scholarly journals Genetics of Host Protection against Helicobacter pylori Infections

2021 ◽  
Vol 22 (6) ◽  
pp. 3192 ◽  
Author(s):  
Rosanna Capparelli ◽  
Domenico Iannelli
Keyword(s):  
Genetic Diversity ◽  
Helicobacter Pylori ◽  
T Regulatory Cells ◽  
Protective Role ◽  
Disease Genes ◽  
Nucleotide Polymorphisms ◽  
High Genetic Diversity ◽  
Host Protection ◽  
High Level

This narrative review discusses the genetics of protection against Helicobacter pylori (Hp) infection. After a brief overview of the importance of studying infectious disease genes, we provide a detailed account of the properties of Hp, with a view to those relevant for our topic. Hp displays a very high level of genetic diversity, detectable even between single colonies from the same patient. The high genetic diversity of Hp can be evaded by stratifying patients according to the infecting Hp strain. This approach enhances the power and replication of the study. Scanning for single nucleotide polymorphisms is generally not successful since genes rarely work alone. We suggest selecting genes to study from among members of the same family, which are therefore inclined to cooperate. Further, extending the analysis to the metabolism would significantly enhance the power of the study. This combined approach displays the protective role of MyD88, TIRAP, and IL1RL1 against Hp infection. Finally, several studies in humans have demonstrated that the blood T cell levels are under the genetic control of the CD39+ T regulatory cells (TREGS).

scholarly journals Species distribution, antibiotic resistance and virulence traits in canine and feline enterococci in Tunisia

2017 ◽  
Vol 65 (2) ◽  
pp. 173-184 ◽  
Author(s):  
Leila Ben Said ◽  
Raoudha Dziri ◽  
Nadia Sassi ◽  
Carmen Lozano ◽  
Karim Ben Slama ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Gel Electrophoresis ◽  
Virulence Genes ◽  
Pulsed Field Gel Electrophoresis ◽  
High Genetic Diversity ◽  
Antibiotic Resistant ◽  
Faecal Samples ◽  
Household Environment ◽  
High Level

In order to investigate the possible role of dogs and cats in the carriage and potential dissemination of resistant enterococci, seventy faecal samples from dogs and cats were tested for enterococci. Fifty-eight enterococci were recovered. Isolates were identified as Enterococcus faecium (n = 31) and E. faecalis (n = 14) E. durans (n = 6), E. casseliflavus (n = 2), E. hirae and E. gallinarum (2 isolates each). Enterococcal isolates showed resistance to ciprofloxacin (n = 35), erythromycin (n = 31), tetracycline (n = 25), kanamycin (n = 15), streptomycin (n = 13), pristinamycin (n = 11), gentamicin (n = 10), chloramphenicol (n = 8), and linezolid (n = 6). The gene erm(B) was detected in 22 out of 31 erythromycin-resistant enterococci. All tetracycline-resistant enterococci carried tet(M) and/or tet(L) genes. The gene aac(6′)-Ie-aph(2″)-Ia was identified in five of high-level gentamicin-resistant isolates, the genes aph(3′)-IIIa and/or aac(6′)-Ie-aph(2″)-Ia in eleven high-level kanamycin-resistant isolates and the gene ant(6)-Ia in eleven high-level streptomycin-resistant isolates. Only one strain harboured cat(A) gene, and five strains contained vat(E) or vat(D) genes. Virulence genes gel(E) (21 strains), esp (11 strains) and cylA/cylB (5 strains) were detected. High genetic diversity was demonstrated among E. faecium isolates by pulsed-field gel electrophoresis (PFGE). Dogs and cats can be carriers of antibiotic-resistant enterococci in their faeces that could shed into the household environment.

scholarly journals Microsatellite genotyping from faeces of Lontra longicaudis from southern Brazil

2009 ◽  
Vol 99 (1) ◽  
pp. 5-11 ◽  
Author(s):  
Laura I. Weber ◽  
Cintia G. Hildebrand ◽  
Anderson Ferreira ◽  
Gustavo Pedarassi ◽  
José A. Levy ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Conservation Status ◽  
Significant Degree ◽  
Southern Brazil ◽  
High Genetic Diversity ◽  
Low Degree ◽  
Faecal Samples ◽  
High Level ◽  
Degree Of Differentiation ◽  
Lontra Longicaudis

