia Ben-Ari Posted May 1, ... a suitable surface, some water and nutrients, and bacteria will likely put down stakes and form biofilms. ...

A prophage tail-like protein is deployed by Burkholderia bacteria to feed on fungi.

Science.gov (United States)

Swain, Durga Madhab; Yadav, Sunil Kumar; Tyagi, Isha; Kumar, Rahul; Kumar, Rajeev; Ghosh, Srayan; Das, Joyati; Jha, Gopaljee

2017-09-01

Some bacteria can feed on fungi, a phenomenon known as mycophagy. Here we show that a prophage tail-like protein (Bg_9562) is essential for mycophagy in Burkholderia gladioli strain NGJ1. The purified protein causes hyphal disintegration and inhibits growth of several fungal species. Disruption of the Bg_9562 gene abolishes mycophagy. Bg_9562 is a potential effector secreted by a type III secretion system (T3SS) and is translocated into fungal mycelia during confrontation. Heterologous expression of Bg_9562 in another bacterial species, Ralstonia solanacearum, confers mycophagous ability in a T3SS-dependent manner. We propose that the ability to feed on fungi conferred by Bg_9562 may help the bacteria to survive in certain ecological niches. Furthermore, considering its broad-spectrum antifungal activity, the protein may be potentially useful in biotechnological applications to control fungal diseases.Some bacteria can feed on live fungi through unclear mechanisms. Here, the authors show that a T3SS-secreted protein, which is homologous to phage tail proteins, allows a Burkholderia gladioli strain to kill and feed on various fungal species.

Biotransformation of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) by a prospective consortium and its most effective isolate Serratia marcescens

Energy Technology Data Exchange (ETDEWEB)

Young, D.M.; Ogden, K.L. [Univ. of Arizona, Tucson, AZ (United States). Dept. of Chemical and Environmental Engineering; Unkefer, P.J. [Los Alamos National Lab., NM (United States). Chemical Science and Technology Div.

1997-03-05

The biotransformation of hexahydro-1,3,5-trinitro-1,3,5 triazine (RDX) has been observed in liquid culture by a consortium of bacteria found in horse manure. Five types of bacteria were found to predominate in the consortium and were isolated. The most effective of these isolates at transforming RDX was Serratia marcescens. The biotransformation of RDX by all of these bacteria was found to occur only in the anoxic stationary phase. The process of bacterial growth and RDX biotransformation was quantified for the purpose of developing a predictive type model. Cell growth was assumed to follow Monod kinetics. All of the aerobic and anoxid growth parameters were determined: {mu}{sub max}, K{sub s}, and Y{sub x/s}. RDX was found to competitively inhibit cell growth in both atmospheres. Degradation of RDX by Serratia marcescens was found to proceed through the stepwise reduction of the three nitro groups to nitroso groups. Each of these reductions was found to be first order in both component and cell concentrations. The degradation rate constant for the first step in this reduction process by the consortium was 0.022 L/g cells {center_dot} h compared to 0.033 L/g cells {center_dot} h for the most efficient isolate.

Sensitive detection of maltose and glucose based on dual enzyme-displayed bacteria electrochemical biosensor.

Science.gov (United States)

Liu, Aihua; Lang, Qiaolin; Liang, Bo; Shi, Jianguo

2017-01-15

Glucoamylase-displayed bacteria (GA-bacteria) and glucose dehydrogenase-displayed bacteria (GDH-bacteria) were co-immobilized on multi-walled carbon nanotubes (MWNTs) modified glassy carbon electrode (GCE) to construct GA-bacteria/GDH-bacteria/MWNTs/GCE biosensor. The biosensor was developed by optimizing the loading amount and the ratio of GA-bacteria to GDH-bacteria. The as-prepared biosensor exhibited a wide dynamic range of 0.2-10mM and a low detection limit of 0.1mM maltose (S/N=3). The biosensor also had a linear response to glucose in the range of 0.1-2.0mM and a low detection limit of 0.04mM glucose (S/N=3). Interestingly, at the same concentration, glucose was 3.75-fold sensitive than that of maltose at the proposed biosensor. No interferences were observed for other possible mono- and disaccharides. The biosensor also demonstrated good long-term storage stability and repeatability. Further, using both GDH-bacteria/MWNTs/GCE biosensor and GA-bacteria/GDH-bacteria/MWNTs/GCE biosensor, glucose and maltose in real samples can be detected. Therefore, the proposed biosensor is capable of monitoring the food manufacturing and fermentation process. Copyright © 2016 Elsevier B.V. All rights reserved.

Biochemical and chemical characterization of pink-pigmented oxidative bacteria.

Science.gov (United States)

Wallace, P L; Hollis, D G; Weaver, R E; Moss, C W

1990-04-01

The biochemical and chemical characteristics were determined for 156 clinical isolates of pink-pigmented bacteria that are similar to but distinct from Methylobacterium extorquens (synonymous with Pseudomonas mesophilica). These isolates were gram-negative, nonfermentative, usually nonvacuolated, coccoid rods; all grew at 35 degrees C and were catalase and urease positive; the majority grew on MacConkey agar and were variable for oxidase production and motility. On the basis of oxidation of xylose and mannitol and hydrolysis of esculin, these 156 strains were subdivided into four groups that were designated "pink coccoid" groups I, II, III, and IV. Groups I, II, and III are similar to an unnamed taxon described by Gilardi and Faur in 1984; only strains of group IV hydrolyze esculin. The cellular fatty acid compositions of strains of groups I, II, and III were essentially identical and differed from strains of group IV by the absence of 3-OH-C14:0 and the presence of C19:0 delta and 2-OH-C19:0 delta. The fatty acid composition of group IV strains was most similar to that of M. extorquens but differed by the presence of small amounts of two C17:1 acids, 3-OH-C16:0, and 2-OH-C18:1.

Marine Bacteria from Eastern Indonesia Waters and Their Potential Use in Biotechnology

Directory of Open Access Journals (Sweden)

Yosmina H Tapilatu

2016-05-01

Full Text Available Indonesian vast marine waters, which constitute 81% of the country’s total area, have a great potential in terms of marine bacteria biodiversity. However, marine bacteria are still under-explored in Indonesia, especially in its eastern area. Known as one of the biodiversity hotspots worldwide, this area surely harbors various marine bacteria of particular interest. Despite the growing number of oceanic expeditions carried out in this area, only little attention has been attributed to marine bacteria. Limited literatures exist on the isolation of marine bacteria producing compounds with potential biotechnological applications from the aforementioned waters. There are two main causes of this problem, namely lack of infrastructures and limited competent human resources. In this paper, I will highlight the preliminary results of isolation and bioprospecting attempts on this group of bacteria during the last fifteen years. These results indicate that research activities on marine bacteria in this area need to be intensified, to uncover their potential applications in various biotechnological fields. Keywords: marine bacteria, eastern Indonesian waters, biotechnological application

H2S: a universal defense against antibiotics in bacteria.

Science.gov (United States)

Shatalin, Konstantin; Shatalina, Elena; Mironov, Alexander; Nudler, Evgeny

2011-11-18

Many prokaryotic species generate hydrogen sulfide (H(2)S) in their natural environments. However, the biochemistry and physiological role of this gas in nonsulfur bacteria remain largely unknown. Here we demonstrate that inactivation of putative cystathionine β-synthase, cystathionine γ-lyase, or 3-mercaptopyruvate sulfurtransferase in Bacillus anthracis, Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli suppresses H(2)S production, rendering these pathogens highly sensitive to a multitude of antibiotics. Exogenous H(2)S suppresses this effect. Moreover, in bacteria that normally produce H(2)S and nitric oxide, these two gases act synergistically to sustain growth. The mechanism of gas-mediated antibiotic resistance relies on mitigation of oxidative stress imposed by antibiotics.

Modeling Bacteria Surface Acid-Base Properties: The Overprint Of Biology

Science.gov (United States)

Amores, D. R.; Smith, S.; Warren, L. A.

2009-05-01

Bacteria are ubiquitous in the environment and are important repositories for metals as well as nucleation templates for a myriad of secondary minerals due to an abundance of reactive surface binding sites. Model elucidation of whole cell surface reactivity simplifies bacteria as viable but static, i.e., no metabolic activity, to enable fits of microbial data sets from models derived from mineral surfaces. Here we investigate the surface proton charging behavior of live and dead whole cell cyanobacteria (Synechococcus sp.) harvested from a single parent culture by acid-base titration using a Fully Optimized ContinUouS (FOCUS) pKa spectrum method. Viability of live cells was verified by successful recultivation post experimentation, whereas dead cells were consistently non-recultivable. Surface site identities derived from binding constants determined for both the live and dead cells are consistent with molecular analogs for organic functional groups known to occur on microbial surfaces: carboxylic (pKa = 2.87-3.11), phosphoryl (pKa = 6.01-6.92) and amine/hydroxyl groups (pKa = 9.56-9.99). However, variability in total ligand concentration among the live cells is greater than those between the live and dead. The total ligand concentrations (LT, mol- mg-1 dry solid) derived from the live cell titrations (n=12) clustered into two sub-populations: high (LT = 24.4) and low (LT = 5.8), compared to the single concentration for the dead cell titrations (LT = 18.8; n=5). We infer from these results that metabolic activity can substantively impact surface reactivity of morphologically identical cells. These results and their modeling implications for bacteria surface reactivities will be discussed.

A representation-theoretic approach to the calculation of evolutionary distance in bacteria

Science.gov (United States)

Sumner, Jeremy G.; Jarvis, Peter D.; Francis, Andrew R.

2017-08-01

In the context of bacteria and models of their evolution under genome rearrangement, we explore a novel application of group representation theory to the inference of evolutionary history. Our contribution is to show, in a very general maximum likelihood setting, how to use elementary matrix algebra to sidestep intractable combinatorial computations and convert the problem into one of eigenvalue estimation amenable to standard numerical approximation techniques.

S3T working group. Report 1: group aims

International Nuclear Information System (INIS)

Pouey, M.

1983-04-01

The work group S3T which is aimed to designing and developing devices using unconventional holographic optics is presented. These devices find applications that are classified here in four items high resolution spectrometers, high definition imaging, high flux devices, metrology and interferometry. The problems to solve and the aims of the group in each of these cases are presented. Three synthesis of lectures are in this report. The main one concerns stigmatism conditions of concave holographic gratings used in normal incidence. This new process of focusing is very interesting for hot plasma diagnostics [fr

[Influence of serious infections due to Gram-negative bacteria on the hospital economy].

Science.gov (United States)

Martínez, B; Gómez, J; Gómez Vargas, J; Guerra, B; Ruiz Gómez, J; Simarro, E; Baños, V; Canteras, M; Valdes, M

2000-12-01

Nosocomial infections due to Gram-negative bacteria are very important since they are associated with high morbidity and high hospital costs. A prospective study of 250 inpatients was carried out, 200 of whom had Gram-negative bacterial infections. Patients were divided into groups of 50 according to the localization of the infection (urinary, surgical wound, respiratory tract and bacteremia), with a control group of 50 patients with similar characteristics but no infection. We calculated the cost for the different groups by multiplying the average length of hospital stay in days by the daily cost of the stay. Significant differences were observed in the average length of stay per patient according to the type of infection and how it was acquired. In terms of cost, nosocomial infection due to Gram-negative bacteria was 1,049,139 pesetas more expensive than community-acquired infection. The cost of the stay for patients with postsurgical infection due to Gram-negative bacteria was 1,108, 252 pesetas more expensive than for the group of control patients. Nosocomial infection due to Gram-negative bacteria is associated with a prolongation in hospital stay of 9 to 28 days, which is the factor that most reflects the cost that can be attributed to nosocomial infection. Consensual and protocolized measures which allow for better clinical management need to be developed.

Bacteria classification using Cyranose 320 electronic nose

Directory of Open Access Journals (Sweden)

Gardner Julian W

2002-10-01

Full Text Available Abstract Background An electronic nose (e-nose, the Cyrano Sciences' Cyranose 320, comprising an array of thirty-two polymer carbon black composite sensors has been used to identify six species of bacteria responsible for eye infections when present at a range of concentrations in saline solutions. Readings were taken from the headspace of the samples by manually introducing the portable e-nose system into a sterile glass containing a fixed volume of bacteria in suspension. Gathered data were a very complex mixture of different chemical compounds. Method Linear Principal Component Analysis (PCA method was able to classify four classes of bacteria out of six classes though in reality other two classes were not better evident from PCA analysis and we got 74% classification accuracy from PCA. An innovative data clustering approach was investigated for these bacteria data by combining the 3-dimensional scatter plot, Fuzzy C Means (FCM and Self Organizing Map (SOM network. Using these three data clustering algorithms simultaneously better 'classification' of six eye bacteria classes were represented. Then three supervised classifiers, namely Multi Layer Perceptron (MLP, Probabilistic Neural network (PNN and Radial basis function network (RBF, were used to classify the six bacteria classes. Results A [6 × 1] SOM network gave 96% accuracy for bacteria classification which was best accuracy. A comparative evaluation of the classifiers was conducted for this application. The best results suggest that we are able to predict six classes of bacteria with up to 98% accuracy with the application of the RBF network. Conclusion This type of bacteria data analysis and feature extraction is very difficult. But we can conclude that this combined use of three nonlinear methods can solve the feature extraction problem with very complex data and enhance the performance of Cyranose 320.

Relative feeding rates on free and particle-bound bacteria by freshwater macrozooplankton

International Nuclear Information System (INIS)

Schoenberg, S.A.; Maccubbin, A.E.

1985-01-01

Feeding suspensions of equivalent particle spectra were assembled with either free-living ( 3 H]thymidine. Clearance (ml ind -1 d -1 ) of attached bacteria was 3-29 x that of free bacteria for the cladocerans Acantholeberis, Chydorus, and Eubosmina. Pseudosida and Ceriodaphnia showed weaker discrimination or no selection, indicating a lower size threshold for filtration in these species. Feeding suspensions composed of isolated free bacteria yielded significantly higher or lower estimates of grazing than free bacteria with the full complement of particles, depending on species. Relative clearance (attached:free) tended to increase with body size within a species and varied for different particle environments. Bacteria associated with large particles may increase detrital energy flow to consumers in eutrophic environments

Screening and isolation of halophilic bacteria producing industrially important enzymes.

Science.gov (United States)

Kumar, Sumit; Karan, Ram; Kapoor, Sanjay; S P, Singh; S K, Khare

2012-10-01

Halophiles are excellent sources of enzymes that are not only salt stable but also can withstand and carry out reactions efficiently under extreme conditions. The aim of the study was to isolate and study the diversity among halophilic bacteria producing enzymes of industrial value. Screening of halophiles from various saline habitats of India led to isolation of 108 halophilic bacteria producing industrially important hydrolases (amylases, lipases and proteases). Characterization of 21 potential isolates by morphological, biochemical and 16S rRNA gene analysis found them related to Marinobacter, Virgibacillus, Halobacillus, Geomicrobium, Chromohalobacter, Oceanobacillus, Bacillus, Halomonas and Staphylococcus genera. They belonged to moderately halophilic group of bacteria exhibiting salt requirement in the range of 3-20%. There is significant diversity among halophiles from saline habitats of India. Preliminary characterization of crude hydrolases established them to be active and stable under more than one extreme condition of high salt, pH, temperature and presence of organic solvents. It is concluded that these halophilic isolates are not only diverse in phylogeny but also in their enzyme characteristics. Their enzymes may be potentially useful for catalysis under harsh operational conditions encountered in industrial processes. The solvent stability among halophilic enzymes seems a generic novel feature making them potentially useful in non-aqueous enzymology.

Pu sorption to activated conglomerate anaerobic bacteria

International Nuclear Information System (INIS)

Sasaki, Takayuki; Kudo, Akira

2001-01-01

The sorption of Pu to the anaerobic bacteria activated under specific conditions of temperature, pH and depleted nutrients after long dormant period was investigated. After 4 h at neutral pH, the distribution coefficient (K d ) between bacteria and aqueous phase at 308 and 278 K had around 10 3 to 10 4 . After over 5 days, however, the K d at only 308 K had increased to over 10 5 . Sterilized (dead) and dormant anaerobic bacteria adsorbed Pu to the same extent. (author)

The seaweed holobiont: understanding seaweed-bacteria interactions.

Science.gov (United States)

Egan, Suhelen; Harder, Tilmann; Burke, Catherine; Steinberg, Peter; Kjelleberg, Staffan; Thomas, Torsten

2013-05-01

Seaweeds (macroalgae) form a diverse and ubiquitous group of photosynthetic organisms that play an essential role in aquatic ecosystems. These ecosystem engineers contribute significantly to global primary production and are the major habitat formers on rocky shores in temperate waters, providing food and shelter for aquatic life. Like other eukaryotic organisms, macroalgae harbor a rich diversity of associated microorganisms with functions related to host health and defense. In particular, epiphytic bacterial communities have been reported as essential for normal morphological development of the algal host, and bacteria with antifouling properties are thought to protect chemically undefended macroalgae from detrimental, secondary colonization by other microscopic and macroscopic epibiota. This tight relationship suggests that macroalgae and epiphytic bacteria interact as a unified functional entity or holobiont, analogous to the previously suggested relationship in corals. Moreover, given that the impact of diseases in marine ecosystems is apparently increasing, understanding the role of bacteria as saprophytes and pathogens in seaweed communities may have important implications for marine management strategies. This review reports on the recent advances in the understanding of macroalgal-bacterial interactions with reference to the diversity and functional role of epiphytic bacteria in maintaining algal health, highlighting the holobiont concept. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

Roseobacter-clade bacteria as probiotics in marine larvaeculture

DEFF Research Database (Denmark)

Grotkjær, Torben

Disease caused by fish pathogenic bacteria can cause large scale crashes in marine fish larval rearing units. One of the biggest challenges for aquaculture is the management of these bacterial outbreaks. Vaccines can be admitted to fish but only the juvenile and the adult fish because they need...... to have a mature immune system. This means that the larvae of the fish, until they are 2-3 weeks old are more prone to bacterial infections. A short term solution is antibiotics but this leaves way for the selection for antibiotic resistance among the pathogenic bacteria, which again can be transferred...... to human pathogens. Alternatives are therefore needed and one could be the use of probiotic bacteria. Marine bacteria from the Roseobacter clade (Phaeobacter inhibens) have shown great potential as probiotic bacteria, and we have hypothesized that they could be used to antagonize pathogenic fish...

Deliverable 3.3.2 Specification of tests and test groups

DEFF Research Database (Denmark)

Peterson, Carrie Beth; Mitseva, Anelia; Harpur, Jill

2009-01-01

Deliverable 3.3.2: Specification of tests and test groups One of the main goals of the ISISEMD project is to offer innovative ICT services to improve the quality of life of elderly persons with cognitive problems or mild dementia and their informal and formal caregivers who provide every day care...... for them. This will be done via integrating intelligent scalable ICT services which will be tested for a period of 12 months under realistic conditions. Offering the services could not be complete without evaluating quality of life improvement, user acceptance and user satisfaction with a representative...... group of the target user groups. This document is devoted to describing important aspects of services evaluation such as: who the test participants will be, inclusion and exclusion criterion, selection standards, how the test participants will be recruited, ethical considerations, etc. Test methodology...

Unusual rise in mercury-resistant bacteria in coastal environs

Digital Repository Service at National Institute of Oceanography (India)

Ramaiah, N.; De, J.

A sharp rise in mercury-resistant bacteria (MRB) capable of tolerating very high concentration of Hg was observed over the last 3-4 years in the coastal environs of India. While none or negligible colony-forming units (CFU) of bacteria were counted...

