Efficacy Assessment of the Co-Administration of Vancomycin and Metronidazole in Clostridioides difficile-Infected Mice Based on Changes in Intestinal Ecology.

Vancomycin (VAN) and metronidazole (MTR) remain the current drugs of choice for the treatment of non-severe Clostridioides difficile infection (CDI); however, while their co-administration has appeared in clinical treatment, the efficacy varies greatly and the mechanism is unknown. In this study, a CDI mouse model was constructed to evaluate the therapeutic effects of VAN and MTR alone or in combination. For a perspective on the intestinal ecology, 16S rRNA amplicon sequencing and non-targeted metabolomics techniques were used to investigate changes in the fecal microbiota and metabolome of mice under the co-administration treatment. As a result, the survival rate of mice under co-administration was not dramatically different compared to that of single antibiotics, and the former caused intestinal tissue hyperplasia and edema. Co-administration also significantly enhanced the activity of amino acid metabolic pathways represented by phenylalanine, arginine, proline, and histidine, decreased the level of deoxycholic acid (DCA), and downregulated the abundance of beneficial microbes, such as Bifidobacterium and Akkermansia. VAN plays a dominant role in microbiota regulation in co-administration. In addition, co-administration reduced or increased the relative abundance of antibiotic-sensitive bacteria, including beneficial and harmful microbes, without a difference. Taken together, there are some risks associated with the co-administration of VAN and MTR, and this combination mode should be used with caution in CDI treatment.

Critical Assessment of MetaProteome Investigation (CAMPI): a multi-laboratory comparison of established workflows.

Metaproteomics has matured into a powerful tool to assess functional interactions in microbial communities. While many metaproteomic workflows are available, the impact of method choice on results remains unclear. Here, we carry out a community-driven, multi-laboratory comparison in metaproteomics: the critical assessment of metaproteome investigation study (CAMPI). Based on well-established workflows, we evaluate the effect of sample preparation, mass spectrometry, and bioinformatic analysis using two samples: a simplified, laboratory-assembled human intestinal model and a human fecal sample. We observe that variability at the peptide level is predominantly due to sample processing workflows, with a smaller contribution of bioinformatic pipelines. These peptide-level differences largely disappear at the protein group level. While differences are observed for predicted community composition, similar functional profiles are obtained across workflows. CAMPI demonstrates the robustness of present-day metaproteomics research, serves as a template for multi-laboratory studies in metaproteomics, and provides publicly available data sets for benchmarking future developments.

Deciphering the Probiotic Potential of Bacillus amyloliquefaciens COFCAU_P1 Isolated from the Intestine of Labeo rohita Through In Vitro and Genetic Assessment.

In this study, a bacterial strain COFCAU_P1, isolated from the digestive tract of a freshwater teleost rohu (Labeo rohita), was identified as Bacillus amyloliquefaciens using 16S rRNA gene sequence analysis combined with amplification of species-specific BamHI and barnase genes. The probiotic potential of the strain was evaluated using an array of in vitro tests along with safety and genetic analyses. The isolate showed potent antimicrobial response against several fish pathogenic bacteria, survived a wide pH range (2-9), and was resistant up to 10% bile salt concentration. With regard to the in vitro adhesion properties, the strain showed significantly high in vitro adhesion to mucus, auto and co-aggregation capacity, and cell surface hydrophobicity. The strain was non-haemolytic, able to produce extracellular enzymes, viz., proteinase, amylase, lipase, and cellulase, and showed significant free radical scavenging activity. A challenge study in rohu revealed the strain COFCAU_P1 as non-pathogenic. The presence of putative probiotic marker genes including 2, 3-bisphosphoglycerate-independent phosphoglycerate mutase, arginine/ornithine antiporter ArcD, choloylglycine hydrolase, LuxS, and E1 ß-subunit of the pyruvate dehydrogenase complex was confirmed by PCR, suggesting the molecular basis of the probiotic-specific functional attributes of the isolate. In conclusion, the in vitro and genetic approaches enabled the identification of a potential probiotic from autochthonous source with a potential of its utilization in the aquaculture industry.

In vivo assessment and characterization of lactic acid bacteria with probiotic profile isolated from human milk powder.

