scholarly journals A comparison of fourteen fully characterized mammalian-associated Campylobacter fetus isolates suggests that loss of defense mechanisms contribute to high genomic plasticity and subspecies evolution

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e10586
Author(s):  
Susan A. Nadin-Davis ◽  
John Chmara ◽  
Catherine D. Carrillo ◽  
Kingsley Amoako ◽  
Noriko Goji ◽  
...  
Keyword(s):  
Defense Mechanisms ◽  
Reproductive Tract ◽  
Adaptive Immune System ◽  
Biochemical Tests ◽  
Host Tropism ◽  
Campylobacter Fetus ◽  
Phenotypic Characterisation ◽  
Animal Pathogens ◽  
Dna Adenine Methylase ◽  
Rapid Discrimination

Campylobacter fetus is currently classified into three main subspecies, but only two of these, C. fetus subspecies fetus and C. fetus subsp. venerealis originate principally from ruminants where they inhabit different niches and cause distinct pathogenicity. Their importance as pathogens in international trade and reporting is also different yet the criteria defining these properties have never been fully substantiated nor understood. The situation is further compromised because the ability to differentiate between these two closely related C. fetus subspecies has traditionally been performed by phenotypic characterisation of isolates, methods which are limited in scope, time-consuming, tedious, and often yield inconsistent results, thereby leading to isolate misidentification. The development of robust genetic markers that could enable rapid discrimination between C. fetus subsp. fetus and subsp. venerealis has also been challenging due to limited differences in the gene complement of their genomes, high levels of sequence repetition, the small number of closed genome sequences available and the lack of standardisation of the discriminatory biochemical tests employed for comparative purposes. To yield a better understanding of the genomic differences that define these C. fetus strains, seven isolates were exhaustively characterised phenotypically and genetically and compared with seven previously well characterised isolates. Analysis of these 14 C. fetus samples clearly illustrated that adaption by C. fetus subsp. venerealis to the bovine reproductive tract correlated with increasing genome length and plasticity due to the acquisition and propagation of several mobile elements including prophages, transposons and plasmids harbouring virulence factors. Significant differences in the repertoire of the CRISPR (clustered regularly interspersed short palindromic repeats)-cas system of all C. fetus strains was also found. We therefore suggest that a deficiency in this adaptive immune system may have permitted the emergence of extensive genome plasticity and led to changes in host tropism through gene disruption and/or changes in gene expression. Notable differences in the sub-species complement of DNA adenine methylase genes may also have an impact. These data will facilitate future studies to better understand the precise genetic differences that underlie the phenotypic and virulence differences between these animal pathogens and may identify additional markers useful for diagnosis and sub-typing.

scholarly journals Identification through Culture and Molecular Methods of Campylobacter jejuni, Campylobacter coli and Campylobacter fetus in Surface Waters in Rasht

2019 ◽  
pp. 1-7
Author(s):  
Keyvan Roshanjo ◽  
Nematallah Jonaidi Jafari ◽  
Leila Asadpour ◽  
Reza Ranjbar ◽  
Davoud Afshar ◽  
...  
Keyword(s):  
Multiplex Pcr ◽  
Campylobacter Jejuni ◽  
Surface Waters ◽  
Disease Transmission ◽  
Cross Sectional Study ◽  
Campylobacter Coli ◽  
Infectious Agents ◽  
Biochemical Tests ◽  
Cross Sectional ◽  
Campylobacter Fetus

Backgrounds: As zoonotic infectious agents, Campylobacter spp. are important factors causing gastroenteritis in humans. Surveys show that the three strains; Campylobacter jejuni, Campylobacter coli and Campylobacter fetus play a major role in human infections. Identification of these infectious agents is valuable for sanitary control of disease transmission through water resources. Objectives: The aim of this study was identification and molecular diagnosis of Campylobacter jejuni, Campylobacter coli and Campylobacter fetus in surface waters in Rasht. Materials and Methods: This cross-sectional study was conducted on 45 samples of surface water in Rasht collected according to water health guidelines. After culture and biochemical tests on collected samples, detection and identification of Campylobacter jejuni, Campylobacter coli and Campylobacter fetus was done using sequence-specific amplification by Multiplex PCR. The results were subjected to statistical analysis using SPSS software. Results: Out of 45 samples tested, 6 were positive in culture, four of which were identified as Campylobacter jejuni after biochemical tests. Using Multiplex PCR, 8 samples were positive, from which 3 were Campylobacter jejuni, 1 Campylobacter coli and 4 were positive for both Campylobacter jejuni and Campylobacter coli. All the samples did not yield C. fetus. Conclusions: Multiplex PCR is regarded a diagnostic method with higher sensitivity and specificity than compared to methods for Campylobacter. The prevalence of Campylobacter jejuni and Campylobacter coli in surface waters in Rasht is considerable. Therefore, public health measures for the control of these organisms are recommended.

