scholarly journals Assessment of Genetic Diversity of ZoonoticBrucellaspp. Recovered from Livestock in Egypt Using Multiple Locus VNTR Analysis

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Ahmed M. S. Menshawy ◽  
Marta Perez-Sancho ◽  
Teresa Garcia-Seco ◽  
Hosein I. Hosein ◽  
Nerea García ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Brucella Melitensis ◽  
Small Ruminants ◽  
High Genetic Diversity ◽  
Domestic Ruminants ◽  
High Discriminatory Power ◽  
Genetic Techniques ◽  
Control Knowledge ◽  
Multiple Locus Vntr Analysis

Brucellosis is endemic in most parts of Egypt, where it is caused mainly byBrucella melitensisbiovar 3, and affects cattle and small ruminants in spite of ongoing efforts devoted to its control. Knowledge of the predominantBrucellaspecies/strains circulating in a region is a prerequisite of a brucellosis control strategy. For this reason a study aiming at the evaluation of the phenotypic and genetic heterogeneity of a panel of 17Brucellaspp. isolates recovered from domestic ruminants (cattle, buffalo, sheep, and goat) from four governorates during a period of five years (2002–2007) was carried out using microbiological tests and molecular biology techniques (PCR, MLVA-15, and sequencing). Thirteen strains were identified asB. melitensisbiovar 3 while all phenotypic and genetic techniques classified the remaining isolates asB. abortus(n=2) andB. suisbiovar 1 (n=2). MLVA-15 yielded a high discriminatory power (h=0.801), indicating a high genetic diversity among theB. melitensisstrains circulating among domestic ruminants in Egypt. This is the first report of the isolation ofB. suisfrom cattle in Egypt which, coupled with the finding ofB. abortus, suggests a potential role of livestock as reservoirs of several zoonoticBrucellaspecies in the region.

High genetic diversity, distant phylogenetic relationships and intraspecies recombination events among natural populations of Yam mosaic virus: a contribution to understanding potyvirus evolution

Microbiology ◽  
2000 ◽  
Vol 81 (1) ◽  
pp. 243-255 ◽  
Author(s):  
M. Bousalem ◽  
E. J. P. Douzery ◽  
D. Fargette
Keyword(s):  
Genetic Diversity ◽  
Mosaic Virus ◽  
Statistical Tests ◽  
Phylogenetic Analyses ◽  
Natural Populations ◽  
High Genetic Diversity ◽  
Single Clade ◽  
Cultivated Species ◽  
Selection Of

To evaluate the genetic diversity and understand the evolution of Yam mosaic virus (YMV), a highly destructive pathogen of yam (Dioscorea sp.), sequencing was carried out of the C-terminal part of the replicase (NIb), the coat protein (CP) and the 3′-untranslated region (3′-UTR) of 27 YMV isolates collected from the three main cultivated species (Dioscorea alata, the complex Dioscorea cayenensis–Dioscorea rotundata and Dioscorea trifida). YMV showed the most variable CP relative to eight other potyviruses. This high variability was structured into nine distant molecular groups, as revealed by phylogenetic analyses and validated by assessment of the molecular evolutionary noise. No correlation was observed between the CP and 3′-UTR diversities and phylogenies. The most diversified and divergent groups included isolates from Africa. The remaining groups clustered in a single clade and a geographical distinction between isolates from the Caribbean, South America and Africa was observed. The role of the host in the selection of particular isolates was illustrated by the case of a divergent cultivar from Burkina Faso. Phylogenetic topological incongruence and complementary statistical tests highlighted the fact that recombination events, with single and multiple crossover sites, largely contributed to the evolution of YMV. We hypothesise an African origin of YMV from the yam complex D. cayenensis–D. rotundata, followed by independent transfers to D. alata and D. trifida during virus evolution.

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 Dogs and Cats: Reservoirs for Highly Diverse Campylobacter jejuni and a Potential Source of Human Exposure

Animals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 838
Author(s):  
Amandine Thépault ◽  
Valérie Rose ◽  
Marilyne Queguiner ◽  
Marianne Chemaly ◽  
Katell Rivoal
Keyword(s):  
Genetic Diversity ◽  
Campylobacter Jejuni ◽  
Human Exposure ◽  
High Genetic Diversity ◽  
Thermophilic Campylobacter ◽  
Potential Link ◽  
Genomic Characterization ◽  
Partial Overlap ◽  
Campylobacter Spp

Assessing the carriage of Campylobacter in animal reservoirs is essential to better understand Campylobacter epidemiology. Here, we evaluated the prevalence of thermophilic Campylobacter spp. in dogs and cats, hereafter defined as pets, and characterized Campylobacter jejuni (C. jejuni) isolates to assess their genetic diversity and their potential link with isolates from other animals or human cases. During a 6-month period, 304 feces samples were collected from pets. A significantly higher prevalence of thermophilic Campylobacter spp. was found in dogs compared with cats, as well as in dogs ≤ 1-year-old compared with older dogs. C. jejuni was the predominant species found in pets, and its genomic characterization revealed a high genetic diversity. Genotypes comparison with previously characterized isolates revealed a partial overlap between C. jejuni isolates from pets, chicken, cattle, and clinical cases. This overlap suggests the potential role of livestock and humans in pets’ exposure to Campylobacter, or vice versa. The isolation of pets’ specific profiles may suggest the existence of other sources of pet contamination or imply that pets may constitute a reservoir for Campylobacter. Because of the proximity between humans and pets, along with their frequent carriage of C. jejuni, human exposure to Campylobacter from pets can be more important than previously thought.