INTRODUCTION: Introduction: breast milk (MH) contains nutrients and bioactive compounds for child development, including probiotic bacteria, which contribute to intestinal maturation. This benefit accompanies the individual until adulthood. There are new methods such as spray drying that give this compound a good conservation without loss of microbiota. Objective: the aim of this study was to analyze the viability of lactic acid bacteria isolated from human milk with probiotic potential after the spray drying process, as well as to evaluate the possible adhesion in the colon of mice of the Balb/C strain after feeding them powdered human milk and a commercial formula milk. Method: we isolated and identified the presence of lactic acid bacteria with possible probiotic potential in powdered human milk using the MALDI-TOF MS technique. Powdered human milk and a commercial formula milk were fed to mice of the Bald/C strain for 14 weeks. Glucose level and weight were measured in the mice. The feces were collected to verify the presence of lactic bacteria. The mice were sacrificed and their intestines were weighed, isolating the lactic acid bacteria both from the intestines and from the feces. The strains isolated from mice fed human milk were evaluated for their probiotic potential, analyzing their ability to inhibit pathogens, resistance to pH, temperature, adhesion, and hydrophobicity. Results: the presence of Lactobacillus fermentum LH01, Lactobacillus rhamnosus LH02, Lactobacullis reuteri LH03, and Lactobacillus plantarum LH05 in powdered human milk was identified. All strains showed a possible probiotic profile due to the ability of bacteria to resist low pH, bile salts, and exposure to gastric enzymes, as well as their hydrophobicity and self-aggregation capacity, and their failure to show hemagglutination or hemolysis activity in a culture medium rich in erythrocytes. We observed that the consumption of powdered human milk prevented weight gain and constipation in mice. Conclusions: after spray drying, strains with possible probiotic potential may be preserved in human milk. The consumption of powdered human milk with probiotic bacteria prevents constipation and weight gain in mice, when compared to those fed a commercial formula milk.

INTRODUCCIÓN: Introducción: la leche materna (HM) contiene los nutrientes y compuestos bioactivos necesarios para el desarrollo infantil, incluidas bacterias probióticas, que contribuyen a la maduración intestinal. Objetivo: el objetivo de este estudio fue analizar la viabilidad de las bacterias acidolácticas aisladas de la leche humana con potencial probiótico, después del proceso de secado, así como evaluar su posible adhesión en el colón de ratones (BAlb/C) alimentados con leche humana en polvo y leche de una fórmula comercial. Método: se aislaron e identificaron mediante la técnica de Maldi-Tof-MS las bacterias acidolácticas con posible potencial probiótico en la leche humana en polvo. Se alimentó con leche humana en polvo y leche de una fórmula comercial a ratones de la cepa Bald/C durante 14 semanas. Se midieron el nivel de glucosa y el peso. Las heces se recolectaron para verificar la presencia de bacterias lácticas. Los ratones se sacrificaron y se pesaron los intestinos, aislando las bacterias lácticas tanto de los intestinos como de las heces. En las cepas aisladas de la leche humana se evaluó el potencial probiótico analizando su capacidad para inhibir patógenos, resistir distintos pH y temperaturas, adherirse y mostrar hidrofobicidad. Resultados: se identificó la presencia de Lactobacillus fermentum LH01, Lactobacillus rhamnosus LH02, Lactobacullis reuteri LH03 y L. plantarum LH05 en la leche humana en polvo. Todas las cepas mostraron resistencia a los pH bajos, a las sales biliares y a la exposición a enzimas gástricas, así como una buena hidrofobicidad y capacidad de autoagregación. Además, no presentaron actividad de hemaglutinación o hemólisis en un medio de cultivo rico en eritrocitos. Observamos que el consumo de leche humana en polvo evita en los ratones el aumento de peso y el estreñimiento. Conclusiones: después del secado por aspersión, las cepas con posible potencial probiótico pueden conservarse en la leche materna. El consumo de leche humana en polvo con bacterias probióticas evita el estreñimiento y el aumento de peso en los ratones, en comparación con los alimentados con leche de una formula comercial.

Virulence assessment of six major pathogenic Candida species in the mouse model of invasive candidiasis caused by fungal translocation.

