bluuebunny/crossref_metadata_2025_split huggingface dataset:
Novel Probiotic Bifidobacterium longum subsp. infantis CECT 7210 Strain Active against Rotavirus Infections
Authors: Moreno Muñoz José Antonio , Chenoll Empar , Casinos Beatriz , Bataller Esther , Ramón Daniel , Genovés Salvador , Montava Rebeca , Ribes Juan Manuel , Buesa Javier , Fàbrega Joan , Rivero Montserrat 
Published: October 2011

ABSTRACT

Rotavirus is the leading cause of severe acute gastroenteritis among children worldwide. It is well known that breast-feeding and vaccination afford infants protection. Since breast-feeding has drastically decreased in developed countries, efforts have been focused on the potential use of probiotics as preventive agents. In this study, a novel
Bifidobacterium longum
subsp.
infantis
strain was isolated from infant feces and selected, based on its capacity to inhibit
in vitro
rotavirus Wa replication (up to 36.05% infectious foci reduction) and also to protect cells from virus infection (up to 48.50% infectious foci reduction) in both MA-104 and HT-29 cell lines. Furthermore, studies using a BALB/c mouse model have proved that this strain provides preliminary
in vivo
protection against rotavirus infection. The strain has been deposited in the Spanish Type Culture Collection under the accession number CECT 7210. This novel strain has the main properties required of a probiotic, such as resistance to gastrointestinal juices, biliary salts, NaCl, and low pH, as well as adhesion to intestinal mucus and sensitivity to antibiotics. The food safety status has been confirmed by the absence of undesirable metabolite production and in acute ingestion studies of mice. Overall, these results demonstrate that
Bifidobacterium longum
subsp.
infantis
CECT 7210 can be considered a probiotic able to inhibit rotavirus infection.
Development and Application of an Enzymatic and Cell Flotation Treatment for the Recovery of Viable Microbial Cells from Environmental Matrices Such as Anaerobic Sludge
Authors: Braun Florence , Hamelin Jérôme , Gévaudan Gaëlle , Patureau Dominique 
Published: October 2011

ABSTRACT
Efficient dissociation of microorganisms from their aggregate matrix is required to study the microorganisms without interaction with their native environment (e.g., biofilms, flocs, granules, etc.) and to assess their community composition through the application of molecular or microscopy techniques. To this end, we combined enzymatic treatments and a cell extraction by density gradient to efficiently recover anaerobic microorganisms from urban wastewater treatment plant sludge. The enzymes employed (amylase, cellulase, DNase, and pectinase) as a pretreatment softly disintegrated the extrapolymeric substances (EPS) interlocked with the microorganisms. The potential damaging effects of the applied procedure on bacterial and archaeal communities were assessed by studying the variations in density (using quantitative PCR), diversity (using capillary electrophoresis single-strand conformation polymorphism fingerprinting [CE-SSCP]), and activity (using a standard anaerobic activity test) of the extracted microorganisms. The protocol preserved the general capacity of the microbial community to produce methane under anaerobic conditions and its diversity; particularly the archaeal community was not affected in terms of either density or structure. This cell extraction procedure from the matrix materials offers interesting perspectives for metabolic, microscopic, and molecular assays of microbial communities present in complex matrices constituted by bioaggregates or biofilms.
Predictive Models for the Effect of Storage Temperature on Vibrio parahaemolyticus Viability and Counts of Total Viable Bacteria in Pacific Oysters (Crassostrea gigas)
Authors: Fernandez-Piquer Judith , Bowman John P. , Ross Tom , Tamplin Mark L. 
Published: October 2011