A genetic study of the neotropical river otter Lontra longicaudis (Olfers, 1818), which has an unknown conservation status, was carried out at the Taim Ecological Station and the margins of the Vargas stream, Rio Grande do Sul, southern Brazil. Faecal samples were collected, and DNA was extracted using a silica-guanidine method. Five microsatellite loci were amplified using PCR with heterologous primers previously described for Lutra lutra (Linnaeus, 1758). Sixteen faecal samples out of 29 from Taim and 11 out of 14 from Vargas stream margins contained enough DNA for genetic analysis. A total of 49 different alleles were found at both localities, from which 18 were exclusively found in individuals from Taim and 17 were exclusives from Vargas individuals. The most common allele was the same at both locations for three loci (Lut715, Lut733, and Lut818). A high level of genetic diversity was found at both sites (NeTaim=4.1, HoTaim=0.299, HeTaim=0.681; NeVargas=4.9, HoVargas=0.355, HeVargas=0.724), being higher at the Vargas stream site. A high and significant level of heterozygote deficiency was observed at most loci according to the χ2 test. The homogeneity χ2 test (P<0.001) showed that there were significant differences in the allele frequencies between the two locations. Genotyping for more than one locus was possible in 81.5% of samples, from which only 37% were possible to genotype for more than three loci. A low degree of relatedness was found among individuals from Taim (R=0.055±0.310), but an even lower value of relatedness was found at the Vargas site (R= -0.285±0.440). The significant degree of differentiation (I=0.890; F ST=0.059) found between Taim and Vargas individuals suggests that there is more than one population of otters in the southern extreme of Brazil, which probably are associated with the water body systems found in this region, the Mirim and the Caiuvá/Flores/Mangueira Lagoons. The high genetic diversity and low relatedness found at the Vargas stream, lead us to believe that the Vargas stream may be acting as a corridor between these water bodies for otter dispersion.

Examination of Humicola lutea Immobilized in Sol-Gel Matrices: Effective Source of α-Galactosidase

2008 ◽  
Vol 63 (11-12) ◽  
pp. 893-897 ◽  
Author(s):  
Dimitrina Spasova ◽  
Penka Aleksieva ◽  
Lilyana Nacheva ◽  
Lyudmila Kabaivanova ◽  
Georgi Chernev ◽  
...  
Keyword(s):  
Sol Gel ◽  
Protective Role ◽  
Growth Behaviour ◽  
Shake Flask Cultivation ◽  
Free Cells ◽  
Repeated Batch ◽  
High Level ◽  
Humicola Lutea ◽  
Effective Source

Abstract α-Galactosidase production by the fungus Humicola lutea 120-5 immobilized in a hybrid sol-gel matrix, consisting of tetraethylorthosilicate (TEOS) as a precursor and a mixture of polyethyleneglycol (PEG) and polyvinylalcohol (PVA), was investigated under semicontinuous shake flask cultivation and compared to the enzyme secretion by free cells. The influence of the carrier weight on the α-galactosidase biosynthesis in repeated batch experiments was followed. Best results were obtained with 2 g of the sol-gel particles per culture flask using 144-h runs. The growth behaviour of the immobilized mycelium during both the growth and productive phases was observed by scanning electron microscopy. The presence of abundant mycelial growth of intact hyphae correlated with a 2-fold higher enzyme activity compared to free cells. The obtained biocatalyst retained a high level of enzyme titer exceeding the activity of free cells during four cycles of operation (24 days). This result is confirmed by the micrographs showing the retained viability of the growing vegetative cells due to the protective role of the carrier.

scholarly journals Host Wnt/β-catenin pathway triggered by Helicobacter pylori correlates with regression of gastric intestinal metaplasia after H. pylori eradication

2009 ◽  
Vol 58 (5) ◽  
pp. 567-576 ◽  
Author(s):  
Kuei-Hsiang Hung ◽  
Jiunn-Jong Wu ◽  
Hsiao-Bai Yang ◽  
Li-Ju Su ◽  
Bor-Shyang Sheu
Keyword(s):  
Helicobacter Pylori ◽  
Intestinal Metaplasia ◽  
Glycogen Synthase ◽  
Nucleotide Polymorphisms ◽  
Ags Cells ◽  
Gastric Intestinal Metaplasia ◽  
Before And After ◽  
Cox 2 ◽  
H Pylori ◽  
High Level

