scholarly journals Genetic diversity and amino acid sequence polymorphism in Helicobacter pylori CagL hypervariable motif and its association with virulence markers and gastroduodenal diseases

2019 ◽  
Vol 8 (4) ◽  
pp. 1619-1632 ◽  
Author(s):  
Abbas Yadegar ◽  
Ashraf Mohabati Mobarez ◽  
Mohammad Reza Zali
Keyword(s):  
Genetic Diversity ◽  
Helicobacter Pylori ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Sequence Polymorphism ◽  
Virulence Markers

scholarly journals Antibiotic Resistance and Genotypes of Helicobacter pylori Strains in Patients with Gastroduodenal Disease in Southeast Poland

2019 ◽  
Vol 8 (7) ◽  
pp. 1071 ◽  
Author(s):  
Izabela Korona-Glowniak ◽  
Halina Cichoz-Lach ◽  
Radoslaw Siwiec ◽  
Sylwia Andrzejczuk ◽  
Andrzej Glowniak ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Helicobacter Pylori ◽  
Test Method ◽  
Rapid Urease Test ◽  
Microbial Culture ◽  
Virulence Markers ◽  
Gastroduodenal Disease ◽  
Urease Test ◽  
Gastric Biopsies ◽  
H Pylori

The aim of this study was to investigate genetic diversity of Helicobacter pylori virulence markers to predict clinical outcome as well as to determine an antibiotic susceptibility of H. pylori strains in Poland. Gastric biopsies from 132 patients with gastrointestinal disorders were tested for presence of H. pylori with the use of rapid urease test, microbial culture, and polymerase chain reaction (PCR) detection. The genetic diversity of 62 H. pylori positive samples was evaluated by detection of cagA and PCR-typing of vacA and iceA virulence-associated genes. Most common H. pylori genotypes were cagA(+)vacAs1m2 (27.4%) and cagA(−)vacAs2m2 (24.2%). In logistic regression analysis, we recognized the subsequent significant associations: gastritis with ureC, i.e., H. pylori infection (p = 0.006), BMI index (p = 0.032); and negatively with iceA1 (p = 0.049) and peptic ulcer with cagA (p = 0.018). Thirty-five H. pylori strains were cultured and tested by E-test method showing that 49% of strains were resistant to at least one of the tested antibiotics. This is the first study that reports the high incidence and diversity of allelic combination of virulence genes in gastroduodenitis patients in Poland. Genotyping of H. pylori strains confirmed the involvement of cagA gene and vacAs1m1 genotype in development and severity of gastric disorder.

scholarly journals Comparison of PCR-Restriction Fragment Length Polymorphism Analysis and PCR-Direct Sequencing Methods for Differentiating Helicobacter pylori ureB Gene Variants

2000 ◽  
Vol 38 (1) ◽  
pp. 165-169
Author(s):  
Toshihito Tanahashi ◽  
Masakazu Kita ◽  
Tadashi Kodama ◽  
Naoki Sawai ◽  
Yoshio Yamaoka ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Helicobacter Pylori ◽  
Amino Acid ◽  
Restriction Fragment Length Polymorphism ◽  
Length Polymorphism ◽  
Fragment Length Polymorphism ◽  
Direct Sequencing ◽  
Base Change ◽  
Pcr Rflp ◽  
Restriction Fragment Length

ABSTRACT A method utilizing PCR-restriction fragment length polymorphism (RFLP) in the Helicobacter pylori genes is widely used to differentiate strains. However, with this typing method only a single base change at a specific restriction site can be detected. In addition, it is unclear whether the nucleotide base change recognized by RFLP is related to a substitution of encoded amino acid. To examine the validity of the PCR-RFLP method, 933-bp PCR products were obtained from 41 different clinical H. pylori isolates and were digested with Sau 3A restriction endonuclease. Furthermore, the nucleotides of the same region in the ureB gene were directly sequenced and compared. PCR-RFLP confirmed that there was genetic diversity within the ureB gene with three distinct types, one being well conserved and the other two being variations. However, the direct sequencing method revealed that there was no difference at the nucleotide level among these RFLP types. Base substitutions recognized by Sau 3A occurred in the third-base position and did not change the encoded amino acid. In addition, many nucleotide mutations, which could not be recognized by Sau 3A, were frequently found. These results suggest that the PCR-RFLP method provides for an easy typing scheme of isolates, but does not reveal the true extent of genetic diversity. It is proposed that careful observation is required for the interpretation of results when clinical isolates are differentiated.

