Number Of Different Strains Research Articles

NEWCASTLE DISEASE IS A PARTICULARLY DANGEROUS PSEUDOCUMA OF BIRDS

Newcastle disease is a serious infectious disease affecting the internal organs, nervous and respiratory systems. It is caused by paramyxovirus PMV-1 and has a large number of different strains that can cause various forms of the disease. These forms can sometimes "masquerade" as other diseases such as cholera, bronchitis, avian flu or laryngotracheitis. Newcastle disease can only be detected by an accurate diagnosis. Poultry of all ages and breeds are susceptible to the disease, but most often Newcastle disease is diagnosed in domestic chickens. Outbreaks of Newcastle disease are reported worldwide and can cause problems for large poultry farms. Although Newcastle disease does not directly affect humans, a flu-like condition can develop after contact with an infected person. Characteristic signs of Newcastle disease in birds include encephalitis, pneumonia and hemorrhage into internal organs due to their damage.The last outbreak of Newcastle disease in birds in the Republic of Kazakhstan was detected in the village of Akhmet in the Nurinsky district of the Karaganda region on October 4, 2023. On October 6, the Karaganda Regional Territorial Inspection of the Veterinary Control and Supervision Committee of the Ministry of Agriculture declared quarantine in rural areas.The study conducted in the Karaganda region of the Republic of Kazakhstan was aimed at studying the outbreak of Newcastle disease in poultry in the village of Akhmet in the Nurinsky district. During the study, veterinary and sanitary measures were carried out, including sampling for laboratory diagnostics, vaccination of livestock and the introduction of quarantine restrictions. The results of the study showed the high effectiveness of the measures taken to localize and eliminate the source of infection. The virus has been identified, which underlines the need for constant monitoring of the epizootic situation. The data obtained make it possible to recommend the expansion of vaccination programs and the strengthening of veterinary control at poultry farms to prevent the further spread of Newcastle disease.Despite the fact that Newcastle disease has been known to veterinarians for several years, no treatment method has yet been developed. However, the control of Newcastle disease in poultry can be achieved through isolation and quarantine of infected animals, vaccination programs, biosafety measures at livestock facilities, monitoring of animal movements and surveillance

Gambling, social integration and sources of strain in cases of suicide: exploring police investigation reports

In this qualitative sociological study we explore the significance of social integration and social strain in gambling suicides. There is evidence that gambling and suicidality are associated. Mental distress is common among people experiencing gambling harm. Indebtedness and financial losses are also associated with suicidality among people experiencing gambling harm. The significance of social factors and social context on gambling suicides is understudied. Social integration theory proposes that social ties, such as marriage, can protect people from suicide. Strain theory explains suicide by social factors causing strain. Our research question is: How are social integration and different sources of strain related to cases of gambling suicides? The data consists of police investigation reports of 21 suicide cases. The data was analyzed with thematic content analysis. The results show variation in the social integration and strain the deceased experienced before their deaths. None of the deceased were without social ties. The entanglement of different sources of strain was manifest. The results suggest that a typology consisting of four categories of suicide contexts can be distinguished by the respective strength of integration and the number of different strains. We conclude that gambling policy with a focus on harm prevention is also a matter of suicide prevention.

The Global dynamics of a SIR model considering competitions among multiple strains in patchy environments

<abstract><p>Pandemics, such as Covid-19 and AIDS, tend to be highly contagious and have the characteristics of global spread and existence of multiple virus strains. To analyze the competition among different strains, a high dimensional SIR model studying multiple strains' competition in patchy environments is introduced in this work. By introducing the basic reproductive number of different strains, we found global stability conditions of disease-free equilibrium and persistence conditions of the model. The competition exclusion conditions of that model are also given. This work gives some insights into the properties of the multiple strain patchy model and all of the analysis methods used in this work could be used in other related high dimension systems.</p></abstract>

Effectiveness of Multistrain Versus Single-strain Probiotics: Current Status and Recommendations for the Future.

