The Experts below are selected from a list of 753 Experts worldwide ranked by ideXlab platform

Lihua Xiao - One of the best experts on this subject based on the ideXlab platform.

Longxian Zhang - One of the best experts on this subject based on the ideXlab platform.

  • natural infection of Cryptosporidium muris in ostriches struthio camelus
    Veterinary Parasitology, 2014
    Co-Authors: Meng Qi, Rongjun Wang, Lina Xu, Junqiang Li, Lihua Xiao, Lei Huang, Longxian Zhang
    Abstract:

    A total of 303 fecal samples were collected from ostriches (Struthio camelus) and 31 samples (10.2%) were Cryptosporidium-positive upon microscopic analysis. The infection rate was 27.6% in ostriches aged 16–60 days, 1.2% in those aged 61–180 days, and 20.4% in those aged >10 years. The Cryptosporidium-positive isolates were genotyped with a restriction fragment length polymorphism analysis and DNA sequence analysis of the small subunit (SSU) rRNA gene. The 22 isolates from ostriches aged >10 years were identified as Cryptosporidium muris, whereas the nine isolates from ostriches <180 days were Cryptosporidium baileyi. Ten of the 22 C. muris isolates were analyzed based on the actin and HSP70 genes, and the results were identical to those observed for the SSU rRNA gene. Cross-transmission studies demonstrated that the C. muris isolate infected BALB/c mice and Mongolian gerbils, but did not infect chickens. C. muris isolated in this study appears to be host-adapted, consistent with a previous multilocus sequence typing analysis. Further studies are required to understand the prevalence and transmission of Cryptosporidium spp. in ostriches in different geographic areas.

  • Natural infection of Cryptosporidium muris in ostriches (Struthio camelus).
    Veterinary Parasitology, 2014
    Co-Authors: Lei Huang, Rongjun Wang, Lihua Xiao, Longxian Zhang
    Abstract:

    A total of 303 fecal samples were collected from ostriches (Struthio camelus) and 31 samples (10.2%) were Cryptosporidium-positive upon microscopic analysis. The infection rate was 27.6% in ostriches aged 16–60 days, 1.2% in those aged 61–180 days, and 20.4% in those aged >10 years. The Cryptosporidium-positive isolates were genotyped with a restriction fragment length polymorphism analysis and DNA sequence analysis of the small subunit (SSU) rRNA gene. The 22 isolates from ostriches aged >10 years were identified as Cryptosporidium muris, whereas the nine isolates from ostriches

  • Multilocus sequence subtyping and genetic structure of Cryptosporidium muris and Cryptosporidium andersoni.
    PloS one, 2012
    Co-Authors: Rongjun Wang, Longxian Zhang, Fuchun Jian, Changshen Ning, Aiqin Liu, Jinfeng Zhao, Yaoyu Feng, Helei Wang
    Abstract:

    In this study, nine C. muris and 43 C. andersoni isolates from various animals in China were subtyped by a multilocus sequence typing (MLST) tool. DNA sequence analyses showed the presence of 1–2 subtypes of C. muris and 2–6 subtypes of C. andersoni at each of the four loci (MS1, MS2, MS3, and MS16), nine of which represented new subtypes. Altogether, two C. muris and 10 C. andersoni MLST subtypes were detected. Linkage disequilibrium analysis indicated although the overall population structure of the two parasites was clonal, the Chinese C. andersoni in cattle has an epidemic structure. Three and two clusters were produced in the C. muris and C. andersoni populations by Structure 2.3.3 analysis, with Chinese C. muris and C. andersoni substructures differing from other countries. Thus, this study suggested the prevalence of C. andersoni in China is not attributed to the introduction of dairy cattle. More studies involving more genetic loci and systematic sampling are needed to better elucidate the population genetic structure of C. muris and C. andersoni in the world and the genetic basis for the difference in host specificity among the two most common gastric parasites.

