scholarly journals A polyphasic approach with molecular phylogeny for the characterization of Anisakis pegreffii (Anisakidae: Nematoda) in fishes from Adriatic Sea

2013 ◽  
Vol 50 (2) ◽  
pp. 112-118
Author(s):  
F. Luca ◽  
A. Vovlas ◽  
A. Troccoli ◽  
N. Vovlas

AbstractIn this study we investigated the morphometric and molecular characterization of a liver encapsulated third-stage larval population of Anisakis spp. infecting Merluccius merluccius and Lophius piscatorius caught in the Adriatic Sea waters (southern Italy). A polyphasic approach based on PCR-RFLP profiles of the ITS region, mitochondrial COI (cytochrome c oxidase subunit 1), sequencing and molecular phylogeny of ITS and mitochondrial COI was used to identify Anisakis larvae collected from fish samples. PCR-RFLP analysis showed three banding pattern corresponding to the peculiar pattern of A. pegreffii. Sequence data from ribosomal ITS and mitochondrial COI were analysed by Neighbour Joining, Minimum Evolution and Maximum Parsimony methods to evaluate the phylogenetic relationships among A. simplex sensu lato. The phylogenetic trees obtained for both ITS and COI revealed the existence of three distinct clades for A. simplex sensu sricto, A. simplex C and A. pegreffii and the sequences obtained in this study clearly clustered together with A. pegreffii sequences present in the database.Histopathological observations of anisakid nematode specimens detected on the liver surface of M. merluccius are illustrated. Encapsulated specimens of the L3 stage of the nematode were similar in size and morphometry to those found into the peritoneal cavity. Anisakis larvae encapsulated on the liver surface within dense and pearl coloured envelops caused host hepatic tissue necrosis, large cavities and oedematous liver spots to the host.

Author(s):  
Warepam Amuchou Singh ◽  
Nandeibam Samarjit Singh ◽  
Elangbam Julia Devi ◽  
Pratap Jyoti Handique ◽  
Huidrom Sunitibala Devi

Pathogens ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 41
Author(s):  
Marcos Godoy ◽  
Daniel A. Medina ◽  
Rudy Suarez ◽  
Sandro Valenzuela ◽  
Jaime Romero ◽  
...  

Piscine orthoreovirus (PRV) belongs to the family Reoviridae and has been described mainly in association with salmonid infections. The genome of PRV consists of about 23,600 bp, with 10 segments of double-stranded RNA, classified as small (S1 to S4), medium (M1, M2 and M3) and large (L1, L2 and L3); these range approximately from 1000 bp (segment S4) to 4000 bp (segment L1). How the genetic variation among PRV strains affects the virulence for salmonids is still poorly understood. The aim of this study was to describe the molecular phylogeny of PRV based on an extensive sequence analysis of the S1 and M2 segments of PRV available in the GenBank database to date (May 2020). The analysis was extended to include new PRV sequences for S1 and M2 segments. In addition, subgenotype classifications were assigned to previously published unclassified sequences. It was concluded that the phylogenetic trees are consistent with the original classification using the PRV genomic segment S1, which differentiates PRV into two major genotypes, I and II, and each of these into two subgenotypes, designated as Ia and Ib, and IIa and IIb, respectively. Moreover, some clusters of country- and host-specific PRV subgenotypes were observed in the subset of sequences used. This work strengthens the subgenotype classification of PRV based on the S1 segment and can be used to enhance research on the virulence of PRV.


2006 ◽  
Vol 106 (3) ◽  
pp. 297-306 ◽  
Author(s):  
A. Llorens ◽  
M.J. Hinojo ◽  
R. Mateo ◽  
M.T. González-Jaén ◽  
F.M. Valle-Algarra ◽  
...  

2015 ◽  
Vol 59 (9) ◽  
pp. 5357-5365 ◽  
Author(s):  
Hilde Smith ◽  
Alex Bossers ◽  
Frank Harders ◽  
Guanghui Wu ◽  
Neil Woodford ◽  
...  

ABSTRACTThe aim of the study was to identify the plasmid-encoded factors contributing to the emergence and spread of epidemic IncI1-Iγ plasmids obtained fromEscherichia coliandSalmonella entericaisolates from animal and human reservoirs. For this, 251 IncI1-Iγ plasmids carrying various extended-spectrum β-lactamase (ESBL) or AmpC β-lactamase genes were compared using plasmid multilocus sequence typing (pMLST). Thirty-two of these plasmids belonging to different pMLST types were sequenced using Roche 454 and Illumina platforms. Epidemic IncI1-Iγ plasmids could be assigned to various dominant clades, whereas rarely detected plasmids clustered together as a distinct clade. Similar phylogenetic trees were obtained using only the plasmid backbone sequences, showing that the differences observed between the plasmids belonging to distinct clades resulted mainly from differences between their backbone sequences. Plasmids belonging to the various clades differed particularly in the presence/absence of genes encoding partitioning and addiction systems, which contribute to stable inheritance during cell division and plasmid maintenance. Despite this, plasmids belonging to the various phylogenetic clades also showed marked resistance gene associations, indicating the circulation of successful plasmid-gene combinations. The variation intraYandexcAgenes found in IncI1-Iγ plasmids is conserved within pMLST sequence types and plays a role in incompatibility, although functional study is needed to elucidate the role of these genes in plasmid epidemiology.