Probiotics are investigated as single-strain and multistrain products. In the market, however, there is an increasing tendency to work with multistrain probiotics, in particular, products with a high number of different strains. There are some thoughts behind this: more strains imply more chances of success; it can mean a broader spectrum of efficacy, and there is often the hope that there are at least additive and, potentially, even synergistic effects. The present review did not find convincing evidence that these assumptions are valid. There is, however, also no strong evidence that the assumptions are incorrect and/or that there is antagonistic activity between strains in a combination. We suggest that, to answer these questions, structured research is conducted. Starting with a systematic review of meta-analyses that have compared single-strain and multistrain probiotic efficacy, dedicated human studies need to be performed, comparing single-strain and multistrain probiotics to each other and placebo. In vitro and animal studies can provide indications and may help understand mechanisms. For human, animal, and in vitro studies, it is recommended to work with the simple setup of 2 single strains, a 2-strain combination, and placebo. It is also important in such research to take into consideration the doses, as a combination product will have a higher total dose.

Saccharomyces cerevisiae populations and other yeasts associated with indigenous beers (chicha) of Ecuador

Chicha, a type of beer made mainly with maize or cassava, is a traditional fermented beverage of the Andean region. There have only been a few studies on yeasts associated with chicha fermentation, and the species diversity occurring during the production of this beverage is not known. The objective of this study was to determine the biodiversity of yeasts in chicha, and to characterize the Saccharomyces cerevisiae populations associated with the production of chicha de jora, seven-grain chicha, chicha de yuca, and chicha de morocho in Ecuador. The molecular diversity of S. cerevisiae populations was determined by restriction polymorphism mitochondrial profiles. The beverages were characterized based on their physicochemical parameters. Twenty-six species were identified, and the most prevalent species were S. cerevisiae and Torulaspora delbrueckii. Other yeast species were isolated at low frequencies. Among 121 isolates of S. cerevisiae, 68 different mtDNA molecular profiles were identified. These results showed that chichas are fermented by a high number of different strains of S. cerevisiae. Some other species provided a minor contribution to the fermentation process. The chicha presented generally similar physicochemical parameters to those observed for other traditional fermented beverages, and can be considered as an acid fermented beverage.

PHENOS: a high-throughput and flexible tool for microorganism growth phenotyping on solid media

BackgroundMicrobial arrays, with a large number of different strains on a single plate printed with robotic precision, underpin an increasing number of genetic and genomic approaches. These include Synthetic Genetic Array analysis, high-throughput Quantitative Trait Loci (QTL) analysis and 2-hybrid techniques. Measuring the growth of individual colonies within these arrays is an essential part of many of these techniques but is useful for any work with arrays. Measurement is typically done using intermittent imagery fed into complex image analysis software, which is not especially accurate and is challenging to use effectively. We have developed a simple and fast alternative technique that uses a pinning robot and a commonplace microplate reader to continuously measure the thickness of colonies growing on solid agar, complemented by a technique for normalizing the amount of cells initially printed to each spot of the array in the first place. We have developed software to automate the process of combining multiple sets of readings, subtracting agar absorbance, and visualizing colony thickness changes in a number of informative ways.ResultsThe “PHENOS” pipeline (PHENotyping On Solid media), optimized for Saccharomyces yeasts, produces highly reproducible growth curves and is particularly sensitive to low-level growth. We have empirically determined a formula to estimate colony cell count from an absorbance measurement, and shown this to be comparable with estimates from measurements in liquid. We have also validated the technique by reproducing the results of an earlier QTL study done with conventional liquid phenotyping, and found PHENOS to be considerably more sensitive.Conclusions“PHENOS” is a cost effective and reliable high-throughput technique for quantifying growth of yeast arrays, and is likely to be equally very useful for a range of other types of microbial arrays. A detailed guide to the pipeline and software is provided with the installation files at https://github.com/gact/phenos.