Gastrointestinal colonization has been considered as the primary source of candidaemia; however, few established mouse models are available that mimic this infection route. We therefore developed a reproducible mouse model of invasive candidiasis initiated by fungal translocation and compared the virulence of six major pathogenic Candida species. The mice were fed a low-protein diet and then inoculated intragastrically with Candida cells. Oral antibiotics and cyclophosphamide were then administered to facilitate colonization and subsequent dissemination of Candida cells. Mice infected with Candida albicans and Candida tropicalis exhibited higher mortality than mice infected with the other four species. Among the less virulent species, stool titres of Candida glabrata and Candida parapsilosis were higher than those of Candida krusei and Candida guilliermondii. The fungal burdens of C. parapsilosis and C. krusei in the livers and kidneys were significantly greater than those of C. guilliermondii. Histopathologically, C. albicans demonstrated the highest pathogenicity to invade into gut mucosa and liver tissues causing marked necrosis. Overall, this model allowed analysis of the virulence traits of Candida strains in individual mice including colonization in the gut, penetration into intestinal mucosa, invasion into blood vessels, and the subsequent dissemination leading to lethal infections.

Intestinal dysbiosis and necrotizing enterocolitis: assessment for causality using Bradford Hill criteria.

In recent years, several studies have shown that premature infants who develop NEC frequently display enteric dysbiosis with increased Gram-negative bacteria for several days to weeks prior to NEC onset. The importance of these findings, for the possibility of a causal role of these bacteria in NEC pathogenesis, and for potential value of gut dysbiosis as a biomarker of NEC, is well-recognized. In this review, we present current evidence supporting the association between NEC in premature infants and enteric dysbiosis, and its evaluation using the Bradford Hill criteria for causality. To provide an objective appraisal, we developed a novel scoring system for causal inference. Despite important methodological and statistical limitations, there is support for the association from several large studies and a meta-analysis. The association draws strength from strong biological plausibility of a role of Gram-negative bacteria in NEC and from evidence for temporality, that dysbiosis may antedate NEC onset. The weakness of the association is in the low level of consistency across studies, and the lack of specificity of effect. There is a need for an improved definition of dysbiosis, either based on a critical threshold of relative abundances or at higher levels of taxonomic resolution.

In vivo safety assessment of Lactobacillus fermentum strains, evaluation of their cholesterol-lowering ability and intestinal microbial modulation.

BACKGROUND: Despite the growing importance of probiotics apparent health benefits, an impediment to the use of new probiotic cultures is their safety. Hence there is a need to strictly examine the biosafety as well as health benefits of probiotics in in vivo model systems. RESULTS: In this study, two lactic acid bacterial (LAB) cultures Lactobacillus fermentum NCMR 2826 and FIX proven for their in vitro probiotic properties were investigated for their in vivo safety in Wistar rats. An acute toxicity study (14 days) with a high dose of biomass (1016 colony-forming units (CFU) mL-1 ) followed by a subchronic test for 13 weeks with oral feeding of the probiotic cultures in three different doses (107 , 108 and 1010 CFU mL-1 ) on a daily basis revealed the safety of the L. fermentum cultures. The probiotic feeding had no toxic effects on survival, body weight and food consumption with any of the dosages used throughout the treatment period. No statistically significant changes in relative organ weights and serum biochemical and hematological indices were found between the control and the probiotic fed animals. In addition to the safety attributes, the L. fermentum culture fed rats showed reduced serum cholesterol levels, macrovesicular steatosis and hepatocyte ballooning compared with control animals. Further, quantification of intestinal microbiota using real-time polymerase chain reaction (PCR) analysis from animal feces indicated a significant increase and stability of Lactobacillus and Bifidobacterium counts but a decrease of Escherichia coli numbers. CONCLUSION: This study of safety and beneficial features highlights the use of the two native L. fermentum isolates as potential probiotic food supplements. © 2019 Society of Chemical Industry.

Metagenomic assessment of the Cebus apella gut microbiota.

