The role of ecological theory in microbial ecology

2007 ◽  
Vol 5 (5) ◽  
pp. 384-392 ◽  
Author(s):  
James I. Prosser ◽  
Brendan J. M. Bohannan ◽  
Tom P. Curtis ◽  
Richard J. Ellis ◽  
Mary K. Firestone ◽  
...  
Keyword(s):  
Microbial Ecology ◽  
Ecological Theory

scholarly journals Bacteriocin-like activity of oral Fusobacterium nucleatum isolated from human and non-human primates

1999 ◽  
Vol 30 (4) ◽  
pp. 324-346 ◽  
Author(s):  
Elerson Gaetti-Jardim Júnior ◽  
Mario Julio Avila-Campos
Keyword(s):  
Oral Cavity ◽  
Microbial Ecology ◽  
Dental Plaque ◽  
Fusobacterium Nucleatum ◽  
Antagonistic Activity ◽  
Healthy Individuals ◽  
Bacterial Microbiota ◽  
Reference Strains

Fusobacterium nucleatum is indigenous of the human oral cavity and has been involved in different infectious processes. The production of bacteriocin-like substances may be important in regulation of bacterial microbiota in oral cavity. The ability to produce bacteriocin-like substances by 80 oral F. nucleatum isolates obtained from periodontal patients, healthy individuals and Cebus apella monkeys, was examinated. 17.5% of all tested isolates showed auto-antagonism and 78.8% iso- or hetero-antagonism. No isolate from monkey was capable to produce auto-inhibition. In this study, the antagonistic substances production was variable in all tested isolates. Most of the F. nucleatum showed antagonistic activity against tested reference strains. These data suggest a possible participation of these substances on the oral microbial ecology in humans and animals. However, the role of bacteriocins in regulating dental plaque microbiota in vivo is discussed.

Non-equilibrium dynamics and stochastic processes

2020 ◽  
pp. 40-52
Author(s):  
Karen C. Abbott
Keyword(s):  
Stochastic Processes ◽  
Density Dependence ◽  
Classical Theory ◽  
Ecological Theory ◽  
Ecological Processes ◽  
Transient Phenomena ◽  
Equilibrium Dynamics ◽  
Theoretical Approaches ◽  
Ecological Understanding

Most standard theoretical approaches emphasize the role of deterministic density dependence in creating and maintaining equilibrium dynamics. At the same time, it is widely recognized that ecological processes are inherently stochastic, and that disturbances and variation in the environment and in the fates of individuals prevent many ecological systems from resting at their theoretical equilibrium. A developing body of stochastic ecological theory aims to bridge the gap between the deterministic tools of classical theory and the stochastic, non-equilibrial questions that real systems present to us. This chapter provides an overview of this developing theory, with an emphasis on approaches that confront the complex interplay between deterministic density dependence, and perturbations. Although intuition may suggest that stochasticity and transient phenomena should obscure ecological understanding, they can actually strengthen it when viewed through the appropriate lens, as illustrated in this chapter.

scholarly journals Effects of atrazine on the black community land function and role of microbial ecology

2020 ◽  
Vol 446 ◽  
pp. 032093
Author(s):  
Yaosheng Zhang ◽  
Long Tian ◽  
Ruixi Ma ◽  
Yanxiang Wei ◽  
Jiali Yang ◽  
...  
Keyword(s):  
Microbial Ecology ◽  
Black Community

scholarly journals Oral Microbial Ecology and the Role of Salivary Immunoglobulin A

1998 ◽  
Vol 62 (1) ◽  
pp. 71-109 ◽  
Author(s):  
Harold Marcotte ◽  
Marc C. Lavoie
Keyword(s):  
Immune System ◽  
Oral Cavity ◽  
Microbial Ecology ◽  
Periodontal Diseases ◽  
Immunoglobulin A ◽  
Basic Knowledge ◽  
Oral Microbiota ◽  
Indigenous Bacteria ◽  
Indigenous Microbiota

