scholarly journals Pathogenesis, Epidemiology and Variants of Melissococcus plutonius (Ex White), the Causal Agent of European Foulbrood

2020 ◽  
Vol 64 (2) ◽  
pp. 173-188
Author(s):  
Adrián Ponce de León-Door ◽  
Gerardo Pérez-Ordóñez ◽  
Alejandro Romo-Chacón ◽  
Claudio Rios-Velasco ◽  
José D. J. Órnelas-Paz ◽  
...  
Keyword(s):  
Morphological Characteristics ◽  
Etiologic Agent ◽  
Infection Process ◽  
Control Measures ◽  
Molecular Tools ◽  
Bacterial Diseases ◽  
Bacterial Development ◽  
Melissococcus Plutonius ◽  
European Foulbrood

AbstractThe bacterium Melissococcus plutonius is the etiologic agent of the European foulbrood (EFB), one of the most harmful bacterial diseases that causes the larvae of bees to have an intestinal infection. Although EFB has been known for more than a century and is practically present in all countries where beekeeping is practiced, the disease has been little studied compared to American foulbrood. Recently, great advances have been made to understand the disease and the interaction between the pathogen and its host. This review summarizes the research and advances to understand the disease. First, the morphological characteristics of M. plutonius, the infection process and bacterial development in the gut of the larva are described. Also, the epidemiological distribution of EFB and factors that favor the development of the disease as well as the classification of M. plutonius according its genomic and phenotype characteristics are reported. Finally, the new molecular tools for the study of M. plutonius, possible virulence factors in its genome, the issue of current EFB control measures and possible alternatives to the use of antibiotics are addressed.

The occurrence of Melissococcus plutonius in healthy colonies of Apis mellifera and the efficacy of European foulbrood control measures

2010 ◽  
Vol 105 (2) ◽  
pp. 164-170 ◽  
Author(s):  
Giles E. Budge ◽  
Ben Barrett ◽  
Ben Jones ◽  
Stéphane Pietravalle ◽  
Gay Marris ◽  
...  
Keyword(s):  
Apis Mellifera ◽  
Control Measures ◽  
Melissococcus Plutonius ◽  
European Foulbrood

RHYNCHOLITES AND THE PROBLEM OF NARROW AND BROAD CONCEPTION OF TAXONS

2018 ◽  
pp. 12-17 ◽  
Author(s):  
I. R. Khuzina ◽  
V. N. Komarov
Keyword(s):  
Sexual Dimorphism ◽  
Morphological Characteristics ◽  
Mass Scale ◽  
Individual Variability ◽  
Point Of View ◽  
The Other ◽  
New Taxon ◽  
Artificial System ◽  
Broad Understanding

The paper considers a point of view, based on the conception of the broad understanding of taxons. According to this point of view, rhyncholites of the subgenus Dentatobeccus and Microbeccus are accepted to be synonymous with the genus Rhynchoteuthis, and subgenus Romanovichella is considered to be synonymous with the genus Palaeoteuthis. The criteria, exercising influence on the different approaches to the classification of rhyncholites, have been analyzed (such as age and individual variability, sexual dimorphism, pathological and teratological features, degree of disintegration of material), underestimation of which can lead to inaccuracy. Divestment of the subgenuses Dentatobeccus, Microbeccus and Romanovichella, possessing very bright morphological characteristics, to have an independent status and denomination to their synonyms, has been noted to be unjustified. An artificial system (any suggested variant) with all its minuses is a single probable system for rhyncholites. The main criteria, minimizing its negative sides and proving the separation of the new taxon, is an available mass-scale material. The narrow understanding of the genus, used in sensible limits, has been underlined to simplify the problem of the passing the view about the genus to the other investigators and recognition of rhyncholites for the practical tasks.

scholarly journals Effects of heterogeneity in infection-exposure history and immunity on the dynamics of a protozoan parasite

2007 ◽  
Vol 4 (16) ◽  
pp. 841-849 ◽  
Author(s):  
Maite Severins ◽  
Don Klinkenberg ◽  
Hans Heesterbeek
Keyword(s):  
Dynamic Behaviour ◽  
Protozoan Parasite ◽  
Host Population ◽  
Infection Process ◽  
Control Measures ◽  
Complex Dynamic ◽  
Systems Models ◽  
Exposure History ◽  
The Relationship ◽  
Initial Contamination

