Chemically Mediated Microbial “Gardening” Capacity of a Seaweed Holobiont Is Dynamic

Terrestrial plants are known to “garden” the microbiota of their rhizosphere via released metabolites (that can attract beneficial microbes and deter pathogenic microbes). Such a “gardening” capacity is also known to be dynamic in plants. Although microbial “gardening” has been recently demonstrated for seaweeds, we do not know whether this capacity is a dynamic property in any aquatic flora like in terrestrial plants. Here, we tested the dynamic microbial “gardening” capacity of seaweeds using the model invasive red seaweed Agarophyton vermiculophyllum. Following an initial extraction of surface-associated metabolites (immediately after field collection), we conducted a long-term mesocosm experiment for 5 months to test the effect of two different salinities (low = 8.5 and medium = 16.5) on the microbial “gardening” capacity of the alga over time. We tested “gardening” capacity of A. vermiculophyllum originating from two different salinity levels (after 5 months treatments) in settlement assays against three disease causing pathogenic bacteria and seven protective bacteria. We also compared the capacity of the alga with field-collected samples. Abiotic factors like low salinity significantly increased the capacity of the alga to deter colonization by pathogenic bacteria while medium salinity significantly decreased the capacity of the alga over time when compared to field-collected samples. However, capacity to attract beneficial bacteria significantly decreased at both tested salinity levels when compared to field-collected samples. Dynamic microbial “gardening” capacity of a seaweed to attract beneficial bacteria and deter pathogenic bacteria is demonstrated for the first time. Such a dynamic capacity as found in the current study could also be applicable to other aquatic host–microbe interactions. Our results may provide an attractive direction of research towards manipulation of salinity and other abiotic factors leading to better defended A. vermiculophyllum towards pathogenic bacteria thereby enhancing sustained production of healthy A. vermiculophyllum in farms.

Download Full-text

Human Three-Dimensional Endometrial Epithelial Cell Model To Study Host Interactions with Vaginal Bacteria and Neisseria gonorrhoeae

Infection and Immunity ◽

10.1128/iai.01049-16 ◽

2017 ◽

Vol 85 (3) ◽

Cited By ~ 29

Author(s):

Paweł Łaniewski ◽

Adriana Gomez ◽

Geoffrey Hire ◽

Magdalene So ◽

Melissa M. Herbst-Kralovetz

Keyword(s):

Epithelial Cell ◽

Neisseria Gonorrhoeae ◽

Pathogenic Bacteria ◽

Three Dimensional ◽

Female Reproductive Tract ◽

Content Type ◽

Endometrial Epithelial Cell ◽

Proinflammatory Mediators ◽

Microbe Interactions ◽

Host Microbe Interactions

ABSTRACT Colonization of the endometrium by pathogenic bacteria ascending from the lower female reproductive tract (FRT) is associated with many gynecologic and obstetric health complications. To study these host-microbe interactions in vitro, we developed a human three-dimensional (3-D) endometrial epithelial cell (EEC) model using the HEC-1A cell line and the rotating wall vessel (RWV) bioreactor technology. Our model, composed of 3-D EEC aggregates, recapitulates several functional/structural characteristics of human endometrial epithelial tissue, including cell differentiation, the presence of junctional complexes/desmosomes and microvilli, and the production of membrane-associated mucins and Toll-like receptors (TLRs). TLR function was evaluated by exposing the EEC aggregates to viral and bacterial products. Treatment with poly(I·C) and flagellin but not with synthetic lipoprotein (fibroblast-stimulating lipoprotein 1 [FSL-1]) or lipopolysaccharide (LPS) significantly induced proinflammatory mediators in a dose-dependent manner. To simulate ascending infection, we infected EEC aggregates with commensal and pathogenic bacteria: Lactobacillus crispatus, Gardnerella vaginalis, and Neisseria gonorrhoeae. All vaginal microbiota and N. gonorrhoeae efficiently colonized the 3-D surface, localizing to crevices of the EEC model and interacting with multiple adjacent cells simultaneously. However, only infection with pathogenic N. gonorrhoeae and not infection with the other bacteria tested significantly induced proinflammatory mediators and significant ultrastructural changes to the host cells. The latter observation is consistent with clinical findings and illustrated the functional specificity of our system. Additionally, we highlighted the utility of the 3-D EEC model for the study of the pathogenesis of N. gonorrhoeae using a well-characterized ΔpilT mutant. Overall, this study demonstrates that the human 3-D EEC model is a robust tool for studying host-microbe interactions and bacterial pathogenesis in the upper FRT.

