Catalogue Search | MBRL
Search Results Heading
Explore the vast range of titles available.
MBRLSearchResults
-
DisciplineDiscipline
-
Is Peer ReviewedIs Peer Reviewed
-
Item TypeItem Type
-
SubjectSubject
-
YearFrom:-To:
-
More FiltersMore FiltersSourceLanguage
Done
Filters
Reset
67
result(s) for
"Katzer, F."
Sort by:
Giardia duodenalis in the UK: current knowledge of risk factors and public health implications
2019
Giardia duodenalis is a ubiquitous flagellated protozoan parasite known to cause giardiasis throughout the world. Potential transmission vehicles for this zoonotic parasite are both water and food sources. As such consumption of water contaminated by feces, or food sources washed in contaminated water containing parasite cysts, may result in outbreaks. This creates local public health risks which can potentially cause widespread infection and long-term post-infection sequelae. This paper provides an up-to-date overview of G. duodenalis assemblages, sub-assemblages, hosts and locations identified. It also summarizes knowledge of potential infection/transmission routes covering water, food, person-to-person infection and zoonotic transmission from livestock and companion animals. Public health implications focused within the UK, based on epidemiological data, are discussed and recommendations for essential Giardia developments are highlighted.
Journal Article
Detection of Neospora caninum DNA in cases of bovine and ovine abortion in the South-West of Scotland
by
Guido, S.
,
Carty, H.
,
Katzer, F.
in
Aborted Fetus - parasitology
,
Abortion
,
abortion (animals)
2019
Neospora caninum is a commonly diagnosed cause of reproductive losses in farmed ruminants worldwide. This study examined 495 and 308 samples (brain, heart and placenta) which were collected from 455 and 119 aborted cattle and sheep fetuses, respectively. DNA was extracted and a nested Neospora ITS1 PCR was performed on all samples. The results showed that for bovine fetuses 79/449 brain [17.6% (14.2–21.4)], 7/25 heart [28.0% (12.1–49.4)] and 5/21 placenta [23.8% (8.2–47.2)] were PCR positive for the presence of Neospora DNA. Overall 82/455 [18.0% (14.6–21.7)] of the bovine fetuses tested positive for the presence of N. caninum DNA in at least one sample. None (0/308) of the ovine fetal samples tested positive for the presence of Neospora DNA in any of the tissues tested. The results show that N. caninum was associated with fetal losses in cattle (distributed across South-West Scotland), compared to sheep in the same geographical areas where no parasite DNA was found. Neospora is well distributed amongst cattle in South-West Scotland and is the potential cause of serious economic losses to the Scottish cattle farming community; however, it does not appear to be a problem amongst the Scottish sheep flocks.
Journal Article
Evidence of the three main clonal Toxoplasma gondii lineages from wild mammalian carnivores in the UK
2013
Toxoplasma gondii is a zoonotic pathogen defined by three main clonal lineages (types I, II, III), of which type II is most common in Europe. Very few data exist on the prevalence and genotypes of T. gondii in the UK. Wildlife can act as sentinel species for T. gondii genotypes present in the environment, which may subsequently be transmitted to livestock and humans. DNA was extracted from tissue samples of wild British carnivores, including 99 ferrets, 83 red foxes, 70 polecats, 65 mink, 64 badgers and 9 stoats. Parasite DNA was detected using a nested ITS1 PCR specific for T. gondii, PCR positive samples were subsequently genotyped using five PCR–RFLP markers. Toxoplasma gondii DNA was detected within all these mammal species and prevalence varied from 6·0 to 44·4% depending on the host. PCR–RFLP genotyping identified type II as the predominant lineage, but type III and type I alleles were also identified. No atypical or mixed genotypes were identified within these animals. This study demonstrates the presence of alleles for all three clonal lineages with potential for transmission to cats and livestock. This is the first DNA-based study of T. gondii prevalence and genotypes across a broad range of wild British carnivores.
