Search

The predator–prey-transmitted cestode Taenia hydatigena infects a wide range of definitive and intermediate hosts all over the world. Domestic and sylvatic cycles of transmission are considered as well. The parasite has considerable economic importance, particularly in sheep. Here, the molecular characters of T. hydatigena cysticerci in sheep from the Nile Delta, Egypt were investigated for the first time. For this purpose, 200 sheep carcasses and their offal were inspected at the municipal abattoir, Dakahlia governorate, Egypt. Cysticerci of T. hydatigena were collected and molecularly characterized employing the mitochondrial 12S rRNA gene. Cysticerci were found in 42 (21%) sheep, mostly attached to the omenti, mesenteries and livers. After molecular confirmation, nine isolates were sequenced displaying six different haplotypes. Analysis of the T. hydatigena 12S rRNA nucleotide sequences deposited in GenBank revealed 55 haplotypes out of 69 isolates, displaying high haplotype (0.797) and low nucleotide (0.00739) diversities. For the Tajima D neutrality index, a negative value (−2.702) was determined, indicating the population expansion of the parasite. Additionally, global data summarized in this study should be useful to set up effective control strategies against this ubiquitous parasite.

Toxocara canis and Toxocara cati are globally occurring zoonotic roundworms of dogs and cats. Migration and persistence of Toxocara larvae in the central nervous system of paratenic hosts including humans may cause clinical signs of neurotoxocarosis (NT). As pathomechanisms of NT and host responses against Toxocara larvae are mostly unknown, whole-genome microarray transcription analysis was performed in cerebra and cerebella of experimentally infected C57Bl/6J mice as paratenic host model at days 14, 28, 70, 98, and 120 post-infection. Neuroinvasion of T. cati evoked 220 cerebral and 215 cerebellar differentially transcribed genes (DTGs), but no particular PANTHER (Protein ANalysis THrough Evolutionary Relationships) pathway was affected. In T. canis-infected mice, 1039 cerebral and 2073 cerebellar DTGs were identified. Statistically significant dysregulations occurred in various pathways, including cholesterol biosynthesis, apoptosis signaling, and the Slit/Robo mediated axon guidance as well as different pathways associated with the immune and defense response. Observed dysregulations of the cholesterol biosynthesis, as well as the Alzheimer disease-amyloid secretase pathway in conjunction with previous histopathological neurodegenerative findings, may promote the discussion of T. canis as a causative agent for dementia and/or Alzheimer’s disease. Furthermore, results contribute to a deeper understanding of the largely unknown pathogenesis and host-parasite interactions during NT, and may provide the basis for prospective investigations evaluating pathogenic mechanisms or designing novel diagnostic and therapeutic approaches.

Infective larvae of Toxocara canis and T. cati, the common roundworms of dogs and cats, may invade the central nervous system of paratenic hosts, including humans, causing neurotoxocarosis (NT). Previous studies on NT in the model organism "mouse" have indicated distinct differences between T. canis and T. cati regarding larval migration patterns as well as the severity of clinical symptoms and behavioural alterations. The objective of the present study was to provide an extensive characterization of the underlying histopathological alterations, comparing T. canis- and T. cati-induced changes in different brain areas over the course of murine infection. Four histological sections of five brains each of T. canis- and T. cati-infected as well as uninfected C57Bl/6 mice were investigated 7, 14, 28, 42, 70 and 98 days post infection (dpi), while brains of T. cati-infected and control mice were also available 120 and 150 dpi. In addition to haematoxylin-eosin and luxol fast blue-cresyl violet staining, immunohistochemistry was employed to study microglia/macrophage cell morphology and to detect accumulation of β-amyloid precursor protein (β-APP) as an indicator of axonal damage. Haemorrhages, eosinophilic vasculitis and activated microglia/macrophages were detected in both infection groups starting 7 dpi, followed by eosinophilic meningitis in cerebra as from 14 dpi. Overall, little differences in the proportion of animals affected by these alterations were found between the two infection groups. In contrast, the proportion of animals displaying β-APP accumulation was significantly higher in the T. canis than T. cati group as from 28 dpi regarding the cerebrum as well as at 98 dpi regarding the cerebellum. In T. canis-infected mice, myelinophagic microglia/macrophages ("gitter cells") appeared as from 14 dpi, whereas these were first observed at 70 dpi in T. cati-infected animals. The proportion of animals displaying demyelination and/or gitter cells in the cerebrum was significantly higher in the T. canis than T. cati group as from 28 dpi, and at 28 and 42 dpi regarding the cerebellum. Earlier and more severe neurodegeneration during T. canis- than T. cati-induced NT, especially in the cerebrum, may explain the differences in behavioural alterations observed in previous studies. In addition to differences in larval migration preferences, immunological processes may contribute to these patterns, which warrant further investigation.

