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Community ecology of denitrifying bacteria in arable land /Enwall, Karin, January 2008 (has links) (PDF)
Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2008. / Härtill 6 uppsatser.
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DEFENCE GENE EXPRESSION IN THE TOMATO-VERTICILLIUM PATHOSYSTEMCastroverde, Christian Danve 22 April 2010 (has links)
In tomato (Solanum lycopersicum), race-specific resistance against the fungal wilt pathogen Verticillium dahliae race 1 (Vd1) is established in the stem. However, the molecular factors and mechanisms leading to this resistance response are still unknown. In this study, Craigella resistant (CR) and susceptible (CS) tomato plants were successfully infected with Vd1 and this was verified by fungal quantification and symptom score assays. Previous microarray results showed interesting patterns of defence gene expression that correlated with biological phenomena. Plant defence genes code for proteins that are responsible for or associated with the plant resistance response. Through RT-PCR, this thesis set out to confirm these microarray observations and also to generate expression data for genes in which sensitivity was an issue in the microarray. The standard RT-PCR data confirmed a number of the microarray results, but some conflicts remained. From the defence genes investigated, there was agreement between the microarray data and the RT-PCR data for pre-mRNA processing factor 8, class IV chitinase, cyclin-dependent kinase inhibitor and IMP dehydrogenase/GMP reductase. Partial agreement was observed for genes coding for ethylene response factor 2, phenylalanine ammonia lyase and P6 protein. However, there
was total disagreement for 14-3-3, beta-glucanase, P1a, RNA-binding protein, calcium-binding protein and S-Adenosyl-L-methionine: hydroxide adenosyltransferase. Real-time
RT-PCR was attempted to clarify the remaining issues but further discrepancies arose, particularly in the Ve resistance genes. To resolve these discrepancies, two approaches were designed: (1) one based on the use of a universal internal control and (2) another based on restriction enzyme digestion. In general, the results were more consistent with standard RT-PCR. Overall, this study showed that standardization of a system involving vascular pathogens, leading to reproducible analysis, was possible but only with proper controls and additional validation. Standard RT-PCR appeared to offer a more accurate picture of the expression of defence genes in the tomato-Verticillium pathosystem. The defence gene expression results confirmed in this study remain as potential insights into the molecular mechanisms for Verticillium resistance in tomato plants.
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Microbial etiology of Inflammatory Bowel Disease: Microbial diversity and the role of Escherichia coliSEPEHRI, SHADI 12 April 2010 (has links)
Inflammatory bowel disease (IBD), comprises Crohn’s disease (CD) and ulcerative colitis (UC), and is a chronic relapsing inflammation of gastrointestinal tract without any known cause or cure. Currently, it is accepted that IBD is a result of a dysfunctional immune response to commensal bacteria in a genetically susceptible host, and that environmental factors can trigger the onset or reactivation of the disease. This thesis considers the possibility of a specific pathogenic agent as well as an imbalance in the composition of the normal microflora in the pathogenesis of IBD. Gut biopsy tissues were taken from a population-based case-control tissue bank held at the University of Manitoba. Automated ribosomal intergenic spacer analysis (ARISA) and terminal restriction fragment length polymorphisms (T-RFLP) were employed to assess the diversity of gut microbiota. The phylogenetic, virulence and biochemical characteristics of Escherichia coli isolated from IBD biopsies were examined using multi-locus sequence typing (MLST), DNA microarray technology and API 20E system. Utilizing ARISA and T-RFLP, a remarkable increase in the order of unclassified Clostridia was detected in inflamed tissues, particularly in CD patients (P < 0.05). Moreover, species richness and diversity were the highest in non-inflamed IBD biopsies. Culture-based quantification detected a significantly higher number of E. coli in IBD tissues (P < 0.05). Phylogenetic analysis revealed the tendency of E. coli isolated from IBD patients to be grouped into separate clonal clusters based on their allelic profiles (P = 0.02). A link was detected between uropathogenic E. coli (UPEC) CFT073 and strains isolated from IBD, with regards to gene distribution and virulence, using microarray technology. Amino acid substitutions N91S and S99N in FimH, the adhesive subunit of E. coli type I fimbria, were significantly associated to IBD (P < 0.05). This study demonstrated an increase in the microbial diversity of non-inflamed IBD tissues and suggested a recruitment phase of bacterial adherence and colonization, before the inflammation sets in. Furthermore, E. coli isolated from IBD tissues were distinct from commensal strains in both clonal and virulence characteristics and shared remarkable traits with extraintestinal pathogenic E. coli. Features involved in bacterial adhesion to epithelial cells may hold the key to E. coli pathogenesis in IBD.
