scholarly journals Characterization of Aggregatibacter actinomycetemcomitans Serotype b Strains with Five Different, Including Two Novel, Leukotoxin Promoter Structures

Vaccines ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 398 ◽  
Author(s):  
Rolf Claesson ◽  
Huei-Min Chiang ◽  
Mark Lindholm ◽  
Carola Höglund Åberg ◽  
Dorte Haubek ◽  
...  
Keyword(s):  
Genetic Characterization ◽  
Close Association ◽  
Typical Feature ◽  
The Past ◽  
Separate Branch ◽  
Enhanced Expression ◽  
Polymerase Chain ◽  
Serotype B

The JP2 genotype of A. actinomycetemcomitans, serotype b has attracted much interest during the past three decades due to its close association with periodontitis in young individuals and the enhanced expression of a leukotoxin (LtxA). A typical feature of this genotype is a 530-base pair (bp) deletion in the ltxCABD promoter region controlling leukotoxin expression. In the present work, we have characterized serotype b strains with four additional promoter types. Two novel types have been recognized, that is, one with a 230-bp deletion and one with a 172-bp duplication. Moreover, a strain with a 640-bp deletion and three strains with a full-length promoter, including the type strain Y4, were included in the present study. The seven strains were characterized by multi locus sequence typing (MLST) and arbitrarily primed polymerase chain reaction (PCR) and assessed for LtxA production. MLST showed that the strains with the non-JP2-like deletions represented distinct monophyletic groups, whereas the JP2 strain, HK1651, represented a separate branch. LtxA production was high in all three strains with a promoter deletion, whereas the other four strains showed significantly lower levels. It can be concluded that the genetic characterization and determination of LtxA production of A. actinomycetemcomitans isolates from individuals with periodontitis can contribute to the identification of novel virulent genotypes of this bacterium.

scholarly journals First Isolation and Molecular Typing of Pathogenic and Intermediate Leptospira Species from Urine of Symptomatic Dogs

2021 ◽  
Vol 8 (12) ◽  
pp. 304
Author(s):  
Ivana Piredda ◽  
Loris Bertoldi ◽  
Giuseppe Benvenuto ◽  
Bruna Palmas ◽  
Aureliana Pedditzi ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Zoonotic Risk ◽  
Leptospira Spp ◽  
Blood And Urine Samples ◽  
Healthy Dogs ◽  
Polymerase Chain ◽  
Sequence Types ◽  
Leptospira Species

Aim of this study was to evaluate, the presence and diversity of Leptospira spp. in blood and urine samples collected from 175 owned-dogs from Sardinia, Italy. After determination of leptospiral infection by microscopic agglutination test (MAT), urine from MAT-positive dogs were examined by real-time polymerase chain reaction (lipL32 rt-PCR) and then isolated by culture. In order to characterize obtained serovars, positive cultures were then subjected to 16S rRNA and secY sequencing, phylogenetic analysis and Multilocus Sequence Typing (MLST). Results showed that seven dogs (4%; 95% CI: 0–55) had Leptospira DNAs in their urine and five strains were isolated from urine cultures. The three different sequence types (ST17, ST198 and ST24) belonging to Leptospira interrogans genomospecies identified by MLST analyses in this study, confirmed that the leptospiral infection was widespread in Sardinian dogs. We also reported the first characterization of a new Leptospira spp. isolated from urine of one dog living in the study area. Whole genome sequencing and phylogenetic analysis, confirmed that this genospecies was closely related to Leptospira hovindhougenii, an intermediate Leptospira spp. with unknown pathogenicity previously isolated from a rat in Denmark. Further studies are required to clarify whether healthy dogs that shed leptospires in their urine could represent a zoonotic risk for humans in this region.

scholarly journals Sex Determination During Inflorescence Bud Differentiation in Monoecious Pistacia chinensis Bunge

Forests ◽  
2019 ◽  
Vol 10 (3) ◽  
pp. 202 ◽  
Author(s):  
Qian Bai ◽  
Chenyi Zhu ◽  
Xia Lei ◽  
Tao Cao ◽  
Shuchai Su ◽  
...  
Keyword(s):  
Sex Determination ◽  
Early Stage ◽  
Sex Differentiation ◽  
Banding Patterns ◽  
Vegetative Period ◽  
Pcr Products ◽  
Polymerase Chain ◽  
Sex Determination Mechanisms