scholarly journals Selective maintenance of multiple CRISPR arrays across prokaryotes

2017 ◽  
Author(s):  
Jake L. Weissman ◽  
William F. Fagan ◽  
Philip L.F. Johnson
Keyword(s):  
Immune System ◽  
Defense Mechanisms ◽  
Short Term Memory ◽  
Memory Span ◽  
Adaptive Immune System ◽  
Long Term Memory ◽  
Term Memory ◽  
Learning Speed ◽  
Single Organism ◽  
Multiple Copies

AbstractProkaryotes are under nearly constant attack by viral pathogens. To protect against this threat of infection, bacteria and archaea have evolved a wide array of defense mechanisms, singly and in combination. While immune diversity in a single organism likely reduces the chance of pathogen evolutionary escape, it remains puzzling why many prokaryotes also have multiple, seemingly redundant, copies of the same type of immune system. Here, we focus on the highly flexible CRISPR adaptive immune system, which is present in multiple copies in a surprising 28% of the prokaryotic genomes in RefSeq. We use a comparative genomics approach looking across all prokaryotes to demonstrate that, on average, organisms are under selection to maintain more than one CRISPR array. We hypothesize that a tradeoff between memory span and learning speed could select for both “long-term memory” and “short-term memory” CRISPR arrays, and we go on to develop a mathematical model to show that such a tradeoff could, in theory, lead to selection for multiple arrays.

scholarly journals Differential Expression of Toll-Like Receptors 2 and 4 in Tissues of the Human Female Reproductive Tract

2004 ◽  
Vol 72 (10) ◽  
pp. 5799-5806 ◽  
Author(s):  
Patricia A. Pioli ◽  
Eyal Amiel ◽  
Todd M. Schaefer ◽  
John E. Connolly ◽  
Charles R. Wira ◽  
...  
Keyword(s):  
Protein Expression ◽  
Defense Mechanisms ◽  
Reproductive Tract ◽  
Female Reproductive Tract ◽  
Central Component ◽  
Mrna Levels ◽  
Fallopian Tubes ◽  
Human Female ◽  
Innate Defense ◽  
Relative Paucity

ABSTRACT Toll-like receptor (TLR) signal transduction is a central component of the innate immune response to pathogenic challenge. Although recent studies have begun to elucidate differences in acquired immunity in tissues of the human female reproductive tract, there is a relative paucity of work regarding innate defense mechanisms. We investigated TLR mRNA and protein expression in tissues of the human female reproductive tract. Constitutive mRNA expression of TLRs 1 to 6 was observed in fallopian tubes, uterine endometrium, cervix, and ectocervix. Furthermore, transcripts of the signaling adapter MyD88 and the accessory molecule CD14 were also detected in all tissues assayed. Quantitative analysis of TLR2 mRNA levels revealed highest expression of this molecule in fallopian tube and cervical tissues, followed by endometrium and ectocervix. In contrast to TLR2, TLR4 expression declined progressively along the tract, with highest expression in the upper tissues (fallopian tubes and endometrium), followed by cervix and ectocervix. In addition to mRNA, protein expression of TLR2 and TLR4 was also documented in these tissues. These data suggest that TLRs are differentially expressed in distinct compartments of the female reproductive tract and may provide insight regarding the regulation of inflammation and immunity within the tract.

scholarly journals Orthopoxvirus Genes That Mediate Disease Virulence and Host Tropism

2012 ◽  
Vol 2012 ◽  
pp. 1-17 ◽  
Author(s):  
Sergei N. Shchelkunov
Keyword(s):  
Experimental Data ◽  
Defense Mechanisms ◽  
Molecular Mechanisms ◽  
Variola Virus ◽  
Infectious Agents ◽  
Host Organism ◽  
Host Tropism ◽  
Defense Systems ◽  
Vaccinia Viruses ◽  
And Function

