Search results for "Colonization"

Colonization Resistance of the Gut Microbiota against Clostridium difficile

2015

Antibiotics strongly disrupt the human gut microbiota, which in consequence loses its colonization resistance capacity, allowing infection by opportunistic pathogens such as Clostridium difficile. This bacterium is the main cause of antibiotic-associated diarrhea and a current problem in developed countries, since its incidence and severity have increased during the last years. Furthermore, the emergence of antibiotic resistance strains has reduced the efficiency of the standard treatment with antibiotics, leading to a higher rate of relapses. Here, we review recent efforts focused on the impact of antibiotics in the gut microbiome and their relationship with C. difficile colonization, as w…

Host-Microbe Interaction on the Skin and Its Role in the Pathogenesis and Treatment of Atopic Dermatitis.

2022

Atopic dermatitis (AD) is a condition with a complex and unclear aetiology. Possible causes of AD encompass alterations in the structure and function of the epidermal barrier, disturbances in the skin microbiome, immune factors, allergens, bacterial and fungal infections as well as environmental and genetic factors. In patients with AD, acute skin lesions are colonized by a greater number of bacteria and fungi than chronic lesions, clinically unchanged atopic skin and the skin of healthy people. Mechanisms promoting skin colonization by pathogens include complex interplay among several factors. Apart from disturbances of the skin microbiome, increased adhesion in atopic skin, defects of inn…

Early root surface colonization by human periodontal ligament fibroblasts following treatment with different biomaterials

2013

The present in-vitro study examined the effects of different biomaterials on early root surface colonization by human periodontal ligament (PDL) fibroblasts using confocal-laser-scanning-microscopy (CLSM).Fifteen periodontally-diseased teeth were extracted, treated with scaling/root planing and longitudinally cut to obtain 30 root fragments. Fragments were treated either with 24% EDTA following application of enamel matrix derivative (EMD), 24% EDTA or EMD only, nanocrystalline hydroxyapatite (NHA) paste or oily calcium hydroxide suspension (OCHS) for 1 h each. The analogue untreated root specimens served as controls. Root fragments were incubated with human PDL fibroblasts and cellular pro…

Diagnosis of sibling species of Drosophila involved in the colonization of North America by D. subobscura

1997

To determine the effects of the recent colonization of the west coast of North America by the Palaearctic species Drosophila subobscura on the dynamics of the Drosophila populations, the sibling species D. athabasca and D. azteca must be classified unambiguously. We have characterized these two species using three molecular techniques: allozymes, mtDNA and RAPDs. All three techniques allow the classification of any individual as belonging to either species. The study of five localities in northern California and southern Oregon show that the area of overlap is larger than previously described.

The temple of visual culture and people with visual impairments: museum accessibility as mental colonization

Accessibility raises political and cultural questions about inclusion and inclusive practices. Museums worldwide now offer multisensory access programs for people with visual impairments, which could appear as an actual implementation of the purpose of the Convention on the Rights of Persons with Disabilities of full inclusion and respect of disabled pleople as part of human diversity. However, by focusing on touch, they often passively exclude people with visual impairments because of their foundation in ocularcentric assumptions about knowledge, misconceptions about visual impairments, and aesthetic and epistemological potential of other 'senses'. Differently, approaches deeply aware of s…

Investigation of the roles of AgrA and σB regulators in Listeria monocytogenes adaptation to roots and soil

2020

ABSTRACT Little is known about the regulatory mechanisms that ensure the survival of the food-borne bacterial pathogen Listeria monocytogenes in the telluric environment and on roots. Earlier studies have suggested a regulatory overlap between the Agr cell–cell communication system and the general stress response regulator σB. Here, we investigated the contribution of these two systems to root colonisation and survival in sterilised and biotic soil. The ability to colonise the roots of the grass Festuca arundinacea was significantly compromised in the double mutant (∆agrA∆sigB). In sterile soil at 25°C, a significant defect was observed in the double mutant, suggesting some synergy between …

Apulian olive sapwood endophytes to cope with Xylella fastidiosa: community analysis, antagonists screening, colonization efficiency, and genes expre…

2021

This dissertation comprises a series of studies aimed at exploring the cultivable endophytic communities indigenous to the sapwood of Apulian olive cultivars, identifying potential antagonists against Xylella fastidiosa, pauca ST53, and demonstrating their colonization efficiency and associated effects on olive defence-related genes. This work starts with an extensive analysis of cultivable sapwood endophytes from resistant and susceptible cultivars distributed across phytosanitary zones in Apulia. After multiple isolation of endophyte colonies, the results were translated into quantitative indicators. It was found that the resistant cultivar 'Leccino' showed high stability and diversity of…

Candida SPP. Colonization in NICU: A 2-Year Surveillance Study

2016

Introduction: Fungal infections are an important cause of increased morbidity and mortality in infants admitted to neonatal intensive care units (NICUs). In VLBW infants, Candida (C.) albicans is the third most common cause of neonatal late onset sepsis (LOS). The overall incidence of candidemia in NICU is increasing because of the longer survival and the invasive procedures related with the intensive care of extremely preterm infants. Prevention of candidemia in neonates is supported by the identification and adequate management of specific risk factors, including low birth weight, use of invasive devices, prolonged hospitalization and use of broad-spectrum antimicrobial agents. Effective …

A Multidisciplinary Approach to the Analysis of Multifactorial Land Mammal Colonization of Islands

2013

A highly debated question that engages paleontologists, zoogeographers, and zoologists is how terrestrial mammals colonize islands. The question’s oversimplification and the subjective and partial responses to it have led to reductionist models. Insular faunas and fossil assemblages result from a complex interaction of geological, biological (in a broad sense), climatic, eustatic, taphonomic, and historical processes. Insular assemblages and their accompanying variables should be investigated on a case-by-case basis. In this article, we discuss not only common misconceptions and their potential origins but also the key issues that should be addressed when dealing with the colonization of is…

Learning can be detrimental for a parasitic wasp

2021

Animals have evolved the capacity to learn, and the conventional view is that learning allows individuals to improve foraging decisions. The parasitoid Telenomus podisi has been shown to parasitize eggs of the exotic stink bug Halyomorpha halys at the same rate as eggs of its coevolved host, Podisus maculiventris, but the parasitoid cannot complete its development in the exotic species. We hypothesized that T. podisi learns to exploit cues from this non-coevolved species, thereby increasing unsuccessful parasitism rates. We conducted bioassays to compare the responses of naïve vs. experienced parasitoids on chemical footprints left by one of the two host species. Both naïve and experienced …