Helicobacter pylori eradication can reverse gastric intestinal metaplasia (IM) in some but not all patients. H. pylori induces high levels of nuclear β-catenin staining in IM tissues, as well as overexpression of cyclooxygenase-2 (COX-2). This study investigated whether the Wnt/β-catenin pathway plays a role in IM regression following H. pylori eradication. Sixty-five H. pylori-infected patients with IM who had achieved successful H. pylori eradication provided paired gastric samples before and after eradication to analyse the persistence of IM, and to assess COX-2 and nuclear β-catenin expression. The host genotypes of single nucleotide polymorphisms (SNPs) of the COX-2, β-catenin (CTNNB1) and adenomatous polyposis coli (APC) genes were analysed. In addition, expression of β-catenin, E-cadherin and phosphorylated and unphosphorylated glycogen synthase kinase 3β (GSK-3β) in cell lines challenged with H. pylori isolates from patients with and without IM persistence was compared by immunoanalysis. After a mean 33.9-month follow-up after H. pylori eradication, 44 patients (67.7 %) with IM persistence had a higher rate of high-level nuclear β-catenin expression in IM tissue than those without IM persistence (P=0.008). The patients with IM persistence had a higher rate of AA, GG and AA APC SNP genotypes at positions 4479, 5268 and 5465, respectively, than the patients without IM persistence (P=0.022). The H. pylori isolates from the patients with IM regression after H. pylori eradication induced more phospho-GSK-3β in AGS cells than isolates from patients with IM persistence (P=0.011). It is likely that interactions with H. pylori and the patient's Wnt/β-catenin genetic predisposition determine the outcome of IM persistence following H. pylori eradication.

scholarly journals Proton motive force-dependent efflux of tetracycline in clinical isolates of Helicobacter pylori

2009 ◽  
Vol 58 (10) ◽  
pp. 1309-1313 ◽  
Author(s):  
Mona Anoushiravani ◽  
Tahereh Falsafi ◽  
Vahid Niknam
Keyword(s):  
Helicobacter Pylori ◽  
Proton Motive Force ◽  
Motive Force ◽  
Clinical Isolates ◽  
Carbonyl Cyanide ◽  
Agar Dilution ◽  
Resistant Mutants ◽  
H Pylori ◽  
High Level

The aim of this study was to evaluate the role of proton motive force (PMF)-dependent efflux in resistance of Helicobacter pylori to tetracycline (Tet). Tet MIC was determined by agar dilution in the presence and absence of carbonyl cyanide m-chlorophenylhydrazone (CCCP), an inhibitor of PMF. Antibiotic accumulation was conducted in the presence or absence of CCCP and the fluorescence of the accumulated antibiotic was measured by spectrofluorometry. In the presence of CCCP, antibiotic accumulation was increased by 2–17-fold in 17/20 Tetr isolates and by 3–10-fold in four of five high-level-resistant mutants. Correlation was observed between this increase and diminution of MIC with CCCP. PMF-dependent efflux mechanisms therefore appear to play an important role in the resistance of clinical isolates of H. pylori to Tet.

scholarly journals Assessment of Genetic Diversity and Marker-Trait Associations Using Selected Early Maize Inbreds Derived From Local Landraces of Eastern Himalayan Regions

2021 ◽  
Author(s):  
E. Lamalakshmi Devi ◽  
Umakanta Ngangkham ◽  
Akoijam Ratankumar Singh ◽  
Bhuvaneswari S ◽  
Konsam Sarika ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Agronomic Traits ◽  
Crop Improvement ◽  
Mean Value ◽  
Cross Combination ◽  
High Genetic Diversity ◽  
Average Value ◽  
Maize Inbreds ◽  
High Level ◽  
Trait Associations