Mass spectrometric detection of the amino acid sequence polymorphism of the hepatitis C virus antigen

2016 ◽  
Vol 229 ◽  
pp. 86-90 ◽  
Author(s):  
A.L. Kaysheva ◽  
Yu. D. Ivanov ◽  
P.A. Frantsuzov ◽  
N.V. Krohin ◽  
T.I. Pavlova ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Virus Antigen ◽  
Sequence Polymorphism ◽  
Mass Spectrometric ◽  
Mass Spectrometric Detection

scholarly journals Genetic diversity of influenza A viruses circulating in Bulgaria during the 2018–2019 winter season

2020 ◽  
Vol 69 (7) ◽  
pp. 986-998
Author(s):  
Neli Korsun ◽  
Rodney Daniels ◽  
Svetla Angelova ◽  
Burcu Ermetal ◽  
Iliyana Grigorova ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Influenza A ◽  
Winter Season ◽  
Vaccine Virus ◽  
Influenza Viruses ◽  
Amino Acid Substitutions ◽  
Influenza A Viruses ◽  
Antigenic Sites

Introduction. Influenza viruses evolve rapidly and change their antigenic characteristics, necessitating biannual updates of flu vaccines. Aim. The aim of this study was to characterize influenza viruses circulating in Bulgaria during the 2018/2019 season and to identify amino acid substitutions in them that might impact vaccine effectiveness. Methodology. Typing/subtyping of influenza viruses were performed using real-time Reverse Transcription-PCR (RT-PCR) and results of phylogenetic and amino acid sequence analyses of influenza strains are presented. Results. A(H1N1)pdm09 (66 %) predominated over A(H3N2) (34 %) viruses, with undetected circulation of B viruses in the 2018/2019 season. All A(H1N1)pdm09 viruses studied fell into the recently designated 6B.1A subclade with over 50 % falling in four subgroups: 6B.1A2, 6B.1A5, 6B.1A6 and 6B.1A7. Analysed A(H3N2) viruses belonged to subclades 3C.2a1b and 3C.2a2. Amino acid sequence analysis of 36 A(H1N1)pdm09 isolates revealed the presence of six–ten substitutions in haemagglutinin (HA), compared to the A/Michigan/45/2015 vaccine virus, three of which occurred in antigenic sites Sa and Cb, together with four–nine changes at positions in neuraminidase (NA), and a number of substitutions in internal proteins. HA1 D222N substitution, associated with increased virulence, was identified in two A(H1N1)pdm09 viruses. Despite the presence of several amino acid substitutions, A(H1N1)pdm09 viruses remained antigenically similar to the vaccine virus. The 28 A(H3N2) viruses characterized carried substitutions in HA, including some in antigenic sites A, B, C and E, in NA and internal protein sequences. Conclusion. The results of this study showed the genetic diversity of circulating influenza viruses and the need for continuous antigenic and molecular surveillance.

scholarly journals Helicobacter pylori Heat Shock Protein A: Serologic Responses and Genetic Diversity

1999 ◽  
Vol 6 (3) ◽  
pp. 377-382 ◽  
Author(s):  
Enders K. W. Ng ◽  
Stuart A. Thompson ◽  
Guillermo I. Pérez-Pérez ◽  
Imad Kansau ◽  
Arie van der Ende ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Helicobacter Pylori ◽  
Amino Acid ◽  
Heat Shock ◽  
Heat Shock Protein ◽  
Sequence Variation ◽  
Protein A ◽  
Nucleotide Sequences ◽  
Serological Response ◽  
H Pylori