  • Population structure inferred by Bayesian clustering using multilocus subtype information.
    2012
    Co-Authors: Rongjun Wang, Longxian Zhang, Fuchun Jian, Changshen Ning, Aiqin Liu, Jinfeng Zhao, Yaoyu Feng, Helei Wang
    Abstract:

    A, Cryptosporidium muris; B, Cryptosporidium andersoni. Each individual is shown as a thin vertical line, which is partitioned into K colored components representing estimated membership fractions in K genetic clusters, and the geographic locations are at the bottom. The pie charts show the distribution of genetic clusters in different countries and various animals. JP = Japan; PE = Peru; Ken = Kenya; EG = Egypt; CS = Czech Republic; CN = China; B = beef cattle; C = bactrian camel; D = dairy cattle; H = hamster; S = sheep.

  • Development of a Multilocus Sequence Tool for Typing Cryptosporidium muris and Cryptosporidium andersoni
    Journal of clinical microbiology, 2010
    Co-Authors: Yaoyu Feng, Martin Kvac, Una Ryan, Longxian Zhang, David Modrý, Bretislav Koudela, Wenli Yang, Ronald Fayer, Lihua Xiao
    Abstract:

    Although widely used for the characterization of the transmission of intestinal Cryptosporidium spp., genotyping tools are not available for C. muris and C. andersoni, two of the most common gastric Cryptosporidium spp. infecting mammals. In this study, we screened the C. muris whole-genome sequencing data for microsatellite and minisatellite sequences. Among the 13 potential loci (6 microsatellite and 7 minisatellite loci) evaluated by PCR and DNA sequencing, 4 were eventually chosen. DNA sequence analyses of 27 C. muris and 17 C. andersoni DNA preparations showed the presence of 5 to 10 subtypes of C. muris and 1 to 4 subtypes of C. andersoni at each locus. Altogether, 11 C. muris and 7 C. andersoni multilocus sequence typing (MLST) subtypes were detected among the 16 C. muris and 12 C. andersoni specimens successfully sequenced at all four loci. In all analyses, the C. muris isolate (TS03) that originated from an East African mole rat differed significantly from other C. muris isolates, approaching the extent of genetic differences between C. muris and C. andersoni. Thus, an MLST technique was developed for the high-resolution typing of C. muris and C. andersoni. It should be useful for the characterization of the population genetics and transmission of gastric Cryptosporidium spp.

Martin Kvac - One of the best experts on this subject based on the ideXlab platform.

  • Course of infection of Cryptosporidium proliferans and Cryptosporidium muris HZ206 in Mastomys coucha based on coprological examination of feces.
    2016
    Co-Authors: Martin Kvac, Nikola Havrdová, Lenka Hlásková, Tereza Daňková, Jiří Kanděra, Jana Ježková, Jiří Vítovec, Bohumil Sak, Ynes Ortega, Lihua Xiao
    Abstract:

    Course of infection of Cryptosporidium proliferans and Cryptosporidium muris HZ206 in Mastomys coucha based on coprological examination of feces.

  • Change of stomach weight of Mastomys coucha during experimental infection with Cryptosporidium proliferans and Cryptosporidium muris HZ206 compared to the control group.
    2016
    Co-Authors: Martin Kvac, Nikola Havrdová, Lenka Hlásková, Tereza Daňková, Jiří Kanděra, Jana Ježková, Jiří Vítovec, Bohumil Sak, Ynes Ortega, Lihua Xiao
    Abstract:

    Change of stomach weight of Mastomys coucha during experimental infection with Cryptosporidium proliferans and Cryptosporidium muris HZ206 compared to the control group.

  • Genetic diversity of Cryptosporidium spp. including novel identification of the Cryptosporidium muris and Cryptosporidium tyzzeri in horses in the Czech Republic and Poland
    Parasitology research, 2015
    Co-Authors: Pavla Wagnerová, Jana Ježková, Bohumil Sak, Michael Rost, John Mcevoy, Agniezska Perec Matysiak, Martin Kvac
    Abstract:

    Faecal samples were collected from 352 horses on 23farms operating under six differentmanagementsystems in the Czech Republic and Poland during 2011 and 2012. Farms were selected without previous knowledge of parasitological status. All faecal samples were screened for Cryptosporidium spp. presence using microscopy, following aniline-carbol- methyl violet staining and PCR analysis of the small-subunit (SSU) rRNA and the 60-kDa glycoprotein (gp60) genes. Cryptosporidium muris-positive samples were additionally genotyped at four minisatellite markers: MS1 (encoding a hypothetical protein), MS2 (encoding a 90-kDa heat shock protein), MS3 (encoding a hypothetical protein) and MS16 (encoding a leucine-rich repeat family protein). Cryptosporidium spp. was detected by PCR in 12/352 (3.4 %) samples from 4 out of 13 farms. None of the samples tested by microscopy was positive. There was no relationship between Cryptosporidium prevalence and age, sex, diarrhoea ormanagementsystem;however,Cryptosporidiumwasfound only on farms where horses were kept on pasture during the day and in a stable overnight. Sequence analyses of SSU and gp60 genes revealed the presence of C. muris RN66 (n=9), Cryptosporidium parvum IIaA15G2R1 (n=1),Cryptosporid- ium tyzzeri IXbA22R9 (n=1), and Cryptosporidium horse ge- notype VIaA15G4 (n=1). The C. muris subtypes were iden- tified as MS1-M1, MS2-M4, novel MS2-M7 and MS16-M1 by multilocus sequence of three minisatellite loci. The MS3 locus was not amplified from any isolate. This is the first report of C. tyzzeri and C. muris subtypes from horses.

  • Life cycle of Cryptosporidium muris in two rodents with different responses to parasitization.
    Parasitology, 2013
    Co-Authors: Janka Melicherová, Martin Kvac, Břetislav Koudela, Bohumil Sak, Jana Ilgová, Andrea Bardůnek Valigurova
    Abstract:

    This study focuses on mapping the life cycle of Cryptosporidium muris in two laboratory rodents; BALB/c mice and the southern multimammate rat Mastomys coucha , differing in their prepatent and patent periods. Both rodents were simultaneously experimentally inoculated with viable oocysts of C. muris (strain TS03). Animals were dissected and screened for the presence of the parasite using a combined morphological approach and nested PCR (SSU rRNA) at different times after inoculation. The occurrence of first developmental stages of C. muris in stomach was detected at 2·5 days post-infection (dpi). The presence of Type II merogony, appearing 36 h later than Type I merogony, was confirmed in both rodents. Oocysts exhibiting different size and thickness of their wall were observed from 5 dpi onwards in stomachs of both host models. The early phase of parasitization in BALB/c mice progressed rapidly, with a prepatent period of 7·5–10 days; whereas in M. coucha , the developmental stages of C. muris were first observed 12 h later in comparison with BALB/c mice and prepatent period was longer (18–21 days). Similarly, the patent periods of BALB/c mice and M. coucha differed considerably, i.e. 10–15 days vs chronic infection throughout the life of the host, respectively.

  • LIFE CYCLE OF Cryptosporidium muris IN TWO RODENTS EXHIBITING A DIFFERENT RESPONSE TO THE PARASITIZATION
    2012
    Co-Authors: Janka Melicherová, Martin Kvac, Břetislav Koudela, Jana Ilgová, Andrea Bardůnek Valigurova
    Abstract:

    Genus Cryptosporidium belongs to the phylum Apicomplexa comprising numerous important human and animal pathogens. Considering their unique epicellular location on the surface of host epithelial cells as well as molecular analyses pointing out their phylogenetic affinity with gregarines, cryptosporidia are recently often excluded from the typical coccidia. Cryptosporidium muris is a gastrointestinal pathogen parasitizing epithelial cells within crypts of the gastric glands and exhibiting a monoxenous life cycle. Main aim of this study was to map the in vivo development of C. muris using a combined microscopic approach and molecular tool (nested PCR amplifying SSU rRNA.Experimental inoculations with infective oocysts were performed simultaneously in two species of laboratory rodents, BALB/c mice and the southern multimammate rat Mastomys coucha, differing in their prepatent and patent period. Emphasis was given to the existence and the chronology of particular developmental stages that are generally described throughout the literature related to cryptosporidia. The presence of merozoites Type II and the thin walled oocysts, that are thought to be responsible for autoinfection, was confirmed in both rodent models; nevertheless, they occurred in these hosts at different time after inoculation and in different abundance. The initial phase of the infection of BALB/c mice progressed rapidly with a prepatent period of 7-10 days, while in M. coucha the developmental stages of C. muris were observed later and its prepatent period was longer (18-21 days). Similarly, the patent periods of BALB/c mice and M. coucha differed significantly, i.e. 10-15 days and chronic infection throughout the life of host respectively. We focused on pathological alterations of the affected gastric tissue. In M. coucha, the first pathological modifications were observed in a chronic phase of infection, while the gastric tissue of BALB/c mice exhibited no observable changes induced by the parasite.