This study aimed to investigate the endoparasite fauna of wild European gray wolves, which are currently recolonizing Germany. In total, 69 fecal samples of wild wolves were collected in Lower Saxony, Germany, from 2013 to 2015, analyzed by the sedimentation-flotation and McMaster techniques and compared to previous results on captive European Gray wolves living in zoological gardens in Germany. In addition to coproscopy, taeniid-positive samples from wild as well as captive wolves were differentiated by amplification and sequencing of small subunit ribosomal RNA (SSU rRNA) and NADH dehydrogenase 1 (nad1) gene fragments. Missing Taenia krabbei SSU rRNA reference sequences were generated from two T. krabbei specimens. Overall, 60.87% (42/69) of wild wolve samples were microscopically positive for at least one of seven egg types. Capillaria/Eucoleus spp. showed the highest frequency (31.88% [22/69]), followed by Taeniidae (21.74% [15/69]), Ancylostomatidae (20.29% [14/69]), Alaria alata (15.94% [11/69]), Toxocara canis (13.04% [9/69]), and Toxascaris leonina and Trichuris vulpis (each 5.80% [4/69]). Amplification of SSU rRNA was successful for 7/15 Taeniidae-positive samples from wild and 20/39 samples from captive wolves, revealing T. hydatigena in two and 14 samples, respectively. Taenia krabbei was detected in two further samples of wild and three samples of captive wolves, while for the remaining samples, no differentiation between T. serialis/T. krabbei was possible. Echinococcus spp. were not detected. Sequence comparisons revealed that the SSU rRNA gene fragment was not suitable to differentiate between T. serialis and T. krabbei. Therefore, the use of this fragment alone cannot be recommended for species identification in future studies.

The predator–prey-transmitted cestode Taenia hydatigena infects a wide range of definitive and intermediate hosts all over the world. Domestic and sylvatic cycles of transmission are considered as well. The parasite has considerable economic importance, particularly in sheep. Here, the molecular characters of T. hydatigena cysticerci in sheep from the Nile Delta, Egypt were investigated for the first time. For this purpose, 200 sheep carcasses and their offal were inspected at the municipal abattoir, Dakahlia governorate, Egypt. Cysticerci of T. hydatigena were collected and molecularly characterized employing the mitochondrial 12S rRNA gene. Cysticerci were found in 42 (21%) sheep, mostly attached to the omenti, mesenteries and livers. After molecular confirmation, nine isolates were sequenced displaying six different haplotypes. Analysis of the T. hydatigena 12S rRNA nucleotide sequences deposited in GenBank revealed 55 haplotypes out of 69 isolates, displaying high haplotype (0.797) and low nucleotide (0.00739) diversities. For the Tajima D neutrality index, a negative value (−2.702) was determined, indicating the population expansion of the parasite. Additionally, global data summarized in this study should be useful to set up effective control strategies against this ubiquitous parasite.

One of the main goals in academia is, and has been, high quality education of students to provide theoretical and practical knowledge essential for professional life. Achieving this goal is highly dependent on teaching procedures and, consequently, on a constant adaptation of teaching styles to align to technical advances and cutting-edge topics. Technical advances can strongly influence teaching and learning in the complex subject area of veterinary parasitology. Today's students are provided with extensive, digital lecture notes, and e-learning offers including virtual microscope technology to independently obtain intensified theoretical knowledge and understanding. As veterinary parasitology is also highly reliant on proficient practical skills, lectures with integrated diagnostic exercises are mandatory. Nowadays, such practical skills, such as carrying out faecal examination procedures, can be strengthened by having access to clinical skills labs. Advances such as digital lecture notes, e-learning and virtual microscopes do not only provide new, innovative opportunities, but can also comprise challenges. In this context, provision of sufficient relevant studying material may discourage students to take on responsibilities for autonomous gathering of information. Besides technical advances, 'Zeitgeist' changes are shaping teaching contents, which are progressively expanding as zoonoses are increasingly being focused on. With the aim of adopting the one-health concept, students today are expected not only to bear responsibilities for animals, but also for their owners and public health. This article will cast light on some key challenges and opportunities in modern veterinary parasitology teaching from the teachers´ and the students´ perspectives.