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Microbial etiology of Inflammatory Bowel Disease: Microbial diversity and the role of Escherichia coliSEPEHRI, SHADI 12 April 2010 (has links)
Inflammatory bowel disease (IBD), comprises Crohn’s disease (CD) and ulcerative colitis (UC), and is a chronic relapsing inflammation of gastrointestinal tract without any known cause or cure. Currently, it is accepted that IBD is a result of a dysfunctional immune response to commensal bacteria in a genetically susceptible host, and that environmental factors can trigger the onset or reactivation of the disease. This thesis considers the possibility of a specific pathogenic agent as well as an imbalance in the composition of the normal microflora in the pathogenesis of IBD. Gut biopsy tissues were taken from a population-based case-control tissue bank held at the University of Manitoba. Automated ribosomal intergenic spacer analysis (ARISA) and terminal restriction fragment length polymorphisms (T-RFLP) were employed to assess the diversity of gut microbiota. The phylogenetic, virulence and biochemical characteristics of Escherichia coli isolated from IBD biopsies were examined using multi-locus sequence typing (MLST), DNA microarray technology and API 20E system. Utilizing ARISA and T-RFLP, a remarkable increase in the order of unclassified Clostridia was detected in inflamed tissues, particularly in CD patients (P < 0.05). Moreover, species richness and diversity were the highest in non-inflamed IBD biopsies. Culture-based quantification detected a significantly higher number of E. coli in IBD tissues (P < 0.05). Phylogenetic analysis revealed the tendency of E. coli isolated from IBD patients to be grouped into separate clonal clusters based on their allelic profiles (P = 0.02). A link was detected between uropathogenic E. coli (UPEC) CFT073 and strains isolated from IBD, with regards to gene distribution and virulence, using microarray technology. Amino acid substitutions N91S and S99N in FimH, the adhesive subunit of E. coli type I fimbria, were significantly associated to IBD (P < 0.05). This study demonstrated an increase in the microbial diversity of non-inflamed IBD tissues and suggested a recruitment phase of bacterial adherence and colonization, before the inflammation sets in. Furthermore, E. coli isolated from IBD tissues were distinct from commensal strains in both clonal and virulence characteristics and shared remarkable traits with extraintestinal pathogenic E. coli. Features involved in bacterial adhesion to epithelial cells may hold the key to E. coli pathogenesis in IBD.
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Phylogeny and molecular identification of Cronobacter strains isolated from south African food productsStrydom, Amy 03 1900 (has links)
Thesis (MSc Food Sc)--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: The genus Cronobacter (Enterobacter sakazakii) contains opportunistic pathogens that can
cause a severe form of neonatal meningitis, necrotising enterocolitis and septicaemia.
Cronobacter infections have been reported in all age groups, however, immunocompromised
infants are more susceptible to these infections. Furthermore, Cronobacter
strains have been reported to show differences in sensitivity to antibiotics and virulence.
These differences led to the reclassification of Cronobacter and currently the genus
contains five distinct species, namely Cronobacter sakazakii, Cronobacter malonaticus,
Cronobacter turicensis, Cronobacter dublinensis and Cronobacter muytjensii. As this
reclassification was only accepted recently, there are not many typing methods optimised
for differentiation between the five Cronobacter species. Typing of Cronobacter strains are
important as the species may be diverse regarding their virulence.