Proteogenomic Investigation of Strain Variation in Clinical Mycobacterium tuberculosis Isolates.

Mycobacterium tuberculosis consists of a large number of different strains that display unique virulence characteristics. Whole-genome sequencing has revealed substantial genetic diversity among clinical M. tuberculosis isolates, and elucidating the phenotypic variation encoded by this genetic diversity will be of the utmost importance to fully understand M. tuberculosis biology and pathogenicity. In this study, we integrated whole-genome sequencing and mass spectrometry (GeLC-MS/MS) to reveal strain-specific characteristics in the proteomes of two clinical M. tuberculosis Latin American-Mediterranean isolates. Using this approach, we identified 59 peptides containing single amino acid variants, which covered ∼9% of all coding nonsynonymous single nucleotide variants detected by whole-genome sequencing. Furthermore, we identified 29 distinct peptides that mapped to a hypothetical protein not present in the M. tuberculosis H37Rv reference proteome. Here, we provide evidence for the expression of this protein in the clinical M. tuberculosis SAWC3651 isolate. The strain-specific databases enabled confirmation of genomic differences (i.e., large genomic regions of difference and nonsynonymous single nucleotide variants) in these two clinical M. tuberculosis isolates and allowed strain differentiation at the proteome level. Our results contribute to the growing field of clinical microbial proteogenomics and can improve our understanding of phenotypic variation in clinical M. tuberculosis isolates.

Impact of diversity of Mycoplasma hyopneumoniae strains on lung lesions in slaughter pigs

The importance of diversity of Mycoplasma hyopneumoniae (M. hyopneumoniae) strains is not yet fully known. This study investigated the genetic diversity of M. hyopneumoniae strains in ten pig herds, and assessed associations between the presence of different strains of M. hyopneumoniae and lung lesions at slaughter. Within each herd, three batches of slaughter pigs were investigated. At slaughter, from each batch, 20 post mortem bronchoalveolar lavage fluid samples were collected for multiple locus variable-number tandem repeat analysis (MLVA), and lung lesions (Mycoplasma-like lesions, fissures) were examined. Multivariable analyses including potential risk factors for respiratory disease were performed to assess associations between the number of different strains per batch (three categories: one strain, two–six strains, ≥seven strains), and the lung lesions as outcome variables. In total, 135 different M. hyopneumoniae strains were found. The mean (min.–max.) number of different strains per batch were 7 (1–13). Batches with two–six strains or more than six strains had more severe Mycoplasma-like lesions (P = 0.064 and P = 0.012, respectively), a higher prevalence of pneumonia [odds ratio (OR): 1.30, P = 0.33 and OR: 2.08, P = 0.012, respectively], and fissures (OR = 1.35, P = 0.094 and OR = 1.70, P = 0.007, respectively) compared to batches with only one strain. In conclusion, many different M. hyopneumoniae strains were found, and batches of slaughter pigs with different M. hyopneumoniae strains had a higher prevalence and severity of Mycoplasma-like lung lesions at slaughter, implying that reducing the number of different strains may lead to less lung lesions at slaughter and better respiratory health of the pigs.

Genotype variation and genetic relationship among Escherichia coli from nursery pigs located in different pens in the same farm

