scholarly journals Yersinia pestis--etiologic agent of plague.

1997 ◽  
Vol 10 (1) ◽  
pp. 35-66 ◽  
Author(s):  
R D Perry ◽  
J D Fetherston
Keyword(s):  
Yersinia Pestis ◽  
Etiologic Agent ◽  
Clinical Aspects ◽  
Virulence Determinants ◽  
Health Issues ◽  
Regulatory Systems ◽  
Wide Range ◽  
Parasite Relationship ◽  
Obligate Pathogen ◽  
Host Parasite

Plague is a widespread zoonotic disease that is caused by Yersinia pestis and has had devastating effects on the human population throughout history. Disappearance of the disease is unlikely due to the wide range of mammalian hosts and their attendant fleas. The flea/rodent life cycle of Y. pestis, a gram-negative obligate pathogen, exposes it to very different environmental conditions and has resulted in some novel traits facilitating transmission and infection. Studies characterizing virulence determinants of Y. pestis have identified novel mechanisms for overcoming host defenses. Regulatory systems controlling the expression of some of these virulence factors have proven quite complex. These areas of research have provide new insights into the host-parasite relationship. This review will update our present understanding of the history, etiology, epidemiology, clinical aspects, and public health issues of plague.

scholarly journals Phytochemicals: A Promising Weapon in the Arsenal against Antibiotic-Resistant Bacteria

Antibiotics ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1044
Author(s):  
Bahman Khameneh ◽  
N. A. Michael Eskin ◽  
Milad Iranshahy ◽  
Bibi Sedigheh Fazly Bazzaz
Keyword(s):  
Antimicrobial Agents ◽  
Scientific Evidence ◽  
Antimicrobial Activities ◽  
Clinical Aspects ◽  
Resistant Bacteria ◽  
Global Public Health ◽  
Health Issues ◽  
Antibiotic Resistant ◽  
Safe Strategy ◽  
Wide Range

The extensive usage of antibiotics and the rapid emergence of antimicrobial-resistant microbes (AMR) are becoming important global public health issues. Many solutions to these problems have been proposed, including developing alternative compounds with antimicrobial activities, managing existing antimicrobials, and rapidly detecting AMR pathogens. Among all of them, employing alternative compounds such as phytochemicals alone or in combination with other antibacterial agents appears to be both an effective and safe strategy for battling against these pathogens. The present review summarizes the scientific evidence on the biochemical, pharmacological, and clinical aspects of phytochemicals used to treat microbial pathogenesis. A wide range of commercial products are currently available on the market. Their well-documented clinical efficacy suggests that phytomedicines are valuable sources of new types of antimicrobial agents for future use. Innovative approaches and methodologies for identifying plant-derived products effective against AMR are also proposed in this review.

Use of Logistic Equation for Detection of the Initial Parasitism Phase of Egyptian Broomrape (Phelipanche aegyptiaca) in Tomato

Weed Science ◽  
2012 ◽  
Vol 60 (1) ◽  
pp. 57-63 ◽  
Author(s):  
Jhonathan E. Ephrath ◽  
Josseph Hershenhorn ◽  
Guy Achdari ◽  
Shalom Bringer ◽  
Hanan Eizenberg
Keyword(s):  
Temperature Regime ◽  
Thermal Time ◽  
Tomato Plants ◽  
Temperature Regimes ◽  
C 23 ◽  
Wide Range ◽  
Host Parasite Relationship ◽  
Parasite Relationship ◽  
Increasing Temperature ◽  
Host Parasite