Cronobacter strains have been isolated from infant formula milk (IFM), the
environment of an IFM processing facility and fresh produce in South Africa. However,
little is known about the phylogeny and prevalence of these strains. The aim of this study
was to classify 24 South African Cronobacter strains (previously identified as E. sakazakii)
and to evaluate the phylogeny of the isolates based on the 16S ribosomal RNA (rRNA) and
rpoA genes. All 24 South African strains were identified as Cr. sakazakii despite a wide
variety of isolation sources. Other studies have also found that irrespective of the isolation
source, the majority of Cronobacter strains are identified as Cr. sakazakii. The South
African strains were found to be phylogenetically closely related. However, two distinct
clusters separated at a 93 % confidence level were observed in the Cr. sakazakii group
based on the 16S rRNA gene analysis.
Strains of Cr. sakazakii, Cr. dublinensis, Cr. turicensis and Cr. muytjensii were
differentiated from each other with sequence data of the 16S rRNA and rpoA genes, but it
was not possible to differentiate between Cr. sakazakii and Cr. malonaticus. The
phylogram based on the rpoA gene sequences did separate Cr. malonaticus and Cr.
sakazakii strains, however, the clusters were separated with a low bootstrap value of 70 %.
Phylogenetic analysis based on the rpoA and 16S rRNA genes were, therefore, not
sufficient to distinguish between all the Cronobacter species. The sequence data of these
two genes can be used to differentiate between the Cronobacter strains when used in
combination with malonate utilisation analysis.
A PCR-RFLP method was subsequently developed to facilitate the simultaneous
differentiation between all five Cronobacter species. The PCR-RFLP assay was based on
the amplification of the rpoB gene followed by the combined digestion with restriction
endonucleases Csp6I and HinP1I. Unique profiles for each of the five Cronobacter species
were obtained and it was also possible to differentiate between Enterobacteriaceae and
Cronobacter strains. Furthermore, two strains which were identified as Cr. sakazakii with
sequencing based on the 16S rRNA and rpoA genes had PCR-RFLP profiles identical to
that of Cr. malonaticus. Sequencing based on the rpoB gene and additional biochemical
analysis with malonate broth confirmed the identities of these two strains as Cr.
malonaticus. This PCR-RFLP assay is, therefore, an accurate typing method that ensures
rapid differentiation between the five species of Cronobacter. / AFRIKAANSE OPSOMMING: Die Cronobacter genus (Enterobacter sakazakii) bevat opportunistiese patogene wat 'n
ernstige vorm van neonatale meningitis, enterokolitis en septisemie kan veroorsaak.
Cronobacter infeksies is al in alle ouderdomsgroepe aangemeld, maar
immuungekompromitteerde babas is die meeste vatbaar vir hierdie infeksies. Verder toon
Cronobacter spesies verskille in virulensie en sensitiwiteit vir antibiotika. Hierdie verskille
het gelei tot die herklassifikasie van Cronobacter en tans bestaan die genus uit vyf
afsonderlike spesies, naamlik Cronobacter sakazakii, Cronobacter malonaticus,
Cronobacter turicensis, Cronobacter dublinensis en Cronobacter muytjensii. Aangesien
hierdie herklassifikasie slegs onlangs aanvaar is, is daar nie baie metodes wat geskik is vir
onderskeiding tussen die vyf Cronobacter spesies nie. Onderskeiding tussen Cronobacter
spesies is belangrik omdat die spesies verskillend kan wees met betrekking tot hulle
virulensie.
Cronobacter is geisoleer uit baba formule melk (BFM), die omgewing van 'n BFM
fabriek en vars produkte in Suid-Afrika. Daar is egter nie baie bekend oor die filogenie en
voorkoms van hierdie isolate nie. Die doel van hierdie studie was om 24 Suid-Afrikaanse
Cronobacter stamme (voorheen geïdentifiseer as E. sakazakii) te klassifiseer en die
filogenie van die isolate te evalueer gebaseer op die 16S ribosomale RNS (rRNS) en rpoA
gene. Al 24 Suid-Afrikaanse stamme is geïdentifiseer as Cr. sakazakii ten spyte van 'n
wye verskeidenheid isolasie bronne. Ander studies het ook gevind dat, ongeag die isolasie
bron, die meerderheid van Cronobacter stamme as Cr. sakazakii geïdentifiseer word. In
hierdie studie is gevind dat die Suid-Afrikaanse stamme filogeneties nou verwant is. Op
grond van die 16S rRNA geen analise is die Cr. sakazakii stamme egter in twee
afsonderlike groepe gedeel met 'n 93% vertrouens vlak.