Abstract North- Eastern parts of India fall under Eastern Himalayan region and it is a diversity hotspot of many crops including maize. Evaluation of genetic diversity is required to tape the potentiality of genetic resources in any crop improvement programmes. In the present study, genetic diversity at fifty two microsatellite markers were conducted in 30 early maize inbreds developed from local landraces of NE India. Genetic diversity analysis revealed a total of 189 alleles with a mean of 3.63 alleles/ locus. The allele size ranged from 50 bp (phi 036) to 295 bp (p 101049) which revealed a high level of genetic diversity among the loci. The PIC among the 30 genotypes ranged from 0.17 (umc 1622) to 0.76 (umc 1153) with an average value of 0.49. The value of Expected Heterozygosity (HExp) ranged from 0.19 to 0.80 with an average of 0.57, whereas the Observed Heterozygosity (HObs) ranged from 0 to 0.89 with a mean of 0.14.The genetic dissimilarity between the genotype pairs ranged from 0.40 to 0.64 with a mean value of 0.57. Cluster analysis grouped the 30 inbreds into distinct three sub-clusters. Similarly, population structure and principal coordinate analysis) analysis also classified the 30 inbred lines into three-subpopulations. AMOVA revealed that 6% of total variance is due to differences among populations, while 94% of total molecular variance is accounted by within populations. Marker-trait associations showed a total of twelve SSR markers significantly associated with seven agronomic traits. From the present finding, these results show that the thirty maize inbreds have high genetic diversity which would be useful for choosing promising parents and for making cross combination based on genetic distance and clustering for genetic improvement programmes of maize.

Environmental patterns in the origin and diversification loci of Early Cambrian skeletalized Metazoa: Evidence from the Avalon microcontinent

2004 ◽  
Vol 10 ◽  
pp. 93-106 ◽  
Author(s):  
Ed Landing ◽  
Stephen R. Westrop
Keyword(s):  
Protective Role ◽  
Uv Damage ◽  
Marine Communities ◽  
Initial Stage ◽  
Key Factor ◽  
Cambrian Radiation ◽  
High Level ◽  
Ediacaran Fauna ◽  
High Diversity

The Cambrian Radiation was expressed as major changes in marine communities. High-diversity skeletalized metazoan faunas appeared and persisted with little change in the most proximal onshore habitats and show little expansion into the offshore through much of the long (ca. 24 m.y.) pretrilobitic Placentian Epoch on the Avalon microcontinent. These small shelly fossil communities and a large number of coelomate burrowers that appeared earlier in the Placentian comprise the Placentian Ecologic Evolutionary Unit (new)—the initial stage of the Cambrian Evolutionary Fauna. Early members of a number of high-level metazoan groups were concentrated in onshore habitats vacated by the demise of the Ediacaran fauna, where they diversified and, possibly, originated no earlier than latter part of the Placentian Epoch (543–ca. 519 (m.y.a.). Development of unstable substrates and predation in open shelf habitats occupied coelomate trace producers may have been a key factor in the restriction of diverse skeletalized metazoan faunas to peritidal habitats, where mineralized skeletons may have served as protection from desiccation and UV-damage. In contrast, the oldest trilobites are most diverse and abundant in offshore habitats, and their appearance in habitats dominated by large trace producers suggests a protective role of their mineralized integument.

The Role of Trust and Control Institutions in Informal Monetary Transactions

2012 ◽  
pp. 48-64
Author(s):  
A. Lyasko
Keyword(s):  
Protective Role ◽  
Economic Agents ◽  
Developing Markets ◽  
Degree Of Control ◽  
Continuous Reproduction ◽  
High Level ◽  
Financial Arrangements ◽  
Financial Transactions ◽  
And Control

Auxiliary institutions fail to perform the function of protecting economic agents trust in the liquidity of various monetary obligations. Still, despite these conclusions, there exist some forms of monetary arrangements that seemingly demonstrate a high level of trust among their participants. The durability and continuous reproduction of these monetary arrangements in both developing markets and mature economies need to be explained. Part of this explanation has to address the question of trust arising among the parties to these financial transactions and its role in preventing opportunism and breach of promises made by their participants. As shown in this paper, a possible answer to this question might consist in the argument that the protective role of trust in these financial arrangements is replaced by the opposite norm of control over the agents behavior within close-knit social and economic communities. The degree of control may vary, but control always crowds out trust in order to add reliability to these financial setups.

scholarly journals Protective Role of Helicobacter pylori Infection in Prognosis of Gastric Cancer: Evidence from 2454 Patients with Gastric Cancer

PLoS ONE ◽  
2013 ◽  
Vol 8 (5) ◽  
pp. e62440 ◽  
Author(s):  
Fang Wang ◽  
Guoping Sun ◽  
Yanfeng Zou ◽  
Fei Zhong ◽  
Tai Ma ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Helicobacter Pylori ◽  
Protective Role ◽  
Helicobacter Pylori Infection
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