Infection systems where traits of the host, such as acquired immunity, interact with the infection process can show complex dynamic behaviour with counter-intuitive results. In this study, we consider the traits ‘immune status’ and ‘exposure history’, and our aim is to assess the influence of acquired individual heterogeneity in these traits. We have built an individual-based model of Eimeria acervulina infections, a protozoan parasite with an environmental stage that causes coccidiosis in chickens. With the model, we simulate outbreaks of the disease under varying initial contaminations. Heterogeneity in the traits arises stochastically through differences in the dose and frequency of parasites that individuals pick up from the environment. We find that the relationship between the initial contamination and the severity of an outbreak has a non-monotonous ‘wave-like’ pattern. This pattern can be explained by an increased heterogeneity in the host population caused by the infection process at the most severe outbreaks. We conclude that when dealing with these types of infection systems, models that are used to develop or evaluate control measures cannot neglect acquired heterogeneity in the host population traits that interact with the infection process.

scholarly journals Morphological Characteristics, Classifications and Difficulties in the Use of Diagnostic Criteria for Serrated Lesions of the Large Intestine

2021 ◽  
Author(s):  
Cesar de Souza Bastos Junior ◽  
Vera Lucia Nunes Pannain ◽  
Adriana Caroli-Bottino
Keyword(s):  
Diagnostic Criteria ◽  
Morphological Characteristics ◽  
World Health ◽  
Diagnostic Tools ◽  
Serrated Adenoma ◽  
The Past ◽  
The World ◽  
Serrated Lesions ◽  
Health Organization

Abstract Introduction Colorectal carcinoma (CRC) is the most common gastrointestinal neoplasm in the world, accounting for 15% of cancer-related deaths. This condition is related to different molecular pathways, among them the recently described serrated pathway, whose characteristic entities, serrated lesions, have undergone important changes in their names and diagnostic criteria in the past thirty years. The multiplicity of denominations and criteria over the last years may be responsible for the low interobserver concordance (IOC) described in the literature. Objectives The present study aims to describe the evolution in classification of serrated lesions, based on the last three publications of the World Health Organization (WHO) and the reproducibility of these criteria by pathologists, based on the evaluation of the IOC. Methods A search was conducted in the PubMed, ResearchGate and Portal Capes databases, with the following terms: sessile serrated lesion; serrated lesions; serrated adenoma; interobserver concordance; and reproducibility. Articles published since 1990 were researched. Results and Discussion The classification of serrated lesions in the past thirty years showed different denominations and diagnostic criteria. The reproducibility and IOC of these criteria in the literature, based on the kappa coefficient, varied in most studies, from very poor to moderate. Conclusions Interobserver concordance and the reproducibility of microscopic criteria may represent a limitation for the diagnosis and appropriate management of these lesions. It is necessary to investigate diagnostic tools to improve the performance of the pathologist's evaluation, for better concordance, and, consequently, adequate diagnosis and treatment.

scholarly journals Emerging trends of nosocomial Citrobacter species surgical wound infection: concern for infection control

1970 ◽  
Vol 9 (1) ◽  
pp. 10-14
Author(s):  
B Thapa ◽  
D Karn ◽  
K Mahat
Keyword(s):  
Infection Control ◽  
Wound Infection ◽  
Infection Process ◽  
Surgical Wound Infection ◽  
Control Measures ◽  
Drug Resistant ◽  
Surgical Wound ◽  
Disk Diffusion Test ◽  
Antibiotic Susceptibility Test ◽  
Study Results

