scholarly journals Appraisal of Microbial Evolution to Commensalism and Pathogenicity in Humans

2013 ◽  
Vol 6 ◽  
pp. CGast.S11858 ◽  
Author(s):  
Asit Ranjan Ghosh
Keyword(s):  
Infectious Diseases ◽  
Human Body ◽  
Microbial Evolution ◽  
Mammalian Host ◽  
Human System ◽  
Present Discussion ◽  
Selective Pressures ◽  
Causative Agents

The human body is host to a number of microbes occurring in various forms of host-microbe associations, such as commensals, mutualists, pathogens and opportunistic symbionts. While this association with microbes in certain cases is beneficial to the host, in many other cases it seems to offer no evident benefit or motive. The emergence and re-emergence of newer varieties of infectious diseases with causative agents being strains that were once living in the human system makes it necessary to study the environment and the dynamics under which this host microbe relationship thrives. The present discussion examines this interaction while tracing the origins of this association, and attempts to hypothesize a possible framework of selective pressures that could have lead microbes to inhabit mammalian host systems.

Widespread infection of the Eastern red-spotted newt (Notophthalmus viridescens) by a new species of Amphibiocystidium, a genus of fungus-like mesomycetozoan parasites not previously reported in North America

Parasitology ◽  
2007 ◽  
Vol 135 (2) ◽  
pp. 203-215 ◽  
Author(s):  
T. R. RAFFEL ◽  
T. BOMMARITO ◽  
D. S. BARRY ◽  
S. M. WITIAK ◽  
L. A. SHACKELTON
Keyword(s):  
New Species ◽  
North America ◽  
Infectious Diseases ◽  
Emerging Infectious Diseases ◽  
Seasonal Distribution ◽  
Notophthalmus Viridescens ◽  
Amphibian Species ◽  
Mortality And Morbidity ◽  
Causative Agents ◽  
A New Species

SUMMARYGiven the worldwide decline of amphibian populations due to emerging infectious diseases, it is imperative that we identify and address the causative agents. Many of the pathogens recently implicated in amphibian mortality and morbidity have been fungal or members of a poorly understood group of fungus-like protists, the mesomycetozoans. One mesomycetozoan, Amphibiocystidium ranae, is known to infect several European amphibian species and was associated with a recent decline of frogs in Italy. Here we present the first report of an Amphibiocystidium sp. in a North American amphibian, the Eastern red-spotted newt (Notophthalmus viridescens), and characterize it as the new species A. viridescens in the order Dermocystida based on morphological, geographical and phylogenetic evidence. We also describe the widespread and seasonal distribution of this parasite in red-spotted newt populations and provide evidence of mortality due to infection.

scholarly journals Enterovirus D: A Small but Versatile Species

2021 ◽  
Vol 9 (8) ◽  
pp. 1758
Author(s):  
Ines Cordeiro Filipe ◽  
Mariana Soares Guedes ◽  
Evgeny M. Zdobnov ◽  
Caroline Tapparel
Keyword(s):  
Nervous System ◽  
Gastrointestinal Tract ◽  
Infectious Diseases ◽  
Respiratory Tract ◽  
Genome Organization ◽  
Neurological Complications ◽  
Tissue Tropism ◽  
Functional Elements ◽  
Diverse Range ◽  
Causative Agents

Enteroviruses (EVs) from the D species are the causative agents of a diverse range of infectious diseases in spite of comprising only five known members. This small clade has a diverse host range and tissue tropism. It contains types infecting non-human primates and/or humans, and for the latter, they preferentially infect the eye, respiratory tract, gastrointestinal tract, and nervous system. Although several Enterovirus D members, in particular EV-D68, have been associated with neurological complications, including acute myelitis, there is currently no effective treatment or vaccine against any of them. This review highlights the peculiarities of this viral species, focusing on genome organization, functional elements, receptor usage, and pathogenesis.

Bacterial Infecfions: Changes in Their Causative Agents—Trends and Possible Basis (Bayer—Symposium III), edited by M. Finland, W. Marget, and K. Bartmann. New York/Heidelberg/Berlin: Springer-Verlag, 1971, 231 pp., $15.00

PEDIATRICS ◽  
1972 ◽  
Vol 50 (5) ◽  
pp. 833-833
Author(s):  
John D. Nelson
Keyword(s):  
United States ◽  
New York ◽  
Great Britain ◽  
Los Angeles ◽  
Infectious Diseases ◽  
Bacterial Infections ◽  
The United States ◽  
New Haven ◽  
Causative Agents ◽  
Changing Patterns

Almost two years ago a group of eminent international authorities in the field of infectious diseases gathered near Cologne, Germany, for a week of reflection and discussion concerning the changing patterns of bacterial infections in recent decades and the possible reasons for the changes. The United States was represented by Drs. M. Finland and E. H. Kass of Boston, F. Daschner of Los Angeles, and A. von Graevenitz of New Haven. Other scientists were from Germany, France, Sweden, Great Britain, Switzerland, and Denmark.