Detection of Sulphate-Reducing Bacteria and Others Cultivable Facultative Bacteria in Dental Tissues

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Lúcio de Souza Gonçalves

2014-01-01

Full Text Available Aim: To detect for the presence of sulphate-reducing bacteria (SRB and evaluate the possible association between SRB and cultivable facultative bacterial of oral sites with different periodontal conditions. Methods: The study was carried out on 9 samples from different oral sites in 8 patients (two samples were collected from the same patient. Material was collected using modified Postgate E culture medium, indicated for the growth and isolation of SRB. In addition, a reducing solution for anaerobic bacteria was used as a transport solution for facultative bacteria and identified by polymerase chain reaction amplification (PCR and sequencing of the 16S rRNA gene. Results: SRB was found in 3 patient samples: the first in a root fragment, the second in a root fragment and a healthy tooth with vertical bone loss and a mobility degree of 3; and the third in a healthy tooth extracted for orthodontic treatment. In the final patient, the cultivable facultative species Lactobacillus casei was identified. Other facultative bacterial species were identified in patient 5 (Kurthia Gibsonii and patient 7 (Pseudomonas aeruginosa. Conclusions: The detection of SRB in different dental tissues with distinct periodontal features demonstrated that new studies need to be developed in order to determine the true role of SRB in the oral microbiota. In addition, it was possible to verify the presence of Lactobacillus casei together with SRB in one sample.

CcpA-dependent carbon catabolite repression in bacteria

NARCIS (Netherlands)

Warner, JB; Lolkema, JS; Warner, Jessica B.

2003-01-01

Carbon catabolite repression (CCR) by transcriptional regulators follows different mechanisms in gram-positive and gram-negative bacteria. In gram-positive bacteria, CcpA-dependent CCR is mediated by phosphorylation of the phosphoenolpyruvate:sugar phosphotransferase system intermediate HPr at a

Bacteria in non-woven textile filters for domestic wastewater treatment.

Science.gov (United States)

Spychała, Marcin; Starzyk, Justyna

2015-01-01

The objective of this study was preliminary identification of heterotrophic and ammonia oxidizing bacteria (AOB) cell concentration in the cross-sectional profile of geotextile filters for wastewater treatment. Filters of thicknesses 3.6 and 7.2 mm, made of non-woven textile TS20, were supplied with septic tank effluent and intermittently dosed and filtered under hydrostatic pressure. The cumulative loads of chemical oxygen demand (COD) and total solids were about 1.36 and 1.06 kg/cm2, respectively. The filters under analysis reached a relatively high removal efficiency for organic pollution 70-90% for biochemical oxygen demand (BOD5) and 60-85% for COD. The ammonia nitrogen removal efficiency level proved to be unstable (15-55%). Biomass samples for dry mass identification were taken from two regions: continuously flooded with wastewater and intermittently flooded with wastewater. The culturable heterotrophic bacteria were determined as colony-forming units (CFUs) on microbiological-selective media by means of the plate method. AOB and nitrite oxidizing bacteria (NOB) were examined using the FISH technique. A relatively wide range of heterotrophic bacteria was observed from 7.4×10(5)/cm2 to 3.8×10(6)/cm2 in geotextile layers. The highest concentration of heterotrophic bacteria (3.8×10(6)/cm2) was observed in the first layer of the textile filter. AOB were identified occasionally--about 8-15% of all bacteria colonizing the last filter layer, but occasionally much higher concentrations and ammonia nitrogen efficiency were achieved. Bacteria oxidizing nitrite to nitrate were not observed. The relation of total and organic fraction of biomass to culturable heterotrophic bacteria was also found.

Identification of Lactic Acid Bacteria and Propionic Acid Bacteria using FTIR Spectroscopy and Artificial Neural Networks

Directory of Open Access Journals (Sweden)

Beata Nalepa

2012-01-01

Full Text Available In the present study, lactic acid bacteria and propionic acid bacteria have been identified at the genus level with the use of artificial neural networks (ANNs and Fourier transform infrared spectroscopy (FTIR. Bacterial strains of the genera Lactobacillus, Lactococcus, Leuconostoc, Streptococcus and Propionibacterium were analyzed since they deliver health benefits and are routinely used in the food processing industry. The correctness of bacterial identification by ANNs and FTIR was evaluated at two stages. At first stage, ANNs were tested based on the spectra of 66 reference bacterial strains. At second stage, the evaluation involved 286 spectra of bacterial strains isolated from food products, deposited in our laboratory collection, and identified by genus-specific PCR. ANNs were developed based on the spectra and their first derivatives. The most satisfactory results were reported for the probabilistic neural network, which was built using a combination of W5W4W3 spectral ranges. This network correctly identified the genus of 95 % of the lactic acid bacteria and propionic acid bacteria strains analyzed.

Lactic acid bacteria as a cell factory for riboflavin production

OpenAIRE

Thakur, Kiran; Tomar, Sudhir Kumar; De, Sachinandan

2015-01-01

Summary Consumers are increasingly becoming aware of their health and nutritional requirements, and in this context, vitamins produced in situ by microbes may suit their needs and expectations. B groups vitamins are essential components of cellular metabolism and among them riboflavin is one of the vital vitamins required by bacteria, plants, animals and humans. Here, we focus on the importance of microbial production of riboflavin over chemical synthesis. In addition, genetic abilities for r...

The spread of carbapenemase-producing bacteria in Africa: a systematic review.

Science.gov (United States)

Manenzhe, Rendani I; Zar, Heather J; Nicol, Mark P; Kaba, Mamadou

2015-01-01

Carbapenems are the last line of defence against ever more prevalent MDR Gram-negative bacteria, but their efficacy is threatened worldwide by bacteria that produce carbapenemase enzymes. The epidemiology of bacteria producing carbapenemases has been described in considerable detail in Europe, North America and Asia; however, little is known about their spread and clinical relevance in Africa. We systematically searched in PubMed, EBSCOhost, Web of Science, Scopus, Elsevier Masson Consulte and African Journals Online, international conference proceedings, published theses and dissertations for studies reporting on carbapenemase-producing bacteria in Africa. We included articles published in English or French up to 28 February 2014. We calculated the prevalence of carbapenemase producers only including studies where the total number of isolates tested was at least 30. Eighty-three studies were included and analysed. Most studies were conducted in North Africa (74%, 61/83), followed by Southern Africa (12%, 10/83), especially South Africa (90%, 9/10), West Africa (8%, 7/83) and East Africa (6%, 6/83). Carbapenemase-producing bacteria were isolated from humans, the hospital environment and community environmental water samples, but not from animals. The prevalence of carbapenemase-producing isolates in hospital settings ranged from 2.3% to 67.7% in North Africa and from 9% to 60% in sub-Saharan Africa. Carbapenemase-producing bacteria have been described in many African countries; however, their prevalence is poorly defined and has not been systematically studied. Antibiotic stewardship and surveillance systems, including molecular detection and genotyping of resistant isolates, should be implemented to monitor and reduce the spread of carbapenemase-producing bacteria. © The Author 2014. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Characterization of lactic acid bacteria from local cow´s milk kefir

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Ismail, YS; Yulvizar, C.; Mazhitov, B.

2018-03-01

One of products from milk fermentation is kefir. It is made by adding kefir grains which are composed of lactic acid bacteria and yeast into milk. The lactic acid bacteria are a group of bacteria that produce antimicrobial substances and able to inhibit the growth of pathogenic bacteria. In this research, the lactic acid bacteria were isolated from Aceh local cow`s milk kefir to determine the genus of the isolates. The methods used in the characterization of lactic acid bacteria are colony morphology, cell morphology, and biochemical tests which includes a catalase test; 5%, 6.5%, and 10% salt endurance tests; 37°C and 14°C temperature endurance tests, SIM test, TSIA test, MR-VP test, and O/F test. Of the four isolates found from the cow’s milk kefir, two isolates were confirmed as lactic acid bacteria (isolates SK-1 and SK-4). Both isolates are Gram positive bacteria, and have negative catalase activity. From the observations of colony morphology, cell morphology, and biochemical tests, it was found that the genus of SK-1 is Lactobacillus and the genus of SK-4 is Enterococcus.

Biodegradation of Mixed PAHs by PAH-Degrading Endophytic Bacteria

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Xuezhu Zhu

2016-08-01

Full Text Available Endophytic bacteria can promote plant growth, induce plant defence mechanisms, and increase plant resistance to organic contaminants. The aims of the present study were to isolate highly PAH-degrading endophytic bacteria from plants growing at PAH-contaminated sites and to evaluate the capabilities of these bacteria to degrade polycyclic aromatic hydrocarbons (PAHs in vitro, which will be beneficial for re-colonizing target plants and reducing plant PAH residues through the inoculation of plants with endophytic bacteria. Two endophytic bacterial strains P1 (Stenotrophomonas sp. and P3 (Pseudomonas sp., which degraded more than 90% of phenanthrene (PHE within 7 days, were isolated from Conyza canadensis and Trifolium pretense L., respectively. Both strains could use naphthalene (NAP, PHE, fluorene (FLR, pyrene (PYR, and benzo(apyrene (B(aP as the sole sources of carbon and energy. Moreover, these bacteria reduced the contamination of mixed PAHs at high levels after inoculation for 7 days; strain P1 degraded 98.0% NAP, 83.1% FLR, 87.8% PHE, 14.4% PYR, and 1.6% B(aP, and strain P3 degraded 95.3% NAP, 87.9% FLR, 90.4% PHE, 6.9% PYR, and negligible B(aP. Notably, the biodegradation of PAHs could be promoted through additional carbon and nitrogen nutrients; therein, beef extract was suggested as the optimal co-substrate for the degradation of PAHs by these two strains (99.1% PHE was degraded within 7 days. Compared with strain P1, strain P3 has more potential for the use in the removal of PAHs from plant tissues. These results provide a novel perspective in the reduction of plant PAH residues in PAH-contaminated sites through inoculating plants with highly PAH-degrading endophytic bacteria.

Multiplex quantification of 16S rDNA of predominant bacteria group within human fecal samples by polymerase chain reaction--ligase detection reaction (PCR-LDR).

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Li, Kai; Chen, Bei; Zhou, Yuxun; Huang, Rui; Liang, Yinming; Wang, Qinxi; Xiao, Zhenxian; Xiao, Junhua

2009-03-01

A new method, based on ligase detection reaction (LDR), was developed for quantitative detection of multiplex PCR amplicons of 16S rRNA genes present in complex mixtures (specifically feces). LDR has been widely used in single nucleotide polymorphism (SNP) assay but never applied for quantification of multiplex PCR products. This method employs one pair of DNA probes, one of which is labeled with fluorescence for signal capture, complementary to the target sequence. For multiple target sequence analysis, probes were modified with different lengths of polyT at the 5' end and 3' end. Using a DNA sequencer, these ligated probes were separated and identified by size and dye color. Then, relative abundance of target DNA were normalized and quantified based on the fluorescence intensities and exterior size standards. 16S rRNA gene of three preponderant bacteria groups in human feces: Clostridium coccoides, Bacteroides and related genera, and Clostridium leptum group, were amplified and cloned into plasmid DNA so as to make standard curves. After PCR-LDR analysis, a strong linear relationship was found between the florescence intensity and the diluted plasmid DNA concentrations. Furthermore, based on this method, 100 human fecal samples were quantified for the relative abundance of the three bacterial groups. Relative abundance of C. coccoides was significantly higher in elderly people in comparison with young adults, without gender differences. Relative abundance of Bacteroides and related genera and C. leptum group were significantly higher in young and middle aged than in the elderly. Regarding the whole set of sample, C. coccoides showed the highest relative abundance, followed by decreasing groups Bacteroides and related genera, and C. leptum. These results imply that PCR-LDR can be feasible and flexible applied to large scale epidemiological studies.

Diversity and characterization of mercury-resistant bacteria in snow, freshwater and sea-ice brine from the High Arctic.

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Møller, Annette K; Barkay, Tamar; Abu Al-Soud, Waleed; Sørensen, Søren J; Skov, Henrik; Kroer, Niels

2011-03-01

It is well-established that atmospheric deposition transports mercury from lower latitudes to the Arctic. The role of bacteria in the dynamics of the deposited mercury, however, is unknown. We characterized mercury-resistant bacteria from High Arctic snow, freshwater and sea-ice brine. Bacterial densities were 9.4 × 10(5), 5 × 10(5) and 0.9-3.1 × 10(3) cells mL(-1) in freshwater, brine and snow, respectively. Highest cultivability was observed in snow (11.9%), followed by freshwater (0.3%) and brine (0.03%). In snow, the mercury-resistant bacteria accounted for up to 31% of the culturable bacteria, but levels of most isolates were not temperature dependent. Of the resistant isolates, 25% reduced Hg(II) to Hg(0). No relation between resistance level, ability to reduce Hg(II) and phylogenetic group was observed. An estimation of the potential bacterial reduction of Hg(II) in snow suggested that it was important in the deeper snow layers where light attenuation inhibited photoreduction. Thus, by reducing Hg(II) to Hg(0), mercury-resistant bacteria may limit the supply of substrate for methylation processes and, hence, contribute to lowering the risk that methylmercury is being incorporated into the Arctic food chains. © 2010 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

Leucine incorporation by aerobic anoxygenic phototrophic bacteria in the Delaware estuary

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Stegman, Monica R; Cottrell, Matthew T; Kirchman, David L

2014-01-01

Aerobic anoxygenic phototrophic (AAP) bacteria are well known to be abundant in estuaries, coastal regions and in the open ocean, but little is known about their activity in any aquatic ecosystem. To explore the activity of AAP bacteria in the Delaware estuary and coastal waters, single-cell 3H-leucine incorporation by these bacteria was examined with a new approach that combines infrared epifluorescence microscopy and microautoradiography. The approach was used on samples from the Delaware coast from August through December and on transects through the Delaware estuary in August and November 2011. The percent of active AAP bacteria was up to twofold higher than the percentage of active cells in the rest of the bacterial community in the estuary. Likewise, the silver grain area around active AAP bacteria in microautoradiography preparations was larger than the area around cells in the rest of the bacterial community, indicating higher rates of leucine consumption by AAP bacteria. The cell size of AAP bacteria was 50% bigger than the size of other bacteria, about the same difference on average as measured for activity. The abundance of AAP bacteria was negatively correlated and their activity positively correlated with light availability in the water column, although light did not affect 3H-leucine incorporation in light–dark experiments. Our results suggest that AAP bacteria are bigger and more active than other bacteria, and likely contribute more to organic carbon fluxes than indicated by their abundance. PMID:24824666

Leucine incorporation by aerobic anoxygenic phototrophic bacteria in the Delaware estuary.

Science.gov (United States)

Stegman, Monica R; Cottrell, Matthew T; Kirchman, David L

2014-11-01

Aerobic anoxygenic phototrophic (AAP) bacteria are well known to be abundant in estuaries, coastal regions and in the open ocean, but little is known about their activity in any aquatic ecosystem. To explore the activity of AAP bacteria in the Delaware estuary and coastal waters, single-cell (3)H-leucine incorporation by these bacteria was examined with a new approach that combines infrared epifluorescence microscopy and microautoradiography. The approach was used on samples from the Delaware coast from August through December and on transects through the Delaware estuary in August and November 2011. The percent of active AAP bacteria was up to twofold higher than the percentage of active cells in the rest of the bacterial community in the estuary. Likewise, the silver grain area around active AAP bacteria in microautoradiography preparations was larger than the area around cells in the rest of the bacterial community, indicating higher rates of leucine consumption by AAP bacteria. The cell size of AAP bacteria was 50% bigger than the size of other bacteria, about the same difference on average as measured for activity. The abundance of AAP bacteria was negatively correlated and their activity positively correlated with light availability in the water column, although light did not affect (3)H-leucine incorporation in light-dark experiments. Our results suggest that AAP bacteria are bigger and more active than other bacteria, and likely contribute more to organic carbon fluxes than indicated by their abundance.

Metagenomic analysis reveals symbiotic relationship among bacteria in Microcystis-dominated community

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Meili eXie

2016-02-01

Full Text Available Microcystis bloom, a cyanobacterial mass occurrence often found in eutrophicated water bodies, is one of the most serious threats to freshwater ecosystems worldwide. In nature, Microcystis forms aggregates or colonies that contain heterotrophic bacteria. The Microcystis-bacteria colonies were persistent even when they were maintained in lab culture for a long period. The relationship between Microcystis and the associated bacteria was investigated by a metagenomic approach in this study. We developed a visualization-guided method of binning for genome assembly after total colony DNA sequencing. We found that the method was effective in grouping sequences and it did not require reference genome sequence. Individual genomes of the colony bacteria were obtained and they provided valuable insights into microbial community structures. Analysis of metabolic pathways based on these genomes revealed that while all heterotrophic bacteria were dependent upon Microcystis for carbon and energy, Vitamin B12 biosynthesis, which is required for growth by Microcystis, was accomplished in a cooperative fashion among the bacteria. Our analysis also suggests that individual bacteria in the colony community contributed a complete pathway for degradation of benzoate, which is inhibitory to the cyanobacterial growth, and its ecological implication for Microcystis bloom is discussed.

Mechanisms and evolution of oxidative sulfur metabolism in green sulfur bacteria

DEFF Research Database (Denmark)

Gregersen, Lea Haarup; Bryant, Donald A.; Frigaard, Niels-Ulrik

2011-01-01

Green sulfur bacteria (GSB) constitute a closely related group of photoautotrophic and thiotrophic bacteria with limited phenotypic variation. They typically oxidize sulfide and thiosulfate to sulfate with sulfur globules as an intermediate. Based on genome sequence information from 15 strains...... product is further oxidized to sulfite by the dissimilatory sulfite reductase (DSR) system. This system consists of components horizontally acquired partly from sulfide-oxidizing and partly from sulfate-reducing bacteria. Depending on the strain, the sulfite is probably oxidized to sulfate by one of two...... in sulfate formation in other bacteria has been replaced by the DSR system in GSB. Sequence analyses suggested that the conserved soxJXYZAKBW gene cluster was horizontally acquired by Chlorobium phaeovibrioides DSM 265 from the Chlorobaculum lineage and that this acquisition was mediated by a mobile genetic...

Gardnerella vaginalis and anaerobic bacteria in genital disease.

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Tabaqchali, S; Wilks, M; Thin, R N

1983-01-01

In a study of Gardnerella vaginalis and anaerobic bacteria in non-specific vaginitis (NSV) and other genital disease 89 patients attending a genital medicine clinic had vaginal samples examined for conventional pathogens and for quantitative analysis of G vaginalis and aerobic and anaerobic bacterial flora. The overall incidence of G vaginalis was 20%; G vaginalis (mean concentration 7.0 log10/g of secretion) occurred predominantly in patients with NSV (57%) but also in sexual contacts of non-specific urethritis (NSU) (37.5%) and in patients with other conditions (11.8%). G vaginalis is therefore a relatively common isolate in patients with vaginal discharge. The concentration of aerobic and anaerobic bacteria ranged from 4.9-11.0 log10/g of secretion with an anaerobe-to-aerobe ratio of 10:1. Anaerobic bacteria, particularly anaerobic Gram-positive cocci (mean concentrations 7.7 log10/g), were present in patients with NSV and in association with G vaginalis, but they also occurred in other clinical groups and with other pathogens, particularly Trichomonas vaginalis. Anaerobic bacteria may therefore play an important role in the pathogenesis of vaginal infections. PMID:6600955

Highly Resolved Sub-Terahertz Vibrational Spectroscopy of Biological Macromolecules and Bacteria Cells

Science.gov (United States)

2016-07-01

HIGHLY RESOLVED SUB-TERAHERTZ VIBRATIONAL SPECTROSCOPY OF BIOLOGICAL MACROMOLECULES AND BACTERIA CELLS ECBC...SUBTITLE Highly Resolved Sub-Terahertz Vibrational Spectroscopy of Biological Macromolecules and Bacteria Cells 5a. CONTRACT NUMBER W911SR-14-P...22 4.3 Bacteria THz Study

Expulsion of swimming bacteria by a circular flow

Science.gov (United States)

Sokolov, Andrey; Aronson, Igor

Macroscopic shear flow alters swimming trajectories in a highly nontrivial way and results in dramatic reduction of viscosity and heterogeneous bacterial distributions. We report on experimental and theoretical studies of rapid expulsion of microswimmers, such as motile bacteria, by a circular flow created by a rotating microparticle. We observed a formation of a macroscopic depletion area in a high-shear region, in the vicinity of a microparticle. The rapid migration of bacteria from the shear-rich area is caused by a circular structure of the flow rather than intrinsic random fluctuations of bacteria orientations, in stark contrast to planar shear flow. Our mathematical model revealed that expulsion is a combined effect of motility and alignment by a vortical flow. Our findings offer a novel approach for manipulation of motile microorganisms and shed new light on bacteria-flow interactions. Was supported by the US DOE, Office of Basic Energy Sciences, Division of Materials Science And Engineering, under Contract No. DE AC02-06CH11357.