ABSTRACT Helicobacter pylori synthesizes an unusual GroES homolog, heat shock protein A (HspA). The present study was aimed at an assessment of the serological response to HspA in a group of Chinese patients with defined gastroduodenal pathologies and determination of whether diversity is present in the nucleotide sequences encoding HspA in isolates from these patients. Serum samples collected from 154 patients who had an upper gastrointestinal pathology and the presence of H. pylori defined by biopsy were tested for an immunoglobulin G (IgG) serologic response to H. pylori HspA by an enzyme linked immunosorbant assay. HspA-encoding nucleotide sequences in H. pylori isolates from 14 patients (7 seropositive and 7 seronegative for HspA) were analyzed by PCR and direct sequencing of the PCR products. The sequencing results were compared to those of 48 isolates from other parts of the world. Of the 154 known H. pylori-positive patients, 54 (35.1%) were seropositive for HspA. The A domain (GroES homology) of HspA was highly conserved in the 14 isolates tested. Although the B domain (metal-binding site unique to H. pylori) resembled that in the known major variant, particular amino acid substitutions allowed definition of an HspA variant associated with isolates from East Asia. There were no associations between patient characteristics and HspA seropositivity or amino acid sequences. We confirmed in this study that the clinical outcomes of H. pylori infection are not related to HspA antigenicity or to sequence variation. However, B-domain sequence variation may be a marker for the study of the genetic diversity of H. pylori strains of different geographic origins.

H. pylori cagL amino acid sequence polymorphism Y58E59 induces a corpus shift of gastric integrin α5β1 related with gastric carcinogenesis

2011 ◽  
Vol 50 (10) ◽  
pp. 751-759 ◽  
Author(s):  
Yi-Chun Yeh ◽  
Wei-Lun Chang ◽  
Hsiao-Bai Yang ◽  
Hsiu-Chi Cheng ◽  
Jiunn-Jung Wu ◽  
...  
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Gastric Carcinogenesis ◽  
Sequence Polymorphism ◽  
Integrin Α5β1 ◽  
H Pylori

The staining pattern of the tropomyosin sequence is displayed in a new paracrystal

1986 ◽  
Vol 44 ◽  
pp. 150-151
Author(s):  
M.K. Lamvik ◽  
L.L. Klatt
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Staining Pattern ◽  
Banding Patterns ◽  
Mass Thickness ◽  
New Form

Tropomyosin paracrystals have been used extensively as test specimens and magnification standards due to their clear periodic banding patterns. The paracrystal type discovered by Ohtsuki1 has been of particular interest as a test of unstained specimens because of alternating bands that differ by 50% in mass thickness. While producing specimens of this type, we came across a new paracrystal form. Since this new form displays aligned tropomyosin molecules without the overlaps that are characteristic of the Ohtsuki-type paracrystal, it presents a staining pattern that corresponds to the amino acid sequence of the molecule.

Isolation and Structural Charaderization of a Potent Inhibitor of Coagulation Factor Xa from the Leech Haementeria ghilianii

1989 ◽  
Vol 61 (03) ◽  
pp. 437-441 ◽  
Author(s):  
Cindra Condra ◽  
Elka Nutt ◽  
Christopher J Petroski ◽  
Ellen Simpson ◽  
P A Friedman ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Salivary Gland ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Western Blot ◽  
Potent Inhibitor ◽  
Factor Xa ◽  
Coagulation Factor ◽  
Sds Page ◽  
Bovine Factor

SummaryThe present work reports the discovery and charactenzation of an anticoagulant protein in the salivary gland of the giant bloodsucking leech, H. ghilianii, which is a specific and potent inhibitor of coagulation factor Xa. The inhibitor, purified to homogeneity, displayed subnanomolar inhibition of bovine factor Xa and had a molecular weight of approximately 15,000 as deduced by denaturing SDS-PAGE. The amino acid sequence of the first 43 residues of the H. ghilianii derived inhibitor displayed a striking homology to antistasin, the recently described subnanomolar inhibitor of factor Xa isolated from the Mexican leech, H. officinalis. Antisera prepared to antistasin cross-reacted with the H. ghilianii protein in Western Blot analysis. These data indicate that the giant Amazonian leech, H. ghilianii, and the smaller Mexican leech, H. officinalrs, have similar proteins which disrupt the normal hemostatic clotting mechanisms in their mammalian host’s blood.