Dit was moontlik om stamme van Cr. sakazakii, Cr. dublinensis, Cr. turicensis en Cr.
muytjensii van mekaar te onderskei met die DNS volgorde data van die 16S rRNA en rpoA
gene, maar geen onderskeid tussen Cr. sakazakii en Cr. malonaticus stamme was
moontlik nie. Die filogram gebaseer op die rpoA DNS volgorde data het aparte takke vir Cr.
malonaticus en Cr. sakazakii stamme getoon, maar die twee takke is met ‘n lae vertrouens
waarde van slegs 70 % geskei. Filogenetiese analise gebaseer op die rpoA en 16S rRNA
gene is dus nie voldoende om te onderskei tussen al die Cronobacter spesies nie. Die
DNS volgorde data van hierdie twee gene sou egter gebruik kon word om te onderskei
tussen die Cronobacter spesies wanneer dit gebruik word in kombinasie met
malonaatbenutting-analises.
'n Polimerase ketting reaksie (PKR) beperkings fragment lengte polimorfisme
(BFLP) metode is ontwikkel om die gelyktydige onderskeiding tussen al vyf Cronobacter
spesies te fasiliteer. Die PKR-BFLP metode is gebaseer op die vermeerdering van die
rpoB geen gevolg deur die gesamentlike vertering met die beperkingsensieme, Csp6I en
HinP1I. Unieke profiele vir elk van die vyf Cronobacter spesies is verkry en dit was ook
moontlik om tussen Enterobacteriaceae en Cronobacter spesies te onderskei. Verder het
twee stamme wat as Cr. sakazakii geïdentifiseer is met DNS volgordebepaling van die 16S
rRNA en rpoA gene, PKR-BFLP profiele identies aan dié van Cr. malonaticus getoon.
DNS volgordebepaling van die rpoB geen en ‘n addisionele biochemiese toets met
malonaat sop het die identiteit van hierdie twee stamme as Cr. malonaticus bevestig.
Hierdie PKR-BFLP is dus 'n akkurate metode wat vinnige onderskeid tussen die vyf
spesies van Cronobacter kan verseker.
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Analýza výskytu vybrané dědičné choroby očí u psůKUBIČKOVÁ, Miroslava January 2017 (has links)
Progressive rod-cone degeneration (PRCD) is the late form of progressive retinal atrophy (PRA). It is an autosomal recessive hereditary retinal defect. This disease in dogs is consistent with one form of retinitis pigmentosa (RP) in humans. Phenotypic manifestations are identical and it is known to be an identical causal mutation. A study of this defect in dogs could also explain a lot in human medicine. The gene for PRCD was mapped in the region of centromer of the canine chromosome 9 (CFA9). In this thesis, genotyping of 120 dogs of different breeds and age was performed. Most represented a breed of English Cocker Spaniel which is predisposed to the disease. Analysis PRA-PRCD was performed by molecular genetic methods PCR-RFLP and the horizontal agarose electrophoresis. Genotypes were determined on the basis of different fragment lengths. The normal allele was 396 bp in length and the mutated allele had a length of 116 bp. Presence of mutated allele was only detected in 25 heterozygotes carriers which were usually breeds with this predisposition. Frequency of the mutated allele was 10.4 %. In the selected population 20.8 % of heterozygotes were represented. The results of the study show approximately one fifth of the tested dogs are heterozygous carriers. Findings of other studies confirm there are generally more heterozygotes than homozygotes in which the disease is manifested during life. However, if this fact is not clearly taken in consideration, the number of sick dogs can rapidly increase during short period of time. In the future, it would be appropriate to adopt measures which would definitely eliminate the occurrence of the mutated allele. These measures could include genetic tests that reliably reveal hidden carriers (heterozygotes) in predisposing breeds. Heterozygotes may increase the representation of this allele in the population. This leads to an increase in the number of diseased animals.