[Utility of MALDI-TOF MS for the identification of anaerobic bacteria].

Science.gov (United States)

Zárate, Mariela S; Romano, Vanesa; Nievas, Jimena; Smayevsky, Jorgelina

2014-01-01

The analysis by MALDI-TOF MS (Matrix-assited laser desorption/ionization time-of-flight mass spectrometry) has become a reference method for the identification of microorganisms in Clinical Microbiology. However, data on some groups of microorganisms are still controversial. The aim of this study is to determine the utility of MALDI-TOF MS for the identification of clinical isolates of anaerobic bacteria. One-hundred and six anaerobic bacteria isolates were analyzed by MALDI-TOF MS and by conventional biochemical tests. In those cases where identification by conventional methodology was not applicable or in the face of discordance between sequencing methodologies, 16 S rRNA gene sequence analysis was performed. The conventional method and MALDI-TOF MS agreed at genus and species level by 95.3 %. Concordance in gram-negative bacilli was 91.4% and 100% among gram-positive bacilli; there was also concordance both in the 8 isolates studied in gram-positive cocci and in the single gram-negative cocci included. The data obtained in this study demonstrate that MALDI-TOF MS offers the possibility of adequate identification of anaerobic bacteria. Copyright © 2014 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.

Diversity of purple nonsulfur bacteria in shrimp ponds with varying mercury levels

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Kanokwan Mukkata

2016-07-01

Full Text Available This research aimed to study the diversity of purple nonsulfur bacteria (PNSB and to investigate the effect of Hg concentrations in shrimp ponds on PNSB diversity. Amplification of the pufM gene was detected in 13 and 10 samples of water and sediment collected from 16 shrimp ponds in Southern Thailand. In addition to PNSB, other anoxygenic phototrophic bacteria (APB were also observed; purple sulfur bacteria (PSB and aerobic anoxygenic phototrophic bacteria (AAPB although most of them could not be identified. Among identified groups; AAPB, PSB and PNSB in the samples of water and sediment were 25.71, 11.43 and 8.57%; and 27.78, 11.11 and 22.22%, respectively. In both sample types, Roseobacter denitrificans (AAPB was the most dominant species followed by Halorhodospira halophila (PSB. In addition two genera, observed most frequently in the sediment samples were a group of PNSB (Rhodovulum kholense, Rhodospirillum centenum and Rhodobium marinum. The UPGMA dendrograms showed 7 and 6 clustered groups in the water and sediment samples, respectively. There was no relationship between the clustered groups and the total Hg (HgT concentrations in the water and sediment samples used (<0.002–0.03 μg/L and 35.40–391.60 μg/kg dry weight for studying the biodiversity. It can be concluded that there was no effect of the various Hg levels on the diversity of detected APB species; particularly the PNSB in the shrimp ponds.

Bacteria abundance and diversity of different life stages of Plutella xylostella (Lepidoptera: Plutellidae), revealed by bacteria culture-dependent and PCR-DGGE methods.

Science.gov (United States)

Lin, Xiao-Li; Pan, Qin-Jian; Tian, Hong-Gang; Douglas, Angela E; Liu, Tong-Xian

2015-03-01

Microbial abundance and diversity of different life stages (fourth instar larvae, pupae and adults) of the diamondback moth, Plutella xylostella L., collected from field and reared in laboratory, were investigated using bacteria culture-dependent method and PCR-DGGE analysis based on the sequence of bacteria 16S rRNA V3 region gene. A large quantity of bacteria was found in all life stages of P. xylostella. Field population had higher quantity of bacteria than laboratory population, and larval gut had higher quantity than pupae and adults. Culturable bacteria differed in different life stages of P. xylostella. Twenty-five different bacterial strains were identified in total, among them 20 strains were presented in larval gut, only 8 strains in pupae and 14 strains in adults were detected. Firmicutes bacteria, Bacillus sp., were the most dominant species in every life stage. 15 distinct bands were obtained from DGGE electrophoresis gel. The sequences blasted in GenBank database showed these bacteria belonged to six different genera. Phylogenetic analysis showed the sequences of the bacteria belonged to the Actinobacteri, Proteobacteria and Firmicutes. Serratia sp. in Proteobacteria was the most abundant species in larval gut. In pupae, unculturable bacteria were the most dominant species, and unculturable bacteria and Serratia sp. were the most dominant species in adults. Our study suggested that a combination of molecular and traditional culturing methods can be effectively used to analyze and to determine the diversity of gut microflora. These known bacteria may play important roles in development of P. xylostella. © 2013 Institute of Zoology, Chinese Academy of Sciences.

Removal of FePO4 and Fe3(PO4)2 crystals on the surface of passive fillers in Fe0/GAC reactor using the acclimated bacteria

International Nuclear Information System (INIS)

Lai, Bo; Zhou, Yuexi; Yang, Ping; Wang, Juling; Yang, Jinghui; Li, Huiqiang

2012-01-01

Highlights: ► Fe 3 (PO 4 ) 2 and FePO 4 crystals would weaken treatment efficiency of Fe 0 /GAC reactor. ► Fe 3 (PO 4 ) 2 and FePO 4 crystals could be removed by the acclimated bacteria. ► FeS and sulfur in the passive film would be removed by the sulfur-oxidizing bacteria. ► Develop a cost-effective bio-regeneration technology for the passive fillers. - Abstract: As past studies presented, there is obvious defect that the fillers in the Fe 0 /GAC reactor begin to be passive after about 60 d continuous running, although the complicated, toxic and refractory ABS resin wastewater can be pretreated efficiently by the Fe 0 /GAC reactor. During the process, the Fe 3 (PO 4 ) 2 and FePO 4 crystals with high density in the passive film are formed by the reaction between PO 4 3− and Fe 2+ /Fe 3+ . Meanwhile, they obstruct the formation of macroscopic galvanic cells between Fe 0 and GAC, which will lower the wastewater treatment efficiency of Fe 0 /GAC reactor. In this study, in order to remove the Fe 3 (PO 4 ) 2 and FePO 4 crystals on the surface of the passive fillers, the bacteria were acclimated in the passive Fe 0 /GAC reactor. According to the results, it can be concluded that the Fe 3 (PO 4 ) 2 and FePO 4 crystals with high density in the passive film could be decomposed or removed by the joint action between the typical propionic acid type fermentation bacteria and sulfate reducing bacteria (SRB), whereas the PO 4 3− ions from the decomposition of the Fe 3 (PO 4 ) 2 and FePO 4 crystals were released into aqueous solution which would be discharged from the passive Fe 0 /GAC reactor. Furthermore, the remained FeS and sulfur (S) in the passive film also can be decomposed or removed easily by the oxidation of the sulfur-oxidizing bacteria. This study provides some theoretical references for the further study of a cost-effective bio-regeneration technology to solve the passive problems of the fillers in the zero-valent iron (ZVI) or Fe 0 /GAC reactor.

Diabetes preventive gluten-free diet decreases the number of caecal bacteria in non-obese diabetic mice

DEFF Research Database (Denmark)

Hansen, Axel Kornerup; Ling, Fenjung; Anne, Kaas

2006-01-01

disease prevention. Methods Two groups of NOD mice from the age of 3 weeks were fed either a gluten-free diet or a standard diet. Each diabetic mouse, when diagnosed, along with a non-diabetic mouse from the same diet group and two nondiabetic mice from the alternate diet group were euthanized and sampled...... qualitatively and quantitatively substantially altered the composition of the caecal bacterial flora in NOD mice. Although Gram-positive bacteria might influence the beta cells through certain digestive products, it is more likely to assume that any effect on diabetes incidence is immunological. Copyright (c...

Differentiating the growth phases of single bacteria using Raman spectroscopy

Science.gov (United States)

Strola, S. A.; Marcoux, P. R.; Schultz, E.; Perenon, R.; Simon, A.-C.; Espagnon, I.; Allier, C. P.; Dinten, J.-M.

2014-03-01

In this paper we present a longitudinal study of bacteria metabolism performed with a novel Raman spectrometer system. Longitudinal study is possible with our Raman setup since the overall procedure to localize a single bacterium and collect a Raman spectrum lasts only 1 minute. Localization and detection of single bacteria are performed by means of lensfree imaging, whereas Raman signal (from 600 to 3200 cm-1) is collected into a prototype spectrometer that allows high light throughput (HTVS technology, Tornado Spectral System). Accomplishing time-lapse Raman spectrometry during growth of bacteria, we observed variation in the net intensities for some band groups, e.g. amides and proteins. The obtained results on two different bacteria species, i.e. Escherichia coli and Bacillus subtilis clearly indicate that growth affects the Raman chemical signature. We performed a first analysis to check spectral differences and similarities. It allows distinguishing between lag, exponential and stationary growth phases. And the assignment of interest bands to vibration modes of covalent bonds enables the monitoring of metabolic changes in bacteria caused by growth and aging. Following the spectra analysis, a SVM (support vector machine) classification of the different growth phases is presented. In sum this longitudinal study by means of a compact and low-cost Raman setup is a proof of principle for routine analysis of bacteria, in a real-time and non-destructive way. Real-time Raman studies on metabolism and viability of bacteria pave the way for future antibiotic susceptibility testing.

Functional bacterial and archaeal community structures of major trophic groups in a full-scale anaerobic sludge digester.

Science.gov (United States)

Ariesyady, Herto Dwi; Ito, Tsukasa; Okabe, Satoshi

2007-04-01

Functional Bacteria and Archaea community structures of a full-scale anaerobic sludge digester were investigated by using a full-cycle 16S rRNA approach followed by microautoradiography (MAR)-fluorescent in situ hybridization (FISH) technique and micromanipulation. FISH analysis with a comprehensive set of 16S and 23S rRNA-targeted oligonucleotide probes based on 16S rRNA clone libraries revealed that the Gram-positive bacteria represented by probe HGC69A-hybridized Actinobacteria (8.5+/-1.4% of total 4', 6-diamidino-2-phenylindole (DAPI)-stained cells) and probe LGC354-hybridized Firmicutes (3.8+/-0.8%) were the major phylogenetic bacterial phyla, followed by Bacteroidetes (4.0+/-1.2%) and Chloroflexi (3.7+/-0.8%). The probe MX825-hybridized Methanosaeta (7.6+/-0.8%) was the most abundant archaeal group, followed by Methanomicrobiales (2.8+/-0.6%) and Methanobacteriaceae (2.7+/-0.4%). The functional community structures (diversity and relative abundance) of major trophic groups were quantitatively analyzed by MAR-FISH. The results revealed that glucose-degrading microbial community had higher abundance (ca. 10.6+/-4.9% of total DAPI-stained cells) and diversity (at least seven phylogenetic groups) as compared with fatty acid-utilizing microbial communities, which were more specialized to a few phylogenetic groups. Despite the dominance of Betaproteobacteria, members of Chloroflexi, Smithella, Syntrophomonas and Methanosaeta groups dominated the [(14)C]glucose-, [(14)C]propionate-, [(14)C]butyrate- and [(14)C]acetate-utilizing microorganism community, and accounted for 27.7+/-4.3%, 29.6+/-7.0%, 34.5+/-7.6% and 18.2+/-9.5%, respectively. In spite of low abundance (ca. 1%), the hitherto unknown metabolic functions of Spirochaeta and candidate phylum of TM7 as well as Synergistes were found to be glucose and acetate utilization, respectively.

Topological Defects in a Living Nematic Ensnare Swimming Bacteria

Science.gov (United States)

Genkin, Mikhail M.; Sokolov, Andrey; Lavrentovich, Oleg D.; Aranson, Igor S.

2017-01-01

Active matter exemplified by suspensions of motile bacteria or synthetic self-propelled particles exhibits a remarkable propensity to self-organization and collective motion. The local input of energy and simple particle interactions often lead to complex emergent behavior manifested by the formation of macroscopic vortices and coherent structures with long-range order. A realization of an active system has been conceived by combining swimming bacteria and a lyotropic liquid crystal. Here, by coupling the well-established and validated model of nematic liquid crystals with the bacterial dynamics, we develop a computational model describing intricate properties of such a living nematic. In faithful agreement with the experiment, the model reproduces the onset of periodic undulation of the director and consequent proliferation of topological defects with the increase in bacterial concentration. It yields a testable prediction on the accumulation of bacteria in the cores of +1 /2 topological defects and depletion of bacteria in the cores of -1 /2 defects. Our dedicated experiment on motile bacteria suspended in a freestanding liquid crystalline film fully confirms this prediction. Our findings suggest novel approaches for trapping and transport of bacteria and synthetic swimmers in anisotropic liquids and extend a scope of tools to control and manipulate microscopic objects in active matter.

Radiographic markers - A reservoir for bacteria?

International Nuclear Information System (INIS)

Tugwell, Jenna; Maddison, Adele

2011-01-01

Introduction: Amongst the most frequently handled objects in the radiology department are radiographic markers. They are personal accessories used with every patient, and are kept in the radiographers pockets when not utilised. Upon enquiry it was discovered that many radiographers disregarded the potential of these accessories to become a vector for cross-contamination thus never or rarely clean them. The aims of this study were therefore to identify if radiographic markers are a reservoir for bacteria and to establish an effective cleaning method for decontaminating them. Methodology: 25 radiographers/student radiographers were selected for this study. Swabbing of their markers prior and post cleaning took place. The microbiology laboratory subsequently analyzed the results by quantifying and identifying the bacteria present. The participants also completed a closed questionnaire regarding their markers (e.g. frequency of cleaning and type of marker) to help specify the results gained from the swabbing procedure. Results: From the sample swabbed, 92% were contaminated with various organisms including Staphylococcus and Bacillus species, the amount of bacteria present ranged from 0 to >50 CFU. There were no significant differences between disinfectant wipes and alcohol gel in decontaminating the markers. Both successfully reduced their bacterial load, with 80% of the markers post cleaning having 0 CFU. Conclusion: The results indicated that radiographic markers can become highly contaminated with various organisms thus serve as a reservoir for bacteria. In addition, the markers need to be cleaned on a regular basis, with either disinfectant wipes or alcohol gel to reduce their bacterial load.

Effects of the inclusion of a mixed Psychrotrophic bacteria strain for sewage treatment in constructed wetland in winter seasons.

Science.gov (United States)

Tang, Meizhen; Li, Zhengtao; Yang, Yuewei; Chen, Junfeng; Jiang, Jie

2018-04-01

Constructed wetlands (CWs) have been used globally in wastewater treatment for years. CWs represent an efficient ecological system which is both energy-saving and low in investment for construction and operational cost. In addition, CWs also have the advantage of being easy to operate and maintain. However, the operation of CWs at northern latitudes (both mid and high) is sometimes quite demanding, due to the inhibitory effect of low temperatures that often occur in winter. To evaluate the wastewater treatment performance of a culture of mixed Psychrotrophic bacteria strains in an integrated vertical-flow CW, the removal rates of ammonia nitrogen (NH 3 -N), chemical oxygen demand (COD), nitrite nitrogen [Formula: see text], nitrate nitrogen [Formula: see text] and total phosphorus (TP) were quantified at different bacterial dosages to determine the best bacterial dosage and establish kinetic degradation models of the mixed strains. The bacterial culture was made up of Psychrobacter TM-1, Sphingobacterium TM-2 and Pseudomonas TM-3, mixed together at a volume/volume ratio of 1 : 1 : 1 (at bacterial suspension concentrations of 4.4 × 10 9  ml -1 ). Results showed that the organic pollutants (nitrogen and phosphorus) in the sewage could be efficiently removed by the culture of mixed Psychrotrophic bacteria. The optimal dosage of this mixed bacteria strain was 2.5%, and the treatment efficiency of COD, NH 3 -N, [Formula: see text], [Formula: see text], total nitrogen and TP were stable at 91.8%, 91.1%, 88.0%, 93.8%, 94.8% and 95.2%, respectively, which were 1.5, 2.0, 2.1, 1.5, 2.2 and 1.3 times those of the control group. In addition, a pseudo-first-order degradation model was a good fit for the degradation pattern observed for each of these pollutants.

Metabolism of gentiopicroside (gentiopicrin) by human intestinal bacteria.

Science.gov (United States)

el-Sedawy, A I; Hattori, M; Kobashi, K; Namba, T

1989-09-01

As a part of our studies on the metabolism of crude drug components by intestinal bacteria, gentiopicroside (a secoiridoid glucoside isolated from Gentiana lutea), was anaerobically incubated with various defined strains of human intestinal bacteria. Many species had ability to transform it to a series of metabolites. Among them, Veillonella parvula ss parvula produced five metabolites, which were identified as erythrocentaurin, gentiopicral, 5-hydroxymethylisochroman-1-one,5-hydroxymethylisochromen-1- one and trans-5,6-dihydro-5-hydroxymethyl-6-methyl-1H,3H-pyrano[3,4-c]pyra n-1-one.

Immobilized Native Bacteria as a Tool for Bioremediation of Soils and Waters: Implementation and Modeling

Directory of Open Access Journals (Sweden)

C. Lobo

2002-01-01

Full Text Available Based on 3,4-dihydroxyphenylacetate (3,4-DHPA dioxygenase amino acid sequence and DNA sequence data for homologous genes, two different oligonucleotides were designed. These were assayed to detect 3,4-DHPA related aromatic compound—degrading bacteria in soil samples by using the FISH method. Also, amplification by PCR using a set of ERIC primers was assayed for the detection of Pseudomonas GCH1 strain, which used in the soil bioremediation process. A model was developed to understand and predict the behavior of bacteria and pollutants in a bioremediation system, taking into account fluid dynamics, molecular/cellular scale processes, and biofilm formation.

A veritable menagerie of heritable bacteria from ants, butterflies, and beyond: broad molecular surveys and a systematic review.

Directory of Open Access Journals (Sweden)

Jacob A Russell

Full Text Available Maternally transmitted bacteria have been important players in the evolution of insects and other arthropods, affecting their nutrition, defense, development, and reproduction. Wolbachia are the best studied among these and typically the most prevalent. While several other bacteria have independently evolved a heritable lifestyle, less is known about their host ranges. Moreover, most groups of insects have not had their heritable microflora systematically surveyed across a broad range of their taxonomic diversity. To help remedy these shortcomings we used diagnostic PCR to screen for five groups of heritable symbionts-Arsenophonus spp., Cardinium hertigii, Hamiltonella defensa, Spiroplasma spp., and Wolbachia spp.-across the ants and lepidopterans (focusing, in the latter case, on two butterfly families-the Lycaenidae and Nymphalidae. We did not detect Cardinium or Hamiltonella in any host. Wolbachia were the most widespread, while Spiroplasma (ants and lepidopterans and Arsenophonus (ants only were present at low levels. Co-infections with different Wolbachia strains appeared especially common in ants and less so in lepidopterans. While no additional facultative heritable symbionts were found among ants using universal bacterial primers, microbes related to heritable enteric bacteria were detected in several hosts. In summary, our findings show that Wolbachia are the dominant heritable symbionts of ants and at least some lepidopterans. However, a systematic review of symbiont frequencies across host taxa revealed that this is not always the case across other arthropods. Furthermore, comparisons of symbiont frequencies revealed that the prevalence of Wolbachia and other heritable symbionts varies substantially across lower-level arthropod taxa. We discuss the correlates, potential causes, and implications of these patterns, providing hypotheses on host attributes that may shape the distributions of these influential bacteria.