BackgroundSo far, little is known about the genetic diversity and relatedness among Escherichia coli (E. coli) populations in the gut of swine. Information on this is required to improve modeling studies on antimicrobial resistance aiming to fight its occurrence and development. This work evaluated the genotype variation of E. coli isolated from swine fecal samples at the single pig and pen level, as well as between pens using repetitive extragenic palindromic (REP) PCR fingerprinting and pulsed field gel electrophoresis (PFGE). The genetic diversity of strains collected from media supplemented with ampicillin or tetracycline was also investigated. Besides, the genetic relationship of strains within each pen, between pens, as well as among strains within each group isolated from media with or without antibiotic, was assessed.ResultsREP-PCR patterns (N = 75) were generated for all the isolates (N = 720). Two profiles (REP_2 and REP_5) dominated, accounting for 23.7 and 23.3% of all isolates, respectively. At the pig and at the pen level, the number of different strains ranged from two to eight, and from 27 to 31, respectively, and multiple isolates from a single pen were found to be identical; however, in some of the pens, additional strains occurred at a lower frequency. E. coli isolates yielding different REP profiles were subjected to PFGE and led to 41 different genotypes which were also compared.ConclusionsDespite the presence of dominant strains, our results suggest a high genetic diversity of E. coli strains exist at the pen level and between pens. Selection with antibiotic seems to not affect the genetic diversity. The dominant REP profiles were the same found in a previous study in Denmark, which highlights that the same predominant strains are circulating in pigs of this country and might represent the archetypal E.coli commensal in pigs.

New genre of antioxidants from renewable natural resources: Synthesis and characterisation of rosemary plant-derived antioxidants and their performance in polyolefins

Several ester derivatives of rosmarinic acid (rosmarinates) were synthesised, characterised (1D and 2D NMR, UV and FTIR spectroscopy) and tested for their potential use as antioxidants derived from a renewable natural resource. The intrinsic free radical scavenging activity of the rosmarinates was assessed, initially using a modified DPPH (2, 2-diphenyl-1-picrylhydrazyl radical) method, and found to be higher than that of commercial synthetic hindered phenol antioxidants Irganox 1076 and Irganox 1010. The thermal stabilising performance of the rosmarinates in polyethylene (PE) and polypropylene (PP) was subsequently examined and compared to that of samples prepared similarly but in the presence of Irganox 1076 (in PE) and Irganox 1010 (in PP) which are typically used for polyolefin stabilisation in industrial practice. The melt stability and the long-term thermo-oxidative stability (LTTS) of processed polymers containing the antioxidants were assessed by measuring the melt flow index (MFI), melt viscosity, oxidation induction time (OIT) and long-term (accelerated) thermal ageing performance. The results show that both the melt and the thermo-oxidative stabilisation afforded by the rosmarinates, and in particular the stearyl derivative, in both PE and PP, are superior to those of Irganox 1076 and Irganox 1010, hence their potential as effective sustainable bio-based antioxidants for polymers.The rosmarinic acid used for the synthesis of the rosmarinates esters in this study was obtained from commercial rosemary extracts (AquaROX80). Furthermore, a large number of different strains of UK-grown rosemary plants (Rosmarinum officinalis) were also extracted and analysed in order to examine their antioxidant content. It was found that the carnosic and the rosmarinic acids, and to a much lesser extent the carnosol, constituted the main antioxidant components of the UK-plants, with the two acids being present at a ratio of 3:1, respectively.