2006 ◽  
Vol 23 (5) ◽  
pp. 418-422 ◽  
Author(s):  
D. Ottaviani ◽  
S. Santarelli ◽  
S. Bacchiocchi ◽  
L. Masini ◽  
C. Ghittino ◽  
...  
Keyword(s):  

2020 ◽  
Author(s):  
Mansoor Kodori ◽  
Zohreh Ghalavand ◽  
Abbas Yadegar ◽  
Gita Eslami ◽  
Masoumeh Azimirad ◽  
...  

Abstract Background: Clostridioides difficile is the main cause of healthcare-associated diarrhea worldwide. It is proposed that certain C. difficile toxinotypes with distinct pathogenicity locus (PaLoc) variants are associated with disease severity and outcomes. Additionally, few studies have described the common C. difficile toxinotypes, and also little is known about the tcdC variants in Iranian isolates. We characterized the toxinotypes and the tcdC genotypes from a collection of Iranian clinical C. difficile tcdA+B+ isolates with known ribotypes (RTs).Methods: Fifty C. difficile isolates with known RTs and carrying the tcdA and tcdB toxin genes were analyzed. Toxinotyping was carried out based on a PCR-RFLP analysis of a 19.6 kb region encompassing the PaLoc. Genetic diversity of the tcdC gene was determined by the sequencing of the gene.Results: Of the 50 C. difficile isolates investigated, five distinct toxinotypes were recognized. Toxinotypes 0 (33/50, 66%) and V (11/50, 22%) were the most frequently found. C. difficile isolates of the toxinotype 0 mostly belonged to RT 001 (12/33, 36.4%), whereas toxinotype V consisted of RT 126 (9/11, 81.8%). The tcdC sequencing showed six variants (35/50, 70%); tcdC-sc3 (24%), tcdC-A (22%), tcdC-sc9 (18%), tcdC-B (2%), tcdC-sc14 (2%), and tcdC-sc15 (2%). The remaining isolates were wild-types (15/50, 30%) in the tcdC gene.Conclusions: The present study demonstrates that the majority of clinical tcdA+B+ isolates of C. difficile frequently harbor tcdC genetic variants. We also found that the RT 001/ toxinotype 0 and the RT 126/ toxinotype V are the most common types among Iranian isolates. Further studies are needed to investigate the putative association of various tcdC genotypes with CDI severity and its recurrence.


2021 ◽  
Vol 118 (12) ◽  
pp. e2021244118
Author(s):  
Alessio Caminata ◽  
Noah Giansiracusa ◽  
Han-Bom Moon ◽  
Luca Schaffler

In 2004, Pachter and Speyer introduced the higher dissimilarity maps for phylogenetic trees and asked two important questions about their relation to the tropical Grassmannian. Multiple authors, using independent methods, answered affirmatively the first of these questions, showing that dissimilarity vectors lie on the tropical Grassmannian, but the second question, whether the set of dissimilarity vectors forms a tropical subvariety, remained opened. We resolve this question by showing that the tropical balancing condition fails. However, by replacing the definition of the dissimilarity map with a weighted variant, we show that weighted dissimilarity vectors form a tropical subvariety of the tropical Grassmannian in exactly the way that Pachter and Speyer envisioned. Moreover, we provide a geometric interpretation in terms of configurations of points on rational normal curves and construct a finite tropical basis that yields an explicit characterization of weighted dissimilarity vectors.


2020 ◽  
Vol 76 (01) ◽  
pp. 6334-2020
Author(s):  
ZEYNEP AKKUTAY-YOLDAR ◽  
TAYLAN KOÇ B.

Canine parvovirus (CPV) type 2 is the causative agent of acute hemorrhagic enteritis and high mortality in the affected dogs. Numerous studies have been done to understand the origin of the virus and to exhibit new variants and circulating strains. This report describes the detection and genomic characterization of CPV strains from indoor and outdoor dogs in Ankara, Turkey. Samples were sent to our laboratory due to clinical symptoms in puppies. We tested blood and swab samples to determine the presence of canine parvovirus (CPV) in three puppies and two adult dogs by reverse transcription-polymerase chain reaction (RT-PCR) using VP2 (capsid protein) region primers of canine parvoviruses. Following that, to provide molecular characterization data Maximum Likelihood (ML) method was used for phylogenetic analyses. Constructed phylogenetic trees from the aligned nucleotide sequences revealed that our CPV strains demonstrated high genetic similarities, with 100% identity match on nucleotide alignments with each other and classified in CPV-2b genotypes.They have placed on a monophyletic clade as a sister branch with CPV VAC S quantum with 98.9% nucleotide homology. Our findings suggest that CPV-2b is actual and frequently seen variant in Turkey and shows high similarities with other CPV variants and a bit less with FPVs in Turkey and around the world. CPV causes high mortality and morbidity in dogs and to develop effective vaccines for protection of dogs in Turkey where there are few numbers of studies that have been done, field strains should be isolated and characterised.


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