Parasite co-evolution alongside the mammalian immune system gave rise to several modulatory strategies by which they prevent exaggerated pathology and facilitate a longer worm survival. As little is known about the immunoregulatory potential of the zoonotic canine parasites Ancylostoma caninum and Toxocara canis in the natural host, the present study aimed to investigate whether their larval excretory-secretory (ES) products can modulate the canine immune system. We demonstrated TcES to increase the frequency of CD4+ Foxp3high T cells, while both AcES and TcES were associated with elevated Helios expression in Foxp3high lymphocytes. ES products were further capable of inducing IL-10 production by lymphocytes, which was mainly attributed to CD8+ T cells. ES treatment of PBMCs prior to mitogen stimulation inhibited polyclonal proliferation of CD4+ and CD8+ T cells. Moreover, monocyte-derived ES-pulsed dendritic cells reduced upregulation of MHC-II and CD80 in response to lipopolysaccharide. The data showed that regulation of the canine immune system by A. caninum and T. canis larvae comprises the modification of antigen-specific and polyclonal T cell responses and dendritic cell maturation.

Toxocara canis and T. cati are worldwide distributed intestinal nematodes of canids and felids and pose a threat to public health due to possible clinical manifestations in humans. Different methods for detection of Toxocara eggs in soil have been described, but conducted studies deal with egg recovery rates of T. canis or "Toxocara spp." only whereas T. cati egg recovery has not been taken into consideration. Thus, flotation properties in sodium chloride solution and adherence characteristics to different substrates possibly coming into contact with Toxocara eggs before or during purification from soil were evaluated for both, T. canis and T. cati eggs. No significant difference was observed in flotation characteristics, but comparison of adherence properties revealed significantly less adherence of T. cati eggs on almost all evaluated substrates ("sand", side sealed bags, glass beaker, centrifuge tube) and different washing solutions (tap water, Tween(®) 80, Triton™ X-100). Mean adhesion rates of T. cati eggs ranged from 15.9% to 68.9%, those of T. canis eggs from 28.3% to 83.9%. While adherence of T. cati eggs on any substrate was significantly reduced when rinsing with Tween(®) 80 solution, no effect on T. canis eggs could be observed. Generally, Toxocara eggs adhere better on plastic than on glass. Evaluation of a method including only non-hazardous substances for purification of Toxocara eggs from soil resulted in a statistically significant higher recovery rate of T. canis (42.6% recovered eggs) compared to T. cati eggs (30.9% recovered eggs). As these percentages are above average for described methods to recover Toxocara eggs from soil, the presented method is considered reliable for prevalence studies.

The zoonotic roundworms Toxocara canis and T. cati are not only present worldwide in their definitive hosts; they also frequently occur in other animal species, including humans. In those so-called paratenic hosts, the larvae do not develop into the adult stage, but rather migrate throughout the somatic tissue and persist as infectious L3 stage for extensive periods. Those arrested larvae may lead to severe inflammatory reactions and consequently to a wide range of pathological and clinical manifestations. However, the infected paratenic hosts also constitute a potential source of infection for the definitive hosts or humans who may also function as paratenic hosts. In the present review, current knowledge of larval migration in a variety of possible paratenic hosts is summarized including variations of migration routes and susceptibilities. Furthermore, information about the clinical and pathological changes for the presented species and possible consequences of the somatic migration of larvae, i.e. the resulting tissue damage as well as adverse host reactions to arrested larvae are reviewed. There are still many questions unanswered regarding larval behaviour in hosts other than their definitive host. Therefore, it is of great importance to continue further elaboration on the biology of Toxocara spp. to prevent further spreading of larvae in both the paratenic and the definitive host.