Background Surgical wound infection is a common problem among patients who undergo operation. Several factors play important role in this infection process including endemic nosocomial infection without proper infection control measures. Objectives To study the occurrence of the pathogens in post-operative wound infections, their antibiotic resistance patterns, and comparison with published reports. Methods Various specimens obtained from the surgical wound during a period of four months were processed for bacteriological culture in the Department of Microbiology, Kathmandu Medical College, Kathmandu. Antibiotic susceptibility test was performed by Kirby-Bauer disk diffusion test for pathogens isolated. The relevant literatures were searched and compared with the present study. Results Among 79 culture positive cultures, Citrobacter sp. (n=23) was most frequently isolated from surgical wound infection. Twenty strains were multidrug resistant. In comparison with other studies, this study highlights the emergence multi-drug resistant Citrobacter sp. as a leading cause of surgical wound infection. E. coli, Staphylococcus aureus, Acinetobacter sp., Klebsiella pneumoniae, Pseudomonas aeruginosa, Proteus sp., and Enterobacter sp. were also isolated from 19, 13, 10, 8, 2, 2, and 2 cultures, respectively. More than 50% of these pathogens were resistant to most of the β-lactam antibiotics tested and most of them were multi-drug resistant while these pathogens showed variable level of resistance to fluroquinolones and amino glycosides. Conclusion The frequent isolation of multi-drug resistant nosocomial strains of Citrobacter sp. in surgical wound infection is a remarkable trend. This pathogen and their resistant genes could be endemic to the institution and can cause difficult-to-treat infection if infection control committee is not revitalized and infection control strategies are not implemented. Key words Citrobacter sp.; Multi-drug resistant; surgical wound infection. DOI: http://dx.doi.org/10.3126/njdvl.v9i1.5762 NJDVL 2010; 9(1): 10-14

scholarly journals Early Iron Age Sword from the Territory of the Middle Yenisei

2021 ◽  
Vol 20 (7) ◽  
pp. 135-143
Author(s):  
Oleg A. Mitko ◽  
Sergey G. Skobelev
Keyword(s):  
Iron Age ◽  
Low Carbon Steel ◽  
Morphological Characteristics ◽  
Early Iron Age ◽  
Low Carbon ◽  
North Caucasus ◽  
Group Iii ◽  
The North ◽  
Minusinsk Basin

Purpose. The article is devoted to the characteristics of a double-edged iron sword, which can be attributed to the unique phenomena of the early Iron Age of the Minusinsk Basin. Results. According to its morphological characteristics, the sword is an increased technological modification of the traditional Tagar dagger. The total length of the sword is 59.5 cm; the width of the lenticular blade in cross-section is about 7 cm. The handle with a volute-like pommel is separated from the blade by a narrow butterfly-shaped crosshair. The length of the hilt is 8 cm, which corresponds to the size of the hilts of most Scythian swords. This is a very small size, since in men the average palm width is about 12 cm. Probably, the rounded outlines of the pommel and narrow crosshairs allow, due to their shape, to hold the short handle of a heavy sword more tightly. Conclusion. According to the classification of O. I. Kura, Scythian swords with a narrow butterfly-shaped crosshair and volute-like pommel are included in Group III, Type II A2 dating from the end of the 5th – 4th centuries BC, which corresponds to the boundary between the Podgorny and Saragashen stages of the Tagar culture. The earliest form of sword hilts with typologically similar forms of crosshairs (kidney-shaped, heart-shaped, butterfly-shaped) with bar-shaped pommels appeared in the North Caucasus in the first half of the 7th century BC. On the territory of the Minusinsk Basin, most morphologically similar daggers are usually dated to the 6th – 4th centuries BC. Before the discovery of the Krasnoyarsk sword, long-bladed iron weapons were not known there. At the same time, swords of the Scythian time were found in the nearest regions of Altai and Kazakhstan. The later appearance of the technology for processing iron in the Minusinsk Basin makes it possible to consider the Krasnoyarsk sword an import item. According to another hypothesis, it belongs to the period of the late 3rd – 2nd centuries BC, when local craftsmen mastered the processing of iron and began to make massive quantities of weapons and tools from low-carbon steel. In doing so, they copied traditional archaic forms.

scholarly journals Characterization of Five New Earthworm Mitogenomes (Oligochaeta: Lumbricidae): Mitochondrial Phylogeny of Lumbricidae

Diversity ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 580
Author(s):  
Hongyi Liu ◽  
Yufeng Zhang ◽  
Wei Xu ◽  
Yu Fang ◽  
Honghua Ruan
Keyword(s):  
Phylogenetic Trees ◽  
Mitochondrial Gene ◽  
Morphological Characteristics ◽  
Molecular Techniques ◽  
Phylogenetic Studies ◽  
Octolasion Tyrtaeum ◽  
Eisenia Nordenskioldi ◽  
Novel Strategy