Taking Advantage of Natural Biodiversity for Wine Making: The WILDWINE Project

Abstract Fermentation processes have proceeded without microbiological control until starter cultures came up in 19th Century. However, in some processes, such as wine making a widespread use of starter cultures did not come up until the end of the 20th Century, when the cellar-friendly active dry wine yeast (ADWY) were available. However, this practice was challenged for the uniformity that brought a limited number of commercially available presentations and new tendencies in wine making have withdrawn the use of ADWY. The return to non-controlled wine fermentations may have considerable set backs especially in terms of economical losses, as these wines have much higher risks of presenting different levels of spoilage (presence of unwanted compounds that will be organoleptically detectable) that will not be acceptable for the consumer. The WILDWINE Project (EU contract 315065) proposed a system to overcome the criticism on the uniformity after use of ADWY by bringing “wild” microorganisms to the starter culture practice. The Project proposed mixed cultures as an alternative to single strain cultures that is the usual practice for starter cultures. This multi-strain and multi-species starter cultures aimed at reproducing the vineyard natural microbiota with the advantage of a selection of those strains and species that could add complexity to the final wines. The WILDWINE Project has focused the selection of this “wild” microorganism in 5 worldwide-recognised wine regions: Nemea and Crete (Greece), Piedmont (Italy), Bordeaux (France) and Priorat (Spain). The basic protocol was the same for all the regions: (i) to establish the natural biodiversity of the regions and determine the “microbial fingerprint” of the region, (ii) oenological screening of all the strains and species isolates to determine their quality for the wine making process and (iii) to use the microbial cocktails at pilot plants and in commercial cellars to determine the “microbial footprint” that the “wild” microorganisms leave on the final wines. In the Priorat region, a limited number of different strains from Saccharomyces cerevisiae were detected after sampling cellars and vineyards in two different harvests (2012 and 2013). These low number of S. cerevisiae strains is in sharp contrast with the high biodiversity observed in the same area 18 years before when a selection of strains of this species was preformed to provide a commercial “autochthonous” strain for the Priorat region. Furthermore, the main species found in the vineyards were the yeast-like fungus Aerobasidium pullulans and Hanseniaspora uvarum. A. pullulans disappeared when grapes were turned into must and then H. uvarum and Candida zemplinina were the main species. Minority species found in musts and later in wines were Metschnokowia pulcherrima and Torulaspora delbrueckii.

Accurate reconstruction of viral quasispecies spectra through improved estimation of strain richness.

BackgroundEstimating the number of different species (richness) in a mixed microbial population has been a main focus in metagenomic research. Existing methods of species richness estimation ride on the assumption that the reads in each assembled contig correspond to only one of the microbial genomes in the population. This assumption and the underlying probabilistic formulations of existing methods are not useful for quasispecies populations where the strains are highly genetically related.The lack of knowledge on the number of different strains in a quasispecies population is observed to hinder the precision of existing Viral Quasispecies Spectrum Reconstruction (QSR) methods due to the uncontrolled reconstruction of a large number of in silico false positives. In this work, we formulated a novel probabilistic method for strain richness estimation specifically targeting viral quasispecies. By using this approach we improved our recently proposed spectrum reconstruction pipeline ViQuaS to achieve higher levels of precision in reconstructed quasispecies spectra without compromising the recall rates. We also discuss how one other existing popular QSR method named ShoRAH can be improved using this new approach.ResultsOn benchmark data sets, our estimation method provided accurate richness estimates (< 0.2 median estimation error) and improved the precision of ViQuaS by 2%-13% and F-score by 1%-9% without compromising the recall rates. We also demonstrate that our estimation method can be used to improve the precision and F-score of ShoRAH by 0%-7% and 0%-5% respectively.ConclusionsThe proposed probabilistic estimation method can be used to estimate the richness of viral populations with a quasispecies behavior and to improve the accuracy of the quasispecies spectra reconstructed by the existing methods ViQuaS and ShoRAH in the presence of a moderate level of technical sequencing errors.Availabilityhttp://sourceforge.net/projects/viquas/

Respiratory tract lung geometry and dosimetry model for male Sprague-Dawley rats

While inhalation toxicological studies of various compounds have been conducted using a number of different strains of rats, mechanistic dosimetry models have only had tracheobronchial (TB) structural data for Long-Evans rats, detailed morphometric data on the alveolar region of Sprague-Dawley rats and limited alveolar data on other strains. Based upon CT imaging data for two male Sprague-Dawley rats, a 15-generation, symmetric typical path model was developed for the TB region. Literature data for the alveolar region of Sprague-Dawley rats were analyzed to develop an eight-generation model, and the two regions were joined to provide a complete lower respiratory tract model for Sprague-Dawley rats. The resulting lung model was used to examine particle deposition in Sprague-Dawley rats and to compare these results with predicted deposition in Long-Evans rats. Relationships of various physiologic variables and lung volumes were either developed in this study or extracted from the literature to provide the necessary input data for examining particle deposition. While the lengths, diameters and branching angles of the TB airways differed between the two Sprague-Dawley rats, the predicted deposition patterns in the three major respiratory tract regions were very similar. Between Sprague-Dawley and Long-Evans rats, significant differences in TB and alveolar predicted deposition fractions were observed over a wide range of particle sizes, with TB deposition fractions being up to 3- to 4-fold greater in Sprague-Dawley rats and alveolar deposition being significantly greater in Long-Evans rats. Thus, strain-specific lung geometry models should be used for particle deposition calculations and interspecies dose comparisons.