scholarly journals Vaccines and Antibodies: Weapons in the Fight Against Ebola Virus

2021 ◽  
Vol 9 ◽  
Author(s):  
Patrice Debré ◽  
Marie Neunez ◽  
Michel Goldman
Keyword(s):  
Infectious Disease ◽  
Immune System ◽  
Infectious Diseases ◽  
Human Body ◽  
Ebola Virus ◽  
Virus Disease ◽  
Ebola Virus Disease ◽  
World Today ◽  
The World ◽  
Stimulation Of

Ebola virus disease is one of the deadliest infections in the world today. The microbe to blame is the Ebola virus. It has already caused numerous outbreaks in Africa, in the regions located south of the Sahara. This article describes the main characteristics of this infectious disease as well as the currently available treatments, namely vaccines and antibodies. Antibodies are produced by the human body when it is infected by a microbe. Antibodies can be collected from the blood of infected humans or animals and purified or manufactured in a laboratory to produce drugs. While vaccines have demonstrated their effectiveness in preventing infectious diseases, antibodies are effective in stopping the progression of several infectious diseases. In this article, you will discover that the stimulation of the immune system, either by the vaccine or by antibodies, is essential to tackle Ebola virus disease.

scholarly journals Modern approaches to genotyping of causative agents of particularly dangerous infections

2014 ◽  
Vol 19 (1) ◽  
pp. 34-44
Author(s):  
O. S. Bondareva ◽  
S. S. Savchenko ◽  
G. A. Tkachenko ◽  
A. I. Abueva ◽  
Yu. O. Muratova ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Infectious Diseases ◽  
Bacterial Pathogens ◽  
Epidemiological Surveillance ◽  
Annual Basis ◽  
High Pathogenicity ◽  
Causative Agents

Currently genotyping of microorganisms is widely used in the investigation of outbreaks of infectious diseases, the implementation of epidemiological surveillance of infections and phylogenetic analysis of bacterial pathogens. Development of methods for genotyping is particularly topical for pathogens of such highly dangerous infections as plague, cholera, anthrax, brucellosis, tularemia, glanders and melioidosis, due to their high pathogenicity and contagiousness. In this overview there is presented the characteristics of different genotyping methods together with an indication of their advantages and drawbacks. There has been analyzed the frequency of the use of genotyping methods on an annual basis and in terms of the type of the causative agents of especially dangerous infections.

scholarly journals Balancing positive and negative selection: in vivo evolution of Candida lusitaniae MRR1

2020 ◽  
Author(s):  
Elora G. Demers ◽  
Jason Stajich ◽  
Alix Ashare ◽  
Patricia Occhipinti ◽  
Deborah A. Hogan
Keyword(s):  
Hydrogen Peroxide ◽  
Population Genomics ◽  
Microbial Evolution ◽  
Chronic Infections ◽  
Gain Of Function ◽  
Multiple Alleles ◽  
Selective Pressures ◽  
Candida Lusitaniae ◽  
Bacterial Products

AbstractThe evolution of pathogens in response to selective pressures present during chronic infections can influence persistence, virulence, and the outcomes of antimicrobial therapy. Because subpopulations within an infection can be spatially separated and the host environment can fluctuate, an appreciation of the pathways under selection may be most easily revealed through the analysis of numerous isolates from single infections. Here, we continued our analysis of a set of clonally-derived Clavispora (Candida) lusitaniae isolates from a single chronic lung infection with a striking enrichment in the number of alleles of MRR1. Genetic and genomic analyses found evidence for repeated acquisition of gain-of-function mutations that conferred constitutive Mrr1 activity. In the same population, there were multiple alleles with both gain-of-function mutations and secondary suppressor mutations that either attenuated or abolished the constitutive activity suggesting the presence of counteracting selective pressures. Our studies demonstrated tradeoffs between high Mrr1 activity, which confers resistance to the antifungal fluconazole, host factors, and bacterial products through its regulation of MDR1, and resistance to hydrogen peroxide, a reactive oxygen species produced in the neutrophilic environment associated with this infection. This inverse correlation between high Mrr1 activity and hydrogen peroxide resistance was observed in multiple Candida species and in serial analysis of populations from this individual collected over three years. These data lead us to propose that dynamic or variable selective pressures can be reflected in population genomics and that these dynamics can complicate the drug resistance profile of the population.ImportanceUnderstanding microbial evolution within patients is critical for managing chronic infections and understanding host-pathogen interactions. Here, our analysis of multiple MRR1 alleles in isolates from a single Clavispora (Candida) lusitaniae infection revealed the selection for both high and low Mrr1 activity. Our studies reveal tradeoffs between high Mrr1 activity, which confers resistance to the commonly used antifungal fluconazole, host antimicrobial peptides and bacterial products, and resistance to hydrogen peroxide. This work suggests that spatial or temporal differences within chronic infections can support a large amount of dynamic and parallel evolution, and that Mrr1 activity is under both positive and negative selective pressure to balance different traits that are important for microbial survival.

