bluuebunny/crossref_metadata_2025_split huggingface dataset:
Efficiency of different enrichment and isolation procedures for the detection of Salmonella serotypes in edible offal
Authors: Arroyo G. , Arroyo J.A. 
Published: March 2008

Rapid detection systems for Salmonella in foodstuffs are currently being developed. However, existing standards still call for application of traditional methods employing pre‐enrichment followed by selective enrichment and isolation. The efficacy of various methods was tested using 264 chicken and lamb organ meats. Pre‐enrichment was carried out in Tryptone Soy Broth (TSB) and enrichment in Tetrathionate Brilliant Green Broth (TTB) at 37°C, Selenite Broth with Brilliant Green and Sulphapyridine at 37°C and 43°C, and Rappaport‐Vassiliadis Broth (RV 10) at 42°C. The isolation media were Brilliant Green Agar (BGA), Deoxycholate Citrate Agar, Hektoen Enteric Agar (HEA) and Salmonella‐Shigella Agar.Enrichment in RV/42°C followed by isolation on BGA as recommended by ISO standard no. 6579 and enrichment in TTB/37°C followed by isolation in HEA, no longer recommended by that standard, produced the best results. Low percentages of positive samples and difficulties in detecting Salmonella are the result of interference by competing organisms (Enterobacteriaceae) and the number of salmonellas present after enrichment.A total of 528 samples (TSB, eggs, lamb liver and chicken liver) were inoculated with Salm. enteritidis, Salm. kapemba and Salm. virchow, and the preceding experiment was repeated. All the TSB and egg samples tested positive, but the percentage of positive samples from the lamb and chicken liver was only 81–92%. Recovery of the salmonellas did not depend upon the method employed or the serotype inoculated but instead on interference by competing flora and the numbers of Salmonella present in the samples.
The antimicrobial activity of lactic acid bacteria from fermented maize (kenkey) and their interactions during fermentation
Authors: Olsen A. , Halm M. , Jakobsen M. 
Published: March 2008

A total of 241 lactic acid bacteria belonging to Lactobacillus plantarum, Pediococcus pentosaceus, Lactobacillus fermentum/reuteri and Lactobacillus brevis from various processing stages of maize dough fermentation were investigated. Results indicated that each processing stage has its own microenvironment with strong antimicrobial activity. About half of the Lact. plantarum and practically all of the Lact. fermentum/reuteri investigated were shown to inhibit other Gram‐positive and Gram‐negative bacteria, explaining the elimination of these organisms during the initial processing stages. Further, widespread microbial interactions amounting to 85% to 18% of all combinations tested were demonstrated amongst lactic acid bacteria within the various processing stages, i.e. raw material, steeping, 0 h and 48 h of fermentation, explaining the microbial succession taking place amongst lactic acid bacteria during fermentation. The antimicrobial effect was explained by the combined effect of acids, compounds sensitive to proteolytic enzymes and other compounds with antimicrobial activity with the acid production being the most important factor.The pattern of antimicrobial factors was not species‐specific and the safety and storage stability of fermented maize seem to depend on a mixed population of lactic acid bacteria with different types of antimicrobial characteristics. This means that introduction of pure cultures as starters may impose a risk to the product.
Specific antibody‐mediated detection of Brochothrix thermosphacta in situ in British fresh sausage
Authors: Stringer S.C. , Chaffey B.J. , Dodd C.E.R. , Morgan M.R.A. , Waites W.M. 
Published: March 2008

S.C. STRINGER, B.J. CHAFFEY, C.E.R. DODD, M.R.A. MORGAN AND W.M. WAITES. 1995. A rabbit polyclonal antibody‐linked probe was developed which detected 76% of 800 food isolates of the spoilage bacterium Brochothrix thermosphacta when cells were bound to nitrocellulose. In slide cross‐reaction tests all six environmental isolates tested were stained but the type strain was not. The antibody did not cross‐react with Listeria grayi, L. monocytogenes, Lactobacillus plantarum, Lactococcus lactis, Streptococcus mutans, Bacillus cereus or B. subtilis.The antibody‐linked probe detected Br. thermosphacta in thin sections of British fresh sausage when the viable count was greater than 106 g−1 Cells were detected mainly within 1 or 2 mm of the surface on the loose starchy material. They were not detected within muscle blocks or in the centre of the sausage. Such results suggest that growth of this organism occurs close to the surface of the sausage.
The effect of a propionic acid bacterial inoculant applied at ensiling, with or without lactic acid bacteria, on the aerobic stability of pearl millet and maize silages
Authors: Weinberg Z.G. , Ashbell G. , Bolsen K.K. , Pahlow G. , Hen Yaira , Azriell A. 
Published: March 2008