Journal Article
Molecular detection of Sarcocystis lutrae in the European badger (Meles meles) in Scotland
2017
Neck samples from 54 badgers and 32 tongue samples of the same badgers (Meles meles), collected in the Lothians and Borders regions of Scotland, were tested using polymerase chain reactions (PCRs) directed against the 18S ribosomal DNA and the internal transcribed spacer (ITS1) region of protozoan parasites of the family Sarcocystidae. Positive results were obtained from 36/54 (67%) neck and 24/32 (75%) tongue samples using an 18S rDNA PCR. A 468 base pair consensus sequence that was generated from the 18S rDNA PCR amplicons (KX229728) showed 100% identity to Sarcocystis lutrae. The ITS1 PCR results revealed that 12/20 (60%) neck and 10/20 (50%) tongue samples were positive for Sarcocystidae DNA. A 1074 bp consensus sequence was generated from the ITS1 PCR amplicons (KX431307) and showed 100% identity to S. lutrae. Multiple sequence alignments and phylogenetic analysis support the finding that the rDNA found in badgers is identical to that of S. lutrae. This parasite has not been previously reported in badgers or in the UK. Sarcocystis lutrae has previously only been detected in tongue, skeletal muscle and diaphragm samples of the Eurasian otter (Lutra lutra) in Norway and potentially in the Arctic fox (Vulpes lagopus).
Journal Article
Respiratory disease due to acute Sarcocystis tenella infection in sheep
2012
Examination of a formalin-fixed sample of the lung revealed subacute interstitial pneumonia with large numbers of intracytoplasmic and cell-free protozoa, multifocal necrosis of alveolar walls and mild bronchiolitis (Fig 1 ). The subacute interstitial pneumonia associated with intralesional protozoa, which exhibited endothelial tropism, the size of the parasites and the immunohistochemical labelling are consistent with a diagnosis of sarcocystosis similar to that previously described in sheep ( Jeffrey 1993 ), goats ( Dubey and others 1981 ) and deer ( Duncan and others 2000 ).
Journal Article
The Association of Anesthesia Type and Neonatal Outcomes Following Category-1 Cesarean Delivery: A Retrospective Cohort Study
2023
Objectives Neuraxial anesthesia is the preferred anesthesia technique for cesarean delivery due to a decreased risk of adverse events. However, general anesthesia is often employed during emergent cesarean deliveries to achieve a shorter decision-to-delivery interval. The objective of this study was to determine if the conversion of epidural labor analgesia to surgical anesthesia for a category-1 cesarean delivery is associated with significant neonatal morbidity. Study design This was a retrospective cohort study of all intrapartum category-1 cesarean deliveries performed at an academic tertiary care institution between August 2016 and July 2021. The primary outcome was neonatal morbidity, defined as a composite of neonatal umbilical artery pH < 7.10 and/or 5-min Apgar score < 7, and/or neonatal intensive care unit admission. A multivariate regression analysis was performed to control for the presence of covariates and examine the degree to which they influenced the outcome. Results A total of 185 mother-neonate pairs qualified for inclusion, of which 23 had cesarean delivery under general anesthesia and 162 under epidural anesthesia. There was no significant difference in adverse neonatal outcomes between category-1 cesarean deliveries done under general anesthesia compared to epidural anesthesia (47% vs 35%, p = 0.3). The incidence of umbilical arterial pH < 7.10 was higher in the general anesthesia group compared to the epidural anesthesia group (35% vs 12%, p = 0.018). The multivariate regression model showed that gestational age (OR = 0.63; 95% CI = 0.51-0.75, p = <0.001) and non-reassuring fetal heart trace (OR = 0.18; 95% CI = 0.05-0.58, p = 0.005) were significant predictors of adverse neonatal outcome. Conclusion Our results suggest that the conversion of epidural analgesia to surgical anesthesia for category-1 cesarean delivery in women with a functional labor epidural catheter is not associated with poorer neonatal outcomes.
Journal Article
Detection and dissemination of Toxoplasma gondii in experimentally infected calves, a single test does not tell the whole story
by
Benavides, Julio
,
Dam-Deisz, Cecile
,
Bartley, Paul M.
in
Beef
,
bioassays
,
Biomedical and Life Sciences
2018
Background
Although the detection of
Toxoplasma gondii
in bovine tissues is rare, beef might be an important source of human infection. The use of molecular techniques, such as magnetic capture qPCR (MC-qPCR), in combination with the gold standard method for isolating the parasite (mouse bioassay), may increase the sensitivity of
T. gondii
detection in infected cattle. The risk of transmission of the parasite to humans from undercooked/raw beef is not fully known and further knowledge about the predilection sites of
T. gondii
within cattle is needed. In the current study, six Holstein Friesian calves (
Bos taurus
) were experimentally infected with 10
6
T. gondii
oocysts of the M4 strain and, following euthanasia (42 dpi), pooled tissues were tested for presence of the parasite by mouse bioassay and MC-qPCR.