Cebus Apella (C. apella) is a species of Nonhuman Primate (NHP) used for biomedical research because it is phylogenetically similar and shares anatomical commonalities with humans. Here, the gut microbiota of three C. apella were examined in the different regions of the intestinal tract. Using metagenomics, the gut microbiota associated with the luminal content and mucus layer for each intestinal region was identified, and functionality was investigated by quantifying the levels of short chain fatty acids (SCFAs) produced. The results of this study show a high degree of similarity in the intestinal communities among C. apella subjects, with multiple shared characteristics. First, the communities in the lumen were more phylogenetically diverse and rich compared to the mucus layer communities throughout the entire intestinal tract. The small intestine communities in the lumen displayed a higher Shannon diversity index compared to the colon communities. Second, all the communities were dominated by aero-tolerant taxa such as Streptococcus, Enterococcus, Abiotrophia, and Lactobacillus, although there was preferential colonization of specific taxa observed. Finally, the primary SCFA produced throughout the intestinal tract was acetic acid, with some propionic acid and butyric acid detected in the colon regions. The small intestine microbiota produced significantly less SCFAs compared to the communities in the colon. Collectively, these data provide an in-depth report on the composition, distribution, and SCFA production of the gut microbiota along the intestinal tract of the C. apella NHP animal model.

Genetically engineered probiotic for the treatment of phenylketonuria (PKU); assessment of a novel treatment in vitro and in the PAHenu2 mouse model of PKU.

Phenylketonuria (PKU) is a genetic disease characterized by the inability to convert dietary phenylalanine to tyrosine by phenylalanine hydroxylase. Given the importance of gut microbes in digestion, a genetically engineered microbe could potentially degrade some ingested phenylalanine from the diet prior to absorption. To test this, a phenylalanine lyase gene from Anabaena variabilis (AvPAL) was codon-optimized and cloned into a shuttle vector for expression in Lactobacillus reuteri 100-23C (pHENOMMenal). Functional expression of AvPAL was determined in vitro, and subsequently tested in vivo in homozygous PAHenu2 (PKU model) mice. Initial trials of two PAHenu2 homozygous (PKU) mice defined conditions for freeze-drying and delivery of bacteria. Animals showed reduced blood phe within three to four days of treatment with pHENOMMenal probiotic, and blood phe concentrations remained significantly reduced (P < 0.0005) compared to untreated controls during the course of experiments. Although pHENOMMenal probiotic could be cultured from fecal samples at four months post treatment, it could no longer be cultivated from feces at eight months post treatment, indicating eventual loss of the microbe from the gut. Preliminary screens during experimentation found no immune response to AvPAL. Collectively these studies provide data for the use of a genetically engineered probiotic as a potential treatment for PKU.

Chronic consequences on human health induced by microbial pathogens: Growth faltering among children in developing countries.

Enteric infections continue to cause approximately 500,000 childhood deaths annually worldwide. In addition to the burden of diarrhea, there is emerging evidence that exposure to enteric pathogens may induce physiologic abnormalities that lead to linear growth faltering. This enteric disease, known as environmental enteric dysfunction (EED) remains cryptic with regard to its causes and features. In this workshop, experts in the field addressed the contribution of enteric pathogens to growth faltering in the absence of clinical diarrhea. Also addressed were the role of the intestinal microbiota in normal childhood growth among children in developing countries. The impact of pathogen exposure could represent direct epithelial injury or could be mediated by perturbations in the normal microbiota or combinations of both.

The Growth-Promoting Effect of Dietary Nucleotides in Fish Is Associated with an Intestinal Microbiota-Mediated Reduction in Energy Expenditure.