Classical swine fever in pigs: recent developments and future perspectives.

Classical swine fever (CSF) is one of the most devastating epizootic diseases of pigs, causing high morbidity and mortality worldwide. The diversity of clinical signs and similarity in disease manifestations to other diseases make CSF difficult to diagnose with certainty. The disease is further complicated by the presence of a number of different strains belonging to three phylogenetic groups. Advanced diagnostic techniques allow detection of antigens or antibodies in clinical samples, leading to implementation of proper and effective control programs. Polymerase chain reaction (PCR)-based methods, including portable real-time PCR, provide diagnosis in a few hours with precision and accuracy, even at the point of care. The disease is controlled by following a stamping out policy in countries where vaccination is not practiced, whereas immunization with live attenuated vaccines containing the 'C' strain is effectively used to control the disease in endemic countries. To overcome the problem of differentiation of infected from vaccinated animals, different types of marker vaccines, with variable degrees of efficacy, along with companion diagnostic assays have been developed and may be useful in controlling and even eradicating the disease in the foreseeable future. The present review aims to provide an overview and status of CSF as a whole with special reference to swine husbandry in India.

Computational Models for Prediction of Yeast Strain Potential for Winemaking from Phenotypic Profiles

Saccharomyces cerevisiae strains from diverse natural habitats harbour a vast amount of phenotypic diversity, driven by interactions between yeast and the respective environment. In grape juice fermentations, strains are exposed to a wide array of biotic and abiotic stressors, which may lead to strain selection and generate naturally arising strain diversity. Certain phenotypes are of particular interest for the winemaking industry and could be identified by screening of large number of different strains. The objective of the present work was to use data mining approaches to identify those phenotypic tests that are most useful to predict a strain's potential for winemaking. We have constituted a S. cerevisiae collection comprising 172 strains of worldwide geographical origins or technological applications. Their phenotype was screened by considering 30 physiological traits that are important from an oenological point of view. Growth in the presence of potassium bisulphite, growth at 40°C, and resistance to ethanol were mostly contributing to strain variability, as shown by the principal component analysis. In the hierarchical clustering of phenotypic profiles the strains isolated from the same wines and vineyards were scattered throughout all clusters, whereas commercial winemaking strains tended to co-cluster. Mann-Whitney test revealed significant associations between phenotypic results and strain's technological application or origin. Naïve Bayesian classifier identified 3 of the 30 phenotypic tests of growth in iprodion (0.05 mg/mL), cycloheximide (0.1 µg/mL) and potassium bisulphite (150 mg/mL) that provided most information for the assignment of a strain to the group of commercial strains. The probability of a strain to be assigned to this group was 27% using the entire phenotypic profile and increased to 95%, when only results from the three tests were considered. Results show the usefulness of computational approaches to simplify strain selection procedures.