A method to detect metal-drug complexes and their interactions with pathogenic bacteria via graphene nanosheet assist laser desorption/ionization mass spectrometry and biosensors

Energy Technology Data Exchange (ETDEWEB)

Abdelhamid, Hani Nasser [Department of Chemistry, National Sun Yat-Sen University, Kaohsiung, 804, Taiwan (China); Wu, Hui-Fen, E-mail: hwu@faculty.nsysu.edu.tw [Department of Chemistry, National Sun Yat-Sen University, Kaohsiung, 804, Taiwan (China); School of Pharmacy, College of Pharmacy, Kaohsiung Medical University, Kaohsiung, 800, Taiwan (China); Center for Nanoscience and Nanotechnology, National Sun Yat-Sen University, Kaohsiung, 804, Taiwan (China); Doctoral Degree Program in Marine Biotechnology, National Sun Yat-Sen University, Kaohsiung, 804, Taiwan (China)

2012-11-02

Highlights: Black-Right-Pointing-Pointer Probe transition metals-complexes based on noncovalent functionalized graphene for MALDI-MS. Black-Right-Pointing-Pointer Study interaction of transition metals complexes with pathogenic bacteria. Black-Right-Pointing-Pointer Propose a new biosensor for two pathogenic bacteria. - Abstract: A new method was proposed to probe the interactions between transition metals of Fe(II), Fe(III), Cu(II) with a non steroidal anti-inflammatory drug (NSAID), flufenamic acid (FF) using graphene as a matrix for Graphene assisted laser desorption ionization mass spectrometry (GALDI-MS). Metal-drug complexation was confirmed via UV absorption spectroscopy, fluorescence spectroscopy, pH meter, and change in solution conductivity. The optimal molar ratios for these complexation interactions are stoichiometry 1:2 in both Cu(II) and Fe(II) complexes, and 1:3 in Fe(III) complexes at physiological pH (7.4). Metal complexation of the drug could enhance fluorescence for 20 fold which is due to the charge transfer reaction or increase rigidity of the drug. The main interaction between graphene and flufenamic acid is the {Pi}-{Pi} interaction which allows us to probe the metal-drug complexation. The GALDI-MS could sensitively detect the drug at m/z 281.0 Da (protonated molecule) with detection limit 2.5 pmol (1.0 {mu}M) and complexation at m/z 661.0, 654.0 and 933.0 Da corresponding to [Cu(II)(FF){sub 2}(H{sub 2}O){sub 2} + H]{sup +}, [Fe(II)(FF){sub 2}(H{sub 2}O){sub 2} + H]{sup +} and [Fe(III) (FF){sub 3}(H{sub 2}O){sub 2} + H]{sup +}, respectively (with limit of detection (LOD) 2.0 pmol (10.0 {mu}M). Matrix assisted laser desorption ionization mass spectrometry (MALDI-MS) spectra show change in the protein profile of intact pathogenic bacteria (Pseudomonas aeroginosa, Staphylococcus aureus). The change in the ionization ability (mainly proton affinity) of pathogenic bacteria may be due to the interactions between the bacteria with the drug (or its

Contributions of gut bacteria to Bacillus thuringiensis-induced mortality vary across a range of Lepidoptera

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Holt Jonathan

2009-03-01

Full Text Available Abstract Background Gut microbiota contribute to the health of their hosts, and alterations in the composition of this microbiota can lead to disease. Previously, we demonstrated that indigenous gut bacteria were required for the insecticidal toxin of Bacillus thuringiensis to kill the gypsy moth, Lymantria dispar. B. thuringiensis and its associated insecticidal toxins are commonly used for the control of lepidopteran pests. A variety of factors associated with the insect host, B. thuringiensis strain, and environment affect the wide range of susceptibilities among Lepidoptera, but the interaction of gut bacteria with these factors is not understood. To assess the contribution of gut bacteria to B. thuringiensis susceptibility across a range of Lepidoptera we examined larval mortality of six species in the presence and absence of their indigenous gut bacteria. We then assessed the effect of feeding an enteric bacterium isolated from L. dispar on larval mortality following ingestion of B. thuringiensis toxin. Results Oral administration of antibiotics reduced larval mortality due to B. thuringiensis in five of six species tested. These included Vanessa cardui (L., Manduca sexta (L., Pieris rapae (L. and Heliothis virescens (F. treated with a formulation composed of B. thuringiensis cells and toxins (DiPel, and Lymantria dispar (L. treated with a cell-free formulation of B. thuringiensis toxin (MVPII. Antibiotics eliminated populations of gut bacteria below detectable levels in each of the insects, with the exception of H. virescens, which did not have detectable gut bacteria prior to treatment. Oral administration of the Gram-negative Enterobacter sp. NAB3, an indigenous gut resident of L. dispar, restored larval mortality in all four of the species in which antibiotics both reduced susceptibility to B. thuringiensis and eliminated gut bacteria, but not in H. virescens. In contrast, ingestion of B. thuringiensis toxin (MVPII following antibiotic

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

Indian Academy of Sciences (India)

Balance of bacterial species in the gut · Immunosensory detection of intestinal bacteria · Pathogenic bacteria release interleukin-8 from HT-29 cells · Lactobacillus GG prevents the IL-8 release in response to pathogens · Effect of probiotic bacteria on chemokine response of epithelia to pathogens · PCR array studies in colon ...

ESTANDARIZACIÓN DE CONDICIONES PARA LA PRUEBA CUANTITATIVA DEL NMP CON BACTERIAS NITRIFICANTES Y DENITRIFICANTES USANDO COMO MATRIZ COMPOST

Directory of Open Access Journals (Sweden)

N. Rodríguez-Moreno

2007-12-01

Full Text Available In order to standardize methodologies that allow to determine the concentration of nitrifying and denitrifyingbacteria in compost, bacteria growth was evaluated at two different concentrations of nitrogen substrate(NH 42 SO4 and KNO3, with and without calcium carbonate. Technique used was the most probablenumber (MPN, revealing the tubes by means Griess reagent (nitrite, Nessler reagent (ammonium, andthe zinc powder (nitrate. Four treatments for nitrifying and denitrifying bacteria were applied respectively,with concentrations of 0,5 or 0,33 g of (NH4 2SO4 and 0,5 or 2g of KNO3. Biomass production wasevaluated. No significant differences were evidenced in biomass of days14 th,15th and 16th for nitrifyingbacteria; however, 15 th day 115.88 MPN/g of compost was obtained for nitrifying bacteria, and 31.42MPN/g for denitrifying bacteria. Treatment 1 (0.5g of (NH42SO4 with 1g of CaCO3 in nitrifying and 0.5gof KNO3 with 5g of CaCO3 in denitrifying group represent the best biomass condition: 112.67 MPN/g and27.53 MPN/g of compost. 15 days were necessary for incubation because it is the time needed to activateenzymes regulating pH with addition of the CaCO3.

Efficacy of a once-a-week screening programme to control extended-spectrum beta-lactamase-producing bacteria in a neonatal intensive care unit.

Science.gov (United States)

Rybczynska, Helena; Melander, Eva; Johansson, Hugo; Lundberg, Fredrik

2014-06-01

Extended-spectrum beta-lactamase (ESBL)-producing bacteria are an escalating problem threatening health. Devastating consequences can result in neonatal intensive care units (NICU) due to these bacteria. The aim of this study was to investigate the efficacy of once-a-week screening (July 2010 to September 2012) versus screening on demand (April 2008 to June 2010). The investigation was an open retrospective descriptive study comparing 2 unpaired groups, the first exposed to screening on demand and the second to screening once a week. All other infection control measures were unchanged. Both groups were cared for in the NICU of Skåne University Hospital. Parameters compared were the proportion of cultured neonates, prevalence, time before detection, number of secondary cases, and clinical infections due to ESBL-producing bacteria. The proportion of cultured neonates increased from 28% to 49% (p control the epidemiology of unwanted pathogens among newborn infants. It provides the opportunity for early intervention, thereby avoiding secondary cases and infections. Premature neonates in particular benefit from this approach. The prevalence of ESBL of 1.77% is low from an international perspective. ESBL appear to be introduced onto the ward by mothers colonized with ESBL.

Effect of biowaste sludge maturation on the diversity of thermophilic bacteria and archaea in an anaerobic reactor.

Science.gov (United States)

Goberna, M; Insam, H; Franke-Whittle, I H

2009-04-01

Prokaryotic diversity was investigated near the inlet and outlet of a plug-flow reactor. After analyzing 800 clones, 50 bacterial and 3 archaeal phylogenetic groups were defined. Clostridia (>92%) dominated among bacteria and Methanoculleus (>90%) among archaea. Significant changes in pH and volatile fatty acids did not invoke a major shift in the phylogenetic groups. We suggest that the environmental filter imposed by the saline conditions (20 g liter(-1)) selected a stable community of halotolerant and halophilic prokaryotes.

Ureolytic/Non-Ureolytic Bacteria Co-Cultured Self-Healing Agent for Cementitious Materials Crack Repair

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Hyeong Min Son

2018-05-01

Full Text Available The present study investigated the CaCO3 precipitation performance of ureolytic and non-ureolytic bacteria co-cultured as a self-healing agent for cementitious materials crack repair. Three different inoculum ratios of ureolytic Sporosarcina pasteurii and non-ureolytic Bacillus thuringiensis (10:0, 8:2, or 5:5 were used. The effect of coculturing ureolytic and non-ureolytic bacteria on microbial metabolism was investigated by measuring the rate of growth in urea-containing medium and the rate of NH4+ and CaCO3 production in urea–calcium lactate medium. The self-healing efficiency of co-cultured bacteria was examined by exposing cement mortar specimens with predefined cracks to media containing single urease-producing or co-cultured bacteria. The obtained results provide new findings, where CaCO3 precipitation is improved by co-culturing ureolytic and non-ureolytic bacteria, owing to the relatively faster growth rate of non-ureolytic bacteria. The crack filling rate correlated with the width of crack, in particular, specimens with a smaller crack width showed the faster filling effect, indicating that the crack width can be a dominant factor influencing the CaCO3 precipitation capacity of co-cultured bacteria.

Bio-corrosion of water pipeline by sulphate-reducing bacteria in a ...

African Journals Online (AJOL)

esiri

2013-11-13

Nov 13, 2013 ... Key words: Sulphate-reducing bacteria, corrosion, water pipeline, biocide. INTRODUCTION ... small amount of organic material required to produce biomass):. )1(. 3. 2 .... Oil, gas and shipping industries are seriously affected.

Revisión bibliográfica. BIOSÍNTESIS DE ÁCIDO INDOL-3-ACÉTICO Y PROMOCIÓN DEL CRECIMIENTO DE PLANTAS POR BACTERIAS

OpenAIRE

Paulina Vega-Celedón; Hayron Canchignia Martínez; Myriam González; Michael Seeger

2016-01-01

La hormona vegetal ácido indol-3-acético (AIA) es la principal auxina en las plantas. El AIA controla diversos procesos fisiológicos como la elongación y división celular, la diferenciación de tejidos y las respuestas a la luz y la gravedad. La concentración de AIA se encuentra regulada en las plantas. Se ha descrito que las bacterias pueden modular los niveles de AIA. Las rutas biosintéticas de AIA más importantes y ampliamente distribuidas en bacterias son las vías anabólicas de indol-3-pir...

Bacteria and lignin degradation

Institute of Scientific and Technical Information of China (English)

Jing LI; Hongli YUAN; Jinshui YANG

2009-01-01

Lignin is both the most abundant aromatic (phenolic) polymer and the second most abundant raw material.It is degraded and modified by bacteria in the natural world,and bacteria seem to play a leading role in decomposing lignin in aquatic ecosystems.Lignin-degrading bacteria approach the polymer by mechanisms such as tunneling,erosion,and cavitation.With the advantages of immense environmental adaptability and biochemical versatility,bacteria deserve to be studied for their ligninolytic potential.

Inhibition effect of calcium hydroxide point and chlorhexidine point on root canal bacteria of necrosis teeth

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Andry Leonard Je

2006-03-01

Full Text Available Calcium Hydroxide point and Chlorhexidine point are new drugs for eliminating bacteria in the root canal. The points slowly and controly realease Calcium Hydroxide and Chlorhexidine into root canal. The purpose of the study was to determined the effectivity of Calcium hydroxide point (Calcium hydroxide plus point and Chlorhexidine point in eleminating the root canal bacteria of nescrosis teeth. In this study 14 subjects were divided into 2 groups. The first group was treated with Calcium hydroxide point and the second was treated with Chlorhexidine poin. The bacteriological sampling were measured with spectrofotometry. The Paired T Test analysis (before and after showed significant difference between the first and second group. The Independent T Test which analysed the effectivity of both groups had not showed significant difference. Although there was no significant difference in statistical test, the result of second group eliminate more bacteria than the first group. The present finding indicated that the use of Chlorhexidine point was better than Calcium hydroxide point in seven days period. The conclusion is Chlorhexidine point and Calcium hydroxide point as root canal medicament effectively eliminate root canal bacteria of necrosis teeth.

Sulphur oxidising bacteria in mangrove ecosystem: A review ...

African Journals Online (AJOL)

Sulphur-oxidizing bacteria such as photoautotrophs, chemolithotrophs and heterotrophs play an important role in the mangrove environment for the oxidation of the toxic sulphide produced by sulphur reducing bacteria and act as a key driving force behind all sulphur transformations in the mangrove ecosystem which is ...

Baiting of bacteria with hyphae of common soil fungi revealed a diverse group of potentially mycophagous secondary consumers in the rhizosphere

NARCIS (Netherlands)

Rudnick, M.B.; van Veen, J.A.; de Boer, W.

2015-01-01

Abstract Fungi and bacteria are primary consumers of plant-derived organic compounds and therefore considered as basal members of soil food webs. Trophic interactions among these microorganisms could, however, induce shifts in food web energy flows. Given increasing evidence for a prominent role of

Rapid identification of bacteria in positive blood culture broths by matrix-assisted laser desorption ionization-time of flight mass spectrometry.

Science.gov (United States)

Stevenson, Lindsay G; Drake, Steven K; Murray, Patrick R

2010-02-01

Matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry is a rapid, accurate method for identifying bacteria and fungi recovered on agar culture media. We report herein a method for the direct identification of bacteria in positive blood culture broths by MALDI-TOF mass spectrometry. A total of 212 positive cultures were examined, representing 32 genera and 60 species or groups. The identification of bacterial isolates by MALDI-TOF mass spectrometry was compared with biochemical testing, and discrepancies were resolved by gene sequencing. No identification (spectral score of blood culture broth. Of the bacteria with a spectral score of > or = 1.7, 162 (95.3%) of 170 isolates were correctly identified. All 8 isolates of Streptococcus mitis were misidentified as being Streptococcus pneumoniae isolates. This method provides a rapid, accurate, definitive identification of bacteria within 1 h of detection in positive blood cultures with the caveat that the identification of S. pneumoniae would have to be confirmed by an alternative test.

Removal of bacteria and viruses from waters using layered double hydroxide nanocomposites

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Song Jin et al

2007-01-01

Full Text Available We have identified synthetic layered double hydroxides (LDH nanocomposites as an effective group of material for removing bacteria and viruses from water. In this study, LDH nanocomposites were synthesized and tested for removing biological contaminants. LDH was used to remove MS2 and X174 (indicator viruses, and Escherichia coli (an indicator bacterium from synthetic groundwater and to remove mixed communities of heterotrophic bacteria from raw river water. Our results indicate that LDH composed of magnesium–aluminium or zinc–aluminium has a viral and bacterial adsorption efficiency ≥99% at viral concentrations between 5.9×106 and 9.1×106 plaque forming units (pfu/L and bacterial concentrations between 1.6×1010 and 2.6×1010 colony forming units (cfu/L when exposed to LDH in a slurry suspension system. Adsorption densities of viruses and bacteria to LDH in suspension ranged from 1.4×1010 to 2.1×1010 pfu/kg LDH and 3.2×1013–5.2×1013 cfu/kg LDH, respectively. We also tested the efficiency of LDH in removing heterotrophic bacteria from raw river water. While removal efficiencies were still high (87–99%, the adsorption capacities of the two kinds of LDH were 4–5 orders of magnitude lower than when exposed to synthetic groundwater, depending on if the LDH was in suspension or a packed column, respectively.

Neutrophil extracellular traps formation by bacteria causing endometritis in the mare.

Science.gov (United States)

Rebordão, M R; Carneiro, C; Alexandre-Pires, G; Brito, P; Pereira, C; Nunes, T; Galvão, A; Leitão, A; Vilela, C; Ferreira-Dias, G

2014-12-01

Besides the classical functions, neutrophils (PMNs) are able to release DNA in response to infectious stimuli, forming neutrophil extracellular traps (NETs) and killing pathogens. The pathogenesis of endometritis in the mare is not completely understood. The aim was to evaluate the in vitro capacity of equine PMNs to secrete NETs by chemical activation, or stimulated with Streptococcus equi subspecies zooepidemicus (Szoo), Escherichia coli (Ecoli) or Staphylococcus capitis (Scap) strains obtained from mares with endometritis. Ex vivo endometrial mucus from mares with bacterial endometritis were evaluated for the presence of NETs. Equine blood PMNs were used either without or with stimulation by phorbol-myristate-acetate (PMA), a strong inducer of NETs, for 1-3h. To evaluate PMN ability to produce NETs when phagocytosis was impaired, the phagocytosis inhibitor cytochalasin (Cyt) was added after PMA. After the addition of bacteria, a subsequent 1-h incubation was carried out in seven groups. NETs were visualized by 4',6-diamidino-2-phenylindole (DAPI) and anti-histone. Ex vivo samples were immunostained for myeloperoxidase and neutrophil elastase. A 3-h incubation period of PMN + PMA increased NETs (p Ecoli or Scap (p < 0.05). Ex vivo NETs were present in mares with endometritis. Scanning electron microscopy showed the spread of NETs formed by smooth fibers and globules that can be aggregated in thick bundles. Formation of NETs and the subsequent entanglement of bacteria suggest that equine NETs might be a complementary mechanism in fighting some of the bacteria causing endometritis in the mare. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Bacteria and fungi respond differently to multifactorial climate change in a temperate heathland, traced with ¹³C-Glycine and FACE CO₂

DEFF Research Database (Denmark)

Andresen, Louise C.; Dungait, Jennifer A.J.; Bol, Roland

2014-01-01

PLFAs for specific microbial groups (Gram positive bacteria, Gram negative bacteria, actinobacteria and fungi) was quantified using gas chromatography-combustion-stable isotope ratio mass spectrometry (GC-C-IRMS). Gram positive bacteria opportunistically utilized the freshly added glycine substrate, i...