In the course of evolution, viruses have developed various molecular mechanisms to evade the defense reactions of the host organism. When understanding the mechanisms used by viruses to overcome manifold defense systems of the animal organism, represented by molecular factors and cells of the immune system, we would not only comprehend better but also discover new patterns of organization and function of these most important reactions directed against infectious agents. Here, study of the orthopoxviruses pathogenic for humans, such as variola (smallpox), monkeypox, cowpox, and vaccinia viruses, may be most important. Analysis of the experimental data, presented in this paper, allows to infer that variola virus and other orthopoxviruses possess an unexampled set of genes whose protein products efficiently modulate the manifold defense mechanisms of the host organisms compared with the viruses from other families.

scholarly journals Phenotypic and Genotypic Characterisation of Pasteurella Multocida Strains Isolated from Pigs in Poland

2013 ◽  
Vol 57 (1) ◽  
pp. 29-34 ◽  
Author(s):  
Katarzyna Stępniwska ◽  
Iwona Markowska-Daniel
Keyword(s):  
Pasteurella Multocida ◽  
Type A ◽  
High Susceptibility ◽  
Biochemical Tests ◽  
Internal Organs ◽  
Type D ◽  
Phenotypic Characterisation ◽  
Nasal Swabs ◽  
Typing Methods ◽  
Capsular Typing

AbstractA total of 319Pasteurella multocida(Pm) strains isolated from pigs in Poland were examined. Phenotypic characterisation included: biochemical tests (to determine species, subspecies, and biovar), capsular typing, and antimicrobial susceptibility. Genotypic characterisation included detection of thetoxAgene by PCR. All testedPmstrains were classified asPmsubsp.multocida: 87.2% biovar 3, 10.7%-2 and 0.9%-12. One strain was classified as biovar 1. Three strains ofPmdid not suit any of the biovars. Using capsular typing methods, 77% ofPmstrains isolated from nasal swabs belonged to type D and 33% to type A. AmongPmstrains isolated from internal organs, 59.5% belonged to type A and 40.5% to type D. All the isolates showed a high susceptibility to β-lactams: ampicillin and amoxicilin with clavulonic acid (97.8%), penicillin (86.7%), doxicilline (100%), oxytetracycline (97.8%), and tetracycline (93.2%). It was found that all strains were susceptible to norfloxacin, 97.8% to enrofloxacin, and 95.6% to SxT. 24.4% and 15.6% of the strains were resistant to linco-spectin and tiamulin, respectively. The presence oftoxAgene was confirmed by PCR in 20.8% of the strains isolated from nasal swabs and 29.1% of isolates from internal organs.

scholarly journals Planarians (Platyhelminthes)—An Emerging Model Organism for Investigating Innate Immune Mechanisms

2021 ◽  
Vol 11 ◽  
Author(s):  
Luis Johnson Kangale ◽  
Didier Raoult ◽  
Pierre-Edouard Fournier ◽  
Prasad Abnave ◽  
Eric Ghigo
Keyword(s):  
Immune System ◽  
Defense Mechanisms ◽  
Model Organism ◽  
Adaptive Immune System ◽  
Innate Immune ◽  
Whole Body ◽  
Immune Recognition ◽  
Immune Mechanisms ◽  
Adaptive Immune ◽  
Antimicrobial Resistance Genes

An organism responds to the invading pathogens such as bacteria, viruses, protozoans, and fungi by engaging innate and adaptive immune system, which functions by activating various signal transduction pathways. As invertebrate organisms (such as sponges, worms, cnidarians, molluscs, crustaceans, insects, and echinoderms) are devoid of an adaptive immune system, and their defense mechanisms solely rely on innate immune system components. Investigating the immune response in such organisms helps to elucidate the immune mechanisms that vertebrates have inherited or evolved from invertebrates. Planarians are non-parasitic invertebrates from the phylum Platyhelminthes and are being investigated for several decades for understanding the whole-body regeneration process. However, recent findings have emerged planarians as a useful model for studying innate immunity as they are resistant to a broad spectrum of bacteria. This review intends to highlight the research findings on various antimicrobial resistance genes, signaling pathways involved in innate immune recognition, immune-related memory and immune cells in planarian flatworms.

scholarly journals Oligosaccharides: Defense Inducers, Their Recognition in Plants, Commercial Uses and Perspectives