The dynamics of the host–parasite relationship between tomato cv. Brigade and Egyptian broomrape is temperature-related. This relationship was utilized for the development of an equation on the basis of thermal time (as measured by growing degree days, GDD, C) to predict the parasitism dynamics of Egyptian broomrape in tomato. To obtain a reliable prediction from thermal time values, studies based on a wide range of temperatures are essential. Four temperature-regime treatments and five levels of infestation with Egyptian broomrape seeds were tested in a multiclimate greenhouse (phytotron) and a temperature-controlled greenhouse, respectively. The day/night temperature regimes were 20/12 C, 23/15 C, 26/18 C, and 29/21 C and the infestation levels were 0 (noninfested control), 1, 5, 10, and 25 mg of Egyptian broomrape seeds per liter of soil. As expected, increasing temperature or infestation levels resulted in faster appearance and higher rate of attachments, respectively. The relation between development of attachments and GDD was described as a three-parameter logistic curve. In both temperature-regime and infestation-level experiments, the development of attachments began 200 GDD after planting and the maximal number of attachments was recorded 800 GDD after planting. A significant reduction in the aboveground biomass of the tomato plants due to increased Egyptian broomrape biomass was recorded only for the 26/18 C and 29/21 C day/night treatments and the three highest infestation levels (5, 10, and 25 mg L−1 soil). The ability to predict the start of parasitism can be used to develop a climate-based system for Egyptian broomrape control with herbicides.

Variation in the host-parasite relationship of a crop disease

1968 ◽  
Vol 71 (1) ◽  
pp. 19-36 ◽  
Author(s):  
M. H. Arnold ◽  
S. J. Brown
Keyword(s):  
Genetic Variation ◽  
Environmental Conditions ◽  
Phage Type ◽  
Resistance Breeding ◽  
Wide Range ◽  
Host Parasite Relationship ◽  
Parasite Relationship ◽  
Main Components ◽  
Host Parasite ◽  
Relationship Of

SummaryVariations in the host–parasite relationship of bacterial blight of cotton, caused by Xanthomonas malvacearum, E. F. Smith (Dowson), axe elucidated in terms of the three main components of variation, namely, genetic variation in the host, genetic variation in the parasite and variations in environment.Although the relative resistance shown by host varieties differed both with the culture of the pathogen used for inoculation and with the environmental conditions, over-riding patterns of host resistance could be detected, showing that certain varieties maintained their resistance over a wide range of conditions.It was found that phage type in X. malvacearum was not related to virulence. Moreover, none of the cultures of the pathogen which had been isolated from different sources, could be shown to be identical when inoculated into a range of host varieties under a range of environmental conditions. It was concluded that the pathogen showed continuous variation in virulence and that it would be difficult and of little value to attempt to define races.Some success was achieved in relating observed variations in the host–parasite relationship to easily measured components of the environment, by using multiple regression analyses. It is suggested that this might provide a means of characterizing the complex variations observed and that the host–parasite relationship could be regarded as a dynamic system, in which disease expression is a function of the interactions of environmental factors and two polygenic systems, that of the host and that of the parasite.Intrapopulation variances were also studied in the host varieties. A population which showed little variation for resistance under one set of conditions might show considerable variation in a different environment or when inoculated with a different culture. It is suggested that selection for resistance under conditions which favour the expression of variation can lead, by repeated selection and inbreeding, to the production of resistant populations which retain their resistance under conditions in which the parental stocks showed no worthwhile resistance. These conclusions are discussed in relation to problems in resistance breeding and genetics.

Yersinia pestis and plague

2003 ◽  
Vol 31 (1) ◽  
pp. 104-107 ◽  
Author(s):  
R.W. Titball ◽  
J. Hill ◽  
D.G. Lawton ◽  
K.A. Brown
Keyword(s):  
Host Cell ◽  
Yersinia Pestis ◽  
Genome Sequence ◽  
Yersinia Pseudotuberculosis ◽  
Cell Types ◽  
Mammalian Host ◽  
Aetiological Agent ◽  
Mild Disease ◽  
Regulatory Systems ◽  
Obligate Pathogen

Yersinia pestis is the aetiological agent of plague, a disease of humans that has potentially devastating consequences. Evidence indicates that Y. pestis evolved from Yersinia pseudotuberculosis, an enteric pathogen that normally causes a relatively mild disease. Although Y. pestis is considered to be an obligate pathogen, the lifestyle of this organism is surprisingly complex. The bacteria are normally transmitted to humans from a flea vector, and Y. pestis has a number of mechanisms which allow survival in the flea. Initially, the bacteria have an intracellular lifestyle in the mammalian host, surviving in macrophages. Later, the bacteria adopt an extracellular lifestyle. These different interactions with different host cell types are regulated by a number of systems, which are not well characterized. The availability of the genome sequence for this pathogen should now allow a systematic dissection of these regulatory systems.