Pistacia chinensis Bunge is widely acknowledged to be dioecious, but rare monoecious individuals have been found. However, the origin of monoecism and the sex differentiation of different sex types remain intriguing questions. Here, sex expressions were explored by identification of sex-associated DNA markers, determination of the sex stability after grafting, and histological characterization of inflorescence bud development using anatomical analysis. The results showed that (1) although polymorphisms among individuals existed, the banding patterns of Polymerase Chain Reaction (PCR) products for different sex types on the same monoecious tree were consistent; (2) the sex expressions of grafted trees were not consistent with those of scions, indicating that monoecism probably did not originate from a stable bud mutation; and (3) both males and females underwent a bisexual period, then the stamen primordia in female buds degenerated into the second round tepals, while the pistil primordia in male buds gradually disappeared. During the sex differentiation phase, female buds were spindle-shaped, while the male buds were full teardrop-shaped, and male buds were bigger than female buds. Taken together, no sex-associated DNA marker was found, sex expressions were unstable after grafting, and the alternative sex organs appeared in the early stage of sex differentiation, suggesting that sex determination occurred during floral development instead of the early vegetative period. These results indicated that the sex expressions may be affected by environmental factors, increasing the understanding of sex determination mechanisms in P. chinensis and other species.

Moving towards an integrated approach to molecular detection and identification ofToxoplasma gondii

Parasitology ◽  
2009 ◽  
Vol 137 (1) ◽  
pp. 1-11 ◽  
Author(s):  
C. SU ◽  
E. K. SHWAB ◽  
P. ZHOU ◽  
X. Q. ZHU ◽  
J. P. DUBEY
Keyword(s):  
Molecular Detection ◽  
Genetic Characterization ◽  
Integrated Approach ◽  
Epidemiological Studies ◽  
Molecular Methods ◽  
Maximum Information ◽  
The Past ◽  
Phylogenetic Studies ◽  
Detection And Identification

SUMMARYThe development of simple, sensitive and rapid methods for the detection and identification ofToxoplasma gondiiis important for the diagnosis and epidemiological studies of the zoonotic disease toxoplasmosis. In the past 2 decades, molecular methods based on a variety of genetic markers have been developed, each with its advantages and limitations. The application of these methods has generated invaluable information to enhance our understanding of the epidemiology, population genetics and phylogeny ofT. gondii. However, since most studies focused solely on the detection but not genetic characterization ofT. gondii, the information obtained was limited. In this review, we discuss some widely used molecular methods and propose an integrated approach for the detection and identification ofT. gondii, in order to generate maximum information for epidemiological, population and phylogenetic studies of this key pathogen.

scholarly journals Genetic Differentiation of Clariid Populations using Microsatellite Markers in Kano State Rivers

2021 ◽  
pp. 35-45
Author(s):  
I. O. Suleiman ◽  
R.O. Okeke ◽  
J. M. Madu ◽  
A. U. Umar ◽  
O.M Akinsola ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Genetic Differentiation ◽  
Dna Extraction ◽  
Genetic Characterization ◽  
Caudal Peduncle ◽  
Fta Cards ◽  
Fish Samples ◽  
Polymerase Chain ◽  
Outbred Populations

This study aimed to investigate the genetic characterization of strains of Clariid fish species in some river bodies in Kano State using microsatellite markers.One hundred and seventy seven Clariid fish samples (Clariasgariepinus and Heterobranchuslongifilis) were collected from six rivers (Thomas, Ghari, Tiga dam, Duddurun Gaya, Karaye and Bagwai) in Kano state. Blood sample was taken from each fish sample by severing the caudal peduncle and drained into FTA cards for DNA extraction, Polymerase Chain Reaction and electrophoresis to determine genetic variation between the Clariid fish populations.Genealex 6.4 software package was used to analyse the resolve bands from DNA extraction to determine their base pair and genetic variation. Results showed that the Fst values ranged from 0.00 to 0.66, Fit ranged from -0.04 to 0.12, Fis ranged from -0.35 to -0.26. It indicated a large number of gene flow (exchange) among the populations with a range of 0.46 to 0.87. There was an established magnitude of genetic divergence (91.86%) among the populations as shown by the result of the percentage polymorphism which depends on the number of alleles detected per locus and their frequencies. It can be concluded that since there was no inbreeding as shown in the study, none of the population exhibited genetic uniqueness. The populations had a high genetic differentiation between populations but moderate differentiation within populations. The populations were outbred populations; an indication that relatives avoided mating in the population.

scholarly journals Genetic diversity of Blastocystis in kindergarten children in southern Xinjiang, China