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Studium genetické variability fytoplazem / The Study of the genetic variability of phytoplasmasROHÁČKOVÁ, Helena January 2011 (has links)
Phytoplasmas are bacterial intracellular plant pathogens that cause devasting yield losses in diverse crops worldwide. Phytoplasmas were detected in clover and Catharanthus roseus plants, pear, apple and apricot trees. SecA and 16S rRNA genes, spacer region and 23S rRNA gene of five phytoplasma isolates were sequenced.
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Contribution of X chromosomal and autosomal genes to species differences in male courtship songs of the <em>Drosophila virilis</em> group speciesPäällysaho, S. (Seliina) 28 November 2001 (has links)
Abstract
In sympatric Drosophila species, songs produced by male wing
vibration during courtship are an effective mechanism preventing interspecific
matings and maintaining sexual isolation between different species. These songs
can vary greatly even between closely related species. The aim of this study was
to localise X chromosomal and autosomal genes affecting species differences in
male courtship song and to study their interaction in the D.
virilis group species. Various genes were probed by in
situ hybridisation on the X chromosomes of six species of the group,
which enabled us to use localised RFLP markers in QTL studies, as well as to
compare gene arrangements of different species.
Genetic analyses of differences between the songs of D.
virilis and D. littoralis showed that
species-specific song traits are affected both by X chromosomal and autosomal
genes. The X chromosomal gene(s) having a major impact on pause and pulse length
in male song were found to be located at the proximal region of the chromosome.
Precise localisation of the song genes was, however, not possible due to multiple
chromosome rearrangements restricting recombination between RFLP markers located
on this area. The same problem was faced when studying hybrids between
D. flavomontana and D. montana with
less diverged X chromosomal gene arrangements.
Interaction between the X chromosomal and autosomal song genes in determining
male song traits was studied in four species belonging to the
virilis and montana phylads of
D. virilis group. The long pauses in courtship song were
found to be mainly caused by X chromosomal song genes (or maternal / cytological
factors), while pulse length was determined by X chromosomal genes interacting
with autosomal genes. This confirms the important role of X chromosomal gene(s)
in song evolution in the montana phylad species. The
direction of dominance in hybrid songs suggests that the songs of the
montana phylad species have been affected by directional
selection favouring shorter pulses and longer pauses between sound pulses during
their evolution.
The levels and patterns of DNA polymorphism in an X-linked
fused (fu) gene was studied in
different D. montana populations. These studies revealed
that D. montana populations are significantly but not
completely isolated, and that a selective sweep at fu (or at
a gene linked to fu) may be the reason for the reduced
levels and patterns of variability of this gene in Finnish D.
montana populations. The methods used in this study will be utilized
to study variation in 'song genes' in the future.
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Genotipagem , utilizando a sequencia de inserção IS6110, de cepas de Mycobacterium tuberculosis isoladas de pacientes portadores da infecção pelo HIV em Moçambique, Africa / IS6110 Polymorphism in Mycobacterium tuberculosis isolates from HIV infected patients living in Mozambique, AfricaBasso, Audrey Jordão 24 August 2006 (has links)
Orientador: Marcelo de Carvalho Ramos / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-08-07T12:21:17Z (GMT). No. of bitstreams: 1
Basso_AudreyJordao_M.pdf: 998979 bytes, checksum: 6b29af1ec17385aea2f4b4f550bb349e (MD5)