Analysis of the Streptococcus agalactiae exoproteome

The two-component regulatory system CovRS is the main regulator of virulence gene expression in Group B Streptococcus (GBS), the leading cause of invasive infections in neonates. In this study we analyzed by mass spectrometry the GBS extracellular protein complex (i.e. the exoproteome) of NEM316 wild-type (WT) strain and its isogenic covRS deletion mutant (ΔcovRS). A total of 53 proteins, 49 of which had classical secretion signals, were identified: 12 were released by both strains while 21 and 20 were released exclusively by WT and ΔcovRS strains, respectively. In addition to known surface proteins, we detected here unstudied cell-wall associated proteins and/or orthologs of putative virulence factors present in other pathogenic streptococci. While the functional role of these proteins remains to be elucidated, our data suggest that the analysis of the exoproteome of bacterial pathogens under different gene expression conditions may be a powerful tool for the rapid identification of novel virulence factors and vaccine candidates. We believe that this manuscript will be of interest to Journal of Proteomics readers since the paper describes the identification of several putative virulence factors and vaccine candidates of the group B streptococcus, an important pathogen, using a simple proteomics strategy involving LC-MS analysis of culture supernatants obtained from two strains with divergent gene expression patterns. This technique provided the most comprehensive inventory of extracellular proteins obtained from a single streptococcal species thus far. The approach described has the added benefit of being easily applicable to a large number of different strains, making it ideal for the identification of conserved vaccine candidates.

Fillet Yields from Four Strains of Nile Tilapia (Oreochromis niloticus) and a Red Variety

Tilapia (Oreochromis, spp.) have been introduced globally and domesticated, resulting in a number of different strains. This diversity offers the potential for difference in body morphology and, in turn, fillet yields. A trial was conducted at Auburn University, Auburn, Alabama, to compare processing characteristics of four populations of Oreochromis niloticus using two domesticated strains (Egypt and Ivory Coast), two less domesticated strains (Sagana and Lake Victoria), and a red variety (Santa Fe). Male tilapia (N = 25/strain) were manually processed and the dress-out percentage and visceral fat calculated. Mean individual weights of pre-processed fish were similar (range = 403.8 ± 27.6 g to 413.8 ± 24.5 g) with the exception of the larger Sagana strain (434.2 ± 15.4 g). The Ivory Coast strain had the highest percent dress out (33.1% ± 2.1%), while the Sagana strain had the lowest (29.6% ± 1.5%). The Red strain had the greatest percent visceral fat (2.3% ± 1.0%) and the Sagana had the lowest (0.2% ± 0.4%).