The Diversity of PAH-degrading bacteria in a deep-sea water column above the Southwest Indian Ridge

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Zongze eShao

2015-08-01

Full Text Available The bacteria involved in organic pollutant degradation in pelagic deep-sea environments are largely unknown. In this report, the diversity of polycyclic aromatic hydrocarbon ( PAH-degrading bacteria was analyzed in deep-sea water on the Southwest Indian Ridge (SWIR. After enrichment with a PAH mixture (phenanthrene, anthracene, fluoranthene and pyrene, 9 nine bacterial consortia were obtained from depths of 3946 m to 4746 m. PAH degradation occurred to all components of the mixture, but when using a single PAH as the sole carbon and energy source, only phenanthrene can be degraded obviously. This indicates the cometabolism of anthracene, fluoranthene and pyrene with phenanthreneWhile the consortia degraded all four PAHs when supplied in a mixture, when PAHs were tested individually, only phenanthrene supported growth. Thus, degradation of the PAH mixture reflected a cometabolism of anthracene, fluoranthene and pyrene with phenanthrene. Further, both culture-dependent and independent methods revealed many new bacteria involved in PAH degradation. Specifically, the alpha and gamma subclasses of Proteobacteria were confirmed as the major groups within the communities. Additionally, Actinobacteria, the CFB group and Firmicutes were detected. Denaturing Gradient Gel Electrophoresis (DGGE analysis showed that bacteria closely affiliated with Alcanivorax, Novosphingobium and Rhodovulum occurred most frequently in different PAH-degrading consortia. More than half of the isolates (34 of 51 isolates were confirmed to have the ability to grow with the PAH mixture By using general heterotrophic media, 51 bacteria were isolated from the consortia and of these 34 grew with the PAH mixture as a sole carbon source. Of these, isolates most closely related to Alterierythrobacter, Citricella, Erythrobacter, Idiomarina, Lutibacterium, Maricaulis, Marinobacter, Martelella, Pseudidiomarina, Rhodobacter, Roseovarius, Salipiger, Sphingopyxis and Stappia were found to

Validation of an automated colony counting system for group A Streptococcus.

Science.gov (United States)

Frost, H R; Tsoi, S K; Baker, C A; Laho, D; Sanderson-Smith, M L; Steer, A C; Smeesters, P R

2016-02-08

The practice of counting bacterial colony forming units on agar plates has long been used as a method to estimate the concentration of live bacteria in culture. However, due to the laborious and potentially error prone nature of this measurement technique, an alternative method is desirable. Recent technologic advancements have facilitated the development of automated colony counting systems, which reduce errors introduced during the manual counting process and recording of information. An additional benefit is the significant reduction in time taken to analyse colony counting data. Whilst automated counting procedures have been validated for a number of microorganisms, the process has not been successful for all bacteria due to the requirement for a relatively high contrast between bacterial colonies and growth medium. The purpose of this study was to validate an automated counting system for use with group A Streptococcus (GAS). Twenty-one different GAS strains, representative of major emm-types, were selected for assessment. In order to introduce the required contrast for automated counting, 2,3,5-triphenyl-2H-tetrazolium chloride (TTC) dye was added to Todd-Hewitt broth with yeast extract (THY) agar. Growth on THY agar with TTC was compared with growth on blood agar and THY agar to ensure the dye was not detrimental to bacterial growth. Automated colony counts using a ProtoCOL 3 instrument were compared with manual counting to confirm accuracy over the stages of the growth cycle (latent, mid-log and stationary phases) and in a number of different assays. The average percentage differences between plating and counting methods were analysed using the Bland-Altman method. A percentage difference of ±10 % was determined as the cut-off for a critical difference between plating and counting methods. All strains measured had an average difference of less than 10 % when plated on THY agar with TTC. This consistency was also observed over all phases of the growth

Occurrence of airborne vancomycin- and gentamicin-resistant bacteria in various hospital wards in Isfahan, Iran.

Science.gov (United States)

Mirhoseini, Seyed Hamed; Nikaeen, Mahnaz; Khanahmad, Hossein; Hassanzadeh, Akbar

2016-01-01

Airborne transmission of pathogenic resistant bacteria is well recognized as an important route for the acquisition of a wide range of nosocomial infections in hospitals. The aim of this study was to determine the prevalence of airborne vancomycin and gentamicin (VM and GM) resistant bacteria in different wards of four educational hospitals. A total of 64 air samples were collected from operating theater (OT), Intensive Care Unit (ICU), surgery ward, and internal medicine ward of four educational hospitals in Isfahan, Iran. Airborne culturable bacteria were collected using all glass impingers. Samples were analyzed for the detection of VM- and GM-resistant bacteria. The average level of bacteria ranged from 99 to 1079 CFU/m(3). The highest level of airborne bacteria was observed in hospital 4 (628 CFU/m(3)) and the highest average concentration of GM- and VM-resistant airborne bacteria were found in hospital 3 (22 CFU/m(3)). The mean concentration of airborne bacteria was the lowest in OT wards and GM- and VM-resistant airborne bacteria were not detected in this ward of hospitals. The highest prevalence of antibiotic-resistant airborne bacteria was observed in ICU ward. There was a statistically significant difference for the prevalence of VM-resistant bacteria between hospital wards (P = 0.012). Our finding showed that the relatively high prevalence of VM- and GM-resistant airborne bacteria in ICUs could be a great concern from the point of view of patients' health. These results confirm the necessity of application of effective control measures which significantly decrease the exposure of high-risk patients to potentially airborne nosocomial infections.

Evaluation of the intestinal colonization by microencapsulated probiotic bacteria in comparison with the same uncoated strains.

Science.gov (United States)

Del Piano, Mario; Carmagnola, Stefania; Andorno, Silvano; Pagliarulo, Michela; Tari, Roberto; Mogna, Luca; Strozzi, Gian Paolo; Sforza, Filomena; Capurso, Lucio

2010-09-01

Beneficial findings concerning probiotics are increasing day by day. However, one of the most important parameter which affects the probiotic activity of a microorganism is its survival during the gastroduodenal transit. Some microencapsulation techniques could be applied to bacterial cells to improve this parameter. A comparison between the intestinal colonization by microencapsulated bacteria and the same not microencapsulated strains has been conducted in a double blind, randomized, cross-over study. The study (April to July 2005) involved 44 healthy volunteers. In particular, participants were divided into 2 groups: group A (21 participants) received a mix of probiotic strains Lactobacillus plantarum LP01 (LMG P-21021) and Bifidobacterium breve BR03 (DSM 16604) in an uncoated form, group B (23 participants) was given the same strains microencapsulated with a gastroresistant material. The not microencapsulated strains were administered at 5 x 10(9) colony forming units/strain/d for 21 days, whereas the microencapsulated bacteria were given at 1 x 10(9) colony forming units/strain/d for 21 days. At the end of the first period of treatment with probiotics a 3 weeks washout phase has been included in the study protocol. At the end of the washout period the groups were crossed: in detail, group A had the microencapsulated and group B the uncoated bacteria. The administered amounts of each strain were the same as the first treatment. The quantitative evaluation of intestinal colonization by strains microencapsulated or not microencapsulated was made by fecal samples examination at the beginning of the clinical trial, after 10 and 21 days of each treatment period. In particular, fecal heterofermentative Lactobacilli and Bifidobacteria have been counted. A statistically significant increase in the fecal amounts of Lactobacilli and Bifidobacteria was recorded in both groups at the end of each treatment compared with d0 or d42 (Pstrains to colonize the human gut, either

Incidence of plant cover over the autotrophic nitrifying bacteria population in a fragment of Andean forest

International Nuclear Information System (INIS)

Gonzalez, Xiomara; Gonzalez, L; Varela, A; Ahumada, J A

1999-01-01

It was determined the incidence of plant cover (forest vs. pasture), on the autotrophy nitrifying bacteria, through the effect of biotic factors (radical exudate) and abiotic factors (temperature, ph and humidity), in a high mountain cloud forest fragment. The site of study was located near La Mesa (Cundinamarca) municipality. The temperature of soil was measured in situ, and soil samples were collected and carried to the laboratory for pH and humidity percentage measurements. Serial soil dilution method was used for plating samples on a selective culture medium with ammonium sulphate as nitrogen source, in order to estimate the autotrophic nitrifying bacteria population levels. Grown colonies were examined macro and microscopically. The quantity of nitrates produced by bacteria cultured in vitro was determined spectra-photometrical. In relation to the abiotic factors, there was no significant differences of pH between both plant covers, but there were significant for soil humidity and temperature (p<0.05). There were highly significant differences with respect to the bacteria population levels (p<0.0001) and with respect to nitrate production. This suggests a higher bacterial activity in the under forest cover. The radical exudate from both types of plant cover reduced the viability of bacteria in vitro, from 1:1 to 1:30 exudate bacteria proportions. In the soils physical and chemical analysis, it was found a higher P and Al concentrations, and a higher CIC and organic matter content under the forest cover. It is suggested the importance of this functional group in this ecosystem

Removal of APIs and bacteria from hospital wastewater by MBR plus O(3), O(3) + H(2)O(2), PAC or ClO(2).

Science.gov (United States)

Nielsen, U; Hastrup, C; Klausen, M M; Pedersen, B M; Kristensen, G H; Jansen, J L C; Bak, S N; Tuerk, J

2013-01-01

The objective of this study has been to develop technologies that can reduce the content of active pharmaceutical ingredients (APIs) and bacteria from hospital wastewater. The results from the laboratory- and pilot-scale testings showed that efficient removal of the vast majority of APIs could be achieved by a membrane bioreactor (MBR) followed by ozone, ozone + hydrogen peroxide or powdered activated carbon (PAC). Chlorine dioxide (ClO(2)) was significantly less effective. MBR + PAC (450 mg/l) was the most efficient technology, while the most cost-efficient technology was MBR + ozone (156 mg O(3)/l applied over 20 min). With MBR an efficient removal of Escherichia coli and enterococci was measured, and no antibiotic resistant bacteria were detected in the effluent. With MBR + ozone and MBR + PAC also the measured effluent concentrations of APIs (e.g. ciprofloxacin, sulfamethoxazole and sulfamethizole) were below available predicted no-effect concentrations (PNEC) for the marine environment without dilution. Iodinated contrast media were also reduced significantly (80-99% for iohexol, iopromide and ioversol and 40-99% for amidotrizoateacid). A full-scale MBR treatment plant with ozone at a hospital with 900 beds is estimated to require an investment cost of €1.6 mill. and an operating cost of €1/m(3) of treated water.

Characterization of acetate-utilizing methanogenic bacteria, depending on varying acetate concentrations, in a biogas plant. Phase 1

International Nuclear Information System (INIS)

Ahring, B.K.

1994-12-01

The present report contains the results of a project concerning behaviour of acetate-utilizing methanogenic bacteria in mesophilic and thermophilic biogas plants, collected in 1992 - 1994 period. Labelled acetates (2-C 14 -CH 3 COOH) have been used to characterize the types of methane bacteria populations in the Danish biogas plants, the optimum acetate concentration for these bacteria and acetate metabolism in mesophilic and thermophilic biogas reactors with low acetate concentrations. 2 publications are included. (EG)

Occurrence of Antimicrobial Resistance in Fish-Pathogenic and Environmental Bacteria Associated with Four Danish Rainbow Trout Farms

DEFF Research Database (Denmark)

Schmidt, Anja S.; Bruun, Morten Sichlau; Dalsgaard, Inger

2000-01-01

in fish, water, and sediment samples, two major fish pathogens (88 Flavobacterium psychrophilum isolates and 134 Yersinia ruckeri isolates) and 313 motile Aeromonas isolates, representing a group of ubiquitous aquatic bacteria, were isolated from the same samples. MICs were obtained applying...... flavobacteria and aeromonads, thus indicating a substantial impact of fish farming on several groups of bacteria associated with aquacultural environments....

Bacteria versus selenium: A view from the inside out

Science.gov (United States)

Staicu, Lucian; Oremland, Ronald S.; Tobe, Ryuta; Mihara, Hisaaki

2017-01-01

Bacteria and selenium (Se) are closely interlinked as the element serves both essential nutrient requirements and energy generation functions. However, Se can also behave as a powerful toxicant for bacterial homeostasis. Conversely, bacteria play a tremendous role in the cycling of Se between different environmental compartments, and bacterial metabolism has been shown to participate to all valence state transformations undergone by Se in nature. Bacteria possess an extensive molecular repertoire for Se metabolism. At the end of the 1980s, a novel mode of anaerobic respiration based on Se oxyanions was experimentally documented for the first time. Following this discovery, specific enzymes capable of reducing Se oxyanions and harvesting energy were found in a number of anaerobic bacteria. The genes involved in the expression of these enzymes have later been identified and cloned. This iterative approach undertaken outside-in led to the understanding of the molecular mechanisms of Se transformations in bacteria. Based on the extensive knowledge accumulated over the years, we now have a full(er) view from the inside out, from DNA-encoding genes to enzymes and thermodynamics. Bacterial transformations of Se for assimilatory purposes have been the object of numerous studies predating the investigation of Se respiration. Remarkable contributions related to the understating of the molecular picture underlying seleno-amino acid biosynthesis are reviewed herein. Under certain circumstances, Se is a toxicant for bacterial metabolism and bacteria have evolved strategies to counteract this toxicity, most notably by the formation of elemental Se (nano)particles. Several biotechnological applications, such as the production of functional materials and the biofortification of crop species using Se-utilizing bacteria, are presented in this chapter.

Arsenic biotransformation and release by bacteria indigenous to arsenic contaminated groundwater.

Science.gov (United States)

Paul, Dhiraj; Kazy, Sufia K; Banerjee, Tirtha Das; Gupta, Ashok K; Pal, Taraknath; Sar, Pinaki

2015-01-01

Arsenic (As) biotransformation and release by indigenous bacteria from As rich groundwater was investigated. Metabolic landscape of 173 bacterial isolates indicated broad catabolic repertoire including abundance of As(5+) reductase activity and abilities in utilizing wide ranges of organic and inorganic respiratory substrates. Abundance of As homeostasis genes and utilization of hydrocarbon as carbon/electron donor and As(5+) as electron acceptor were noted within the isolates. Sediment microcosm study (for 300 days) showed a pivotal role of metal reducing facultative anaerobic bacteria in toxic As(3+) release in aqueous phase. Inhabitant bacteria catalyze As transformation and facilitate its release through a cascade of reactions including mineral bioweathering and As(5+) and/or Fe(3+) reduction activities. Compared to anaerobic incubation with As(5+) reducing strains, oxic state and/or incubation with As(3+) oxidizing bacteria resulted in reduced As release, thus indicating a strong role of such condition or biocatalytic mechanism in controlling in situ As contamination. Copyright © 2015 Elsevier Ltd. All rights reserved.

Inhibition of cell division in hupA hupB mutant bacteria lacking HU protein.

Science.gov (United States)

Dri, A M; Rouviere-Yaniv, J; Moreau, P L

1991-01-01

Escherichia coli hupA hypB double mutants that lack HU protein have severe cellular defects in cell division, DNA folding, and DNA partitioning. Here we show that the sfiA11 mutation, which alters the SfiA cell division inhibitor, reduces filamentation and production of anucleate cells in AB1157 hupA hupB strains. However, lexA3(Ind-) and sfiB(ftsZ)114 mutations, which normally counteract the effect of the SfiA inhibitor, could not restore a normal morphology to hupA hupB mutant bacteria. The LexA repressor, which controls the expression of the sfiA gene, was present in hupA hupB mutant bacteria in concentrations half of those of the parent bacteria, but this decrease was independent of the specific cleavage of the LexA repressor by activated RecA protein. One possibility to account for the filamentous morphology of hupA hupB mutant bacteria is that the lack of HU protein alters the expression of specific genes, such as lexA and fts cell division genes. Images PMID:2019558

Beneficial effects of bacteria-plant communication based on quorum sensing molecules of the N-acyl homoserine lactone group.

Science.gov (United States)

Schikora, Adam; Schenk, Sebastian T; Hartmann, Anton

2016-04-01

Bacterial quorum sensing (QS) mechanisms play a crucial role in the proper performance and ecological fitness of bacterial populations. Many key physiological processes are regulated in a QS-dependent manner by auto-inducers, like the N-acyl homoserine lactones (AHLs) in numerous Gram-negative bacteria. In addition, also the interaction between bacteria and eukaryotic hosts can be regulated by AHLs. Those mechanisms gained much attention, because of the positive effects of different AHL molecules on plants. This positive impact ranges from growth promotion to induced resistance and is quite contrasting to the rather negative effects observed in the interactions between bacterial AHL molecules and animals. Only very recently, we began to understand the molecular mechanisms underpinning plant responses to AHL molecules. In this review, we gathered the latest information in this research field. The first part gives an overview of the bacterial aspects of quorum sensing. Later we focus on the impact of AHLs on plant growth and AHL-priming, as one of the most understood phenomena in respect to the inter-kingdom interactions based on AHL-quorum sensing molecules. Finally, we discuss the potential benefits of the understanding of bacteria-plant interaction for the future agricultural applications.

[Application of anaerobic bacteria detection in oral and maxillofacial infection].

Science.gov (United States)

Bao, Zhen-ying; Lin, Qin; Meng, Yan-hong; He, Chun; Su, Jia-zeng; Peng, Xin

2016-02-18

To investigate the distribution and drug resistance of anaerobic bacteria in the patients with oral and maxillofacial infection. Aerobic and anaerobic bacteria cultures from 61 specimens of pus from the patients with oral and maxillofacial infection in the Department of Oral and Maxillofacial Surgery, Peking University School of Stomatology were identified. The culture type was evaluated by API 20A kit and drug resistance test was performed by Etest method. The clinical data and antibacterial agents for the treatment of the 61 cases were collected, and the final outcomes were recorded. The bacteria cultures were isolated from all the specimens, with aerobic bacteria only in 6 cases (9.8%), anaerobic bacteria only in 7 cases (11.5%), and both aerobic and anaerobic bacteria in 48 cases (78.7%). There were 55 infected cases (90.2%) with anaerobic bacteria, and 81 anaerobic bacteria stains were isolated. The highest bacteria isolation rate of Gram positive anaerobic bacteria could be found in Peptostreptococcus, Bifidobacterium and Pemphigus propionibacterium. No cefoxitin, amoxicillin/carat acid resistant strain was detected in the above three Gram positive anaerobic bacteria. The highest bacteria isolation rate of Gram negative anaerobic bacteria could be detected in Porphyromonas and Prevotella. No metronidazole, cefoxitin, amoxicillin/carat acid resistant strain was found in the two Gram negative anaerobic bacteria. In the study, 48 patients with oral and maxillofacial infection were treated according to the results of drug resistance testing, and the clinical cure rate was 81.3%. Mixed aerobic and anaerobic bacteria cultures are very common in most oral and maxillofacial infection patients. Anaerobic bacteria culture and drug resistance testing play an important role in clinical treatment.

Isolation of oxalotrophic bacteria associated with Varroa destructor mites.

Science.gov (United States)

Maddaloni, M; Pascual, D W

2015-11-01

Bacteria associated with varroa mites were cultivated and genotyped by 16S RNA. Under our experimental conditions, the cultivable bacteria were few in number, and most of them proved to be fastidious to grow. Cultivation with seven different media under O2 /CO2 conditions and selection for colony morphology yielded a panel of species belonging to 13 different genera grouped in two different phyla, proteobacteria and actinobacteria. This study identified one species of actinobacteria that is a known commensal of the honey bee. Some isolates are oxalotrophic, a finding that may carry ramifications into the use of oxalic acid to control the number of phoretic mites in the managed colonies of honey bees. Oxalic acid, legally or brevi manu, is widely used to control phoretic Varroa destructor mites, a major drive of current honey bees' colony losses. Unsubstantiated by sanctioned research are rumours that in certain instances oxalic acid is losing efficacy, forcing beekeepers to increase the frequency of treatments. This investigation fathoms the hypothesis that V. destructor associates with bacteria capable of degrading oxalic acid. The data show that indeed oxalotrophy, a rare trait among bacteria, is common in bacteria that we isolated from V. destructor mites. This finding may have ramifications in the use of oxalic acid as a control agent. © 2015 The Society for Applied Microbiology.

Sheep manure vermicompost supplemented with a native diazotrophic bacteria and mycorrhizas for maize cultivation.