Paris I Dysfibrinogenemia: A Point Mutation in Intron 8 Results in Insertion of a 15 Amino Acid Sequence in the Fibrinogen γ-Chain

1993 ◽  
Vol 69 (03) ◽  
pp. 217-220 ◽  
Author(s):  
Jonathan B Rosenberg ◽  
Peter J Newman ◽  
Michael W Mosesson ◽  
Marie-Claude Guillin ◽  
David L Amrani
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Point Mutation ◽  
Genomic Dna ◽  
Comparative Sequence Analysis ◽  
Chain Gene ◽  
Molecular Defect ◽  
Nucleotide Position ◽  
Normal Individuals ◽  
Polymerase Chain

SummaryParis I dysfibrinogenemia results in the production of a fibrinogen molecule containing a functionally abnormal γ-chain. We determined the basis of the molecular defect using polymerase chain reaction (PCR) to amplify the γ-chain region of the Paris I subject’s genomic DNA. Comparative sequence analysis of cloned PCR segments of normal and Paris I genomic DNA revealed only an A→G point mutation occurring at nucleotide position 6588 within intron 8 of the Paris I γ-chain gene. We examined six normal individuals and found only normal sequence in this region, indicating that this change is not likely to represent a normal polymorphism. This nucleotide change leads to a 45 bp fragment being inserted between exons 8 and 9 in the mature γparis I chain mRNA, and encodes a 15 amino acid insert after γ350 [M-C-G-E-A-L-P-M-L-K-D-P-C-Y]. Alternative splicing of this region from intron 8 into the mature Paris I γ-chain mRNA also results after translation into a substitution of S for G at position γ351. Biochemical studies of 14C-iodoacetamide incorporation into disulfide-reduced Paris I and normal fibrinogen corroborated the molecular biologic predictions that two additional cysteine residues exist within the γpariS I chain. We conclude that the insertion of this amino acid sequence leads to a conformationallyaltered, and dysfunctional γ-chain in Paris I fibrinogen.

Complete Covalent Structure of Human Platelet Factor 4

1979 ◽  
Vol 42 (05) ◽  
pp. 1652-1660 ◽  
Author(s):  
Francis J Morgan ◽  
Geoffrey S Begg ◽  
Colin N Chesterman
Keyword(s):  
Amino Acids ◽  
Molecular Weight ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Human Platelet ◽  
Platelet Factor 4 ◽  
Platelet Factor ◽  
Disulphide Bonds ◽  
Covalent Structure

SummaryThe amino acid sequence of the subunit of human platelet factor 4 has been determined. Human platelet factor 4 consists of identical subunits containing 70 amino acids, each with a molecular weight of 7,756. The molecule contains no methionine, phenylalanine or tryptophan. The proposed amino acid sequence of PF4 is: Glu-Ala-Glu-Glu-Asp-Gly-Asp-Leu-Gln-Cys-Leu-Cys-Val-Lys-Thr-Thr-Ser- Gln-Val-Arg-Pro-Arg-His-Ile-Thr-Ser-Leu-Glu-Val-Ile-Lys-Ala-Gly-Pro-His-Cys-Pro-Thr-Ala-Gin- Leu-Ile-Ala-Thr-Leu-Lys-Asn-Gly-Arg-Lys-Ile-Cys-Leu-Asp-Leu-Gln-Ala-Pro-Leu-Tyr-Lys-Lys- Ile-Ile-Lys-Lys-Leu-Leu-Glu-Ser. From consideration of the homology with p-thromboglobulin, disulphide bonds between residues 10 and 36 and between residues 12 and 52 can be inferred.

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