194 research outputs found

    The Therapeutic Potential of the “Yin-Yang” Garden in Our Gut

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    The gut microbiota is made up of trillion microorganisms comprising bacteria, archaea, and eukaryota living in an intimate relationship with the host. This is a highly diverse microbial community and is essentially an open ecosystem despite being deeply embedded in the human body. The gut microbiome is continually exposed to allochthonous bacteria that primarily originates from food intake. Comprising more than 1000 bacterial species, the gut microbiota endows so many different functions—so many that can be considered as an endocrine organ of its own. In this book chapter, we summarize the importance of gut microbiota in the development and maintenance of a healthy human body. We first describe how the gut microbiota is formed during the birth of a human baby and how a healthy microflora is established overtime. We also discuss how important it is to maintain the microbiota in its homeostatic condition. A discussion is also given on how alterations in the microbiota are characteristic of many diseased conditions. Recent investigations report that reestablishing a healthy microbiota in a diseased individual using fecal microbial transplant can be used as a therapeutic approach in curing many diseases. We conclude this chapter with a detailed discussion on fecal microbial transplants

    Complete nucleotide sequence of pVQS1 containing a quinolone resistance determinant from Salmonella enterica serovar Virchow associated with foreign travel

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    Objectives Nalidixic acid-resistant Salmonella enterica serovars Kentucky (n = 5) and Virchow (n = 6) cultured from individuals were investigated for the presence of plasmid-mediated quinolone resistance (PMQR) determinants. Methods PMQR markers and mutations within the quinolone resistance-determining regions of the target genes were investigated by PCR followed by DNA sequencing. Conjugation, plasmid profiling and targeted PCR were performed to demonstrate the transferability of the qnrS1 gene. Subsequently, a plasmid was identified that carried a quinolone resistance marker and this was completely sequenced. Results A Salmonella Virchow isolate carried a qnrS1 gene associated with an IncN incompatibility group conjugative plasmid of 40 995 bp, which was designated pVQS1. The latter conferred resistance to ampicillin and nalidixic acid and showed sequence similarity in its core region to plasmid R46, whilst the resistance-encoding region was similar to pAH0376 from Shigella flexneri and pINF5 from Salmonella Infantis and contained an IS26 remnant, a complete Tn3 structure, a truncated IS2 element and a qnrS1 marker, followed by IS26. In contrast to pINF5, IS26 was identified immediately downstream of the qnrS1 gene. Conclusions This is the first known report of a qnrS1 gene in Salmonella spp. in Switzerland. Analysis of the complete nucleotide sequence of the qnrS1-containing plasmid showed a novel arrangement of this antibiotic resistance-encoding regio

    gyrA Mutations in Fluoroquinolone-resistant Clostridium difficile PCR-027

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    The development of underground infrastructure, environmental concerns, and economic trend is influencing society. Due to the increasingly critical nature of installations of utility systems especially in congested areas, the need for monitoring and control system has increased. The microtunneling system will therefore have to provide for possibility of minimized surface disruption. Suitable selection of Microtunneling Boring Machine (MTBM) is the most curial decision that manager must be done. Because once the trenchless excavation has started, it might be too late to make any changes in equipment without extra costs and delays. Therefore, the various factors and parameters are affecting the choice of machine. In this paper discusses a developed methodology based on Fuzzy Analytic Hierarchy Process (FAHP) in order to determine weights of the criteria and sub criteria and then ranking them. Within the proposed model, four criteria site, machinery, structural, labor force impact and 18 sub-criteria are specified. The linguistic level of comparisons produced by experts are tapped and constructed in a form of triangular fuzzy numbers in order to construct fuzzy pair wise comparison matrices. Therefore, FAHP uses the pair wise comparison matrices for determining the weights of the criteria and sub-criteria.El desarrollo de infraestructura subterránea, con preocupaciones ambientales y tendencias económicas, está influyendo a la sociedad. Debido a la naturaleza crecientemente crítica de las instalaciones de sistemas utilitarios, especialmente en áreas congestionadas, ha aumentado la necesidad de sistemas de monitoreo y control. Por lo tanto el sistema de microtunelación ayudará a minimizar la superficie perturbada. La selección adecuada de Máquinas Taladradoras de Microtúnel (MTBM, por sus siglas en inglés) es la decisión más juiciosa que puede hacerse, puesto que una vez que la excavación sin zanjas ha iniciado, podría ser muy tarde para hacer cambios en el equipo sin un costo ni atrasos adicionales. Luego, los diversos factores y parámetros afectan la escogencia de la máquina. En este artículo se discute una metodología desarrollada, que se basa en el Proceso Jerárquico Analítico Difuso (FACH) para determinar pesos de los criterios y subcriterios, y luego ordenarlos. En el modelo propuesto se especifican cuatro criterios de sitio, maquinaria, estructura, impacto de la fuerza laboral y 18 subcriterios. Los niveles lingüísticos de comparaciones producidos por expertos se construyen en forma de números difusos triangulares para construir matrices de comparación difusa por parejas. Por lo tanto el FAHP usa las matrices de comparación por parejas para determinar los pesos de los criterios y subcriterios

    Antimicrobial resistant bacteria in wild mammals and birds: a coincidence or cause for concern?