Z.G. WEINBERG, G. ASHBELL, K.K. BOLSEN, G. PAHLOW, Y. HEN AND A. AZRIELI. 1995. The effect of applying a new strain of Propionibacterium shermanii (PS), alone or with lactic acid bacteria inoculants (LAB) at ensiling, on the aerobic stability of pearl millet and maize silages was studied under laboratory conditions. The LAB inoculants comprised of Pediococcus pentosaceus (PP) in the experiments with millet, and PP +Lactobacillus plantarum (LP) in various combinations in the experiments with maize. The inoculants (made by Lallemand, France) were applied each at 0˙5 times 106 cfu g−1 Silages with no additives served as controls. The pearl millet used was either fresh, or wilted for 2 or 4 d (at 201, 268 and 448 g DM kg−1, respectively). There were two experiments with maize (at 401 and 353 g DM kg−1). After treatment, the chopped forages were ensiled in 15–1 anaerobic jars. Three jars per treatment were sampled on days 2, 5, 10 and 90. At the end of the experiments, the silages were subjected to an aerobic stability test lasting 6 d, in which CO2 production was measured along with chemical and microbiological parameters, to evaluate aerobic deteioration.The PS inoculant resulted in improvement in the aerobic stability as compared with the control, only in the fresh and 2‐d wilted pearl millet silages. The amounts of CO2 (g kg‐1 DM) produced were 8˙5 ± 7˙7 and 6˙8 ± 1˙1 vs 18˙8 ± 22˙7 and 27˙0 ± 18˙5 in the PS treated and control of the fresh and 2‐d‐wilted pearl millet, respectively. All silages of the 4‐d‐wilted millet were stable upon aerobic exposure. In the first maize experiment the PS treatment and the control were more stable than the LAB inoculated silages. In the second experiment with maize, none of the silages were stable upon aerobic exposure; they showed increased pH values and CO2 production around 20 g kg‐1 DM.The propionic acid bacteria inoculant had only a marginal effect on the aerobic stability of the pearl millet and maize silages, probably because it could not sustain under silage conditions.
Spray drying as a method for preparing concentrated cultures of Lactobacillus bulgaricus
Authors: Teixeira P. , Castro H. , Kirby R. 
Published: March 2008

P. TEIXEIRA, H. CASTRO AND R. KIRBY. 1995. Spray drying and freeze drying as methods for concentration of Lactobacillus bulgaricus starter cultures were compared in terms of viability, lag phase until onset of pH decrease and total acid production. For the experimental conditions used, no significant differences were detected between the methods.The effect of spray drying on the cell membrane of Lactobacillus bulgaricus was studied. Five separate methods were used to study the theory that spray drying causes cell membrane damage; three relating to leakage of intracellular components from the cell into the surrounding environment (260 and 280 nm absorbing materials, potassium ions and proteins); and two relating to increased cell permeability (increased sensitivity to NaCl and increased permeability to o‐nitrophenyl‐β‐D‐galactopyranoside (ONPG). Partial loss of some cytoplasmic material from the damaged cells was observed. The dried cells also became sensitive to NaCl and permeable to ONPG. Heat shock increased the survival of exponential cells as compared to controls but did not result in normal levels found with unshocked stationary phase cells. Heat shock had no effect on stationary phase cells. Different rehydration methods and media were investigated: slow rehydration increased survival.
Detection of Salmonella typhi by polymerase chain reaction
Authors: Zhu Q. , Lim C.K. , Chan Y.N. 
Published: March 2008