Science.gov (United States)

Gutiérrez-Miceli, F A; Moguel-Zamudio, B; Abud-Archila, M; Gutiérrez-Oliva, V F; Dendooven, L

2008-10-01

An orthogonal experimental design L9 (3(4)) with 10 repetitions was used to investigate the effect of Glomus claroideum (0, 1 or 2g(-1) plant), G. fasciculatum (0, 1 or 2g plant(-1)), native diazotrophic bacteria (0, 10(3) and 10(5) UFC ml(-1)) and sheep manure vermicompost (0%, 5% and 10% v/v) on maize plant growth, N and P in leaves and mycorrhization percent. Vermicompost explained most of the variation found for leaf number, wet weight, stem height, and diameter. Both mycorrhizas increased the plant wet weight but G. fasciculatum the most. Mycorrhization increased the P content, but not the N content. Mycorrhizal colonization increased when diazotrophic bacteria and vermicompost were added. It was found that weight of maize plants cultivated in peat moss amended with vermicompost increased when supplemented with G. fasciculatum and diazotrophic bacteria.

Bacteriocins and lactic acid bacteria - a minireview | Savadogo ...

African Journals Online (AJOL)

Fermentation of various foods by lactic acid bacteria (LAB) is one of the oldest forms of biopreservation practised by mankind. Bacterial antagonism has been recognized for over a century but in recent years this phenomenon has received more scientific attention, particulary in the use of various strains of lactic acid bacteria.

Lubricating oil-degrading bacteria in soils from filling stations and ...

African Journals Online (AJOL)

STORAGESEVER

2008-06-03

Jun 3, 2008 ... 1Department of Biochemistry and Microbiology, Faculty of Science, University of ... Key words: environmental pollution, oil-degrading bacteria, heterotrophic bacteria, physico-chemical factors, ..... Manual of Environmental.

Monitoring of airborne bacteria and aerosols in different wards of hospitals - Particle counting usefulness in investigation of airborne bacteria.

Science.gov (United States)

Mirhoseini, Seyed Hamed; Nikaeen, Mahnaz; Khanahmd, Hossein; Hatamzadeh, Maryam; Hassanzadeh, Akbar

2015-01-01

The presence of airborne bacteria in hospital environments is of great concern because of their potential role as a source of hospital-acquired infections (HAI). The aim of this study was the determination and comparison of the concentration of airborne bacteria in different wards of four educational hospitals, and evaluation of whether particle counting could be predictive of airborne bacterial concentration in different wards of a hospital. The study was performed in an operating theatre (OT), intensive care unit (ICU), surgery ward (SW) and internal medicine (IM) ward of four educational hospitals in Isfahan, Iran. A total of 80 samples were analyzed for the presence of airborne bacteria and particle levels. The average level of bacteria ranged from 75-1194 CFU/m (3) . Mean particle levels were higher than class 100,000 cleanrooms in all wards. A significant correlation was observed between the numbers of 1-5 µm particles and levels of airborne bacteria in operating theatres and ICUs. The results showed that factors which may influence the airborne bacterial level in hospital environments should be properly managed to minimize the risk of HAIs especially in operating theaters. Microbial air contamination of hospital settings should be performed by the monitoring of airborne bacteria, but particle counting could be considered as a good operative method for the continuous monitoring of air quality in operating theaters and ICUs where higher risks of infection are suspected.

Actinomycetes of Orthosipon stamineus rhizosphere as producer of antibacterial compound against multidrug resistant bacteria

Science.gov (United States)

Rante, H.; Yulianty, R.; Usmar; Djide, N.; Subehan; Burhamzah, R.; Prasad, M. B.

2017-11-01

The increasing case of antibiotic resistence has become an important problem to be faced in treating the infection diseases. The diversities of microbia, especially actinomycetes bacteria which originated from rizosphere soil of medicinal plant, has opened a chance for discovering the metabolites which can be used in solving the antibiotic resistant pathogenic bacteria problems. The aim of this research was to isolate the actinobacteria originated from medicinal plant rizosphere of Orthosipon stamineus as the producer of anti-multidrug resistances bacteria compounds. Three isolates of actinomycetes has been isolated from Orthosipon stamineus rhizosphere named KC3-1, KC3-2 and KC3-3. One isolate (KC3-3) showed big activity in inhibiting the test microbes by antagonistic test of actinomycetes isolates against Staphylococcus aureus and Eschericia coli antibiotic resistant bacteria. Furthermore, the KC3-3 isolate was fermented in Starch Nitrate Broth (SNB) medium for 14 days. The supernatant and the biomass of the fermentation yield were separated. The supernatant were extracted using ethyl acetate as the solvent and the biomass were extracted using methanol. The antibacterial activity test of ethyl acetate and methanol extract revealed that the extracts can inhibit the bacteria test up to 5% concentration. The ethyl acetate and methanol extracts can inhibit the bacteria test up to 5% concentration.

Periodontal disease associated with red complex bacteria in dogs.

Science.gov (United States)

Di Bello, A; Buonavoglia, A; Franchini, D; Valastro, C; Ventrella, G; Greco, M F; Corrente, M

2014-03-01

Red complex bacteria (Treponema denticola, Tannerella forsythia and Porphyromonas gingivalis) play a major role in the aetiology of periodontal disease in humans. This study was designed to evaluate the association of such bacteria with periodontal disease in dogs. Seventy-three subgingival samples taken from dogs ranging from 2 months to 12 years (median age 4 years) were tested for red complex bacteria using a polymerase chain reaction assay. Thirty-six of 73 (49 · 3%) dogs were found to be positive for T. forsythia and P. gingivalis. Dogs with gingivitis or periodontitis were more likely to be infected with T. forsythia and P. gingivalis [odds ratio (OR) 5 · 4 (confidence interval (CI) 1 · 9-15 · 6), P = 0 · 002] than healthy animals. Only 3 (4 · 1%) of 73 samples were positive for red complex bacteria, but the association with periodontal disease was not significant. The results indicate that involvement of red complex bacteria in periodontal disease in dogs is similar to that observed in humans. Only the concurrent presence of T. forsythia and P. gingivalis were correlated to periodontal disease in dogs in this study. © 2014 British Small Animal Veterinary Association.

On a non-traditional realisation of the group SO(3)

International Nuclear Information System (INIS)

Fecko, M.

1985-01-01

A representation of group SO(3) in the space of wave functions of the so-called linear top is described. The generators of rotations have a non-standard form. Functions which provide the basis of the representation are found in explicit form. Their connection with Wigner functions D km l (φ, θ, ψ) is shown. (author)

Architecture of class 1, 2 and 3 integrons from Gram negative bacteria recovered among fruits and vegetables.

Directory of Open Access Journals (Sweden)

Daniela Jones-Dias

2016-09-01

Full Text Available The spread of antibiotic resistant bacteria throughout the food chain constitutes a public health concern. To understand the contribution of fresh produce in shaping antibiotic resistance bacteria and integron prevalence in the food chain, 333 antibiotic resistance Gram negative isolates were collected from organic and conventionally produced fruits (pears, apples and strawberries and vegetables (lettuces, tomatoes and carrots. Although low levels of resistance have been detected, the bacterial genera identified in the assessed fresh produce are often described not only as environmental, but mostly as commensals and opportunistic pathogens. The genomic characterization of integron-harboring isolates revealed a high number of mobile genetic elements and clinically relevant antibiotic resistance genes, of which we highlight the presence of as mcr-1, qnrA1, blaGES-11, mphA and oqxAB. The study of class 1 (n=8, class 2 (n=3 and class 3 (n=1 integrons, harbored by species such as Morganella morganii, Escherichia coli, Klebsiella pneumoniae, led to the identification of different integron promoters (PcW, PcH1, PcS and PcWTNG-10 and cassette arrays (containing drfA, aadA, cmlA, estX, sat and blaGES. In fact, the diverse integron backbones were associated with transposable elements (e.g. Tn402, Tn7, ISCR1, Tn2*, IS26, IS1326 and IS3 that conferred greater mobility. This is also the first appearance of In1258, In1259 and In3-13, which should be monitored to prevent their establishment as successfully dispersed mobile resistance integrons. These results underscore the growing concern about the dissemination of acquired resistance genes by mobile elements in the food chain.

Anaerobic Bacteria in Clinical Specimens - Frequent, But a Neglected Lot: A Five Year Experience at a Tertiary Care Hospital.

Science.gov (United States)

Shenoy, Padmaja Ananth; Vishwanath, Shashidhar; Gawda, Ashwini; Shetty, Seema; Anegundi, Renuka; Varma, Muralidhar; Mukhopadhyay, Chiranjay; Chawla, Kiran

2017-07-01

Anaerobic bacteria which constitute a significant proportion of the normal microbiota also cause variety of infections involving various anatomic sites. Considering the tedious culture techniques with longer turnaround time, anaerobic cultures are usually neglected by clinicians and microbiologists. To study the frequency of isolation of different anaerobic bacteria from various clinical specimens. A retrospective study to analyse the frequency of isolation of different anaerobic bacteria, was conducted over a period of five years from 2011 to 2015 including various clinical specimens submitted to anaerobic division of Microbiology laboratory. Anaerobic bacteria were isolated and identified following standard bacteriological techniques. Pathogenic anaerobes (n=336) were isolated from 278 (12.48%) of overall 2227 specimens processed with an average yield of 1.2 isolates. Anaerobes were isolated as polymicrobial flora with or without aerobic bacterial pathogens in 159 (57.2%) patients. Anaerobic Gram-negative bacilli (140, 41.7%) were the predominant isolates. B. fragilis group (67, 19.9%) were the most commonly isolated anaerobic pathogens. Anaerobes were predominantly isolated from deep seated abscess (23.9%). Pathogenic anaerobes were isolated from various infection sites. Unless culture and susceptibility tests are performed as a routine, true magnitude of antimicrobial resistance among anaerobic pathogens will not be known. Knowledge of the distribution of these organisms may assist in the selection of appropriate empirical therapy for anaerobic infections.

[Darwin and bacteria].

Science.gov (United States)

Ledermann D, Walter

2009-02-01

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

Motility of magnetotactic bacteria/MTB to Geomagnetic fields

Science.gov (United States)

Hidajatullah-Maksoed, Fatahillah

2016-03-01

Bacteria with motility directed by a local geomagnetic fields have been observed in marine sediments'' discussed by R. Blakemore, 1975. Magnetotactic bacteria/MTB discovered in 1963 by Salvatore Bellini. For ``off-axis electron holography in the transmission electron microscope was used to correlates the physical & magnetic microstructure of magnetite nanocrystals in magnetotactic bacteria'' sought ``single-domain magnetite in hemopelagic sediments'' from JF Stolz. Otherwise, for potential source of bioproducts- product meant from result to multiplier -of magnetotactic bacteria[ACV Araujo, et.al, 2014 ] of marine drugs retrieved the `measurement of cellular chemotaxis with ECIS/Taxis, from KM Pietrosimone, 2012, whereas after ``earth magnetic field role on small living models'' are other interpretation of ``taxis'' as a movement of a cell instead usual ``tax'' for yew's taxus cuspidate, hired car & taxes in financial realms. Acknowledgements to HE. Mr. H. TUK SETYOHADI, Jl. Sriwijaya Raya 3, South-Jakarta, INDONESIA.

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

OpenAIRE

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...

SAR11 bacteria linked to ocean anoxia and nitrogen loss

DEFF Research Database (Denmark)

Tsementzi, Despina; Wu, Jieying; Deutsch, Samuel

2016-01-01

Bacteria of the SAR11 clade constitute up to one half of all microbial cells in the oxygen-rich surface ocean. SAR11 bacteria are also abundant in oxygen minimum zones (OMZs), where oxygen falls below detection and anaerobic microbes have vital roles in converting bioavailable nitrogen to N2 gas...... activity. These results link SAR11 to pathways of ocean nitrogen loss, redefining the ecological niche of Earth’s most abundant organismal group....

Microbiology and management of joint and bone infections due to anaerobic bacteria.

Science.gov (United States)

Brook, Itzhak

2008-03-01

To describes the microbiology, diagnosis, and management of septic arthritis and osteomyelitis due to anaerobic bacteria. The predominant anaerobes in arthritis are anaerobic Gram-negative bacilli (AGNB) including the Bacteroides fragilis group, Fusobacterium spp., Peptostreptococcus spp., and Propionibacterium acnes. Infection with P. acnes is associated with a prosthetic joint, previous surgery, and trauma. B. fragilis group is associated with distant infection, Clostridium spp. with trauma, and Fusobacterium spp. with oropharyngeal infection. Most cases of anaerobic arthritis, in contrast to anaerobic osteomyelitis, involved a single isolate, and most cases are secondary to hematogenous spread. The predominant anaerobes in osteomyelitis are Bacteroides, Peptostreptococcus, Fusobacterium, and Clostridium spp. as well as P. acnes. Conditions predisposing to bone infections are vascular disease, bites, contiguous infection, peripheral neuropathy, hematogenous spread, and trauma. Pigmented Prevotella and Porphyromonas spp. are mostly isolated in skull and bite infections, members of the B. fragilis group in hand and feet infections, and Fusobacterium spp. in skull, bite, and hematogenous long bone infections. Many patients with osteomyelitis due to anaerobic bacteria have evidence of an anaerobic infection elsewhere in the body that is the source of the organisms involved in the osteomyelitis. Treatment of arthritis and osteomyelitis involving anaerobic bacteria includes symptomatic therapy, immobilization in some cases, adequate drainage of purulent material, and antibiotic therapy effective against these organisms. Anaerobic bacteria can cause septic arthritis and osteomyelitis. Correct diagnosis and appropriate therapy are important contributor to successful outcome.

Potential effects of bacteria on radionuclide transport from a Swedish high level nuclear waste repository

International Nuclear Information System (INIS)

Pedersen, K.

1990-01-01

Microorganisms can influence radionuclide migration if their concentration are high in comparison with other organic particles. Data on the numbers of microorganisms in undisturbed ground-water have been collected. The average number of cells in the samples from 17 levels in 5 boreholes was 3.0 x 10 5 cells ml -1 . A biofilm experiment indicated an active microbial rock surface population. Radiographic uptake experiments suggest inactive bulk water populations. The bulk water microbial cells in deep ground water might then be inactive cells detached from active biofilms. Enrichment cultures for anaerobic bacteria demonstrated the presence of anaerobic bacteria capable of growth on C-1 compounds with hydrogen and carbon dioxide, presumably methanogenic bacteria. Further, growth in enrichment cultures with sulphate as electron-acceptor and lactate as carbon source proved dissimilatory sulphate reducing bacteria to be present. (author)

A study on the radionuclide transport by bacteria in geologic media

International Nuclear Information System (INIS)

Han, Byoung Sub

1997-02-01

The purpose of this paper is to provide a methodology to develop a predictive model based on a conceptual three phase system and to investigate the influence of bacteria and their generation on the transport of radionuclide in porous and fractured media. The mass balance for bacteria, substrate and radionuclide were formulated. To illustrate the model simply, an equilibrium condition was assumed to partition the substrate, bacteria and radionuclide concentrations between the solid soil matrix, aqueous phase, rock matrix and bacterial surface. From the numerical calculation of the radionuclide transport in the presence of bacteria, it was found that the growth of bacteria and supplied primary substrate as limiting or stimulating growth factor of bacteria are the most important factors of the radionuclide transport. We also found that, depend on the transport of bacteria the temporal and spatial distribution of radionuclide concentration was significantly altered. The model proposed in this study will improve the evaluation of the role of the bacteria in the transport of radionuclide in groundwater systems. Furthermore, this model would be usefully utilized in analyzing the important role of colloidal particulate on the overall performance of radioactive waste safety

The Paradigms They Are a-Changin': past, present and future of PVC bacteria research.

Science.gov (United States)

Rivas-Marín, Elena; Devos, Damien P

2018-06-01

These are exciting times for PVC researchers! The PVC superphylum is composed of the bacterial phyla Planctomycetes, Verrucomicrobia, Chlamydiae (those three founders giving it its name), Lentisphaerae and Kirimatiellaeota as well as some uncultured candidate phyla, such as the Candidatus Omnitrophica (previously known as OP3). Despite early debates, most of the disagreements that surround this group of bacteria have been recently resolved. In this article, we review the history of the study of PVC bacteria, with a particular focus on the misinterpretations that emerged early in the field and their resolution. We begin with a historical perspective that describes the relevant facts of PVC research from the early times when they were not yet termed PVC. Those were controversial times and we refer to them as the "discovery age" of the field. We continue by describing new discoveries due to novel techniques and data that combined with the reinterpretations of old ones have contributed to solve most of the discordances and we refer to these times as the "illumination age" of PVC research. We follow by arguing that we are just entering the "golden age" of PVC research and that the future of this growing community is looking bright. We finish by suggesting a few of the directions that PVC researches might take in the future.

Highly efficient removal of pathogenic bacteria with magnetic graphene composite.

Science.gov (United States)

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%.

Co-existence of Anaerobic Ammonium Oxidation Bacteria and Denitrifying Anaerobic Methane Oxidation Bacteria in Sewage Sludge: Community Diversity and Seasonal Dynamics

DEFF Research Database (Denmark)

Xu, Sai; Lu, Wenjing; Mustafa, Muhammad Farooq

2017-01-01

Anaerobic ammonium oxidation (ANAMMOX) and denitrifying anaerobic methane oxidation (DAMO) have been recently discovered as relevant processes in the carbon and nitrogen cycles of wastewater treatment plants. In this study, the seasonal dynamics of ANAMMOX and DAMO bacterial community structures......, and an unknown cluster was primarily detected in autumn and winter. Similar patterns of seasonal variation in the community structure of DAMO bacteria were also observed. Group B was the dominant in spring and summer, whereas in autumn and winter, group A and group B presented almost the same proportion...

Smart Biointerface with Photoswitched Functions between Bactericidal Activity and Bacteria-Releasing Ability.

Science.gov (United States)

Wei, Ting; Zhan, Wenjun; Yu, Qian; Chen, Hong

2017-08-09

Smart biointerfaces with capability to regulate cell-surface interactions in response to external stimuli are of great interest for both fundamental research and practical applications. Smart surfaces with "ON/OFF" switchability for a single function such as cell attachment/detachment are well-known and useful, but the ability to switch between two different functions may be seen as the next level of "smart". In this work reported, a smart supramolecular surface capable of switching functions reversibly between bactericidal activity and bacteria-releasing ability in response to UV-visible light is developed. This platform is composed of surface-containing azobenzene (Azo) groups and a biocidal β-cyclodextrin derivative conjugated with seven quaternary ammonium salt groups (CD-QAS). The surface-immobilized Azo groups in trans form can specially incorporate CD-QAS to achieve a strongly bactericidal surface that kill more than 90% attached bacteria. On irradiation with UV light, the Azo groups switch to cis form, resulting in the dissociation of the Azo/CD-QAS inclusion complex and release of dead bacteria from the surface. After the kill-and-release cycle, the surface can be easily regenerated for reuse by irradiation with visible light and reincorporation of fresh CD-QAS. The use of supramolecular chemistry represents a promising approach to the realization of smart, multifunctional surfaces, and has the potential to be applied to diverse materials and devices in the biomedical field.

Isolation, Characterization, and Genetic Diversity of Ice Nucleation Active Bacteria on Various Plants

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DIANA ELIZABETH WATURANGI

2009-06-01

Full Text Available Ice nucleation active (INA bacteria is a group of bacteria with the ability to catalyze the ice formation at temperature above -10 °C and causing frost injury in plants. Since, most of the literature on INA bacteria were from subtropical area, studies of INA bacteria from tropical area are needed. We sampled eight fruits and 36 leaves of 21 plant species, and then identified through biochemical and genetic analysis. INA bacteria were characterized for INA protein classification, pH stability, and optimization of heat endurance. We discovered 15 INA bacteria from seven plants species. Most of bacteria are oxidase and H2S negative, catalase and citrate positive, gram negative, and cocoid formed. These INA bacteria were classified in to three classes based on their freezing temperature. Most of the isolates were active in heat and pH stability assay. Some isolates were analysed for 16S rRNA gene. We observed that isolates from Morinda citrifolia shared 97% similiarity with Pseudomonas sp. Isolate from Piper betle shared 93% similarity with P. pseudoalcaligenes. Isolate from Carica papaya shared 94% similarity with Pseudomonas sp. While isolate from Fragaria vesca shared 90% similarity with Sphingomonas sp.