Immune response to Leishmania mexicana: the host–parasite relationship

2020 ◽  
Vol 78 (8) ◽  
Author(s):  
Mayra A Rodríguez-Serrato ◽  
Mario C Salinas-Carmona ◽  
Alberto Yairh Limón-Flores
Keyword(s):  
Immune Response ◽  
Monoclonal Antibodies ◽  
Passive Immunization ◽  
Public Health Problem ◽  
World Health ◽  
Leishmania Mexicana ◽  
Wide Range ◽  
Host Parasite Relationship ◽  
Parasite Relationship ◽  
Host Parasite

ABSTRACT Leishmaniosis is currently considered a serious public health problem and it is listed as a neglected tropical disease by World Health Organization (WHO). Despite the efforts of the scientific community, it has not been possible to develop an effective vaccine. Current treatment consists of antimonials that is expensive and can cause adverse effects. It is essential to fully understand the immunopathogenesis of the disease to develop new strategies to prevent, treat and eradicate the disease. Studies on animal models have shown a new paradigm in the resolution or establishment of infection by Leishmania mexicana where a wide range of cytokines, antibodies and cells are involved. In recent years, the possibility of a new therapy with monoclonal antibodies has been considered, where isotype, specificity and concentration are critical for effective therapy. Would be better to create/generate a vaccine to induce host protection or produce passive immunization with engineering monoclonal antibodies to a defined antigen? This review provides an overview that includes the current known information on the immune response that are involved in the complex host–parasite relationship infection caused by L. mexicana.

scholarly journals Toll-Like Receptor Initiated Host Defense againstToxoplasma gondii

2010 ◽  
Vol 2010 ◽  
pp. 1-7 ◽  
Author(s):  
Eric Y. Denkers
Keyword(s):  
Host Defense ◽  
Immune Dysfunction ◽  
Enteric Infection ◽  
Intracellular Pathogen ◽  
Toll Like Receptor ◽  
Critical Pathway ◽  
Wide Range ◽  
Host Parasite Relationship ◽  
Parasite Relationship ◽  
Host Parasite

Toxoplasma gondiiis an intracellular pathogen notable for its ability to establish a stable host-parasite relationship amongst a wide range of host species and in a large percentage of the human population. Toll-like receptor signaling through MyD88 is a critical pathway in initiating defense against this opportunistic protozoan and may also be a mediator of pathology during immune dysfunction. Other MyD88 independent signaling pathways are also involved in the host-parasite interaction. These responses can be triggered by the parasite itself, but interactions with the intestinal microbiota add additional complexity during enteric infection.

scholarly journals THE EMERGENCE OF PSEUDOTUBERCULOSIS IN RATS GIVEN CORTISONE

1952 ◽  
Vol 95 (4) ◽  
pp. 393-408 ◽  
Author(s):  
Charles LeMaistre ◽  
Ralph Tompsett ◽  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
High Frequency ◽  
Bacterial Flora ◽  
Severe Infection ◽  
Etiologic Agent ◽  
Albino Rats ◽  
Similar Group ◽  
Host Parasite Relationship ◽  
Parasite Relationship ◽  
Host Parasite

The emergence of a severe infection in albino rats during cortisone administration is reported. Evidence is present that the causative agent of the disease was Corynebacterium pseudotuberculosis murium, a microbial species not demonstrably a part of the usual bacterial flora of the host. It has been possible to reproduce the disease in rats by a relatively large infecting inoculum of this strain of Corynebacterium, but the susceptibility of normal rats to infection has been found to be low. The disease occurred in 41 of 50 rats given cortisone and in 28 of 30 instances in which isolation of the etiologic agent was attempted, this strain of Corynebacterium was recovered. The disease was characterized by widespread necrotizing lesions, with multiple coalescent lesions occurring in the lungs, and similar, though smaller lesions of the pericardium, pleurae, liver, and kidneys. In its gross appearance the pulmonary disease was similar to that of a disseminated, far advanced tuberculous process. The histologic appearance of the lesions, however, was sufficiently distinctive so that they could be readily differentiated from the lesions characteristically produced by Mycobacterium tuberculosis. Moreover, the host-parasite relationship established by the experimental infection with avian tubercle bacilli, was not markedly altered by the factors which led to the emergence of the pseudotuberculosis. In contrast to the high frequency of pseudotuberculosis in rats given cortisone, no instance of this disease has been encountered in a similar group of animals given large quantities of corticotropin.