Download Full-text

Mechanically Resolved Imaging of Bacteria using Expansion Microscopy

10.1101/622654 ◽

2019 ◽

Author(s):

Youngbin Lim ◽

Margarita Khariton ◽

Keara M. Lane ◽

Anthony L. Shiver ◽

Katharine M. Ng ◽

...

Keyword(s):

Cell Walls ◽

Pathogenic Bacteria ◽

Cell Envelope ◽

Grand Challenge ◽

Bacterial Cells ◽

Spectral Separation ◽

Microbe Interactions ◽

Microscopy Method ◽

Host Microbe Interactions

AbstractImaging dense and diverse microbial communities has broad applications in basic microbiology and medicine, but remains a grand challenge due to the fact that many species adopt similar morphologies. While prior studies have relied on techniques involving spectral labeling, we have developed an expansion microscopy method (μExM) in which cells are physically expanded prior imaging and their expansion patterns depend on the structural and mechanical properties of their cell walls, which vary across species and conditions. We use this phenomenon as a quantitative and sensitive phenotypic imaging contrast orthogonal to spectral separation in order to resolve bacterial cells of different species or in distinct physiological states. Focusing on host-microbe interactions that are difficult to quantify through fluorescence alone, we demonstrate the ability of μExM to distinguish species within a dense community throughin vivoimaging of a model gut microbiota, and to sensitively detect cell-envelope damage caused by antibiotics or previously unrecognized cell-to-cell phenotypic heterogeneity among pathogenic bacteria as they infect macrophages.

Download Full-text

Effects of Salinity on Physiological, Biochemical and Gene Expression Parameters of Black Tiger Shrimp (Penaeus monodon): Potential for Farming in Low-Salinity Environments

Biology ◽

10.3390/biology10121220 ◽

2021 ◽

Vol 10 (12) ◽

pp. 1220

Author(s):

Md. Lifat Rahi ◽

Khairun Naher Azad ◽

Maliha Tabassum ◽

Hasna Hena Irin ◽

Kazi Sabbir Hossain ◽

...

Keyword(s):

Abiotic Factors ◽

Penaeus Monodon ◽

Production Performance ◽

Growth And Survival ◽

Factors Affecting ◽

Black Tiger Shrimp ◽

Low Salinity ◽

Tiger Shrimp ◽

Wide Range ◽

Salinity Levels

Salinity is one of the most important abiotic factors affecting growth, metabolism, immunity and survival of aquatic species in farming environments. As a euryhaline species, the black tiger shrimp (Penaeus monodon) can tolerate a wide range of salinity levels and is farmed between brackish to marine water conditions. The current study tested the effects of six different salinity levels (0‰, 2.5‰, 5‰, 10‰, 20‰ and 30‰) on the selected physiological, biochemical and genetic markers (individual changes in the expression pattern of selected candidate genes) in the black tiger shrimp. Experimental salinity levels significantly affected growth and survival performance (p < 0.05); the highest levels of growth and survival performance were observed at the control (20‰) salinity. Salinity reductions significantly increased free fatty acid (FFA), but reduced free amino acid (FAA) levels. Lower salinity treatments (0–10‰) significantly reduced hemolymph osmolality levels while 30‰ significantly increased osmolality levels. The five different salinity treatments increased the expression of osmoregulatory and hemolymph regulatory genes by 1.2–8-fold. In contrast, 1.2–1.6-fold lower expression levels were observed at the five salinity treatments for growth (alpha amylase) and immunity (toll-like receptor) genes. O2 consumption, glucose and serotonin levels, and expression of osmoregulatory genes showed rapid increase initially with salinity change, followed by reducing trend and stable patterns from the 5th day to the end. Hemocyte counts, expression of growth and immunity related genes showed initial decreasing trends, followed by an increasing trend and finally stability from 20th day to the end. Results indicate the farming potential of P. monodon at low salinity environments (possibly at freshwater) by proper acclimation prior to stocking with minimal effects on production performance.