Emerging and Reemerging Viral Pathogens: A Microscopic Overview

2001 ◽  
Vol 7 (S2) ◽  
pp. 172-173
Author(s):  
Cynthia S. Goldsmith ◽  
Sherif R. Zaki
Keyword(s):  
Infectious Diseases ◽  
The United States ◽  
Microbial Evolution ◽  
Infectious Agents ◽  
Institute Of Medicine ◽  
Viral Pathogens ◽  
Urban Sanitation ◽  
Dramatic Decline ◽  
Major Factors ◽  
Global Travel

During the 20th century, the advent of vaccines and antibiotics, and continued improvements in urban sanitation and water quality resulted in a dramatic decline in mortality due to infectious diseases. There was a brief period of optimism in the mid-1900's that infectious pathogens would no longer be a significant cause of death in the United States. For a number of reasons, this trend had reversed by the end of the century, and the rates of death caused by infectious diseases began rising. in recognition of this change, the Institute of Medicine issued a report in 1992 that called attention to the major factors contributing to the emergence and reemergence of infectious diseases. Among these were the following: increased human encroachment on wilderness habitats, resulting in changes in the ecosystem and increased contact with animal and insect vectors which may harbor unknown infectious agents; sizable growth in human population, resulting in increased urbanization and crowding; increased global travel; changes in human behaviors; and microbial evolution.

Deep sequencing-based identification of pathogen-specific microRNAs in the plasma of rabbits infected withSchistosoma japonicum

Parasitology ◽  
2013 ◽  
Vol 140 (14) ◽  
pp. 1751-1761 ◽  
Author(s):  
GUOFENG CHENG ◽  
RONG LUO ◽  
CHAO HU ◽  
JIE CAO ◽  
YOUXIN JIN
Keyword(s):  
Deep Sequencing ◽  
Mammalian Host ◽  
Argonaute 2 ◽  
Signalling Molecules ◽  
Novel Mirna ◽  
Sequencing Method ◽  
Causative Agents ◽  
Diagnosis Of Cancer ◽  
Novel Biomarkers ◽  
Host Parasite

SUMMARYCirculating microRNAs (miRNAs) have received considerable attention as a novel class of biomarkers for the diagnosis of cancer and as signalling molecules in mediating intercellular communication. Schistosomes, the causative agents of schistosomiasis, live in the blood vessels of a mammalian host in the adult stage. In the present study, we characterized schistosome-specific small RNA populations in the plasma of rabbits infected withSchistosoma japonicum(S. japonicum) using a deep sequencing method and then identified five schistosome-specific miRNAs, including four known miRNAs (Bantam, miR-3479, miR-10 and miR-3096), and one novel miRNA (miR-0001, miRBase ID: sja-miR-8185). Four of the five schistosome-specific miRNAs were also detected by real-time RT–PCR in the plasma ofS. japonicum-infected mice. In addition, our study indicated that schistosome Argonaute 2/3 may be an excretory-secretory (ES) protein. In summary, our findings are expected to provide useful information for further development of novel biomarkers for the diagnosis of schistosomiasis and also for deeper understanding of the mechanism of host–parasite interaction.

scholarly journals Interaction between mycotoxins and causative agents of swine infective diseases

2011 ◽  
pp. 251-259
Author(s):  
Jasna Prodanov-Radulovic ◽  
Radoslav Dosen ◽  
Igor Stojanov ◽  
Ivan Pusic ◽  
Milica Zivkov-Balos ◽  
...  
Keyword(s):  
Infectious Diseases ◽  
Animal Feed ◽  
Point Of View ◽  
Swine Industry ◽  
Positive Interaction ◽  
Predisposing Factor ◽  
Production Chain ◽  
Swine Farms ◽  
Causative Agents ◽  
Immunological System

Mycotoxins are secondary metabolites of fungi that can contaminate animal feeds at all stages of food production chain. Consumption of feed contaminated with mycotoxins may result in immunosuppression, which represents a predisposing factor for occurence of infectious diseases in livestock. The influence on immune system is of special interest in swine industry. The technology on swine farms demands frequent vaccinations, which may be a problem in the case of immunocompromised animals. The aim of this paper was evaluation of mycotoxin influence on swine farms, as secondary factors for destabilization of animals? immunological system. Material for this research included the samples from five swine farms, where health disorders, i.e. clinical and patomorphological signs resembling the problem with infectious diseases in different swine categories, were detected. The applied research methods included: epidemiological and clinical evaluation, pathomorphological examination, laboratory testing of bacteriological and virusological tissue originating from dead animals, and microbiological feed testing in order to examine the presence of fungi and mycotoxins. The obtained results indicated the existence of positive interaction between mycotoxins and causative agents of swine infective diseases. Despite continual pharmaco- and immunoprophylaxis in swine, the health problems of bacterial ethiology (colibacilosis, enteroxemia, dysentery, pneumonia, endometritis) were detected. From an epidemiological point of view, the presence of mycotoxins in animal feed may induce a breakdown of active immunity and occurrence of disease even in properly vaccinated animals.

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