Results
Toxoplasma gondii
was detected by both MC-qPCR and mouse bioassay from distinct pools (100 g) of tissues comprising: liver, tongue, heart, diaphragm,
semitendinosus
(hindlimb),
longissimus dorsi
muscle (sirloin) and
psoas major
muscle (fillet). When a selection of individual tissues which had been used for mouse bioassay were examined by MC-qPCR, parasite DNA could only be detected from two animals, despite all calves showing seroconversion after infection.
Conclusions
It is apparent that one individual test will not provide an answer as to whether a calf harbours
T. gondii
tissue cysts. Although the calves received a known number of infectious oocysts and highly sensitive methods for the detection of the parasite within bovine tissues were applied (mouse bioassay and MC-qPCR), the results confirm previous studies which report low presence of viable
T. gondii
in cattle and no clear predilection site within bovine tissues.
Journal Article
Genome of the Host-Cell Transforming Parasite Theileria annulata Compared with T. parva
by
Rabbinowitsch, Ester
,
Barrell, Bart
,
Squares, Robert
in
Amino Acid Motifs
,
Animals
,
Biological and medical sciences
2005
Theileria annulata and T. parva are closely related protozoan parasites that cause lymphoproliferative diseases of cattle. We sequenced the genome of T. annulata and compared it with that of T. parva to understand the mechanisms underlying transformation and tropism. Despite high conservation of gene sequences and synteny, the analysis reveals unequally expanded gene families and species-specific genes. We also identify divergent families of putative secreted polypeptides that may reduce immune recognition, candidate regulators of host-cell transformation, and a Theileria-specific protein domain [frequently associated in Theileria (FAINT)] present in a large number of secreted proteins.
Journal Article
Study of Theileria annulata population structure during bovine infection and following transmission to ticks
by
GUBBELS, M.-J.
,
KATZER, F.
,
JONGEJAN, F.
in
Animals
,
Antigenic Variation - genetics
,
Antigens, Protozoan - genetics
2001
Tams1 is the polymorphic immunodominant merozoite-piroplasm surface protein of Theileria annulata. Evidence for selection of divergent forms of Tams1 has been obtained recently. This study was performed to address whether selection takes place during persistent infection of the bovine host or during passage through the Hyalomma tick vector. Four calves were infected with a T. annulata isolate representing multiple parasite genotypes. The development of the parasite population was analysed by denaturing gradient gel electrophoresis (DGGE) using the Tams1 gene as a marker. In addition, the parasitaemia was measured by a semi-quantitative reverse line blot hybridization assay in order to correlate Tams1 variation to changes in parasitaemia. It was found that both parasitaemia and parasite population displayed limited variation during persistent infection. Ticks were allowed to acquire T. annulata during 2 periods of the bovine infection. Tams1 alleles detected in ticks fed during acute infection were identical to the population in the bovine host. However, ticks fed during the carrier status acquired parasites showing a single Tams1 isotype that represented, in several cases, a minor population in the bovine host at the time of infestation. Although only a limited number of ticks were studied, these preliminary data suggest that specific parasite genotypes may be selected during tick transmission from a carrier animal.
Journal Article
Genetic and phenotypic analysis of Tunisian Theileria annulata clones
2003
Many parasite species are known to show high levels of genetic diversity, yet the consequences of this diversity for host–parasite interactions are not well understood. Variation in phenotypic traits such as growth rates and the ability to form transmission stages are raw material for natural and artificial selection to act upon with consequences for the evolution of the parasite species and disease control. In order to study genetic and phenotypic diversity amongst Theileria annulata parasites, a collection of 52 parasite clones was generated from cattle isolates and tick material recently collected in Tunisia. Genetic diversity was assessed using PCR-RFLP and monoclonal antibody markers, and genetically distinct clones selected for further study. Clones varied significantly in their growth rates in culture at 37 °C, their viability after a period of culture at 41 °C and their differentiation rates into transmission stages after culturing at 41 °C. The viability of a clone after culturing at 41 °C could not be predicted from its growth rate at 37 °C, but across clones, differentiation rates were positively correlated with growth rates at 37 °C. All 3 in vitro measures are likely to have relevance to parasite–host interactions in animals with clinical theileriosis, and should be acted on by within-host and between-host selection.
Journal Article