Previous issue date: 2006 / Resumo: A técnica do estudo do polimorfismo de fragmentos de restrição, com a pesquisa da seqüência de inserção IS6110 (IS6110-RFLP), é o método de genotipagem mais empregado mundialmente para a caracterização de isolados de M. tuberculosis. Ela pode ser empregada para o estudo de surtos, epidemias ou para estudos de genética populacional. Em Moçambique, onde a tuberculose tem uma elevada prevalência, não há informação suficiente sobre os padrões genotípicos obtidos com a IS6110-RFLP de cepas locais de M. tuberculosis. A descrição dos padrões obtidos com essa metodologia pode ser útil localmente para propósitos epidemiológicos ou, internacionalmente, para descrever o relacionamento de cepas isoladas em Moçambique com outras áreas do mundo. Neste estudo, uma coleção de 158 isolados de M. tuberculosis, identificados com o emprego da análise de fragmentos de restrição após a amplificação de trecho do gene hsp65 (hsp65-PRA), recuperados de pacientes infectados pelo HIV com tuberculose pulmonar e que residiam em Maputo, Moçambique, foram genotipados. O número de seqüências IS6110 obtido variou de 1 to 18, com 21.5% dos isolados exibindo menos de seis cópias. Um total de 10 ¿clusters¿ foram caracterizados, um com três isolados e os demais com dois cada. Os isolados que exibiram menos de seis seqüências não foram incluídos na análise, dado o baixo poder discriminatório do método. Baseado no coeficiente de similaridade, 85% dos isolados tinham mais do que 65% de homologia. Esses dados mostram que, isolados de M. tuberculosis obtidos em Moçambique, África, podem ser analisados, para fins epidemiológicos com o auxílio dessa técnica de genotipagem. Entretanto, um considerável número de isolados exibiu um número pequeno de cópias da seqüência IS6110 e um segundo marcador genético, como a espoligotipagem, deve ser utilizado / Abstract: IS6110 RFLP has been the most widely used genetic subtyping method for M. tuberculosis strains, to characterize disease outbreaks or for evolutionary genetics studies. In Mozambique, where tuberculosis exhibits a high prevalence, there is not enough information about IS6110-RFLP patterns of local M. tuberculosis strains. The description of the fingerprinting patterns obtained with this methodology can be useful locally for epidemiological purposes, and internationally to investigate the relatedness of strains isolated in Mozambique to other areas of the world. In this study, a collection of 158 isolates of M. tuberculosis strains, as identified by using hsp65-PRA, recovered from HIV-infected patients with pulmonary tuberculosis residing in Maputo, Mozambique, was genotyped. The number of IS6110 copies ranged from 1 to 18, with 21.5% of strains exhibiting less than six copies. A total of 10 clusters were found, one consisting of three strains and all the others of two strains. Isolates showing less than six bands were not included in the cluster analyses due to low discriminatory power of the analysis. Based on similarity coefficients 85% of strains had more than 65% homology. This data show that M. tuberculosis strains obtained in Mozambique, Africa can be analyzed for epidemiological purposes with the use of this genotyping technique. However, a considerable number of strains exhibited a low number of IS6110 copies, and a second genetic marker as spoligotyping has to be used. / Mestrado / Clinica Medica / Mestre em Clinica Medica
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Untersuchungen zum Vorkommen von Toxoplasma gondii in Wild in BrandenburgStollberg, Kaya Christina 16 June 2023 (has links)
Die Toxoplasmose, nach ihrem Verursacher, dem Parasiten Toxoplasma gondii (T. gondii) benannt, ist eine weltweit häufig auftretende Zoonose. Einen wichtigen Infektionsweg stellt der Verzehr von nicht ausreichend erhitztem oder rohem Fleisch, welches Gewebezysten enthält, dar.
In Deutschland hat der Konsum von Wildbret in den letzten 10 Jahren zugenommen. Schwarzwild (Sus scrofa), Rehwild (Capreolus capreolus), Damwild (Dama dama) und Rotwild (Cervus elaphus) sind das am häufigsten gejagte Schalenwild in Deutschland. Dennoch gibt es nur wenige Informationen über das Vorkommen
von T. gondii in Wildtieren in Deutschland, so dass die Bedeutung von Wild als Quelle für eine Infektion des Menschen mit T. gondii weitgehend unbekannt ist.
Ziel dieser Studie war es, die Datenlage zum Vorkommen von T. gondii in Schwarzwild, Rehwild, Damwild und Rotwild in Deutschland zu verbessern und eine fundierte Bewertung des von dem Verzehr von Wildtieren ausgehenden potenziellen Risikos zu ermöglichen.
Neben dem indirekten serologischen Nachweis soll der Nachweis mittels direkter Nachweisverfahren einen Einblick in die tatsächliche Anwesenheit von T. gondii im Muskelgewebe und einen potenziellen Zusammenhang von Seropositivität und der Anwesenheit von T. gondii im Gewebe geben.