Andrea Bardůnek Valigurova - One of the best experts on this subject based on the ideXlab platform.

  • Structural changes of cell lines after the real and simulated inoculations with Cryptosporidium muris oocysts.
    2014
    Co-Authors: Janka Melicherová, Andrea Bardůnek Valigurova
    Abstract:

    In the present study, two types of cell lines, HCT8 and HT29, were used for an in vitro cultivation of the gastric parasite Cryptosporidium muris (Cryptosporidiidae, Apicomplexa). Evaluations of structural changes of both cell lines were carried out after 24, 48 and 72 DPI using combined approaches of light, electron and confocal laser scanning microscopy. So far, we succeed to detect sporozoites released from oocysts, free sporozoites gliding on the cell line surface that were equipped with a typically prolonged apical end and seemed to search for appropriate infection site, and few structures closely resembling full or already emptied cryptosporidian parasitophorous sacs. Evidently, newly formed round cells or gaps in a discontinuous layer characteristic for young cell cultures were frequently preferred and attacked by invading sporozoites. Interestingly, after 24 DPI, both cell lines started to embrace unexcysted oocysts of C. muris. These oocysts were found to be completely or partially enveloped by projections of individual host cells. The experimental inoculation with polystyrene microspheres was designed in order to verify whether this behaviour of cell lines is provoked by oocysts of C. muris or it represents their innate reaction to foreign objects in general. The microspheres were found only occasionally to be covered by a tiny filamentous projections arising from host cells or remnants in old cell cultures. Direct comparison and evaluation of both cell lines inoculated either with C. muris oocysts or with polystyrene microspheres confirmedthat the enclosing of oocysts by HT29 and HCT8 cells was induced by the parasite. Based on present data, we consider this to be a natural adherence of biological garbage to the surface of polystyrene microspheres. Acknowledgement: Financial support was provided by a postdoctoral grant GPP506/10/P372.

  • Responses of cell lines to the real and simulated inoculations with Cryptosporidium muris oocysts.
    2014
    Co-Authors: Janka Melicherová, Jana Ilgová, Andrea Bardůnek Valigurova
    Abstract:

    In present study two types of cell lines, HCT8 and HT29, were used for an in vitro cultivation of the gastric parasite Cryptosporidium muris. Our observations were carried out after 24, 48 and 72 DPI using combined approach of light, electron and confocal laser scanning microscopy. So far, we succeed to detect free sporozoites with typically prolonged apical ends that seemed to search for appropriate host cell/infection site, few structures closely resembling full or already emptied cryptosporidian parasitophorous sacs, and free merozoites especially in HT29 cell line. Evidently, invading sporozoites preferred newly formed round cells or gaps in a discontinuous layer characteristic for young cell cultures. Interestingly, however, unexcysted oocysts of C. muris were found to be completely or partially enveloped by projections of individual host cells after 24 DPI in both cell lines. The experimental inoculation with polystyrene microspheres was designed in order to verify whether this behaviour of cell lines is provoked by oocysts of C. muris or it represents their innate reaction to foreign objects in general. Direct comparison and evaluation of both cell lines inoculated either with C. muris oocysts or with polystyrene microspheres confirmed that the enclosing of oocysts by HT29 and HCT8 cells was induced by the parasite. The microspheres were found only occasionally to be covered by a tiny filamentous projections arising from host cells or remnants from old cell cultures. Based on present data, we consider this to be a natural adherence of biological garbage to the surface of polystyrene microspheres. Financial support was provided by a postdoctoral grant GPP506/10/P372 and partially by the project GAP505/11/1163, both from the Czech Science Foundation.