ABSTRACTVibrio parahaemolyticusis an indigenous bacterium of marine environments. It accumulates in oysters and may reach levels that cause human illness when postharvest temperatures are not properly controlled and oysters are consumed raw or undercooked. Predictive models were produced by injecting Pacific oysters (Crassostrea gigas) with a cocktail ofV. parahaemolyticusstrains, measuring viability rates at storage temperatures from 3.6 to 30.4°C, and fitting the data to a model to obtain parameter estimates. The models were evaluated with Pacific and Sydney Rock oysters (Saccostrea glomerata) containing natural populations ofV. parahaemolyticus. V. parahaemolyticusviability was measured by direct plating samples on thiosulfate-citrate-bile salts-sucrose (TCBS) agar for injected oysters and by most probable number (MPN)-PCR for oysters containing natural populations. In parallel, total viable bacterial counts (TVC) were measured by direct plating on marine agar. Growth/inactivation rates forV. parahaemolyticuswere −0.006, −0.004, −0.005, −0.003, 0.030, 0.075, 0.095, and 0.282 log10CFU/h at 3.6, 6.2, 9.6, 12.6, 18.4, 20.0, 25.7, and 30.4°C, respectively. The growth rates for TVC were 0.015, 0.023, 0.016, 0.048, 0.055, 0.071, 0.133, and 0.135 log10CFU/h at 3.6, 6.2, 9.3, 14.9, 18.4, 20.0, 25.7, and 30.4°C, respectively. Square root and Arrhenius-type secondary models were generated forV. parahaemolyticusgrowth and inactivation kinetic data, respectively. A square root model was produced for TVC growth. Evaluation studies showed that predictive growth forV. parahaemolyticusand TVC were “fail safe.” The models can assist oyster companies and regulators in implementing management strategies to minimizeV. parahaemolyticusrisk and enhancing product quality in supply chains.
Carboxylases in Natural and Synthetic Microbial Pathways
Authors: Erb Tobias J. 
Published: October 2011

ABSTRACTCarboxylases are among the most important enzymes in the biosphere, because they catalyze a key reaction in the global carbon cycle: the fixation of inorganic carbon (CO2). This minireview discusses the physiological roles of carboxylases in different microbial pathways that range from autotrophy, carbon assimilation, and anaplerosis to biosynthetic and redox-balancing functions. In addition, the current and possible future uses of carboxylation reactions in synthetic biology are discussed. Such uses include the possible transformation of the greenhouse gas carbon dioxide into value-added compounds and the production of novel antibiotics.
Estimation of Mycobacterium avium subsp. paratuberculosis Growth Parameters: Strain Characterization and Comparison of Methods
Authors: Elguezabal Natalia , Bastida Felix , Sevilla Iker A. , González Nuria , Molina Elena , Garrido Joseba M. , Juste Ramón A. 
Published: October 2011

ABSTRACTThe growth rate ofMycobacterium aviumsubsp.paratuberculosiswas assessed by different methods in 7H9 medium supplemented with OADC (oleic acid, albumin, dextrose, catalase), Tween 80, and mycobactin J. Generation times and maximum specific growth rates were determined by wet weight, turbidometric measurement, viable count, and quantitative PCR (ParaTB-Kuanti; F57 gene) for 8M. aviumsubsp.paratuberculosisstrains (K10, 2E, 316F, 81, 445, 764, 22G, and OVICAP 49). Strain-to-strain differences were observed in growth curves and calculated parameters. The quantification methods gave different results for each strain at specific time points. Generation times ranged from an average of 1.4 days for viable count and qPCR to approximately 10 days for wet weight and turbidometry. The wet-weight, turbidometry, and ParaTB-Kuanti qPCR methods correlated best with each other. Generally, viability has been assessed by viable count as a reference method; however, due toM. aviumsubsp.paratuberculosisclumping problems and the presence of noncultivableM. aviumsubsp.paratuberculosiscells, we conclude that qPCR of a single-copy gene may be used reliably for rapid estimation ofM. aviumsubsp.paratuberculosisbacterial numbers in a sample.
Mycosporine-Like Amino Acids from Coral Dinoflagellates
Authors: Rosic Nedeljka N. , Dove Sophie 
Published: October 2011