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    BACKGROUND: The emergence and dissemination of antimicrobial resistance (AMR) is a growing concern to public and animal health. The contribution attributable to wildlife remains unclear. In this study two unrelated wildlife species herring gulls (Larus argentatus) and a hybrid deer (Cervus elaphus x Cervus nippon) were investigated for the presence of Escherichia coli expressing an AMR phenotype. FINDINGS: Bacterial isolates resistant to β-lactam compounds were identified in both animal species and the production of functional β-lactamase was confirmed using nitrocefin. The prevalence of resistant isolates was higher in herring gulls (87%) compared to deer (31%). Resistance to this class of antibiotic was found only in non-pathogenic E. coli in herring gulls and in both pathogenic and non-pathogenic E. coli strains in deer. CONCLUSIONS: The presence of AMR in wildlife has implications for public health, food safety and potable water source protection among others

    Antimicrobial resistance in commensal faecal Escherichia coli of hospitalised horses

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    The objective of this study was to examine the impact of hospitalisation and antimicrobial drug administration on the prevalence of resistance in commensal faecal E. coli of horses. Faecal samples were collected from ten hospitalised horses treated with antimicrobials, ten hospitalised horses not treated with antimicrobials and nine non-hospitalised horses over a consecutive five day period and susceptibility testing was performed on isolated E. coli. Results revealed that hospitalisation alone was associated with increased prevalence of antimicrobial resistance and multidrug resistance in commensal E. coli of horses. Due to the risk of transfer of resistance between commensal and pathogenic bacteria, veterinarians need to be aware of possible resistance in commensal bacteria when treating hospitalised horses

    An investigation of the effect of rapid slurry chilling on blown pack spoilage of vacuum-packaged beef primals

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    The aim of this study was to investigate if rapid slurry chilling would retard or prevent blown pack spoilage (BPS) of vacuum-packaged beef primals. Beef primals were inoculated with Clostridium estertheticum subspp. estertheticum (DSMZ 8809), C. estertheticum subspp. laramenise (DSMZ 14864) and C. gasigenes (DSMZ 12272), and vacuum-packaged with and without heat shrinkage (90°C for 3 s). These packs were then subjected to immediate chilling in an ice slurry or using conventional blast chilling systems and stored at 2°C for up to 100 days. The onset and progress of BPS was monitored using the following scale; 0-no gas bubbles in drip; 1-gas bubbles in drip; 2-loss of vacuum; 3-‘blown’; 4-presence of sufficient gas inside the packs to produce pack distension and 5-tightly stretched, ‘overblown’ packs/packs leaking. Rapid slurry chilling (as compared to conventional chilling) did not significantly affect (P > 0.05) the time to the onset or progress of BPS. It was therefore concluded that rapid chilling of vacuum-packaged beef primals, using an ice slurry system, may not be used as a control intervention to prevent or retard blown pack spoilage. Significance and Impact of the Study: This study adds to our growing understanding of blown pack spoilage of vacuum-packaged beef primals and suggests that rapid chilling of vacuum-packaged beef primals is not a control option for the beef industry. The results suggest that neither eliminating the heat shrinkage step nor rapid chilling of vacuum-packaged beef retard the time to blown pack spoilage

    Investigation of the Causes of Shigatoxigenic Escherichia coli PCR Positive and Culture Negative Samples

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    peer-reviewedMolecular methods may reveal the presence of pathogens in samples through the detection of specific target gene(s) associated with microorganisms, but often, the subsequent cultural isolation of the pathogen is not possible. This discrepancy may be related to low concentration of the cells, presence of dead cells, competitive microflora, injured cells and cells in a viable but non-culturable state, free DNA and the presence of free bacteriophages which can carry the target gene causing the PCR-positive/culture-negative results. Shiga-toxigenic Escherichia coli (STEC) was used as a model for studying this phenomenon, based on the phage-encoded cytotoxins genes (Stx family) as the detection target in samples through real-time qPCR. Stx phages can be integrated in the STEC chromosome or can be isolated as free particles in the environment. In this study, a combination of PCR with culturing was used for investigating the presence of the stx1 and stx2 genes in 155 ovine recto-anal junction swab samples (method (a)-PCR). Samples which were PCR-positive and culture-negative were subjected to additional analyses including detection of dead STEC cells (method (b)-PCR-PMA dye assay), presence of Stx phages (method (c)-plaque assays) and inducible integrated phages (method (d)-phage induction). Method (a) showed that even though 121 samples gave a PCR-positive result (78%), only 68 samples yielded a culturable isolate (43.9%). Among the 53 (34.2%) PCR-positive/culture-negative samples, 21 (39.6%) samples were shown to have STEC dead cells only, eight (15.1%) had a combination of dead cells and inducible stx phage, while two samples (3.8%) had a combination of dead cells, inducible phage and free stx phage, and a further two samples had Stx1 free phages only (3.8%). It was thus possible to reduce the samples with no explanation to 20 (37.7% of 53 samples), representing a further step towards an improved understanding of the STEC PCR-positive/culture-negative phenomenon