scholarly journals How ancient forest fragmentation and riparian connectivity generate high levels of genetic diversity in a micro-endemic Malagasy tree

2020 ◽  
Author(s):  
Jordi Salmona ◽  
Axel Dresen ◽  
Anicet E. Ranaivoson ◽  
Sophie Manzi ◽  
Barbara Le Pors ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Forest Fragmentation ◽  
Forest Cover ◽  
Chloroplast Microsatellites ◽  
List Type ◽  
Sequencing Data ◽  
High Genetic Diversity ◽  
Vegetation Dynamic ◽  
Ancient Forest

AbstractUnderstanding landscape changes is central to predicting evolutionary trajectories and defining conservation practices. While human-driven deforestation is intense throughout Madagascar, exception in areas like the Loky-Manambato region (North) raises questions. This region also harbors a rich and endemic flora, whose evolutionary origin remains poorly understood.We assessed the genetic diversity of an endangered micro-endemic Malagasy olive species (Noronhia spinifolia) to better understand the vegetation dynamic in the Loky-Manambato region and its influence on past evolutionary processes. We characterized 72 individuals sampled across eight forests through nuclear and mitochondrial restriction associated sequencing data (RADseq) and chloroplast microsatellites (cpSSR).Extremely high genetic diversity was revealed in the three genomic compartments (chloroplast h = 0.99, mitochondrial h = 0.85, and nuclear HO = 0.07-0.20). Combined population and landscape genetics analyses indicate that N. spinifolia diversity is best explained by the current forest cover (R2 = 0.90), highlighting a long-standing forest fragmentation in the region. Our results further suggest a predominant role of forestdwelling organisms in mediating pollen and seed dispersals.This sustains a major and long-term role of riparian corridors in maintaining connectivity across those antique mosaic-habitats, calling for the study of organismal interactions that promote gene flow.

scholarly journals Evolution and Genetic Diversity of Primate Cytomegaloviruses

2020 ◽  
Vol 8 (5) ◽  
pp. 624
Author(s):  
Rachele Cagliani ◽  
Diego Forni ◽  
Alessandra Mozzi ◽  
Manuela Sironi
Keyword(s):  
Genetic Diversity ◽  
Opportunistic Pathogen ◽  
Clinical Samples ◽  
High Genetic Diversity ◽  
Viral Genetics ◽  
Technological Advances ◽  
Similar Genomic Organization ◽  
Insight Into ◽  
Core Genes

Cytomegaloviruses (CMVs) infect many mammals, including humans and non–human primates (NHPs). Human cytomegalovirus (HCMV) is an important opportunistic pathogen among immunocompromised patients and represents the most common infectious cause of birth defects. HCMV possesses a large genome and very high genetic diversity. NHP–infecting CMVs share with HCMV a similar genomic organization and coding content, as well as the course of viral infection. Recent technological advances have allowed the sequencing of several HCMV strains from clinical samples and provided insight into the diversity of NHP–infecting CMVs. The emerging picture indicates that, with the exclusion of core genes (genes that have orthologs in all herpesviruses), CMV genomes are relatively plastic and diverse in terms of gene content, both at the inter– and at the intra–species level. Such variability most likely underlies the strict species–specificity of these viruses, as well as their ability to persist lifelong and with relatively little damage to their hosts. However, core genes, despite their strong conservation, also represented a target of adaptive evolution and subtle changes in their coding sequence contributed to CMV adaptation to different hosts. Indubitably, important knowledge gaps remain, the most relevant of which concerns the role of viral genetics in HCMV–associated human disease.

scholarly journals In vivo and in vitro models show unexpected degrees of virulence among Toxoplasma gondii type II and III isolates from sheep

2021 ◽  
Vol 52 (1) ◽  
Author(s):  
Mercedes Fernández-Escobar ◽  
Rafael Calero-Bernal ◽  
Javier Regidor-Cerrillo ◽  
Raquel Vallejo ◽  
Julio Benavides ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Toxoplasma Gondii ◽  
Small Ruminants ◽  
Parasite Burden ◽  
Target Cells ◽  
Post Inoculation ◽  
Type Ii ◽  
High Genetic Diversity