ABSTRACT

Coral reefs are one of the most important marine ecosystems, providing habitat for approximately a quarter of all marine organisms. Within the foundation of this ecosystem, reef-building corals form mutualistic symbioses with unicellular photosynthetic dinoflagellates of the genus
Symbiodinium
. Exposure to UV radiation (UVR) (280 to 400 nm) especially when combined with thermal stress has been recognized as an important abiotic factor leading to the loss of algal symbionts from coral tissue and/or a reduction in their pigment concentration and coral bleaching. UVR may damage biological macromolecules, increase the level of mutagenesis in cells, and destabilize the symbiosis between the coral host and their dinoflagellate symbionts. In nature, corals and other marine organisms are protected from harmful UVR through several important photoprotective mechanisms that include the synthesis of UV-absorbing compounds such as mycosporine-like amino acids (MAAs). MAAs are small (<400-Da), colorless, water-soluble compounds made of a cyclohexenone or cyclohexenimine chromophore that is bound to an amino acid residue or its imino alcohol. These secondary metabolites are natural biological sunscreens characterized by a maximum absorbance in the UVA and UVB ranges of 310 to 362 nm. In addition to their photoprotective role, MAAs act as antioxidants scavenging reactive oxygen species (ROS) and suppressing singlet oxygen-induced damage. It has been proposed that MAAs are synthesized during the first part of the shikimate pathway, and recently, it has been suggested that they are synthesized in the pentose phosphate pathway. The shikimate pathway is not found in animals, but in plants and microbes, it connects the metabolism of carbohydrates to the biosynthesis of aromatic compounds. However, both the complete enzymatic pathway of MAA synthesis and the extent of their regulation by environmental conditions are not known. This minireview discusses the current knowledge of MAA synthesis, illustrates the diversity of MAA functions, and opens new perspectives for future applications of MAAs in biotechnology.
Genetic Screening of Functional Properties of Lactic Acid Bacteria in a Fermented Pearl Millet Slurry and in the Metagenome of Fermented Starchy Foods
Authors: Turpin Williams , Humblot Christèle , Guyot Jean-Pierre 
Published: October 2011

ABSTRACT

Lactic acid bacteria (LAB) (
n
= 152) in African pearl millet slurries and in the metagenomes of amylaceous fermented foods were investigated by screening 33 genes involved in probiotic and nutritional functions. All isolates belonged to six species of the genera
Pediococcus
and
Lactobacillus
, and
Lactobacillus fermentum
was the dominant species. We screened the isolates for the abilities to survive passage through the gastrointestinal tract and to synthesize folate and riboflavin. The isolates were also tested
in vitro
for their abilities to survive exposure to bile salts and to survive at pH 2. Because the ability to hydrolyze starch confers an ecological advantage on LAB that grow in starchy matrixes as well as improving the nutritional properties of the gruels, we screened for genes involved in starch metabolism. The results showed that genes with the potential ability to survive passage through the gastrointestinal tract were widely distributed among isolates and metagenomes, whereas
in vitro
tests showed that only a limited set of isolates, mainly those belonging to
L. fermentum
, could tolerate a low pH. In contrast, the wide distribution of genes associated with bile salt tolerance, in particular
bsh
, is consistent with the high frequency of tolerance to bile salts observed. Genetic screening revealed a potential for folate and riboflavin synthesis in both isolates and metagenomes, as well as high variability among genes related to starch metabolism. Genetic screening of isolates and metagenomes from fermented foods is thus a promising approach for assessing the functional potential of food microbiotas.
Cold Spots in Neonatal Incubators Are Hot Spots for Microbial Contamination
Authors: de Goffau Marcus C. , Bergman Klasien A. , de Vries Hendrik J. , Meessen Nico E. L. , Degener John E. , van Dijl Jan Maarten , Harmsen Hermie J. M. 
Published: October 2011

ABSTRACT
Thermal stability is essential for the survival and well-being of preterm neonates. This is achieved in neonatal incubators by raising the ambient temperature and humidity to sufficiently high levels. However, potentially pathogenic microorganisms also can thrive in such warm and humid environments. We therefore investigated whether the level of microbial contamination (i.e., the bacterial load) inside neonatal incubators can be predicted on the basis of their average temperature and relative humidity settings, paying special attention to local temperature differences. Swab samples were taken from the warmest and coldest spots found within Caleo incubators, and these were plated to determine the number of microbial CFU per location. In incubators with high average temperature (≥34°C) and relative humidity (≥60%) values, the level of microbial contamination was significantly higher at cold spots than at hot spots. This relates to the fact that the local equilibrium relative humidity at cold spots is sufficiently high to sustain microbial growth. The abundance of staphylococci, which are the main causative agents of late-onset sepsis in preterm neonates, was found to be elevated significantly in cold areas. These findings can be used to improve basic incubator hygiene.
Marine Bacteria from Danish Coastal Waters Show Antifouling Activity against the Marine Fouling Bacterium Pseudoalteromonas sp. Strain S91 and Zoospores of the Green Alga Ulva australis Independent of Bacteriocidal Activity
Authors: Bernbom Nete , Ng Yoke Yin , Kjelleberg Staffan , Harder Tilmann , Gram Lone 
Published: October 2011