Identification based on conventional morphological characteristics is typically difficult and time-consuming. The development of molecular techniques provides a novel strategy that relies on specific mitochondrial gene fragments to conduct authentication. For this study, five newly sequenced partial mitogenomes of earthworms (Bimastos parvus, Dendrobaena octaedra, Eisenia andrei, Eisenia nordenskioldi, and Octolasion tyrtaeum) with lengths ranging from 14,977 to 15,715 were presented. Each mitogenome possessed a putative control region that resided between tRNA-Arg and tRNA-His. All of the PCGs were under negative selection according to the value of Ka/Ks. The phylogenetic trees supported the classification of Eisenia and Lumbricus; however, the trees based on cox1 did not. Through various comparisons, it was determined that cox1 fragments might be more suitable for molecular identification. These results lay the foundation for further phylogenetic studies on Lumbricidae.

scholarly journals Bacterial community associated with worker honeybees (Apis mellifera) affected by European foulbrood

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3816 ◽  
Author(s):  
Tomas Erban ◽  
Ondrej Ledvinka ◽  
Martin Kamler ◽  
Bronislava Hortova ◽  
Marta Nesvorna ◽  
...  
Keyword(s):  
Apis Mellifera ◽  
Clinical Symptoms ◽  
Clinical Signs ◽  
Illumina Miseq ◽  
Amplicon Sequencing ◽  
Rrna Gene ◽  
Melissococcus Plutonius ◽  
European Foulbrood ◽  
Bacterial Groups ◽  
V3 Region

BackgroundMelissococcus plutoniusis an entomopathogenic bacterium that causes European foulbrood (EFB), a honeybee (Apis melliferaL.) disease that necessitates quarantine in some countries. In Czechia, positive evidence of EFB was absent for almost 40 years, until an outbreak in the Krkonose Mountains National Park in 2015. This occurrence of EFB gave us the opportunity to study the epizootiology of EFB by focusing on the microbiome of honeybee workers, which act as vectors of honeybee diseases within and between colonies.MethodsThe study included worker bees collected from brood combs of colonies (i) with no signs of EFB (EFB0), (ii) without clinical symptoms but located at an apiary showing clinical signs of EFB (EFB1), and (iii) with clinical symptoms of EFB (EFB2). In total, 49 samples from 27 honeybee colonies were included in the dataset evaluated in this study. Each biological sample consisted of 10 surface-sterilized worker bees processed for DNA extraction. All subjects were analyzed using conventional PCR and by metabarcoding analysis based on the 16S rRNA gene V1–V3 region, as performed through Illumina MiSeq amplicon sequencing.ResultsThe bees from EFB2 colonies with clinical symptoms exhibited a 75-fold-higher incidence ofM. plutoniusthan those from EFB1 asymptomatic colonies.Melissococcus plutoniuswas identified in all EFB1 colonies as well as in some of the control colonies. The proportions ofFructobacillus fructosus,Lactobacillus kunkeei,Gilliamella apicola,Frischella perrara, andBifidobacterium coryneformewere higher in EFB2 than in EFB1, whereasLactobacillus melliswas significantly higher in EFB2 than in EFB0.Snodgrassella alviandL. melliventris,L. helsingborgensisand,L. kullabergensisexhibited higher proportion in EFB1 than in EFB2 and EFB0. The occurrence ofBartonella apisandCommensalibacter intestiniwere higher in EFB0 than in EFB2 and EFB1.Enterococcus faecalisincidence was highest in EFB2.ConclusionsHigh-throughput Illumina sequencing permitted a semi-quantitative analysis of the presence ofM. plutoniuswithin the honeybee worker microbiome. The results of this study indicate that worker bees from EFB-diseased colonies are capable of transmittingM. plutoniusdue to the greatly increased incidence of the pathogen. The presence ofM. plutoniussequences in control colonies supports the hypothesis that this pathogen exists in an enzootic state. The bacterial groups synergic to both the colonies with clinical signs of EFB and the EFB-asymptomatic colonies could be candidates for probiotics. This study confirms thatE. faecalisis a secondary invader toM. plutonius; however, other putative secondary invaders were not identified in this study.

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