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Meng Qi ◽  
Zilin Wei ◽  
Ying Zhang ◽  
Qiyuan Zhang ◽  
Juanfeng Li ◽  
...  
Keyword(s):  
Ribosomal Rna ◽  
Genetic Characterization ◽  
Intestinal Parasites ◽  
Small Subunit ◽  
Kindergarten Children ◽  
Chain Reaction ◽  
Significant Difference ◽  
Polymerase Chain ◽  
Southern Xinjiang

Abstract Background Blastocystis is one of the most common intestinal parasites in humans and various animals worldwide. Few studies are available regarding the genetic characterization of Blastocystis infections in humans in China. Methods In the present study, 609 fecal samples were collected from two- to six-year-old kindergarten children in southern Xinjiang and were examined by polymerase chain reaction (PCR). Results The infection rate of Blastocystis was 14.3% (87/609); no significant difference was observed among counties and between sexes. Blastocystis subtypes ST1 (n = 38), ST2 (n = 8), and ST3 (n = 41) were identified by sequence analysis of the small subunit ribosomal RNA gene. Genetic polymorphisms were observed at the intra-subtype level, including seven variations for ST1 (ST1A to ST1G), four for ST2 (ST2A to ST2D), and two for ST3 (ST3A and ST3B); with ST1F and ST2B being new variations. Conclusions ST1 and ST3 are the two common Blastocystis subtypes in the study area. More extensive studies in both humans and animals in different regions are needed to better characterize the transmission of Blastocystis.

Genetic characterization of Spermophagus niger (Coleoptera: Chrysomelidae: Bruchinae: Amblycerini) pest associated to seeds of Sorrel (Hibiscus sabdariffa L.) in Burkina Faso

2016 ◽  
Vol 6 (1) ◽  
pp. 07-14
Author(s):  
Jean Christophe Koussoubé ◽  
Fatimata Mbaye ◽  
Cheikh Abdou Khadre Mbacké Dia ◽  
Mbacké Sembène ◽  
Antoine Sanon
Keyword(s):  
Amino Acid ◽  
Burkina Faso ◽  
Genetic Parameters ◽  
Genetic Characterization ◽  
Mitochondrial Gene ◽  
Hibiscus Sabdariffa ◽  
Polymerase Chain ◽  
The One ◽  
First Time

In Burkina Faso, the seeds of sorrel, Hibiscus sabdariffa L. are attacked by a pest identified morphologically as Spermophagus niger which is maintained all year on seeds and causing considerable damages. In the current study, for the first time, genetic characterization for S. niger was performed to determine its genetic identity and place it in its phyletic group. Mitochondrial gene, the Cytochrome oxidase I (COI) of the pest was partially sequenced after extraction and amplification by Polymerase Chain Reaction (PCR). Then the variability of genetic parameters namely the number of polymorphic and monomorphic sites, the frequencies of the different nucleotides and amino acid composition were determined. The nucleotide sequence of S. niger ob-tained was submitted in Genbank and the accession number is KU710716. Nucleotide sequences of S. niger obtained and those of different species of Spermophagus and Z. subfasciatus available in the GenBank database, we determined the percentage of similarity on the one hand and kinship through Phylogenetics reconstructions on the other hand. The results showed the absence of polymorphic sites for 406 sites obtained with 36.5% of thymine, 17.5% of cytosine, adenine 31% and 15% of guanine. Leucine was the majority amino acid (14.50%); the lysine was minority amino acid (0.76%) and cysteine was absent. The percentage of similarity obtained and phylogenetics reconstructions showed that S. niger is very close to the different species of Spermophagus particularly S. drak and different from Z. sub-fasciatus.

Importance of flagella and enterotoxins for Aeromonas virulence in a mouse model

2007 ◽  
Vol 53 (2) ◽  
pp. 261-269 ◽  
Author(s):  
Keya Sen ◽  
Dennis Lye
Keyword(s):  
Drinking Water ◽  
Virulence Factor ◽  
Genetic Characterization ◽  
Aeromonas Veronii ◽  
Aeromonas Caviae ◽  
Polymerase Chain ◽  
Immunocompromised Mice ◽  
Immunocompromised Hosts ◽  
Virulence Factor Genes

A genetic characterization of eight virulence factor genes, elastase, lipase, polar flagella (flaA/flaB, flaG), lateral flagella (lafA), and the enterotoxins alt, act, and ast, was performed using polymerase chain reaction with 55 drinking water and nine clinical isolates. When 16 Aeromonas hydrophila strains, seven Aeromonas veronii strains, and seven Aeromonas caviae strains exhibiting different combinations of virulence factor genes were tested in immunocompromised mice by intraperitoneal injection, only those strains that had one or more of the enterotoxins flaA, flaB, and either flaG or lafA showed signs of being virulent. The correlation was seen in 97% (29/30) of the strains, which included strains from drinking water. Thus, Aeromonas water isolates have the potential to be pathogenic in immunocompromised hosts.