ABSTRACT

The aims of this study were to determine if marine bacteria from Danish coastal waters produce antifouling compounds and if antifouling bacteria could be ascribed to specific niches or seasons. We further assess if antibacterial effect is a good proxy for antifouling activity. We isolated 110 bacteria with anti-
Vibrio
activity from different sample types and locations during a 1-year sampling from Danish coastal waters. The strains were identified as
Pseudoalteromonas
,
Phaeobacter
, and
Vibrionaceae
based on phenotypic tests and partial 16S rRNA gene sequence similarity. The numbers of bioactive bacteria were significantly higher in warmer than in colder months. While some species were isolated at all sampling locations, others were niche specific. We repeatedly isolated
Phaeobacter gallaeciensis
at surfaces from one site and
Pseudoalteromonas tunicata
at two others. Twenty-two strains, representing the major taxonomic groups, different seasons, and isolation strategies, were tested for antiadhesive effect against the marine biofilm-forming bacterium
Pseudoalteromonas
sp. strain S91 and zoospores of the green alga
Ulva australis
. The antiadhesive effects were assessed by quantifying the number of strain S91 or
Ulva
spores attaching to a preformed biofilm of each of the 22 strains. The strongest antifouling activity was found in
Pseudoalteromonas
strains. Biofilms of
Pseudoalteromonas piscicida
,
Pseudoalteromonas tunicata
, and
Pseudoalteromonas ulvae
prevented
Pseudoalteromonas
S91 from attaching to steel surfaces.
P. piscicida
killed S91 bacteria in the suspension cultures, whereas
P. tunicata
and
P. ulvae
did not; however, they did prevent adhesion by nonbactericidal mechanism(s). Seven
Pseudoalteromonas
species, including
P. piscicida
and
P. tunicata
, reduced the number of settling
Ulva
zoospores to less than 10% of the number settling on control surfaces. The antifouling
alpP
gene was detected only in
P. tunicata
strains (with purple and yellow pigmentation), so other compounds/mechanisms must be present in the other
Pseudoalteromonas
strains with antifouling activity.
Test of Direct and Indirect Effects of Agrochemicals on the Survival of Fecal Indicator Bacteria
Authors: Staley Zachery R. , Rohr Jason R. , Harwood Valerie J. 
Published: October 2011

ABSTRACT

Water bodies often receive agrochemicals and animal waste carrying fecal indicator bacteria (FIB) and zoonotic pathogens, but we know little about the effects of agrochemicals on these microbes. We assessed the direct effects of the pesticides atrazine, malathion, and chlorothalonil and inorganic fertilizer on
Escherichia coli
and enterococcal survival in simplified microcosms held in the dark.
E. coli
strain composition in sediments and water column were positively correlated, but none of the agrochemicals had significant direct effects on
E. coli
strain composition or on densities of culturable FIBs. In a companion study, microcosms with nondisinfected pond water and sediments were exposed to or shielded from sunlight to examine the potential indirect effects of atrazine and inorganic fertilizer on
E. coli
. The herbicide atrazine had no effect on
E. coli
in dark-exposed microcosms containing natural microbial and algal communities. However, in light-exposed microcosms, atrazine significantly lowered
E. coli
densities in the water column and significantly increased densities in the sediment compared to controls. This effect appears to be mediated by the effects of atrazine on algae, given that atrazine significantly reduced phytoplankton, which was a positive and negative predictor of
E. coli
densities in the water column and sediment, respectively. These data suggest that atrazine does not directly affect the survival of FIB, rather that it indirectly alters the distribution and abundance of
E. coli
by altering phytoplankton and periphyton communities. These results improve our understanding of the influence of agricultural practices on FIB densities in water bodies impacted by agricultural runoff.
Novel Yeast Bioassay for High-Throughput Screening of Matrix Metalloproteinase Inhibitors
Authors: Diehl Bjoern , Hoffmann Thorsten M. , Mueller Nina C. , Burkhart Jens L. , Kazmaier Uli , Schmitt Manfred J. 
Published: October 2011