AbstractToxoplasma gondii is an important zoonotic agent with high genetic diversity, complex epidemiology, and variable clinical outcomes in animals and humans. In veterinary medicine, this apicomplexan parasite is considered one of the main infectious agents responsible for reproductive failure in small ruminants worldwide. The aim of this study was to phenotypically characterize 10 Spanish T. gondii isolates recently obtained from sheep in a normalized mouse model and in an ovine trophoblast cell line (AH-1) as infection target cells. The panel of isolates met selection criteria regarding such parameters as genetic diversity [types II (ToxoDB #1 and #3) and III (#2)], geographical location, and sample of origin (aborted foetal brain tissues or adult sheep myocardium). Evaluations of in vivo mortality, morbidity, parasite burden and histopathology were performed. Important variations between isolates were observed, although all isolates were classified as “nonvirulent” (< 30% cumulative mortality). The isolates TgShSp16 (#3) and TgShSp24 (#2) presented higher degrees of virulence. Significant differences were found in terms of in vitro invasion rates and tachyzoite yield at 72 h post-inoculation (hpi) between TgShSp1 and TgShSp24 isolates, which exhibited the lowest and highest rates, respectively. The study of the CS3, ROP18 and ROP5 loci allelic profiles revealed only type III alleles in ToxoDB #2 isolates and type II alleles in the #1 and #3 isolates included. We concluded that there are relevant intra- and inter-genotype virulence differences in Spanish T. gondii isolates, which could not be inferred by genetic characterization using currently described molecular markers.

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 Detection of Multiple Variants of Grapevine Fanleaf Virus in Single Xiphinema index Nematodes

Viruses ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 1139
Author(s):  
Shahinez Garcia ◽  
Jean-Michel Hily ◽  
Véronique Komar ◽  
Claude Gertz ◽  
Gérard Demangeat ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Bottleneck ◽  
Grapevine Fanleaf Virus ◽  
High Genetic Diversity ◽  
Genomic Rnas ◽  
Xiphinema Index ◽  
Virus Diversity ◽  
Positive Sense ◽  
Multiple Variants

Grapevine fanleaf virus (GFLV) is responsible for a widespread disease in vineyards worldwide. Its genome is composed of two single-stranded positive-sense RNAs, which both show a high genetic diversity. The virus is transmitted from grapevine to grapevine by the ectoparasitic nematode Xiphinema index. Grapevines in diseased vineyards are often infected by multiple genetic variants of GFLV but no information is available on the molecular composition of virus variants retained in X. index following nematodes feeding on roots. In this work, aviruliferous X. index were fed on three naturally GFLV-infected grapevines for which the virome was characterized by RNAseq. Six RNA-1 and four RNA-2 molecules were assembled segregating into four and three distinct phylogenetic clades of RNA-1 and RNA-2, respectively. After 19 months of rearing, single and pools of 30 X. index tested positive for GFLV. Additionally, either pooled or single X. index carried multiple variants of the two GFLV genomic RNAs. However, the full viral genetic diversity found in the leaves of infected grapevines was not detected in viruliferous nematodes, indicating a genetic bottleneck. Our results provide new insights into the complexity of GFLV populations and the putative role of X. index as reservoirs of virus diversity.

scholarly journals Assessing the role of livestock and sympatric wild ruminants in spreading antimicrobial resistant Campylobacter and Salmonella in alpine ecosystems

2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Johan Espunyes ◽  
Oscar Cabezón ◽  
Andrea Dias-Alves ◽  
Pol Miralles ◽  
Teresa Ayats ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Alpine Ecosystems ◽  
High Genetic Diversity ◽  
Alpine Environment ◽  
Rupicapra Pyrenaica ◽  
Pyrenean Chamois ◽  
Free Ranging ◽  
Alpine Environments ◽  
Cattle And Sheep

Abstract Background Livestock play an important role as reservoir of enteric pathogens and antimicrobial resistance (AMR), a health and economic concern worldwide. However, little is known regarding the transmission and maintenance of these pathogens at the wildlife-livestock interface. In this study, we assessed the occurrence, genetic diversity and AMR of Campylobacter spp. and Salmonella spp. shed by sympatric free-ranging livestock and a wild herbivore in an alpine ecosystem. Results Campylobacter spp. was isolated from 23.3 % of cattle and 7.7 % of sheep but was not isolated from horses nor Pyrenean chamois (Rupicapra pyrenaica). Campylobacter jejuni was the most frequent species. A high genetic diversity and certain host specificity of C. jejuni isolates was observed. The main AMR detected in Campylobacter isolates was to nalidixic acid (88.2 %), ciprofloxacin (82.4 %) and tetracycline (82.4 %); only 11.7 % of the isolates were pan-susceptible and 17.6 % were multi-resistant. Salmonella ser. Newport was isolated only from one Pyrenean chamois and was pan-susceptible. Conclusions Results show that free-ranging cattle and sheep are spreaders of Campylobacter as well as their AMR strains in the alpine environment. Therefore, contaminated alpine pastures or streams may constitute a source for the dissemination of AMR enteropathogens. However, apparently, alpine wild ungulates such as Pyrenean chamois play a negligible role in the epidemiology of zoonotic enteropathogens and AMR, and are not potential bioindicators of the burden of alpine environments.

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