SUMMARY In the oral cavity, indigenous bacteria are often associated with two major oral diseases, caries and periodontal diseases. These diseases seem to appear following an inbalance in the oral resident microbiota, leading to the emergence of potentially pathogenic bacteria. To define the process involved in caries and periodontal diseases, it is necessary to understand the ecology of the oral cavity and to identify the factors responsible for the transition of the oral microbiota from a commensal to a pathogenic relationship with the host. The regulatory forces influencing the oral ecosystem can be divided into three major categories: host related, microbe related, and external factors. Among host factors, secretory immunoglobulin A (SIgA) constitutes the main specific immune defense mechanism in saliva and may play an important role in the homeostasis of the oral microbiota. Naturally occurring SIgA antibodies that are reactive against a variety of indigenous bacteria are detectable in saliva. These antibodies may control the oral microbiota by reducing the adherence of bacteria to the oral mucosa and teeth. It is thought that protection against bacterial etiologic agents of caries and periodontal diseases could be conferred by the induction of SIgA antibodies via the stimulation of the mucosal immune system. However, elucidation of the role of the SIgA immune system in controlling the oral indigenous microbiota is a prerequisite for the development of effective vaccines against these diseases. The role of SIgA antibodies in the acquisition and the regulation of the indigenous microbiota is still controversial. Our review discusses the importance of SIgA among the multiple factors that control the oral microbiota. It describes the oral ecosystems, the principal factors that may control the oral microbiota, a basic knowledge of the secretory immune system, the biological functions of SIgA, and, finally, experiments related to the role of SIgA in oral microbial ecology.

scholarly journals Impact of cleaning and disinfection procedures on microbial ecology and Salmonella antimicrobial resistance in a pig slaughterhouse

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Arnaud Bridier ◽  
Patricia Le Grandois ◽  
Marie-Hélène Moreau ◽  
Charleyne Prénom ◽  
Alain Le Roux ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Microbial Ecology ◽  
Bacterial Diversity ◽  
Food Environments ◽  
Short Term ◽  
Short Term Study ◽  
Before And After ◽  
Associated Surfaces ◽  
Cleaning And Disinfection

Abstract To guarantee food safety, a better deciphering of ecology and adaptation strategies of bacterial pathogens such as Salmonella in food environments is crucial. The role of food processing conditions such as cleaning and disinfection procedures on antimicrobial resistance emergence should especially be investigated. In this work, the prevalence and antimicrobial resistance of Salmonella and the microbial ecology of associated surfaces communities were investigated in a pig slaughterhouse before and after cleaning and disinfection procedures. Salmonella were detected in 67% of samples and isolates characterization revealed the presence of 15 PFGE-patterns belonging to five serotypes: S.4,5,12:i:-, Rissen, Typhimurium, Infantis and Derby. Resistance to ampicillin, sulfamethoxazole, tetracycline and/or chloramphenicol was detected depending on serotypes. 16S rRNA-based bacterial diversity analyses showed that Salmonella surface associated communities were highly dominated by the Moraxellaceae family with a clear site-specific composition suggesting a persistent colonization of the pig slaughterhouse. Cleaning and disinfection procedures did not lead to a modification of Salmonella susceptibility to antimicrobials in this short-term study but they tended to significantly reduce bacterial diversity and favored some genera such as Rothia and Psychrobacter. Such data participate to the construction of a comprehensive view of Salmonella ecology and antimicrobial resistance emergence in food environments in relation with cleaning and disinfection procedures.

scholarly journals Dynamic role of single‐celled fungi in ruminal microbial ecology and activities

2019 ◽  
Vol 128 (4) ◽  
pp. 950-965 ◽  
Author(s):  
M.M.Y. Elghandour ◽  
A. Khusro ◽  
M.J. Adegbeye ◽  
Z. Tan ◽  
S.H. Abu Hafsa ◽  
...  
Keyword(s):  
Microbial Ecology

scholarly journals Roman Grain Pests in Britain: Implications for Grain Supply and Agricultural Production

Britannia ◽  
2011 ◽  
Vol 42 ◽  
pp. 243-262 ◽  
Author(s):  
David Smith ◽  
Harry Kenward
Keyword(s):  
Agricultural Production ◽  
Ecological Theory ◽  
Economic Modelling ◽  
Medieval Period ◽  
Early Medieval ◽  
Roman Britain ◽  
Norman Conquest ◽  
Economic Changes ◽  
Early Medieval Period

AbstractIt is over 30 years since Paul Buckland first presented a series of arguments concerning beetle (Coleoptera) grain pests: their origin, the timing of their introduction to Britain, and their implications for agricultural production during the Roman occupation. Here we return to the topic in the light of new data from a range of archaeological deposits, including civilian and military sites dating from the earliest period of Roman occupation. Infestation rates and, potentially, grain loss may have been high throughout Roman Britain, though many infestations may have been in equine feed. Beetle grain pests are not recorded in Britain prior to the Roman invasion, and it appears that they were absent, or extremely rare, in the early medieval period and up to the Norman Conquest. This pattern of occurrence is reviewed and it is suggested that ecological theory offers an explanation which is in accord with supposed socio-economic changes and trade. The role of grain pests is considered in the economic modelling of Romano-British agriculture.

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