Background: Nucleotides have been used as functional nutrients to improve the growth and health of animals, including fish. The mechanism involved in the growth-promotion effect of nucleotides is still unclear.Objective: We investigated the bioenergetic mechanism underlying the growth-promotion effect of nucleotides in zebrafish and the associated roles played by the intestinal microbiota.Methods: Larval zebrafish were fed a control or a 0.1% mixed nucleotides-supplemented diet for 2 wk. Standard metabolic rate, the minimal rate of energy expenditure by animals at rest, was evaluated by oxygen consumption with the use of a respirometer. The expressions of fasting-induced adipose factor (Fiaf), inflammatory cytokines, and genes involved in fatty acid (FA) oxidation were tested by quantitative reverse transcriptase-polymerase chain reaction. The intestinal microbiota from the nucleotide-fed fish (NT fish) or control fish was transferred to 3-d postfertilization germ-free zebrafish in which oxygen consumption and expression of cytokines and fiaf were evaluated.Results: Compared with controls, nucleotide supplementation at 0.1% increased the weight and energy gains of zebrafish by 10% and 25%, respectively (P < 0.01). Standard metabolic rate was 28% lower in NT fish than in controls (P < 0.001). Nucleotide supplementation downregulated the inflammatory tone in the head kidney of the fish. Moreover, NT fish had a 51% lower intestinal expression of fiaf than did controls (P < 0.05), which was consistent with decreased expression of key genes involved in FA oxidation [carnitine:palmitoyl transferase 1a (cpt1a) and medium-chain acyl coenzyme A dehydrogenase (mcad)] in liver and muscle. Germ-free zebrafish colonized with microbiota from NT fish had a 25% lower standard metabolic rate than did those colonized by control microbiota (P < 0.01), whereas direct nucleotide feeding of germ-free zebrafish did not affect standard metabolic rate relative to germ-free controls that were not fed nucleotides. Furthermore, germ-free zebrafish colonized with nucleotide microbiota exhibited downregulated inflammatory tone and 33% lower fiaf expression compared with their control microbiota-colonized counterparts.Conclusions: The growth-promoting effect of dietary nucleotides in zebrafish involves 2 intestinal microbiota-mediated mechanisms that result in reduced standard metabolic rate: 1) lower inflammatory tone and 2) reduced FA oxidation associated with increased microbial suppression of intestinal fiaf.

Metabolism of strawberry mono- and dimeric ellagitannins in rats fed a diet containing fructo-oligosaccharides.

PURPOSE: We investigated the effects of dietary supplementation with strawberry extracts rich in ETs and fructo-oligosaccharides (FOS) on the intestinal microbiota and the formation of bacterial metabolites in the distal intestine, as well as the absorption of ET metabolites and antioxidant status in rats. METHODS: Rats were allocated into six groups of eight animals each and fed for 4 weeks with a control diet (group C), a control diet supplemented with FOS (group C + FOS) or modifications of these diets, in which a monomeric or dimeric ET-rich extract was added (groups ME and ME + FOS or DE and DE + FOS, respectively). RESULTS: The extract addition, the FOS addition and their interaction significantly affected the total and selected bacterial counts in the caecal digesta (all P < 0.005). The total bacterial count was the highest in group C + FOS, lower in group DE and the lowest in group ME + FOS (10.6, 10.3 and 8.52 log cells/g, respectively; P ≤ 0.05). The total caecal content of ET metabolites was higher in the ME and ME + FOS group than in the DE and DE + FOS group, respectively (67.8 and 89.5 vs. 13.0 and 18.0 µg/g, respectively; P < 0.001). The total plasma concentration of ET metabolites was higher in the ME + FOS and DE + FOS group than in the ME group (248 and 281 vs. 8.13 ng/mL, respectively; P < 0.001). CONCLUSIONS: ETs of the monomeric ET-rich extract are more prone to intestinal breakdown than those of the dimeric ET-rich extract, and absorption of their metabolites can be increased by dietary FOS; however, together, they evoke strong antibacterial activity.

Excellent N-fixing and P-solubilizing traits in earthworm gut-isolated bacteria: A vermicompost based assessment with vegetable market waste and rice straw feed mixtures.

Vermicomposting is a dependable waste recycling technology which greatly augments N and P levels mainly through microbial action. This paper aims to identify efficient N-fixing (NFB) and P-solubilizing (PSB) bacteria from earthworm intestines. Various combinations of vegetable market waste, rice straw, and cowdung were fed to two earthworm species (Eisenia fetida and Perionyx excavatus). Total organic C decreased, pH shifted towards neutrality, and NPK availability, and microbial (NFB, PSB, and total bacteria) population increased remarkably during vermicomposting with E. fetida. Therefore, 45 NFB and 34 PSB strains isolated from Eisenia gut were initially screened, their inter-dominance assessed, and 8 prolific strains were identified through 16SrRNA sequencing. Interestingly, two novel N-fixing strains of Kluyvera ascorbata emerged as an efficient biofertilizer candidate. Moreover, both N-fixing and P-solubilizing strains of Serratia and Bacillus were isolated from earthworm gut. All the isolated strains significantly improved soil health and facilitated crop growth as compared to commercial biofertilizers.