Background Rickettsioses are caused by pathogenic species of the genus Rickettsia and play an important role as emerging diseases. The bacteria are transmitted to mammal hosts including humans by arthropod vectors. Since detection, especially in tick vectors, is usually based on PCR with genus-specific primers to include different occurring Rickettsia species, subsequent species identification is mainly achieved by Sanger sequencing. In the present study a real-time pyrosequencing approach was established with the objective to differentiate between species occurring in German Ixodes ticks, which are R. helvetica, R. monacensis, R. massiliae, and R. felis. Tick material from a quantitative real-time PCR (qPCR) based study on Rickettsia-infections in I. ricinus allowed direct comparison of both sequencing techniques, Sanger and real-time pyrosequencing. Methods A sequence stretch of rickettsial citrate synthase (gltA) gene was identified to contain divergent single nucleotide polymorphism (SNP) sites suitable for Rickettsia species differentiation. Positive control plasmids inserting the respective target sequence of each Rickettsia species of interest were constructed for initial establishment of the real-time pyrosequencing approach using Qiagen’s PSQ 96MA Pyrosequencing System operating in a 96-well format. The approach included an initial amplification reaction followed by the actual pyrosequencing, which is traceable by pyrograms in real-time. Afterwards, real-time pyrosequencing was applied to 263 Ixodes tick samples already detected Rickettsia-positive in previous qPCR experiments. Results Establishment of real-time pyrosequencing using positive control plasmids resulted in accurate detection of all SNPs in all included Rickettsia species. The method was then applied to 263 Rickettsia-positive Ixodes ricinus samples, of which 153 (58.2%) could be identified for their species (151 R. helvetica and 2 R. monacensis) by previous custom Sanger sequencing. Real-time pyrosequencing identified all Sanger-determined ticks as well as 35 previously undifferentiated ticks resulting in a total number of 188 (71.5%) identified samples. Pyrosequencing sensitivity was found to be strongly dependent on gltA copy numbers in the reaction setup. Whereas less than 101 copies in the initial amplification reaction resulted in identification of 15.1% of the samples only, the percentage increased to 54.2% at 101-102 copies, to 95.6% at >102-103 copies and reached 100% samples identified for their Rickettsia species if more than 103 copies were present in the template. Conclusions The established real-time pyrosequencing approach represents a reliable method for detection and differentiation of Rickettsia spp. present in I. ricinus diagnostic material and prevalence studies. Furthermore, the method proved to be faster, more cost-effective as well as more sensitive than custom Sanger sequencing with simultaneous high specificity.

To the Editor: Bacteria of the genus Bartonella are transmitted by arthropods and are often implicated in human disease. Even though ticks are known to transmit a variety of pathogens, vector competences for transmission of Bartonella spp. by ticks were speculative (1) until recently, when in vivo transmission of B. birtlesii by Ixodes ricinus ticks was demonstrated in mice (2). This finding suggests that this tick species, which is common in Europe, may also transmit zoonotic Bartonella spp. Evidence of possible tick transmission of bartonellae to humans under natural conditions was provided by Eskow et al. (3) and Angelakis et al. (4), who identified Bartonella spp. in tissue samples of patients who were recently bitten by ticks. We determined the prevalence of Bartonella spp. in questing I. ricinus ticks in the city of Hanover, Germany, which is nicknamed The Green Metropolis and was selected the German Capital of Biodiversity in 2011. During April–October 2010, we collected 2,100 questing ticks, consisting of 372 adults (177 female and 195 male), 1,698 nymphs, and 30 larvae, from 10 recreation areas in Hanover. Tick DNA was extracted by using the NucleoSpin 8 Blood kit (Macherey-Nagel, Duren, Germany). Plasmid DNA constructed from B. henselae reference strain ATCC49793 containing the 249-bp target sequence of the gltA gene was used as positive control. Bartonella spp. in ticks was detected by quantitative PCR (qPCR) by using the Mx3005 Multiplex Quantitative PCR System (Stratagene, Heidelberg, Germany) according to the protocol described by Mietze et al. (5), with minor modifications. Samples positive by qPCR were verified by gel electrophoresis. Bartonella species were differentiated by sequencing (Eurofins MWG Operon, Ebersberg, Germany), and obtained sequences underwent BLAST (http://blast.ncbi.nlm.nih.gov/Blast.cgi) comparison to published sequences. On the basis of the amplicon-specific melting temperature and DNA bands representing the specific size of 249-bp after gel electrophoresis, results of qPCR showed 100 (4.76%) infected I. ricinus ticks (Table). Positive results did not vary by developmental tick stages; 4.84% (18/372) adult ticks (5.08% [9/177] female and 4.62% [9/195] male), 4.71% (80/1,698) nymphs, and 6.67% (2/30) larvae were infected (Table). Because Bartonella spp. do not seem to be transmitted transovarially (6), it is likely that larvae had interrupted blood meals and thus did not take up enough blood to develop into the nymphal stage. Table Seasonal distribution of Ixodes ricinus ticks infected with Bartonella spp., Hanover, Germany, 2010* Seasonal changes in Bartonella spp. infection rates resulted in a higher peak in May (38/300 [12.67%]) than in the other months (Table). For sampling locations, infection rates for grassy sampling location 6 (4/210 [1.90%] infected ticks) differed significantly (Bonferroni-Holm adjusted p