ABSTRACT

Diverse malfunctions in the expression and regulation of matrix metalloproteinases (MMPs) are often the cause of severe human diseases, bringing the identification of specific MMP inhibitors into major focus, particularly in anticancer treatment. Here, we describe a novel bioassay based on recombinant yeast cells (
Pichia pastoris
) that express, deliver, and incorporate biologically active human MMP-2 and MMP-9 at the yeast cell surface. Using Sed1p for cell wall targeting and covalent anchorage, a highly efficient bioassay was established that allows high-throughput screening and subsequent validation of novel MMP inhibitors as potential anticancer drugs. In addition, we developed a straightforward synthesis of a new aspartate-derived MMP inhibitor active in the nM range and bearing an amino functionality that should allow the introduction of a wide range of side chains to modify the properties of these compounds.
Quest for a Realistic
In Vivo
Test Method for Antimicrobial Hand-Rub Agents: Introduction of a Low-Volume Hand Contamination Procedure
Authors: Macinga David R. , Beausoleil Christopher M. , Campbell Esther , Mulberry Gayle , Brady Ann , Edmonds Sarah L. , Arbogast James W. 
Published: October 2011

ABSTRACT

A novel method has been developed for the evaluation of alcohol-based hand rubs (ABHR) that employs a hand contamination procedure that more closely simulates the in-use conditions of ABHR. Hands of human subjects were contaminated with 0.2 ml of a concentrated suspension of
Serratia marcescens
(ATCC 14756) to achieve baseline contamination between 8 and 9 log
10
CFU/hand while allowing product to be applied to dry hands with minimal soil load. Evaluation of 1.5 ml of an ABHR gel containing 62% ethanol produced log
10
reductions of 2.66 ± 0.96, 2.40 ± 0.50, 2.41 ± 0.61, and 2.33 ± 0.49 (means ± standard deviations) after 1, 3, 7, and 10 successive contamination/product application cycles. In a study comparing this low-volume contamination (LVC) method to ASTM E1174, product dry times were more realistic and log
10
reductions achieved by the ABHR were significantly greater when LVC was employed (
P
< 0.05). These results indicate that a novel low-volume hand contamination procedure, which more closely represents ABHR use conditions, provides more realistic estimates of in-use ABHR efficacies. Based on the LVC method, log
10
reductions produced by ABHR were strongly dependent on the test product application volume (
P
< 0.0001) but were not influenced by the alcohol concentration when it was within the range of 62 to 85% (
P
= 0.378).
Serotypes and Virulence Profiles of Non-O157 Shiga Toxin-Producing Escherichia coli Isolates from Bovine Farms
Authors: Monaghan Áine , Byrne Brian , Fanning Séamus , Sweeney Torres , McDowell David , Bolton Declan J. 
Published: October 2011

ABSTRACT

Non-O157 Shiga toxin-producing
Escherichia coli
(STEC) strains are clinically significant food-borne pathogens. However, there is a dearth of information on serotype prevalence and virulence gene distribution, data essential for the development of public health protection monitoring and control activities for the meat and dairy industries. Thus, the objective of this study was to examine the prevalence of non-O157 STEC on beef and dairy farms and to characterize the isolates in terms of serotype and virulence markers. Bovine fecal samples (
n
= 1,200) and farm soil samples (
n
= 600) were collected from 20 farms throughout Ireland over a 12-month period. Shiga toxin-positive samples were cultured and colonies examined for the presence of
stx
1
and/or
stx
2
genes by PCR. Positive isolates were serotyped and examined for a range of virulence factors, including
eaeA
,
hlyA
,
tir
,
espA
,
espB
,
katP
,
espP
,
etpD
,
saa
,
sab
,
toxB
,
iha
,
lpfA
O157/OI-141
,
lpfA
O113
, and
lpfA
O157/OI-154
. Shiga toxin and intimin genes were further examined for known variants. Significant numbers of fecal (40%) and soil (27%) samples were
stx
positive, with a surge observed in late summer-early autumn. One hundred seven STEC isolates were recovered, representing 17 serotypes. O26:H11 and O145:H28 were the most clinically significant, with O113:H4 being the most frequently isolated. However, O2:H27, O13/O15:H2, and ONT:H27 also carried
stx
1
and/or
stx
2
and
eaeA
and may be emerging pathogens.