Edible Safety Assessment of Genetically Modified Rice T1C-1 for Sprague Dawley Rats through Horizontal Gene Transfer, Allergenicity and Intestinal Microbiota.

In this study, assessment of the safety of transgenic rice T1C-1 expressing Cry1C was carried out by: (1) studying horizontal gene transfer (HGT) in Sprague Dawley rats fed transgenic rice for 90 d; (2) examining the effect of Cry1C protein in vitro on digestibility and allergenicity; and (3) studying the changes of intestinal microbiota in rats fed with transgenic rice T1C-1 in acute and subchronic toxicity tests. Sprague Dawley rats were fed a diet containing either 60% GM Bacillus thuringiensis (Bt) rice T1C-1 expressing Cry1C protein, the parental rice Minghui 63, or a basic diet for 90 d. The GM Bt rice T1C-1 showed no evidence of HGT between rats and transgenic rice. Sequence searching of the Cry1C protein showed no homology with known allergens or toxins. Cry1C protein was rapidly degraded in vitro with simulated gastric and intestinal fluids. The expressed Cry1C protein did not induce high levels of specific IgG and IgE antibodies in rats. The intestinal microbiota of rats fed T1C-1 was also analyzed in acute and subchronic toxicity tests by DGGE. Cluster analysis of DGGE profiles revealed significant individual differences in the rats' intestinal microbiota.

An update discussion on the current assessment of the safety of veterinary antimicrobial drug residues in food with regard to their impact on the human intestinal microbiome.

The human gastrointestinal tract ecosystem consists of complex and diverse microbial communities that have now been collectively termed the intestinal microbiome. Recent scientific breakthroughs and research endeavours have increased our understanding of the important role the intestinal microbiome plays in human health and disease. The use of antimicrobial new animal drugs in food-producing animals may result in the presence of low levels of drug residues in edible foodstuffs. There is concern that antimicrobial new animal drugs in or on animal-derived food products at residue-level concentrations could disrupt the colonization barrier and/or modify the antimicrobial resistance profile of human intestinal bacteria. Therapeutic doses of antimicrobial drugs have been shown to promote shifts in the intestinal microbiome, and these disruptions promote the emergence of antimicrobial-resistant bacteria. To assess the effects of antimicrobial new animal drug residues in food on human intestinal bacteria, many national regulatory agencies and international committees follow a harmonized process, VICH GL36(R), which was issued by a trilateral organization of the European Union, the USA, and Japan called the International Cooperation on Harmonization of Technical Requirements for Veterinary Medicinal Products (VICH). The guidance describes a general approach currently used by national regulatory agencies and international committees to assess the effects of antimicrobial new animal drug residues in animal-derived food on human intestinal bacteria. The purpose of this review is to provide an overview of this current approach as part of the antimicrobial new animal drug approval process in participating countries, give insights on the microbiological endpoints used in this safety evaluation, and discuss the availability of new information. Copyright © 2016 John Wiley & Sons, Ltd.

Economic evaluation of fecal microbiota transplantation for the treatment of recurrent Clostridium difficile infection in Australia.

BACKGROUND AND AIM: Clostridium difficile is the most common cause of hospital-acquired diarrhea in Australia. In 2013, a randomized controlled trial demonstrated the effectiveness of fecal microbiota transplantation (FMT) for the treatment of recurrent Clostridium difficile infection (CDI). The aim of this study is to evaluate the cost-effectiveness of fecal microbiota transplantation-via either nasoduodenal or colorectal delivery-compared with vancomycin for the treatment of recurrent CDI in Australia. METHODS: A Markov model was developed to compare the cost-effectiveness of fecal microbiota transplantation compared with standard antibiotic therapy. A literature review of clinical evidence informed the structure of the model and the choice of parameter values. Clinical effectiveness was measured in terms of quality-adjusted life years. Uncertainty in the model was explored using probabilistic sensitivity analysis. RESULTS: Both nasoduodenal and colorectal FMT resulted in improved quality of life and reduced cost compared with vancomycin. The incremental effectiveness of either FMT delivery compared with vancomycin was 1.2 (95% CI: 0.1, 2.3) quality-adjusted life years, or 1.4 (95% CI: 0.4, 2.4) life years saved. Treatment with vancomycin resulted in an increased cost of AU$4094 (95% CI: AU$26, AU$8161) compared with nasoduodenal delivery of FMT and AU$4045 (95% CI: -AU$33, AU$8124) compared with colorectal delivery. The mean difference in cost between colorectal and nasoduodenal FMT was not significant. CONCLUSIONS: If FMT, rather than vancomycin, became standard care for recurrent CDI in Australia, the estimated national healthcare savings would be over AU$4000 per treated person, with a substantial increase in quality of life.