Molecules ◽  
2020 ◽  
Vol 25 (24) ◽  
pp. 5972
Author(s):  
Nathalie Guarnizo ◽  
Diego Oliveros ◽  
Walter Murillo-Arango ◽  
María Bianney Bermúdez-Cardona
Keyword(s):  
Defense Mechanisms ◽  
High Efficiency ◽  
Adaptive Immune System ◽  
Innate Immune ◽  
Pathogenic Microorganisms ◽  
Commercial Products ◽  
Resistance Induction ◽  
Adaptive Immune ◽  
Cellular Events ◽  
Increase Productivity

Plants have innate immune systems or defense mechanisms that respond to the attack of pathogenic microorganisms. Unlike mammals, they lack mobile defense cells, so defense processes depend on autonomous cellular events with a broad repertoire of recognition to detect pathogens, which compensates for the lack of an adaptive immune system. These defense mechanisms remain inactive or latent until they are activated after exposure or contact with inducing agents, or after the application of the inductor; they remain inactive only until they are affected by a pathogen or challenged by an elicitor from the same. Resistance induction represents a focus of interest, as it promotes the activation of plant defense mechanisms, reducing the use of chemical synthesis pesticides, an alternative that has even led to the generation of new commercial products with high efficiency, stability and lower environmental impact, which increase productivity by reducing not only losses but also increasing plant growth. Considering the above, the objective of this review is to address the issue of resistance induction with a focus on the potential of the use of oligosaccharides in agriculture, how they are recognized by plants, how they can be used for commercial products and perspectives.

scholarly journals Non-Reflex Defense Mechanisms of Upper Airway Mucosa: Possible Clinical Application

2020 ◽  
pp. S55-S67 ◽  
Author(s):  
H. Pedan ◽  
V. Janosova ◽  
A. Hajtman ◽  
V. Calkovsky
Keyword(s):  
Immune System ◽  
Defense Mechanisms ◽  
Upper Airway ◽  
Adaptive Immune System ◽  
Daily Practice ◽  
Upper Respiratory Tract ◽  
Mucosal Vaccination ◽  
Adaptive Immune ◽  
Airway Mucosa ◽  
Sinonasal Mucosa

The sinonasal mucosa has an essential role in defense mechanisms of the upper respiratory tract. The innate immune system presents the primary defense against noxious microorganisms followed by induction of the adaptive immune mechanisms as a consequence of the presence of pathogens. This well-known activation of adaptive immune system in response to presence of the antigen on mucosal surfaces is now broadly applicated in vaccinology research. Prevention of infectious diseases belongs to substantial challenges in maintaining the population health. Non-invasive, easily applicable mucosal vaccination purposes various research opportunities that could be usable in daily practice. However, the existence of multiple limitations such as rapid clearance of vaccine from nasal mucosa by means of mucociliary transport represents a great challenge in development of safe and efficient vaccines. Here we give an updated view on nasal functions with focus on nasal mucosal immunity and its potential application in vaccination in nearly future.

Effect of Contraceptive Steroids on the Endometrium of Guinea Pig: SEM study

1977 ◽  
Vol 35 ◽  
pp. 668-669
Author(s):  
Mai M. Said ◽  
Ramesh K. Nayak ◽  
Randall E. McCoy
Keyword(s):  
Guinea Pig ◽  
Reproductive Tract ◽  
Three Dimensional ◽  
Female Reproductive Tract ◽  
Human Female ◽  
Surface Ultrastructure ◽  
Transmission Electron ◽  
Sem Study ◽  
Uterine Mucosa ◽  
Group 1

Burgos and Wislocki described changes in the mucosa of the guinea pig uterus, cervix and vagina during the estrous cycle investigated by transmission electron microscopy. More recently, Moghissi and Reame reported the effects of progestational agents on the human female reproductive tract. They found drooping and shortening of cilia in norgestrel and norethindrone- treated endometria. To the best of our knowledge, no studies concerning the effects of mestranol and norethindrone given concurrently on the three-dimensional surface features on the uterine mucosa of the guinea pig have been reported. The purpose of this study was to determine the effect of mestranol and norethindrone on surface ultrastructure of guinea pig uterus by SEM.Seventy eight animals were used in this study. They were allocated into two groups. Group 1 (20 animals) was injected intramuscularly 0.1 ml vegetable oil and served as controls.

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