Isolation, Characterization, and Genetic Diversity of Ice Nucleation Active Bacteria on Various Plants

Directory of Open Access Journals (Sweden)

DIANA ELIZABETH WATURANGI

2009-06-01

Full Text Available Ice nucleation active (INA bacteria is a group of bacteria with the ability to catalyze the ice formation at temperature above -10 oC and causing frost injury in plants. Since, most of the literature on INA bacteria were from subtropical area, studies of INA bacteria from tropical area are needed. We sampled eight fruits and 36 leaves of 21 plant species, and then identified through biochemical and genetic analysis. INA bacteria were characterized for INA protein classification, pH stability, and optimization of heat endurance. We discovered 15 INA bacteria from seven plants species. Most of bacteria are oxidase and H2S negative, catalase and citrate positive, gram negative, and cocoid formed. These INA bacteria were classified in to three classes based on their freezing temperature. Most of the isolates were active in heat and pH stability assay. Some isolates were analysed for 16S rRNA gene. We observed that isolates from Morinda citrifolia shared 97% similiarity with Pseudomonas sp. Isolate from Piper betle shared 93% similarity with P. pseudoalcaligenes. Isolate from Carica papaya shared 94% similarity with Pseudomonas sp. While isolate from Fragaria vesca shared 90% similarity with Sphingomonas sp.

Release of Antibiotic Resistant Bacteria by a Waste Treatment Plant from Romania.

Science.gov (United States)

Lupan, Iulia; Carpa, Rahela; Oltean, Andreea; Kelemen, Beatrice Simona; Popescu, Octavian

2017-09-27

The occurrence and spread of bacterial antibiotic resistance are subjects of great interest, and the role of wastewater treatment plants has been attracting particular interest. These stations are a reservoir of bacteria, have a large range of organic and inorganic substances, and the amount of bacteria released into the environment is very high. The main purpose of the present study was to assess the removal degree of bacteria with resistance to antibiotics and identify the contribution of a wastewater treatment plant to the microbiota of Someşul Mic river water in Cluj county. The resistance to sulfamethoxazole and tetracycline and some of their representative resistance genes: sul1, tet(O), and tet(W) were assessed in this study. The results obtained showed that bacteria resistant to sulphonamides were more abundant than those resistant to tetracycline. The concentration of bacteria with antibiotic resistance changed after the treatment, namely, bacteria resistant to sulfamethoxazole. The removal of all bacteria and antibiotic-resistant bacteria was 98-99% and the degree of removal of bacteria resistant to tetracycline was higher than the bacteria resistant to sulfamethoxazole compared to total bacteria. The wastewater treatment plant not only contributed to elevating ARG concentrations, it also enhanced the possibility of horizontal gene transfer (HGT) by increasing the abundance of the intI1 gene. Even though the treatment process reduced the concentration of bacteria by two orders of magnitude, the wastewater treatment plant in Cluj-Napoca contributed to an increase in antibiotic-resistant bacteria concentrations up to 10 km downstream of its discharge in Someşul Mic river.

Differential activity of a lectin from Solieria filiformis against human pathogenic bacteria

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M.L. Holanda

2005-12-01

Full Text Available A lectin isolated from the red alga Solieria filiformis was evaluated for its effect on the growth of 8 gram-negative and 3 gram-positive bacteria cultivated in liquid medium (three independent experiments/bacterium. The lectin (500 µg/mL stimulated the growth of the gram-positive species Bacillus cereus and inhibited the growth of the gram-negative species Serratia marcescens, Salmonella typhi, Klebsiella pneumoniae, Enterobacter aerogenes, Proteus sp, and Pseudomonas aeruginosa at 1000 µg/mL but the lectin (10-1000 µg/mL had no effect on the growth of the gram-positive bacteria Staphylococcus aureus and B. subtilis, or on the gram-negative bacteria Escherichia coli and Salmonella typhimurium. The purified lectin significantly reduced the cell density of gram-negative bacteria, although no changes in growth phases (log, exponential and of decline were observed. It is possible that the interaction of S. filiformis lectin with the cell surface receptors of gram-negative bacteria promotes alterations in the flow of nutrients, which would explain the bacteriostatic effect. Growth stimulation of the gram-positive bacterium B. cereus was more marked in the presence of the lectin at a concentration of 1000 µg/mL. The stimulation of the growth of B. cereus was not observed when the lectin was previously incubated with mannan (125 µg/mL, its hapten. Thus, we suggest the involvement of the binding site of the lectin in this effect. The present study reports the first data on the inhibition and stimulation of pathogenic bacterial cells by marine alga lectins.

Effect of ionizing radiation on the antigenic composition of typhoid bacteria

International Nuclear Information System (INIS)

Sinilova, N.G.; Nikolaeva, L.A.; Tumanyan, M.A.

1978-01-01

Changes in the antigenic composition of typhoid bacteria occurring during the exposure of microbial suspension to different doses of gamma radiation ( 60 Co) ranging between 0.5 and 3.0 Mrad were studied. Immunoelectrophoresis in agar was used to determine the antigenic composition of different samples of irradiated bacteria. The antigenic composition of bacteria irradiated with doses up to 2.5 Mrad was found to be similar to that of non-irradiated bacteria. Antigens demonstrated by means of Vi, H and O antisera are preserved in these bacteria. However, all irradiated bacteria in general slightly differ from non-irradiated bacteria; this is manifest in a different configuration and position of the precipitation lines in the cathodic part of the immunophoreograms. The content of the component migrating rapidly towards the cathode, evidently the O antigen in the R form, in the irradiated bacteria increases with the dose of radiation. No new serologically active substances, non-existent in non-irradiated bacteria, were found to appear in the process of irradiation. (author)

The roles of the various plasma agents in the inactivation of bacteria

International Nuclear Information System (INIS)

Lu Xinpei; Xiong Qing; Tang Zhiyuan; Xiong Zhilan; Hu Jing; Jiang Zhonghe; Pan Yuan; Ye Tao; Cao Yingguang; Sun Ziyong

2008-01-01

The roles of various plasma agents in the inactivation of bacteria have recently been investigated. However, up to now, the effect of the charged particles on the inactivation of bacteria is not well understood. In this paper, an atmospheric pressure plasma jet device, which generates a cold plasma plume carrying a peak current of 300 mA, is used to investigate the role of the charged particles in the inactivation process. It is found that the charged particles play a minor role in the inactivation process when He/N 2 (3%) is used as working gas. On the other hand, when He/O 2 (3%) is used, the charged particles are expected to play an important role in the inactivation of bacteria. Further analysis shows that the negative ions O 2 - might be the charged particles that are playing the role. Besides, it is found that the active species, including O, O 3 , and metastable state O 2 *, can play a crucial role in the inactivation of the bacteria. However, the excited He*, N 2 C 3 Π u , and N 2 + B 2 Σ u + have no significant direct effect on the inactivation of bacteria. It is also concluded that heat and UV play no or minor role in the inactivation process

Competitive binding of polyethyleneimine-coated gold nanoparticles to enzymes and bacteria: a key mechanism for low-level colorimetric detection of gram-positive and gram-negative bacteria

International Nuclear Information System (INIS)

Thiramanas, Raweewan; Laocharoensuk, Rawiwan

2016-01-01

The article describes a simple and rapid method for colorimetric detection of bacteria. It is based on competitive binding of positively charged polyethyleneimine-coated gold nanoparticles (PEI-AuNPs) to negatively charged enzymes and bacteria. The PEI-AuNPs are electrostatically attracted by both the bacterial surface and the enzyme β-galactosidase (β-Gal). Binding to the latter results in the inhibition of enzyme activity. However, in the presence of a large number of bacteria, the PEI-AuNPs preferentially bind to bacteria. Hence, the enzyme will not be inhibited and its activity can be colorimetrically determined via hydrolysis of the chromogenic substrate chlorophenol red β-D-galactopyranoside (CPRG). The detection limit of this assay is as low as 10 cfu·mL −1 , and the linear range extends from 10 6 to 10 8 cfu·mL −1 . The assay is applicable to both Gram-negative (such as enterotoxigenic Escherichia coli; ETEC) and Gram-positive (Staphylococcus aureus; S. aureus) bacteria. Results are obtained within 10 min using an optical reader, and within 2–3 h by bare-eye detection. The method was applied to the identification of ETEC contamination at a level of 10 cfu·mL −1 in spiked drinking water. Given its low detection limit and rapidity (sample preconcentration is not required), this method holds great promise for on-site detection of total bacterial contamination. (author)

Gram-negative, but not Gram-positive, bacteria elicit strong PGE2 production in human monocytes.

Science.gov (United States)

Hessle, Christina C; Andersson, Bengt; Wold, Agnes E

2003-12-01

Gram-positive and Gram-negative bacteria induce different cytokine patterns in human mononuclear cells. We have seen that Gram-positives preferentially induce IL-12 and TNF-alpha, whereas Gram-negatives induce more IL-10, IL-6, and IL-8. In this study, we compared the capacity of these two groups of bacteria to induce PGE2. Monocytes stimulated with Gram-negative bacterial species induced much more PGE2 than did Gram-positive bacteria (5600 +/- 330 vs. 1700 +/- 670 pg/mL, p Gram-positive and Gram-negative bacteria. We suggest that Gram-positive and Gram-negative bacteria may stimulate different innate effector functions; Gram-positive bacteria promoting cell-mediated effector functions whereas Gram-negative bacteria inducing mediators inhibiting the same.

Meat, dairy and plant proteins alter bacterial composition of rat gut bacteria

Science.gov (United States)

Zhu, Yingying; Lin, Xisha; Zhao, Fan; Shi, Xuebin; Li, He; Li, Yingqiu; Zhu, Weiyun; Xu, Xinglian; Lu, Chunbao; Zhou, Guanghong

2015-01-01

Long-term consumption of red meat has been considered a potential risk to gut health, but this is based on clinic investigations, excessive intake of fat, heme and some injurious compounds formed during cooking or additions to processed meat products. Whether intake of red meat protein affects gut bacteria and the health of the host remains unclear. In this work, we compared the composition of gut bacteria in the caecum, by sequencing the V4-V5 region of 16S ribosomal RNA gene, obtained from rats fed with proteins from red meat (beef and pork), white meat (chicken and fish) and other sources (casein and soy). The results showed significant differences in profiles of gut bacteria between the six diet groups. Rats fed with meat proteins had a similar overall structure of caecal bacterial communities separated from those fed non-meat proteins. The beneficial genus Lactobacillus was higher in the white meat than in the red meat or non-meat protein groups. Also, rats fed with meat proteins and casein had significantly lower levels of lipopolysaccharide-binding proteins, suggesting that the intake of meat proteins may maintain a more balanced composition of gut bacteria, thereby reducing the antigen load and inflammatory response in the host. PMID:26463271

Meat, dairy and plant proteins alter bacterial composition of rat gut bacteria.

Science.gov (United States)

Zhu, Yingying; Lin, Xisha; Zhao, Fan; Shi, Xuebin; Li, He; Li, Yingqiu; Zhu, Weiyun; Xu, Xinglian; Li, Chunbao; Lu, Chunbao; Zhou, Guanghong

2015-10-14

Long-term consumption of red meat has been considered a potential risk to gut health, but this is based on clinic investigations, excessive intake of fat, heme and some injurious compounds formed during cooking or additions to processed meat products. Whether intake of red meat protein affects gut bacteria and the health of the host remains unclear. In this work, we compared the composition of gut bacteria in the caecum, by sequencing the V4-V5 region of 16S ribosomal RNA gene, obtained from rats fed with proteins from red meat (beef and pork), white meat (chicken and fish) and other sources (casein and soy). The results showed significant differences in profiles of gut bacteria between the six diet groups. Rats fed with meat proteins had a similar overall structure of caecal bacterial communities separated from those fed non-meat proteins. The beneficial genus Lactobacillus was higher in the white meat than in the red meat or non-meat protein groups. Also, rats fed with meat proteins and casein had significantly lower levels of lipopolysaccharide-binding proteins, suggesting that the intake of meat proteins may maintain a more balanced composition of gut bacteria, thereby reducing the antigen load and inflammatory response in the host.

Pepsin homologues in bacteria

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Bateman Alex

2009-09-01

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

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

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Alix M Denoncourt

2014-05-01

Full Text Available 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.

Novel Group of Leaderless Multipeptide Bacteriocins from Gram-Positive Bacteria.

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Ovchinnikov, Kirill V; Chi, Hai; Mehmeti, Ibrahim; Holo, Helge; Nes, Ingolf F; Diep, Dzung B

2016-09-01

-resistant bacteria, but the number of bacteriocins with very broad antimicrobial spectra is very small. In this study, we have found and purified a novel three-peptide bacteriocin, garvicin KS. By homology search, we were able to find one known and three novel sequence-related bacteriocins consisting of 3 or 4 peptides. None of the peptides has modified amino acids in its sequence. Thus, the activity of all bacteriocins was confirmed with chemically synthesized peptides. All of them, especially garvicin KS, have very broad antibacterial spectra, thus representing a great potential in antimicrobial applications in the food industry and medicine. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Identification of antibiotic resistant bacteria community and a GeoChip based study of resistome in urban watersheds.

Science.gov (United States)

Low, Adrian; Ng, Charmaine; He, Jianzhong

2016-12-01

Urban watersheds from point sources are potential reservoirs of antibiotic resistance genes (ARGs). However, few studies have investigated urban watersheds of non-point sources. To understand the type of ARGs and bacteria that might carry such genes, we investigated two non-point source urban watersheds with different land-use profiles. Antibiotic resistance levels of two watersheds (R1, R3) were examined using heterotrophic plate counts (HPC) as a culturing method to obtain counts of bacteria resistant to seven antibiotics belonging to different classes (erythromycin, kanamycin, lincomycin, norfloxacin, sulfanilamide, tetracycline and trimethoprim). From the HPC study, 239 antibiotic resistant bacteria were characterized for resistance to more antibiotics. Furthermore, ARGs and antimicrobial biosynthesis genes were identified using GeoChip version 5.0 to elucidate the resistomes of surface waters in watersheds R1 and R3. The HPC study showed that water samples from R1 had significantly higher counts of bacteria resistant to erythromycin, kanamycin, norfloxacin, sulfanilamide, tetracycline and trimethoprim than those from R3 (Analysis of Similarity (ANOSIM), R = 0.557, p antibiotics tested, lincomycin and trimethoprim resistant bacteria are greater in abundances. The 239 antibiotic resistant isolates represent a subset of resistant bacterial populations, including bacteria not previously known for resistance. Majority of the isolates had resistance to ampicillin, vancomycin, lincomycin and trimethoprim. GeoChip revealed similar ARGs in both watersheds, but with significantly higher intensities for tetX and β-lactamase B genes in R1 than R3. The genes with the highest average normalized intensities in R1 and R3 were tetracycline (tet) and fosfomycin (fosA) resistance genes, respectively. The higher abundance of tetX genes in R1 is congruent with the higher abundance of tetracycline resistant HPC observed in R1 samples. Strong correlations (r ≥ 0.8) of efflux

Synthesis and in-vitro antibacterial activity of N-piperazinyl quinolone derivatives with 5-chloro-2-thienyl group

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2008-08-01

Full Text Available Background and the purpose of the study: Fluoroquinolones are an important group of antimicrobial agents that are used widely in the treatment of various infectious diseases. The purpose of the present study was to synthesize new N-piperazinyl quinolone derivatives with 5-chloro-2-theinyl group having possible antimicrobial activity. Methods: Reaction of ciprofloxacin (1, norfloxacin (2 and enoxacin (3 with α-bromoketone 10 or α-bromooxime derivatives 11a-c in DMF, in the presence of NaHCO3 at room temperature, afforded corresponding ketones 4a-c or oxime derivatives 5-7(a-c, respectively. Results and major conclusion: The synthesized compounds were tested against a series of Gram-positive and Gram-negative bacteria. The results of MIC tests against both Gram-positive and Gram-negative bacteria revealed that ciprofloxacin derivatives (compounds 4a, 5a, 6a and 7a were more active than norfloxacin and enoxacin analogues. Compound 5a, containing N-[2-(5-chlorothiophen-2-yl-2-hydroxyiminoethyl] residue provided a high in vitro antibacterial activity against Gram-positive bacteria, with MIC of 0.06, 0.125, 0.5 and 0.125 μg/mL against S. aureus, S. epidermidis, E. feacalis and B. subtilis, respectively. Its activity was found to be 4 to 8 times better than reference drug (ciprofloxacin against all Gram-positive bacteria with the exception of E. feacalis.

The identification of a tetracycline resistance gene tet(M), on a Tn916-like transposon, in the Bacillus cereus group

DEFF Research Database (Denmark)

Agersø, Yvonne; Jensen, Lars Bogø; Givskov, Michael Christian

2002-01-01

In order to investigate whether resistance genes present in bacteria in manure could transfer to indigenous soil bacteria, resistant isolates belonging to the Bacillus cereus group (Bacillus cereus, Bacillus anthracis and Bacillus thuringiensis) were isolated from farm soil (72 isolates) and manure...

Potency of Amylase-producing Bacteria and Optimization Amylase Activities

Science.gov (United States)

Indriati, G.; Megahati, R. R. P.; Rosba, E.

2018-04-01

Enzymes are capable to act as biocatalyst for a wide variety of chemical reactions. Amylase have potential biotechnological applications in a wide range of industrial processes and account for nearly 30% of the world’s enzyme market. Amylase are extracellular enzymes that catalyze the hydrolysis of internal α-1,4-glycosidic linkages in starch to dextrin, and other small carbohydrate molecules constituted of glucose units. Although enzymes are produced from animal and plant sources, the microbial sources are generally the most suitable for commercial applications. Bacteria from hot springs is widely used as a source of various enzymes, such as amylase. But the amount of amylase-producing bacteria is still very limited. Therefore it is necessary to search sources of amylase-producing bacteria new, such as from hot springs Pariangan. The purpose of this study was to isolation of amylase-producing bacteria from Pariangan hot spring, West Sumatera and amylase activity optimization. The results were obtained 12 isolates of thermophilic bacteria and 5 isolates of amyalse-producing bacteria with the largest amylolytic index of 3.38 mm. The highest amylase activity was obtained at 50°C and pH 7.5.

Abundance of pollution indicator and pathogenic bacteria in Mumbai waters

Digital Repository Service at National Institute of Oceanography (India)

Ramaiah, N.; Kolhe, V.; Sadhasivan, A

As a part of environmental assessment in the Mumbai Harbour region, where large numbers of ships either take in ballast from- or discharge their ballast, many groups of indicator and human pathogenic bacteria were quantified. Samples (water...