A rapid and sensitive method for detection of Salmonella typhi would help in preventing the spread of outbreaks and in clinical diagnosis. In order to develop unique PCR primers to detect Salm. typhi, ribosomal RNA genes from Salm. typhi (Rawlings) were cloned in pUC18. The resulting clone was confirmed by sequencing. The cloned DNA fragment contained the 5S, part of the 23S rRNA genes and the 5S‐23S spacer region (EMBL/GenBank accession No. U04734).It was expected that the 5S‐23S spacer region is divergent unlike the highly conserved 23S+5S genes. This was confirmed by comparison with the rRNA gene sequences in the EMBL/GenBank database. A pair of PCR primers specific for Salm. typhi was obtained, based on this spacer region sequence. The specificity of this pair of primers was tested with 54 Salm. typhi strains (of 27 different phage types). All these Salm. typhi strains showed the positive 300 bp PCR product with this pair of primers. Six other Salmonella species as well as six other non‐Salmonella bacteria were tested and none showed the 300 bp PCR product. The sensitivity of the detection level was 0·1 pg of pure Salm. typhi genomic DNA, or approximately 40 Salm. typhi cells in a spiked food sample. This pair of primers therefore has the potential for development into a diagnostic tool for the rapid diagnosis of typhoid fever.
Heights of occupied patient beds: a possible risk factor for inpatient falls
Authors: Tzeng Huey‐Ming , Yin Chang‐Yi 
Published: March 2008

Aims.  The aim of this study was to ascertain the average height of occupied patient beds in a general medical ward and to investigate the relationship between staff working‐height for patient beds, time and whether the patient was on fall precaution.Background.  The height of occupied patient beds can be an overlooked contributor to inpatient falls. Better physical design of hospital equipment such as patient beds may reduce patient falls and injuries.Methods.  This study took place in an acute medical ward of a Michigan medical center. One researcher collected all the data and used the same metric for all the measurements. Univariate analyses were performed.Results.  The average staff working‐height measurement taken at the weekend was significantly higher than that taken on weekdays. The average height of patient beds on fall precaution was significantly higher than of those not on fall precaution.Conclusions.  A higher patient/nurse ratio at weekends than on weekdays may result in fewer bedside nursing hours and nurses being less conscientious about keeping beds in the low position after treatments. In an effort to prevent high‐fall‐risk patients from falling, nurses may have consciously or unconsciously kept their beds in higher positions.Relevance to clinical practice.  If the patient bed can be manually or automatically adjusted, nurses must lower the height of the bed to the lowest position after completing treatments or tasks. This after‐procedure activity should be enforced and monitored regularly as part of a hospital's patient fall prevention programme. Low beds should be used for patients at high risk of falling. Future research should investigate patients’ and staff's views on hospital equipment to provide evidence‐based information for policy‐makers determining the design‐regulation standard for hospital bedframes.
Genetic consequences of natal dispersal in the colonial lesser kestrel
Authors: ORTEGO JOAQUÍN , CALABUIG GUSTAU , APARICIO JOSÉ MIGUEL , CORDERO PEDRO J. 
Published: March 2008

AbstractDispersal is a life‐history trait that plays a fundamental role in population dynamics, influencing evolution, species distribution, and the genetics and structure of populations. In spite of the fact that dispersal has been hypothesized to be an efficient behavioural mechanism to avoid inbreeding, the expected relationship between dispersal and mate relatedness still remains controversial. Here, we examine the genetic consequences of natal dispersal, namely the higher chance of obtaining genetically less similar mates as a result of moving from natal to breeding sites, in a lesser kestrel (Falco naumanni) population. Relatedness between individuals tended to decrease with distance between their breeding colonies, indicating that the study population follows an ‘isolation‐by‐distance’ pattern of spatial genetic structure. Such a fine‐scale genetic structure generates a scenario in which individuals can potentially increase the chance of obtaining genetically less similar mates by dispersing over larger distances from their natal colony. Using dispersal information and genotypic data, we showed that mate relatedness decreased with natal dispersal distance, an effect that remained significant both while including and excluding philopatric individuals from the data set. These results, together with the well known detrimental consequences of reduced genetic diversity in the study population, suggest that dispersal may have evolved, at least in part, to avoid the negative fitness consequences of mating with genetically similar individuals.
Age at maturity in wild baboons: genetic, environmental and demographic influences
Authors: CHARPENTIER M. J. E. , TUNG J. , ALTMANN J. , ALBERTS S. C. 
Published: March 2008

