mSphere of Influence: Surface Sensing in Biofilm Formation

ABSTRACT Kara B. De Leόn works in the field of microbial ecology, environmental biofilms, and microbial genetics. In this mSphere of Influence article, she reflects on how the paper “Multigenerational memory and adaptive adhesion in early bacterial biofilm communities” by C. K. Lee et al. (C. K. Lee, J. de Anda, A. E. Baker, R. R. Bennett, et al., Proc Natl Acad Sci U S A 115:4471–4476, 2018, https://dx.doi.org/10.1073/pnas.1720071115) made an impact on her by changing the way she thinks about initial cell attachment to a surface in an environment.

Maintaining Symbiotic Homeostasis: How Do Plants Engage With Beneficial Microorganisms While at the Same Time Restricting Pathogens?

This article is part of the Top 10 Unanswered Questions in MPMI invited review series. That plants recruit beneficial microbes while simultaneously restricting pathogens is critical to their survival. Plants must exclude pathogens; however, most land plants are able to form mutualistic symbioses with arbuscular mycorrhizal fungi. Plants also associate with the complex microbial communities that form the microbiome. The outcome of each symbiotic interaction—whether a specific microbe is pathogenic, commensal, or mutualistic—relies on the specific interplay of host and microbial genetics and the environment. Here, we discuss how plants use metabolites as a gate to select which microbes can be symbiotic. Once present, we discuss how plants integrate multiple inputs to initiate programs of immunity or mutualistic symbiosis and how this paradigm may be expanded to the microbiome. Finally, we discuss how environmental signals are integrated with immunity to fine-tune a thermostat that determines whether a plant engages in mutualism, resistance to pathogens, and shapes associations with the microbiome. Collectively, we propose that the plant immune thermostat is set to select for and tolerate a largely nonharmful microbiome while receptor-mediated decision making allows plants to detect and dynamically respond to the presence of potential pathogens or mutualists. [Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

Antibiotic Resistance in Marine Microbial Communities Proximal to a Florida Sewage Outfall System

Water samples were collected at several wastewater treatment plants in southeast Florida, and water and sediment samples were collected along and around one outfall pipe, as well as along several transects extending both north and south of the respective outfall outlet. Two sets of samples were collected to address potential seasonal differences, including 38 in the wet season (June 2018) and 42 in the dry season (March 2019). Samples were screened for the presence/absence of 15 select antibiotic resistance gene targets using the polymerase chain reaction. A contrast between seasons was found, with a higher frequency of detections occurring in the wet season and fewer during the dry season. These data illustrate an anthropogenic influence on offshore microbial genetics and seasonal flux regarding associated health risks to recreational users and the regional ecosystem.