In den Jahren 2017-2020 wurden in Brandenburg 306 Stück Schwarzwild, 184 Stück Rehwild, 80 Stück Damwild und 65 Stück Rotwild beprobt. Den 635 Wildtieren wurden Blutproben und Proben von Herz- und Vorderlaufmuskulatur entnommen.
Das aus den Blutproben gewonnene Serum wurde mittels eines kommerziell erhältlichen ELISA untersucht.
Zum direkten Nachweis von T. gondii wurde zur Analyse der aus den Muskelproben gewonnenen DNA eine real-time PCR (qPCR) eingesetzt, die auf das 529-bp-repetitive Element abzielt.
Die DNA wurde auf drei unterschiedliche Arten gewonnen: direkt aus 5 g Muskelgewebe extrahiert, aus einem Pellet nach saurem Pepsinverdau von 50 g Muskelgewebe extrahiert, und die Ziel-DNA durch Magnetic Capture aus weiteren 50 g Muskelgewebe angereichert.
Die Übereinstimmung der Ergebnisse des molekularen Nachweises und ihre Übereinstimmung mit den ELISA-Ergebnissen wurde ermittelt. Der molekulare Nachweis wurde bei 23 Proben von einem Maus-Bioassay begleitet. Zusätzlich wurde eine PCR-RFLP zur Genotypisierung bei qPCR-positiven Proben durchgeführt. Fisher’s exact Test, Cohen’s kappa (κ) und Odds Ratio wurden für die
statistische Analyse genutzt.
T. gondii-spezifische Antikörper wurden in 20,3 % der Schwarzwildproben, 10,9 % der Rehwildproben und 6,2 % der Rotwildproben nachgewiesen. Bei allen untersuchten Wildarten wurde ein Anstieg der Seroprävalenz mit zunehmendem Alter festgestellt, welcher bei Schwarzwild und Rehwild statistisch signifikant war (p = 0,004 und < 0,001).
Bei der Untersuchung von Herzmuskulatur wurde T. gondii-DNA mit mindestens einer direkten Nachweismethode in 11,8 % der Schwarzwildproben, 5,5 % der Rehwildproben, 2 % der Damwildproben und 1,9 % der Rotwildproben nachgewiesen. Der höchste Anteil an Tieren, die positiv auf T. gondii-DNA getestet wurden, wurde durch die qPCR-Analyse von DNA aus 50 g Herzmuskulatur nach Magnetic Capture nachgewiesen (10 %). Die Ergebnisse der Methoden zeigten
insgesamt eine mäßige Übereinstimmung (κ = 0,47-0,59). Die höchste Übereinstimmung zeigten die Ergebnisse von DNA aus 50 g Herzmuskulatur nach Pepsin-Verdau und DNA aus 50 g Herzmuskulatur nach Magnetic Capture (κ = 0,59). Insgesamt ergab die Untersuchung von 50 g Herzmuskulatur einen signifikant höheren Anteil an positiven qPCR-Ergebnissen als die Analyse von
5 g Herzmuskulatur (p = 0,048).
Die qPCR-Ergebnisse von Herz- und Vorderlaufmuskelgewebe zeigten beim Schwarzwild eine beachtliche und bei der gemeinsamen Betrachtung aller untersuchten Wildarten eine mäßige Übereinstimmung (κ = 0,62 bzw. 0,46).
Ein statistisch signifikanter Zusammenhang zwischen Seropositivität und direktem Nachweis war bei Schwarzwild und Rehwild erkennbar (p < 0,001).
In allen T. gondii-DNA-positiven Proben, bei denen zusätzlich ein Bioassay durchgeführt wurde, konnte Infektiosität bestätigt werden (4/4).
Sowohl in den T. gondii-DNA-positiven Schwarzwildproben als auch in den positiven Rehwildproben waren die spezifischen Allele von T. gondii-Typ II am weitesten verbreitet.
Die durch diese Arbeit generierten Daten zeigen, dass T. gondii in Schwarzwild, Rehwild, Damwild und Rotwild in Brandenburg vorkommt und Wild eine relevante Quelle für T. gondii-Infektionen beim Menschen darstellen könnte.
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