scholarly journals Transfer of Plasmid DNA to Clinical Coagulase-Negative Staphylococcal Pathogens by Using a Unique Bacteriophage

2015 ◽  
Vol 81 (7) ◽  
pp. 2481-2488 ◽  
Author(s):  
Volker Winstel ◽  
Petra Kühner ◽  
Bernhard Krismer ◽  
Andreas Peschel ◽  
Holger Rohde
Keyword(s):  
Plasmid Dna ◽  
Genetic Manipulation ◽  
Current Knowledge ◽  
Virulence Determinants ◽  
Coagulase Negative Staphylococci ◽  
Reliable Technique ◽  
Content Type ◽  
Research Activities ◽  
Wide Range ◽  
Genetic Barriers

ABSTRACTGenetic manipulation of emerging bacterial pathogens, such as coagulase-negative staphylococci (CoNS), is a major hurdle in clinical and basic microbiological research. Strong genetic barriers, such as restriction modification systems or clustered regularly interspaced short palindromic repeats (CRISPR), usually interfere with available techniques for DNA transformation and therefore complicate manipulation of CoNS or render it impossible. Thus, current knowledge of pathogenicity and virulence determinants of CoNS is very limited. Here, a rapid, efficient, and highly reliable technique is presented to transfer plasmid DNA essential for genetic engineering to important CoNS pathogens from a uniqueStaphylococcus aureusstrain via a specificS. aureusbacteriophage, Φ187. Even strains refractory to electroporation can be transduced by this technique once donor and recipient strains share similar Φ187 receptor properties. As a proof of principle, this technique was used to delete the alternative transcription factor sigma B (SigB) via allelic replacement in nasal and clinicalStaphylococcus epidermidisisolates at high efficiencies. The described approach will allow the genetic manipulation of a wide range of CoNS pathogens and might inspire research activities to manipulate other important pathogens in a similar fashion.

scholarly journals Exploring Suppliers’ Approaches toward Workplace Safety Compliance in the Global Garment Sector: From Bangladesh Perspective

2021 ◽  
Vol 10 (3) ◽  
pp. 90
Author(s):  
Md Sultan Mahmood ◽  
Nilima Haque Ruma ◽  
Toufiq Ahmed ◽  
Yukari Nagai
Keyword(s):  
Case Study Research ◽  
Code Of Conduct ◽  
Workplace Safety ◽  
Research Strategy ◽  
Social Needs ◽  
Health Issues ◽  
Labor Laws ◽  
Wide Range ◽  
Safety Compliance ◽  
Health Rights

The readymade garment (RMG) sector is one of the main drivers of the Bangladesh economy with over 4 million employed. In the 2013 Rana Plaza accident aftermath, the implementation of workplace safety compliance (WSC) became imperative. The paper investigated the WSC initiatives implemented by the RMG sector to overcome safety challenges and their effectiveness for a safe and healthy workplace. We employed a multi-case study research strategy over three Bangladeshi garment manufacturers to resolve these queries. The result revealed that the manufacturers joined in the safety governance programs to protect workers’ health safety rights immediately after the accidents. They participated in inspections and remediations programs over structural, electrical, and fire protection as a priority. Moreover, several other human rights conventions, national labor laws and, buyer code of conduct were also adopted as regulatory and voluntary initiatives to settle workers’ health rights and social needs. The WSC enforcement empowered workers to bargain their rights toward a safe workplace and made them responsible for responding during an emergency. Finally, the paper argues that the WSC in the RMG sector nowadays covers a wide range of initiatives in three broad areas: physical environment safety, workers’ health issues, and workers’ rights.

Sign in / Sign up

Export Citation Format

Share Document