AbstractThe timing of early life‐history events, such as sexual maturation and first reproduction, can greatly influence variation in individual fitness. In this study, we analysed possible sources of variation underlying different measures of age at social and physical maturation in wild baboons in the Amboseli basin, Kenya. The Amboseli baboons are a natural population primarily comprised of yellow baboons (Papio cynocephalus) that occasionally hybridize with anubis baboons (Papio anubis) from outside the basin. We found that males and females differed in the extent to which various factors influenced their maturation. Surprisingly, we found that male maturation was most strongly related to the proportion of anubis ancestry revealed by their microsatellite genotypes: hybrid males matured earlier than yellow males. In contrast, although hybrid females reached menarche slightly earlier than yellow females, maternal rank and the presence of maternal relatives had the largest effects on female maturation, followed by more modest effects of group size and rainfall. Our results indicate that a complex combination of demographic, genetic, environmental, and maternal effects contribute to variation in the timing of these life‐history milestones.
Prevalence of RNA polymerase stalling at Escherichia coli promoters after open complex formation
Authors: Hatoum Asma , Roberts Jeffrey 
Published: March 2008

SummaryRNA polymerase (RNAP) trapped in intermediate stages of promoter escape, as well as RNAP paused at promoter‐proximal σ70‐dependent pause sites, gives rise to stable, transcriptionally engaged stalled complexes that can limit promoter function and present potential sites for transcription regulation. To investigate the prevalence of such intermediates, we screened 118 Escherichia coli candidate promoters for RNAP stalling at or near the promoter, using in vivo KMnO4 mapping of RNAP on chromosomal DNA. Of 34 active promoters, the seven preceding lacZ, tnaA, cspA, cspD, rplK, rpsA and rpsU harboured stalled RNAP in vivo; this finding suggests that RNAP stalling after initiation is widespread in E. coli. Consistent with the characteristics of both abortive and promoter‐proximal σ70‐dependent paused complexes, RNAP trapping at most of the newly identified stall sites was eliminated by the rpoDL402Fσ70 mutational alteration and by site mutations, and was enhanced by GreA deficiency. In addition to promoter‐proximal RNAP trapping, we observed transcription‐dependent DNA modifications spanning the tnaA and cspA leader regions up to 100 bp downstream of the transcription start site.
MSP119 miniproteins can serve as targets for invasion inhibitory antibodies in Plasmodium falciparum provided they contain the correct domains for cell surface trafficking
Authors: Gilson Paul R. , O'Donnell Rebecca A. , Nebl Thomas , Sanders Paul R. , Wickham Mark E. , McElwain Terry F. , De Koning‐Ward Tania F. , Crabb Brendan S. 
Published: March 2008

SummaryAntibodies from malaria‐exposed individuals can agglutinate merozoites released from Plasmodium schizonts, thereby preventing them from invading new erythrocytes. Merozoite coat proteins attached to the plasma membrane are major targets for host antibodies and are therefore considered important malaria vaccine candidates. Prominent among these is the abundant glycosylphosphatidylinositol (GPI)‐anchored merozoite surface protein 1 (MSP1) and particularly its C‐terminal fragment (MSP119) comprised of two epidermal growth factor (EGF)‐like modules. In this paper, we revisit the role of agglutination and immunity using transgenic fluorescent marker proteins. We describe expression of heterologous MSP119‘miniproteins’ on the surface of Plasmodium falciparum merozoites. To correctly express these proteins, we determined that GPI‐anchoring and the presence of a signal sequence do not allow default export of proteins from the endoplasmic reticulum to merozoite surface and that extra sequence elements are required. The EGFs are insufficient for correct trafficking unless they are fused to additional residues that normally reside upstream of this fragment. Antibodies specifically targeting the surface‐expressed miniprotein can inhibit erythrocyte invasion in vitro despite the presence of endogenous MSP1. Using a line expressing a green fluorescent protein–MSP1 fusion protein, we demonstrate that one mode of inhibition by antibodies targeting the MSP119 domain is the rapid agglutinating of merozoites prior to erythrocyte attachment.
FliZ, a flagellar regulator, is at the crossroads between motility, haemolysin expression and virulence in the insect pathogenic bacterium Xenorhabdus
Authors: Lanois Anne , Jubelin Grégory , Givaudan Alain 
Published: March 2008