Cochrane Review: Probiotics for treating acute infectious diarrhoea

AbstractBackgroundProbiotics may offer a safe intervention in acute infectious diarrhoea to reduce the duration and severity of the illness.ObjectivesTo assess the effects of probiotics in proven or presumed acute infectious diarrhoea.Search strategyWe searched the Cochrane Infectious Diseases Group's trials register (July 2010), the Cochrane Controlled Trials Register (The Cochrane Library Issue 2, 2010), MEDLINE (1966 to July 2010), EMBASE (1988 to July 2010), and reference lists from studies and reviews. We also contacted organizations and individuals working in the field, and pharmaceutical companies manufacturing probiotic agents.Selection criteriaRandomized and quasi‐randomized controlled trials comparing a specified probiotic agent with a placebo or no probiotic in people with acute diarrhoea that is proven or presumed to be caused by an infectious agent.Data collection and analysisTwo reviewers independently assessed the methodological quality of the trial and extracted data. Primary outcomes were the mean duration of diarrhoea, stool frequency on day 2 after intervention and ongoing diarrhoea on day 4. A random‐effects model was used.Main resultsSixty‐three studies met the inclusion criteria with a total of 8014 participants. Of these, 56 trials recruited infants and young children. The trials varied in the definition used for acute diarrhoea and the end of the diarrhoeal illness, as well as in the risk of bias. The trials were undertaken in a wide range of different settings and also varied greatly in organisms tested, dosage, and participants' characteristics. No adverse events were attributed to the probiotic intervention.Probiotics reduced the duration of diarrhoea, although the size of the effect varied considerably between studies.The average of the effect was significant for mean duration of diarrhoea (mean difference 24.76 hours; 95% confidence interval 15.9 to 33.6 hours; n=4555, trials=35) diarrhoea lasting ≥4 days (risk ratio 0.41; 0.32 to 0.53; n=2853, trials=29) and stool frequency on day 2 (mean difference 0.80; 0.45 to 1.14; n=2751, trials=20).The differences in effect size between studies was not explained by study quality, probiotic strain, the number of different strains, the viability of the organisms, dosage of organisms, the causes of diarrhoea, or the severity of the diarrhoea, or whether the studies were done in developed or developing countries.Authors' conclusionsUsed alongside rehydration therapy, probiotics appear to be safe and have clear beneficial effects in shortening the duration and reducing stool frequency in acute infectious diarrhoea. However, more research is needed to guide the use of particular probiotic regimens in specific patient groups.Plain Language SummaryProbiotics for treating acute infectious diarrhoeaEpisodes of acute infectious diarrhoea remain a major disease burden throughout the world, especially in developing countries. They are due to infection by many different organisms. Most episodes are self‐limiting and usually investigations are not done to identify the infectious agent. The main risk to health is dehydration and management aims to improve and maintain hydration status. However, rehydration fluids do not reduce the stool volume or shorten the episode of diarrhoea. Probiotics are "friendly" bacteria that improve health and are not harmful in themselves. A number of randomized controlled trials have been done to see whether probiotics are beneficial in acute infectious diarrhoea. We have searched for as many of these trials as possible and collected together the data in a systematic way to try to discover whether or not probiotics are beneficial in acute diarrhoea. We identified 63 trials, which included a total of 8014 people ‐ mainly infants and children. Probiotics were not associated with any adverse effects. Nearly all studies reported a shortened duration of diarrhoea and reduced stool frequency in people who received probiotics compared to the controls. Overall, probiotics reduced the duration of diarrhoea by around 25 hours, the risk of diarrhoea lasting four or more days by 59% and resulted in about one fewer diarrhoeal stool on day 2 after the intervention. However, there was very marked variability in the study findings and so these estimates are approximate. We concluded that these results were very encouraging but more research is needed to identify exactly which probiotics should be used for which groups of people, and also to assess the cost effectiveness of this treatment.

A Multidisciplinary Approach to the Microbial Species Concept: The Role of Bioinformatics in the Search of Detectable Discontinuities

The problem of species and in particular microbial species is central in biology. An active collaboration of various specialists such as taxonomists, epistemologists, mathematicians and bioinformatics experts is desirable for its solution. This article intended to show the possibilities and perspectives of bioinformatics research in understanding the ontological problem of species, i.e. the problem of the existence of the microbial species. The approach undertaken of this paper is based on the concept that if microbial species exist, then there should be detectable discontinuities or disconnections between microorganisms assigned to different species. A yeast model has been used to show how the distances from a reference organism raise with the increase of the number of different strains included in the study.

Effects of grape marcs acidification treatment on the evolution of indigenous yeast populations during the production of grappa

Grappa is a typical Italian product obtained from the distillation of grape marcs, the main by-product of grape crushing. One technological treatment frequently performed on marcs is their acidification, in order to contrast the development of unwanted spoilage bacteria during the storage period needed for alcoholic fermentation. A pilot-scale experiment was set-up to study the dynamics of yeast populations during a 30-day fermentation of acidified and nonacidified Prosecco grape pomace. Saccharomyces cerevisiae population, examined after 4 and 15 days of storage by mitochondrial DNA-RFLP analysis, resulted considerably different at strain level upon acidification. In particular, although the number of different strains rescued appeared particularly high in both kind of marcs compared with what happens in must fermentation, in the acidified material such number tends to moderately decrease during storage. Results obtained evidence that the acidification treatment did not influence yeast population neither in terms of number of cells nor in terms of biodiversity at species level. Therefore, such treatment can be used in distillery without negatively influencing ethanol production. Even though some data are available on the effects of technological treatments on the chemical composition of the distillate, no microbiological studies have been published so far on the consequence of these practices on composition, biodiversity and evolution of yeast population.