    Flow cytometric and 16S sequencing methodologies for monitoring the physiological status of the microbiome in powdered infant formula production

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    The aim of this study was to develop appropriate protocols for flow cytometric (FCM) and 16S rDNA sequencing investigation of the microbiome in a powdered infant formula (PIF) production facility. Twenty swabs were collected from each of the three care zones of a PIF production facility and used for preparing composite samples. For FCM studies, the swabs were washed in 200 mL phosphate buffer saline (PBS). The cells were harvested by three-step centrifugation followed by a single stage filtration. Cells were dispersed in fresh PBS and analyzed with a flow cytometer for membrane integrity, metabolic activity, respiratory activity and Gram characteristics of the microbiome using various fluorophores. The samples were also plated on agar plates to determine the number of culturable cells. For 16S rDNA sequencing studies, the cells were harvested by centrifugation only. Genomic DNA was extracted using a chloroform-based method and used for 16S rDNA sequencing studies. Compared to the dry low and high care zones, the wet medium care zone contained a greater number of viable, culturable, and metabolically active cells. Viable but non-culturable cells were also detected in dry-care zones. In total, 243 genera were detected in the facility of which 42 were found in all three care zones. The greatest diversity in the microbiome was observed in low care. The genera present in low, medium and high care were mostly associated with soil, water, and humans, respectively. The most prevalent genera in low, medium and high care were Pseudomonas, Acinetobacter, and Streptococcus, respectively. The integration of FCM and metagenomic data provided further information on the density of different species in the facility

    Nucleotide sequences of 16 transmissible plasmids identified in nine multidrug-resistant Escherichia coli isolates expressing an ESBL phenotype isolated from food-producing animals and healthy humans

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    Objectives Nine extended-spectrum β-lactamase (ESBL)-producing Escherichia coli isolated from healthy humans and food-producing animals were found to transfer their cefotaxime resistance marker at high frequency in laboratory conjugation experiments. The objective of this study was to completely characterize 16 transmissible plasmids that were detected in these bacterial isolates. Methods The nucleotide sequences of all 16 plasmids were determined from transconjugants using next-generation sequencing technology. Open reading frames were assigned using Rapid Annotation using Subsystem Technology and analysed by BLASTn and BLASTp. The standard method was used for plasmid multilocus sequence typing (pMLST) analysis. Plasmid structures were subsequently confirmed by PCR amplification of selected regions. Results The complete circularized nucleotide sequence of 14 plasmids was determined, along with that of a further two plasmids that could not be confirmed as closed. These ranged in size from 1.8 to 166.6 kb. Incompatibility groups and pMLSTs identified included IncI1/ST3, IncI1/ST36, IncN/ST1, IncF and IncB/O, and those of the same Inc types presented a similar backbone structure despite being isolated from different sources. Eight plasmids contained blaCTX-M-1 genes that were associated with either ISEcp1 or IS26 insertion sequence elements. Six plasmids isolated from humans and chickens were identical or closely related to the IncI1 reference plasmid, R64. Conclusions These data, based on comparative sequence analysis, highlight the successful spread of blaESBL-harbouring plasmids of different Inc types among isolates of human and food-producing animal origin and provide further evidence for potential dissemination route

    Genomic insights into persistence of Listeria species in the food processing environment

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    Aims: Listeria species may colonize and persist in food processing facilities for prolonged periods of time, despite hygiene interventions in place. To understand the genetic factors contributing to persistence of Listeria strains, this study undertook a comparative analysis of seven persistent and six presumed non-persistent strains, isolated from a single food processing environment, to identify genetic markers correlating to promoting persistence of Listeria strains, through whole genome sequence analysis. Methods and Results: A diverse pool of genetic markers relevant to hygiene tolerance was identified, including disinfectant resistance markers qacH, emrC and the efflux cassette bcrABC. Both persistent and presumed non-persistent cohorts encoded a range of stress resistance markers, including heavy metal resistance, oxidative and pH stress, although trends were associated with each cohort (e.g., qacH and cadA1C resistance was more frequently found in persistent isolates). Persistent isolates were more likely to contain mutations associated with attenuated virulence, including a truncated InlA. Plasmids and transposons were widespread between cohorts. Conclusions: Results suggest that no single genetic marker identified was universally responsible for a strain's ability to persist. Persistent strains were more likely to harbour mutation associated with hypovirulence. Significance and Impact of the Study: This study provides additional insights into the distribution of genetic elements relevant to persistence across Listeria species, as well as strain virulence potential
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