Background Infective larvae of the worldwide occurring zoonotic roundworm T. canis exhibit a marked affinity to the nervous tissues of paratenic hosts. In humans, most cases of neurotoxocarosis are considered to be caused by larvae of T. canis as T. cati larvae have rarely been found in the CNS in previous studies. However, direct comparison of studies is difficult as larval migration depends on a variety of factors including mouse strains and inoculation doses. Therefore, the present study aims to provide a direct comparison of both roundworm species in mice as a model for paratenic hosts with specific focus on the CNS during the acute and chronic phase of disease to provide a basis for further studies dealing with neurotoxocarosis. Methods C57Bl/6J mice were infected with 2000 embryonated T. canis and T. cati eggs, respectively as well as Balb/c mice infected with T. cati eggs only. On 8 time points post infection, organs were removed and microscopically examined for respective larvae. Special focus was put on the CNS, including analysis of larval distribution in the cerebrum and cerebellum, right and left hemisphere as well as eyes and spinal cord. Additionally, brains of all infection groups as well as uninfected controls were examined histopathologically to characterize neurostructural damage. Results Significant differences in larval distribution were observed between and within the infection groups during the course of infection. As expected, significantly higher recovery rates of T. canis than T. cati larvae were determined in the brain. Surprisingly, significantly more T. canis larvae could be found in cerebra of infected mice whereas T. cati larvae were mainly located in the cerebellum. Structural damage in brain tissue could be observed in all infection groups, being more severe in brains of T. canis infected mice. Conclusions The data obtained provides an extensive characterization of migrational routes of T. canis and T. cati in the paratenic host mouse in direct comparison. Even though to a lesser extent, structural damage in the brain was also caused by T. cati larvae and therefore, the potential as pathogenic agents should not be underestimated.

The present study investigated the prevalence of Borrelia burgdorferi sensu lato (s.l.) genospecies in Ixodes ricinus ticks collected in Hanover, Northern Germany, in 2010. At the same time the study served as fifth-year-follow-up study for data comparison with 2005.A total of 2100 questing ticks were collected and analysed by quantitative real-time PCR (qPCR) with subsequent species differentiation via Reverse Line Blot and Sanger sequencing. Simultaneously, results obtained in 2010 were compared to infection rates from 2005 to evaluate the development of B. burgdorferi s.l. infection rates in Hanoverian ticks.Overall, 22.7% (476/2,100) of collected ticks were tested positive for B. burgdorferi s.l. infections. Adult ticks showed an infection rate of 33.3% (124/372), subdivided into 29.6% (58/196) positive males and 37.5% (66/176) positive females. Nymph and larvae infection rates were found to be 20.3% (344/1,697) and 25.8% (8/31), respectively. Species identification was successful for 59.2% (282/476) of positive ticks with B. afzelii as the most frequently detected genospecies, followed by B. garinii (including B. bavariensis) and B. spielmanii. B. burgdorferi sensu stricto (s.s.), B. bissettii, B. valaisiana and B. lusitaniae were also identified. Significant differences concerning seasonal fluctuations as well as local differences were observed. Comparing infection rates of Hanoverian ticks between years, a significant increase (P = 0.002) could be observed for larvae with 1.7% positives (2/60) in 2005 and 25.8% positives (8/31) in 2010. In the latter year, coinfections with Borrelia and Rickettsiales were detected in a total of 7.8% (163/2,100) of collected ticks. Of these, 7.3% (153/2,100) were coinfected with Rickettsia spp., 0.3% (7/2,100) with A. phagocytophilum and 0.1% (3/2,100) were coinfected with all three pathogens. Between years 2005 and 2010, no statistically significant differences in coinfection rates were found.Comparing B. burgdorferi s.l. infections in Hanoverian I. ricinus ticks in 2010 with data from 2005, a statistically significant increase of infected larvae was noted, whereas the other stages revealed no statistically significant differences. Whether the increased larvae infection rate is an isolated event or results from factual circumstances, e.g. increasing effectiveness of transovarial transmission due to unknown factors, has to be evaluated in further studies.