The Polymerase Chain Reaction (PCR) in the routine genetic characterization of retinoblastoma: A tool for the clinical laboratory

1997 ◽  
Vol 41 (4) ◽  
pp. 331-340 ◽  
Author(s):  
Domenico Mastrangelo ◽  
Nicola Squitieri ◽  
Stefano Bruni ◽  
Theodora Hadjistilianou ◽  
Renato Frezzotti
Keyword(s):  
Polymerase Chain Reaction ◽  
Genetic Characterization ◽  
Clinical Laboratory ◽  
Chain Reaction ◽  
Polymerase Chain

scholarly journals Characterization of a transgenic mouse line over-expressing the human ornithine decarboxylase gene

1991 ◽  
Vol 278 (3) ◽  
pp. 895-898 ◽  
Author(s):  
M Halmekytö ◽  
L Alhonen ◽  
J Wahlfors ◽  
R Sinervirta ◽  
T Eloranta ◽  
...  
Keyword(s):  
Transgenic Mouse ◽  
Ornithine Decarboxylase ◽  
Transgenic Animals ◽  
Metabolizing Enzymes ◽  
Transgenic Mouse Line ◽  
Adenosylmethionine Decarboxylase ◽  
Transgenic Lines ◽  
Polymerase Chain

We have produced several transgenic mouse lines over-expressing the human ornithine decarboxylase (ODC) gene. We have now characterized one of the transgenic lines as regards the tissue accumulation of the polyamines and the activities of their metabolizing enzymes. Among the tissues analysed, the polyamine pattern was most strikingly changed in testis and brain of the transgenic animals. ODC activity was greatly enhanced in all tissues, except kidney, of the transgenic animals. The most dramatic increase, 80-fold, was found in brain of the transgenic mice. The activities of S-adenosylmethionine decarboxylase and spermidine and spermine syntheses were likewise significantly increased in testis of the transgenic animals. The activities of the enzymes involved in the back-conversion of the polyamines, namely spermidine/spermine acetyltransferase and polyamine oxidase, were similar in the transgenic and non-transgenic animals. As analysed by reverse transcriptase/polymerase chain reaction, all the six tissues of the transgenic animals expressed human-specific ODC mRNA. Determination of the half-life of testicular ODC revealed a stabilization of the enzyme in the transgenic males.

scholarly journals Παλαιοπεριβαλλοντική εξέλιξη της λιμνοθάλασσας του Κίτρους Πιερίας, ΒΔ Θερμαϊκός Κόλπος

2017 ◽  
Vol 44 ◽  
pp. 90
Author(s):  
Α.Σ. Δημητράκος ◽  
Κ. Βουβαλίδης ◽  
Γ. Συρίδης ◽  
Κ. Αλμπανάκης
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
The West ◽  
Rapid Phase ◽  
The Past ◽  
Initial Stage ◽  
Geomorphological Evolution ◽  
Low Rate

This paper deals with the palaeoenvironmental evolution of the Kitros Pierias Lagoon, located at the west coastline of the Thermaikos Gulf, during the upper Holocene. In addition, the palaeoenvi-ronmental units distinguished in the study area were correlated with the Holocene sea level rise in Thermaikos Gulf. The study is based on the sedimentological and stratigraphical analysis of a core 9.5 m long. Sedimentological and palaeontological analysis was carried out in all selected core sam-ples. The determination of the lithophases and biophases allowed the estimation of the stratigraphy-cal units, the interpretation of the geomorphological evolution and the characterization of the palaeo-environmental conditions. According to the results, we can conclude that the area under investigation was a transitional lagoonal environment, semi-enclosed at its initial stage progressively transformed to an isolated sallow basin. The formation of the semi-enclosed lagoon has been commenced after the conclusion of the rapid phase of sea level rise i.e. 6,000 BP years. Finally, the gradual isolation of the lagoon is attributed to low rate of the sea level rise e.g. over the past 4,000 years..

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