Download Full-text

Dynamics of the bacterial community associated withPhaeodactylum tricornutumcultures

10.1101/077768 ◽

2016 ◽

Cited By ~ 2

Author(s):

Fiona Wanjiku Moejes ◽

Ovidiu Popa ◽

Antonella Succurro ◽

Julie Maguire ◽

Oliver Ebenhöh

Keyword(s):

Bacterial Community ◽

Phaeodactylum Tricornutum ◽

Large Scale ◽

Model Organism ◽

Interdisciplinary Approach ◽

Pennate Diatom ◽

Microbe Interactions ◽

Host Microbe Interactions ◽

Insight Into ◽

Over Time

AbstractThe pennate diatomPhaeodactylum tricornutumis a model organism able to synthesise industrially-relevant molecules. Large-scale monocultures are prone to bio-contamination, however, little is known about the identity of the invading organisms. To gain insight into the bacterial community associated with diatoms, we translated the complexity of a natural system into reproducible experiments where we investigated the microbiome ofP. tricornutumcultures. The results revealed a dynamic bacterial community that changed over time and in differing media conditions. We propose a network of putative interactions betweenP. tricornutumand the main bacterial factions, which is translated into a set of ordinary differential equations constituting a computational dynamic model. The proposed mathematical model is able to capture the population dynamics, further supporting the hypothesised interactions. The interdisciplinary approach implemented provides a framework for understanding the dynamics of diatom-associated microbial communities, and provides a foundation for further systematic investigations of host-microbe interactions.

Download Full-text

Host–microbe interactions: the difficult yet peaceful coexistence of the microbiota and the intestinal mucosa

British Journal Of Nutrition ◽

10.1017/s0007114512004035 ◽

2013 ◽

Vol 109 (S2) ◽

pp. S12-S20 ◽

Cited By ~ 18

Author(s):

Fermín Sánchez de Medina ◽

Mercedes Ortega-González ◽

Raquel González-Pérez ◽

Fermín Capitán-Cañadas ◽

Olga Martínez-Augustin

Keyword(s):

Immune System ◽

Intestinal Microbiota ◽

Pathogenic Bacteria ◽

Reciprocal Regulation ◽

New Therapeutic Approaches ◽

Intestinal Immune System ◽

Pathogen Recognition Receptors ◽

Microbe Interactions ◽

Specific Receptors ◽

Host Microbe Interactions

The immune system has evolved to live in a collaborative relationship with the microbiota, while still serving its seminal function to fight off invasive pathogenic bacteria. The mechanisms that rule the interactions between the intestinal microbiota and the intestinal immune system are the focus of intense research. Here, we describe how the innate immunity is, to a great extent, in charge of the control of the microbiota in the intestine and relies on non-specific receptors called pathogen-recognition receptors. While the microbiota has a well-defined effect on the host immune homoeostasis, it has become clear that the opposite is also true, i.e., the mucosal immune system has the capacity to shape the microbial population. The mechanisms that rule the reciprocal regulation between host immunity and commensal bacteria (including specific bacteria) are currently being elucidated and will be described here. A better knowledge of how the host and bacteria interact and how the intestinal microbiota and the immune system are co-regulated will provide the basis for a better understanding of intestinal and systemic immunopathologies and for the development of new therapeutic approaches.

Download Full-text