RESISTENCIA A ANTIBIOTICOS DE BACTERIAS AISLADAS DE BIOPELÍCULAS EN UNA PLANTA DE ALIMENTOS

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María Vanegas L

2009-08-01

Full Text Available Objetivo. Evaluar la resistencia a antibióticos y la capacidad de formación de biopelículas de bacterias aisladas en una planta de producción de alimentos. Materiales y métodos. Se tomaron muestras de 3 zonas diferentes, en una planta procesadora de alimentos; en la lavadora de canastas, la mesa de producción y en la banda empacadora. Se aislaron e identificaron las bacterias presentes en cada una de las tres zonas y se determinó la capacidad formadora de biopelículas por medio de cuantificación celular. Asimismo se evaluó la resistencia de cada una de las bacterias aisladas frente a ocho diferentes antibióticos. Resultados. Se recuperaron 29 cepas, correspondientes a 13 géneros diferentes, los cuales fueron todos formadores de biopelículas. Se encontró que cerca del 50% de las bacterias aisladas fueron resistentes a antibióticos como la penicilina G y vancomicina. Adicionalmente se evidenció un alto grado de multirresistencia a los diferentes antibióticos. Conclusiones. La alta multirresistencia encontrada a antibióticos entre las bacterias analizadas podría ser un problema para salud pública ya que pueden ser transmitidas por alimentos. De igual manera es de gran importancia la capacidad de producción de biopelículas de la microbiota analizada así como la alta concentración de bacterias entéricas y ambientales, lo que sugiere deficiencia del programa de limpieza y desinfección de la planta.

Nanotextile membranes for bacteria Escherichia coli capturing

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Jaroslav Lev

2010-01-01

Full Text Available The article describes an experimental study dealing with the possibility of nanotextile materials usa­ge for microbiologically contaminated water filtration. The aim of the study is to verify filtration ability of different nanotextile materials and evaluate the possibilities of practical usage. Good detention ability of these materials in the air filtration is the presumption for nanotextile to be used for bacteria filtration from a liquid. High nanotextile porosity with the nanotextile pores dimensions smaller than a bacteria size predicates the possibility of a successful usage of these materials. For the experiment were used materials made from electrospinning nanofibres under the label PA612, PUR1, PUR2 s PUR3 on the supporting unwoven textiles (viscose and PP. As a model simulation of the microbial contamination, bacteria Escherichia coli was chosen. Contaminated water was filtered during the overpressure activity of 105Pa on the input side of the filter from the mentioned material. After three-day incubation on the nutrient medium, cultures found in the samples before and after filtration were compared. In the filtrated water, bacteria E. coli were indicated, which did not verify the theoretical presumptions about an absolut bacteria detention. However, used materials caught at least 94% of bacteria in case of material PUR1 and up to 99,996% in case of material PUR2. These results predict the possibility of producing effective nanotextile filters for microbiologically contaminated water filtration.Recommendation: For the production of materials with better filtrating qualities, experiments need to be done, enabling better understanding of the bacteria detention mechanisms on the nanotextile material, and parameters of the used materials that influence the filtrating abilities need to be verified.

Embeddings of SU/sup c/3 in unifying gauge groups

International Nuclear Information System (INIS)

Slansky, R.

1978-01-01

Hypothetical models that attempt to unify electromagnetic, weak, and strong interactions into a simple, compact gauge group G are discussed. The problem of embedding the strong group SU 3 /sup c/ in any larger simple group is solved, and a complete classification of theories where the color in some representation is restricted to 1/sup c/, 3/sup c/, and anti 3/sup c/ is given

Accumulation of reserve carbohydrate by rumen protozoa and bacteria in competition for glucose.

Science.gov (United States)

Denton, Bethany L; Diese, Leanne E; Firkins, Jeffrey L; Hackmann, Timothy J

2015-03-01

The aim of this study was to determine if rumen protozoa could form large amounts of reserve carbohydrate compared to the amounts formed by bacteria when competing for glucose in batch cultures. We separated large protozoa and small bacteria from rumen fluid by filtration and centrifugation, recombined equal protein masses of each group into one mixture, and subsequently harvested (reseparated) these groups at intervals after glucose dosing. This method allowed us to monitor reserve carbohydrate accumulation of protozoa and bacteria individually. When mixtures were dosed with a moderate concentration of glucose (4.62 or 5 mM) (n = 2 each), protozoa accumulated large amounts of reserve carbohydrate; 58.7% (standard error of the mean [SEM], 2.2%) glucose carbon was recovered from protozoal reserve carbohydrate at time of peak reserve carbohydrate concentrations. Only 1.7% (SEM, 2.2%) was recovered in bacterial reserve carbohydrate, which was less than that for protozoa (P protozoa can sequester sugar away from bacteria by accumulating reserve carbohydrate, giving protozoa a competitive advantage and stabilizing fermentation in the rumen. Similar experiments could be used to investigate the importance of starch sequestration. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Assessment of the bacteria reduction in the infected root canal irradiated with diode laser

International Nuclear Information System (INIS)

Radaelli, Claudia Amaral Rabello de Mello

2002-01-01

High success rates are achieved in conventional endodontic treatment of vital pulp teeth. However, in cases of non-vital pulp, a decrease in the rate of success occurs due to difficulties in achieving a complete disinfection of the root canals system. Some bacteria, such as Enterococcus faecalis, are frequently found in cases of endodontic treatment failure due to their high resistance to the conventional endodontic treatment. The aim of this study was to evaluate the efficiency of a high power diode laser irradiation in bacterial reduction of contaminated canals associated with dressing compose by calcium hydroxide paste propylene glycol and camphorated paramonochlorophenol. Eighty-two root canals were infected in vitro with Enterococcus faecalis in a concentration of 1x10 8 CFU/ml. Specimens were high intensity irradiated with a diode laser model Opus 10, at a wavelength of 830 nm. Two different parameters were employed in continuous mode: 3 W and 2,5 W with a 360 μm optical fiber at an angle of approximately 5 degrees respect to the dentine surface during 5 seconds, in 4 applications, with 20 seconds intervals among them. After these proceedings specimens were vortexed in peptone water and dilutions performed. Aliquots of the dilution were plated on m-Enterococcus agar, incubated, and the Colonies Forming Units (CFU) of ali groups was counted. The results showed a significant reduction of bacteria on ali groups after laser irradiation. A high reduction rate was achieved: 98.5% immediately after the laser irradiation; 48 hours after, the reduction was of 96,73% and, finally, a 100% reduction was achieved through the combination of laser irradiation and a long lasting dressing of calcium hydroxide paste, propylene glycol and camphorated paramonochlorophenol. High rates of bacteria reduction were achieved using the parameter of 3 W in continuous mode with the power of 2,9473 KW/cm 2 . The temperature was monitored with a K-pipe thermocouple placed at the

A genomic investigation of ecological differentiation between free-living and Drosophila-associated bacteria.

Science.gov (United States)

Winans, Nathan J; Walter, Alec; Chouaia, Bessem; Chaston, John M; Douglas, Angela E; Newell, Peter D

2017-09-01

Various bacterial taxa have been identified both in association with animals and in the external environment, but the extent to which related bacteria from the two habitat types are ecologically and evolutionarily distinct is largely unknown. This study investigated the scale and pattern of genetic differentiation between bacteria of the family Acetobacteraceae isolated from the guts of Drosophila fruit flies, plant material and industrial fermentations. Genome-scale analysis of the phylogenetic relationships and predicted functions was conducted on 44 Acetobacteraceae isolates, including newly sequenced genomes from 18 isolates from wild and laboratory Drosophila. Isolates from the external environment and Drosophila could not be assigned to distinct phylogenetic groups, nor are their genomes enriched for any different sets of genes or category of predicted gene functions. In contrast, analysis of bacteria from laboratory Drosophila showed they were genetically distinct in their universal capacity to degrade uric acid (a major nitrogenous waste product of Drosophila) and absence of flagellar motility, while these traits vary among wild Drosophila isolates. Analysis of the competitive fitness of Acetobacter discordant for these traits revealed a significant fitness deficit for bacteria that cannot degrade uric acid in culture with Drosophila. We propose that, for wild populations, frequent cycling of Acetobacter between Drosophila and the external environment prevents genetic differentiation by maintaining selection for traits adaptive in both the gut and external habitats. However, laboratory isolates bear the signs of adaptation to persistent association with the Drosophila host under tightly defined environmental conditions. © 2017 John Wiley & Sons Ltd.

Conspicuous veils formed by vibrioid bacteria on sulfidic marine sediment

DEFF Research Database (Denmark)

Thar, Roland Matthias; Kühl, Michael

2002-01-01

, but the bacteria have so far not been isolated in pure culture, and a detailed characterization of their metabolism is still lacking. The bacteria are colorless, gram-negative, and vibrioid-shaped (1.3- to 2.5- by 4- to 10-µm) cells that multiply by binary division and contain several spherical inclusions of poly......We describe the morphology and behavior of a hitherto unknown bacterial species that forms conspicuous veils (typical dimensions, 30 by 30 mm) on sulfidic marine sediment. The new bacteria were enriched on complex sulfidic medium within a benthic gradient chamber in oxygen-sulfide countergradients......, forming a cohesive whitish veil at the oxic-anoxic interface. Bacteria attached to the veil kept rotating and adapted their stalk lengths dynamically to changing oxygen concentrations. The joint action of rotating bacteria on the veil induced a homogeneous water flow from the oxic water region toward...

Host Immune Selection of Rumen Bacteria through Salivary Secretory IgA

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Janelle M. Fouhse

2017-05-01

Full Text Available The rumen microbiome is integral to efficient production in cattle and shows strong host specificity, yet little is known about what host factors shape rumen microbial composition. Secretory immunoglobulin A (SIgA is produced in large amounts in the saliva, can coat both commensal and pathogenic microbes within the gut, and presents a plausible mechanism of host specificity. However, the role salivary SIgA plays in commensal bacteria selection in ruminants remains elusive. The main objectives of this study were to develop an immuno-affinity benchtop method to isolate SIgA-tagged microbiota and to determine if salivary SIgA preferentially binds selected bacteria. We hypothesized that SIgA-tagged bacteria would differ from total bacteria, thus supporting a potential host-derived mechanism in commensal bacterial selection. Whole rumen (n = 9 and oral secretion samples (n = 10 were incubated with magnetic beads conjugated with anti-secretory IgA antibodies to enrich SIgA-tagged microbiota. Microbial DNA from the oral secretion, whole rumen, SIgA-tagged oral secretion, and SIgA-tagged rumen was isolated for amplicon sequencing of V1–V3 region of 16S rDNA genes. Whole rumen and oral secretion had distinctive (P < 0.05 bacterial compositions indicated by the non-parametric multidimensional scaling plot using Euclidean distance metrics. The SIgA-tagged microbiota from rumen and oral secretion had similar abundance of Bacteroidetes, Actinobacteria, Fibrobacter, candidate phyla TM7, and Tenericutes and are clustered tightly. Composition of SIgA-tagged oral secretion microbiota was more similar to whole rumen microbiota than whole oral secretion due to enrichment of rumen bacteria (Lachnospiraceae and depletion of oral taxa (Streptococcus, Rothia, Neisseriaceae, and Lactobacillales. In conclusion, SIgA-tagged oral secretion microbiota had an increased resemblance to whole rumen microbiota, suggesting salivary SIgA-coating may be one host

Antibacterial activity of Pinus elliottii against anaerobic bacteria present in primary endodontic infections.

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Caetano da Silva, Sandro Donizete; Mendes de Souza, Maria Gorete; Oliveira Cardoso, Miguel Jorge; da Silva Moraes, Thais; Ambrósio, Sérgio Ricardo; Sola Veneziani, Rodrigo Cássio; Martins, Carlos Henrique G

2014-12-01

Endodontic infections have a polymicrobial nature, but anaerobic bacteria prevail among the infectious microbes. Considering that it is easy to eliminate planktonic bacteria, biofilm-forming bacteria still challenge clinicians during the fight against endodontic diseases. The chemical constituents of the oleoresin of Pinus elliottii, a plant belonging to the family Pinaceae, stand out in the search for biologically active compounds based on natural products with potential application in the treatment of endodontic infections. Indeed, plant oleoresins are an abundant natural source of diterpenes that display significant and well-defined biological activities as well as potential antimicrobial action. In this context, this study aimed to (1) evaluate the in vitro antibacterial activity of the oleoresin, fractions, and subfractions of P. elliottii as well as the action of dehydroabietic acid against 11 anaerobic bacteria that cause endodontic infection in both their planktonic and biofilm forms and (2) assess the in vitro antibiofilm activity of dehydroabietic acid against the same group of bacteria. The broth microdilution technique helped to determine the minimum inhibitory concentration (MIC) of the oleoresin and fractions. This same technique aided determination of the MIC values of nine subfractions of Fraction 1, the most active fraction. The MIC, minimum bactericidal concentration, and antibiofilm activity of dehydroabietic acid against the tested anaerobic bacteria were also examined. The oleoresin and fractions, especially fraction PE1, afforded promising MIC values, which ranged from 0.4 to 50 μg/mL. Concerning the nine evaluated subfractions, PE1.3 and PE1.4 furnished the most noteworthy MIC values, between 6.2 and 100 μg/mL. Dehydroabietic acid displayed antibacterial activity, with MIC values lying from 6.2 to 50 μg/mL, as well as bactericidal effect for all the investigated bacteria, except for Prevotella nigrescens. Assessment of the antibiofilm

Differential Susceptibility of Bacteria to Mouse Paneth Cell a-Defensins under Anaerobic Conditions

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Jennifer R. Mastroianni

2014-10-01

Full Text Available Small intestinal Paneth cells secrete a-defensin peptides, termed cryptdins (Crps in mice, into the intestinal lumen, where they confer immunity to oral infections and define the composition of the ileal microbiota. In these studies, facultative bacteria maintained under aerobic or anaerobic conditions displayed differential sensitivities to mouse a-defensins under in vitro assay conditions. Regardless of oxygenation, Crps 2 and 3 had robust and similar bactericidal activities against S. typhimurium and S. flexneri, but Crp4 activity against S. flexneri was attenuated in the absence of oxygen. Anaerobic bacteria varied in their susceptibility to Crps 2-4, with Crp4 showing less activity than Crps 2 and 3 against Enterococcus faecalis, and Bacteroides fragilis in anaerobic assays, but Fusobacterium necrophorum was killed only by Crp4 and not by Crps 2 and 3. The influence of anaerobiosis in modulating Crp bactericidal activities in vitro suggests that a-defensin effects on the enteric microbiota may be subject to regulation by local oxygen tension.

A novel surface-enhanced Raman scattering (SERS) detection for natural gas exploration using methane-oxidizing bacteria.

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Liang, Weiwei; Chen, Qiao; Peng, Fang; Shen, Aiguo; Hu, Jiming

2018-07-01

Methane-oxidizing bacteria (MOB), a unique group of Gram-negative bacteria utilizing methane as a sole source of carbon and energy, have been proved to be a biological indicator for gas prospecting. Field and cultivation-free detection of MOB is important but still challenging in current microbial prospecting of oil and gas (MPOG) system. Herein, SERS was used for the first time to our knowledge to investigate two species of methanotrophs and four closely relevant bacteria that universally coexisted in the upper soil of natural gas. A special but very simple approach was utilized to make silver nanoparticles (Ag NPs) sufficiently contact with every single bacterial cell, and highly strong and distinct Raman signals free from any native fluorescence have been obtained, and successfully utilized for distinguishing MOB from other species. A more convincing multi-Raman criterion based on single Raman bands, and further the entire Raman spectrum in combination with statistical analysis (e.g., principal component analysis (PCA)), which were found capable of classifying MOB related bacterial cells in soil with an accuracy of 100%. This study therefore demonstrated sensitive and rapid SERS measurement technique accompanied by complete Raman database of various gas reservoirs related bacteria could aid field exploration of natural gas reservoir. Copyright © 2018 Elsevier B.V. All rights reserved.

Phenotypic and genotypic characterization of some lactic Acid bacteria isolated from bee pollen: a preliminary study.

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Belhadj, Hani; Harzallah, Daoud; Bouamra, Dalila; Khennouf, Seddik; Dahamna, Saliha; Ghadbane, Mouloud

2014-01-01

In the present work, five hundred and sixty-seven isolates of lactic acid bacteria were recovered from raw bee pollen grains. All isolates were screened for their antagonistic activity against both Gram-positive and Gram-negative pathogenic bacteria. Neutralized supernatants of 54 lactic acid bacteria (LAB) cultures from 216 active isolates inhibited the growth of indicator bacteria. They were phenotypically characterized, based on the fermentation of 39 carbohydrates. Using the simple matching coefficient and unweighted pair group algorithm with arithmetic averages (UPGMA), seven clusters with other two members were defined at the 79% similarity level. The following species were characterized: Lactobacillus plantarum, Lactobacillus fermentum, Lactococcus lactis, Pediococcus acidilactici, Pediococcus pentosaceus, and unidentified lactobacilli. Phenotypic characteristics of major and minor clusters were also identified. Partial sequencing of the 16S rRNA gene of representative isolates from each cluster was performed, and ten strains were assigned to seven species: Lactobacillus plantarum, Lactobacillus fermentum, Lactococcus lactis, Lactobacillus ingluviei, Pediococcus pentosaceus, Lactobacillus acidipiscis and Weissella cibaria. The molecular method used failed to determine the exact taxonomic status of BH0900 and AH3133.

[Comparative studying of anaerobic bacteria located in woman's reproductive ways in normal condition and dysbiosis].

Science.gov (United States)

Polishko, T N; Sirokvasha, E A; Klokov, V V; Vinnikov, A I

2008-01-01

Bacteriological investigation of obligate anaerobic bacteria located in UGT of two groups of the observed women has shown: that the microbiocoenosis of UGT of women of the group 1 can be determined as normal. Identification of these anaerobic bacteria revealed the presence of representatives of the following species: Lactobacillus spp., Bifidobacterium spp., Eubacterium spp., Bacteroides spp., Fusobacterium spp., Peptococcus spp., Peptostreptococcus spp. The microbiocoenosis of UGT of the women of group 2 is diagnosed as vaginosis, thus in addition to the listed previously bacteria is added another one, Clostridium spp. Characteristic feature of Vaginosis is from one side a considerable decrease in the frequency of finding (cultivation) and concentration of Lactobacillus spp. and Bifidobacterium spp. and from another side--a considerable increase of frequency finding (cultivation) and concentration of Bacteroides spp. In addition, there is change of metabolism of Lactobacillus spp. and Bifidobacterium spp resulting in decrease in specific intensity of secretion of acids.

Characteristics of lactic acid bacteria isolates and their effect on silage fermentation of fruit residues.

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Yang, Jinsong; Tan, Haisheng; Cai, Yimin

2016-07-01

The natural lactic acid bacteria (LAB) population, chemical composition, and silage fermentation of fruit residues were studied. Eighty-two strains of LAB were isolated from fruit residues such as banana leaf and stem, pineapple peel, and papaya peel. All strains were gram-positive and catalase-negative bacteria, and they were divided into 7 groups (A-G) according to morphological and biochemical characters. Strains in groups A to F were rods, and group G was cocci. Group F produced gas from glucose; other groups did not. Groups A to C and F formed dl-lactic acid, whereas groups D, E, and G formed l-lactic acid. Based on the 16S rRNA gene sequence and DNA-DNA hybridization analysis, groups A to G strains were identified as Lactobacillus plantarum (54.9% of the total isolates), Lactobacillus paraplantarum (3.6%), Lactobacillus nagelii (8.5%), Lactobacillus perolens (4.9%), Lactobacillus casei (11.0%), Lactobacillus fermentum (9.8%), and Enterococcus gallinarum (7.3%), respectively. Lactobacillus plantarum and Lactobacillus casei are the most frequently isolated from fruit residues as a dominant species, and they could grow at a lower pH conditions and produce more lactic acid than other isolates. Pineapple and papaya peels contained higher crude protein (11.5-13.8%) and water-soluble carbohydrate (16.8-22.4%), but lower acid detergent fiber contents (21.2 to 26.4%) than banana stems and leaves (8.2% crude protein, 42.8% acid detergent fiber, and 5.1% water-soluble carbohydrate). Compared with banana stem and leaf silages, the pineapple and papaya peel silages were well preserved with a lower pH and higher lactate content. The study suggests that the fruit residues contain excellent LAB species and abundant feed nutrients, and that they can be preserved as silage to be potential food resources for livestock. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Cable Bacteria in Freshwater Sediments

DEFF Research Database (Denmark)