Assessment of Environmental Enteric Dysfunction in the SHINE Trial: Methods and Challenges.

Environmental enteric dysfunction (EED) is a virtually ubiquitous, but poorly defined, disorder of the small intestine among people living in conditions of poverty, which begins early in infancy and persists. EED is characterized by altered gut structure and function, leading to reduced absorptive surface area and impaired intestinal barrier function. It is hypothesized that recurrent exposure to fecal pathogens and changes in the composition of the intestinal microbiota initiate this process, which leads to a self-perpetuating cycle of pathology. We view EED as a primary gut disorder that drives chronic systemic inflammation, leading to growth hormone resistance and impaired linear growth. There is currently no accepted case definition or gold-standard biomarker of EED, making field studies challenging. The Sanitation Hygiene Infant Nutrition Efficacy (SHINE) trial in Zimbabwe is evaluating the independent and combined effects of a package of infant feeding and/or water, sanitation, and hygiene interventions on stunting and anemia. SHINE therefore provides an opportunity to longitudinally evaluate EED in a well-characterized cohort of infants, using a panel of biomarkers along the hypothesized causal pathway. Our aims are to describe the evolution of EED during infancy, ascertain its contribution to stunting, and investigate the impact of the randomized interventions on the EED pathway. In this article, we describe current concepts of EED, challenges in defining the condition, and our approach to evaluating EED in the SHINE trial.

The cost of promiscuity: sexual transmission of Nosema microsporidian parasites in polyandrous honey bees.

Multiple mating (and insemination) by females with different males, polyandry, is widespread across animals, due to material and/or genetic benefits for females. It reaches particularly high levels in some social insects, in which queens can produce significantly fitter colonies by being polyandrous. It is therefore a paradox that two thirds of eusocial hymenopteran insects appear to be exclusively monandrous, in spite of the fitness benefits that polyandry could provide. One possible cost of polyandry could be sexually transmitted parasites, but evidence for these in social insects is extremely limited. Here we show that two different species of Nosema microsporidian parasites can transmit sexually in the honey bee Apis mellifera. Honey bee males that are infected by the parasite have Nosema spores in their semen, and queens artificially inseminated with either Nosema spores or the semen of Nosema-infected males became infected by the parasite. The emergent and more virulent N. ceranae achieved much higher rates of infection following insemination than did N. apis. The results provide the first quantitative evidence of a sexually transmitted disease (STD) in social insects, indicating that STDs may represent a potential cost of polyandry in social insects.

High-throughput assessment of bacterial ecology in hog, cow and ovine casings used in sausages production.

Natural casings derived from different intestine portions have been used for centuries in the production of fresh and dry-fermented sausages. Here we analysed by means of culture-dependent methods and Illumina high-throughput sequencing of 16S rRNA amplicons the bacterial ecology of hog, cow and ovine casings at different stages of their preparation for sausages production. Several strains of Staphylococcus, Lactobacillus, Bifidobacterium, Vagococcus and Clostridium were counted, isolated and characterised at phylogenetic level. High-throughput sequencing analyses revealed a high bacterial diversity, which differed strongly between casings of different animal species. The technological processes involved in the preparation for casing had also a strong impact on the casings bacterial ecology, with a significant reduction of undesired microorganisms, and an increase in the proportion of lactobacilli and staphylococci. Natural casings were demonstrated to be complex ecological environments, whose role as microbiological inoculants in the production of sausages should not be underestimated.