SummaryThere is a complex interplay between the regulation of flagellar motility and the expression of virulence factors in many bacterial pathogens. We investigated the role of FliZ in the regulation of flagellar and virulence genes in Xenorhabdus nematophila, an insect pathogen. The fliZ gene is the second gene in the fliAZ operon in X. nematophila. In vivo transcription analysis revealed a positive feedback loop of fliAZ transcription in which FliZ activates flhDC, the master operon of flagellar regulon in X. nematophila, leading to an increased transcription of the FlhDC‐dependent promoter of fliAZ. We also showed that fliAZ and flhDC mutants lacked motility, had no haemolysin or Tween lipase activity and displayed an attenuated virulence phenotype in insects. Lipase activity is controlled by FliA, whereas haemolysin production and full virulence phenotype have been reported to be FliZ‐dependent. Transcriptional analysis revealed that FliZ directly controlled expression of the xhlBA and xaxAB operons, which encode haemolysins from the two‐partner secretion system and the binary XaxAB toxin family respectively. We suggest that this regulatory pathway may also occur in other pathogenic enterobacteria with genes encoding members of these two growing families of haemolysins.
Three‐dimensional sequence analysis of a subsurface carbonate ramp, Mississippian Appalachian foreland basin, West Virginia, USA
Authors: WYNN THOMAS C. , READ JAMES F. 
Published: March 2008

AbstractWell‐cuttings, wireline logs and limited core and outcrop data were used to generate a regional, three‐dimensional sequence framework for Upper Mississippian (Chesterian), Greenbrier Group carbonates in the Appalachian foreland basin, West Virginia, USA. The resulting maps were used to document the stratigraphic response of the basin to tectonics and to glacio‐eustasy during the transition into ice‐house conditions. The ramp facies include inner ramp red beds and aeolianites, lagoonal muddy carbonates, mid‐ramp ooid and skeletal grainstone shoal complexes, and outer ramp wackestone–mudstone, that grades downslope into laminated silty lime mudstone. The facies make up fourth‐order sequences, a few metres to over 90 m (300 ft) thick. The sequences are bounded along the ramp margin by lowstand sandstones and calcareous siltstones. On the ramp, sequence boundaries are overlain by thin transgressive siliciclastics and aeolianites, and only a few are calichified. Maximum flooding surfaces on the outer ramp lie beneath deeper water facies that overlie lowstand to transgressive siliciclastic or carbonate units. On the shallow ramp, maximum flooding surfaces overlie siliciclastic‐prone transgressive systems tracts, that are overlain by highstand carbonates with significant grainstone units interlayered with lagoonal lime mudstones. The fourth‐order sequences are the major mappable subsurface units; they are bundled into weak composite sequences which are bounded by red beds. In spite of differential subsidence rates across the foreland basin (1 to 3 cm/k.y. up to 25 cm/k.y.), eustatic sea‐level changes controlled regional sequence development. Thrust‐load induced differential subsidence of fault‐blocks, coupled with in‐plane stress, controlled the rapid basinward thickening of the depositional wedge, whose thickness and facies were influenced by subtle structures such as arches trending at high angles as well as parallel to the margin.
Carbonate aeolianites of western Saurashtra, India: experimental decipherment of the depositional mechanisms
Authors: DASGUPTA PRABIR , BANDYOPADHYAY SUBIKASH 
Published: March 2008

AbstractGranular carbonate deposits of Late Pleistocene to Early Holocene age, commonly referred to as ‘miliolite limestone’, occur in a linear belt, parallel to the southern coast of Saurashtra, India. In the present study area these carbonate deposits are found in select valleys between ridges and mounds of pyroclastic material present in the Deccan trap plateau. Two different depositional histories have been proposed for these sediments. The presence of marine bioclasts led to the postulation of a marine origin for these deposits. The second school of thought propounded redeposition of the coastal sediments by aeolian processes. Although a few features could not be explained by the proposed aeolian model, critical comparison of these two views favoured the aeolian origin. The mode of occurrence, lithological and structural attributes, and microscopic evidence presented here, also support a possible aeolian origin for these deposits. Experimental observation indicates that these carbonate aeolianites represent backflow deposits, which accumulated because of the flow separation caused by the presence of topographic highs. The conspicuous concave‐up geometry of the deposit conformed to the shape of the separation bulb. In view of the inferred depositional mechanism, the disposition of the deposits and the signature of the palaeoflow direction suggest that the carbonate particles were derived from the north‐western coast of Saurashtra by strong south‐easterly winds. Massive granular carbonates with outsized basement clasts appear to be the product of avalanching of granular material from the higher contours because of oversteepening of the primary deposit.