  • Cell motility in sporozoites of Cryptosporidium muris.
    2014
    Co-Authors: Andrea Bardůnek Valigurova, Veronika Mazourová, Isabelle Florent, Janka Melicherová
    Abstract:

    Although the motility of cryptosporidian sporozoites is considered as the main mechanism facilitating the host cell invasion, our observations show that motility of C. muris sporozoites is very limited and featureless, and differs from other apicomplexan zoites. As cryptosporidian sporozoites possess a single rhoptry, they have only one attempt for successful attachment to the host cell. Within the host organism, released sporozoites of C. muris rapidly penetrate deeply into the bottom of the pits of the gastric glands to avoid the adverse conditions in the host stomach. In cell cultures, using various media, including those enriched by BSA and vitamins, the activity of freshly released sporozoites decreases very rapidly and after several minutes, sporozoites do not show any signs of vitality. The apical region of invasive sporozoites is obviously prolonged and their three-layered pellicle is smooth lacking any grooves or folds. Using immunofluorescence we were able to obtain myosin labelling, which is considered an essential part of apicomplexan motility motor. Labelling of actin with a specific antibody recognizing the actin in Toxoplasma gondii and Plasmodium falciparum was not successful despite multiple repetitions of staining procedure of C. muris sporozoites. However, immunoblotting assays of sporozoites soluble proteins indicated the presence of actin (42 kDa) in relatively low concentrations. In addition, we were able to amplify by PCR and sequence the C. muris actin gene from genomic DNA. Using the both immunofluorescence and immunoblotting, we were able to detect alfa-tubulin (50 kDa), which represents an elemental component of subpellicular microtubules. Therefore, the currently obtained data support the presence, in C. muris, of basic mechanism of apicomplexan motility that is expected to be based on the orientation of the actomyosin motor by subpellicular microtubules.

  • Life cycle of Cryptosporidium muris in two rodents with different responses to parasitization.
    Parasitology, 2013
    Co-Authors: Janka Melicherová, Martin Kvac, Břetislav Koudela, Bohumil Sak, Jana Ilgová, Andrea Bardůnek Valigurova
    Abstract:

    This study focuses on mapping the life cycle of Cryptosporidium muris in two laboratory rodents; BALB/c mice and the southern multimammate rat Mastomys coucha , differing in their prepatent and patent periods. Both rodents were simultaneously experimentally inoculated with viable oocysts of C. muris (strain TS03). Animals were dissected and screened for the presence of the parasite using a combined morphological approach and nested PCR (SSU rRNA) at different times after inoculation. The occurrence of first developmental stages of C. muris in stomach was detected at 2·5 days post-infection (dpi). The presence of Type II merogony, appearing 36 h later than Type I merogony, was confirmed in both rodents. Oocysts exhibiting different size and thickness of their wall were observed from 5 dpi onwards in stomachs of both host models. The early phase of parasitization in BALB/c mice progressed rapidly, with a prepatent period of 7·5–10 days; whereas in M. coucha , the developmental stages of C. muris were first observed 12 h later in comparison with BALB/c mice and prepatent period was longer (18–21 days). Similarly, the patent periods of BALB/c mice and M. coucha differed considerably, i.e. 10–15 days vs chronic infection throughout the life of the host, respectively.

  • Electron microscopic visualization of alterations in rodentgastric tissue induced by Cryptosporidium muris
    2013
    Co-Authors: Janka Melicherová, Jana Ilgová, Andrea Bardůnek Valigurova
    Abstract:

    The phylum Apicomplexa includes significant unicellular parasites of humans and animals. One of these is the genus Cryptosporidium that is the causative agent of zoonotic disease of the gastrointestinal and respiratory tract, called cryptosporidiosis. This study compares the progress of Cryptosporidium muris infection in gastric tissue of laboratory rodents, BALB/c mice and Mastomys coucha. The glandular and non-glandular parts of stomach were examined at selected time points after oral inoculation with a dose of 106 infective oocysts of C. muris. Rodents exhibited significant differences in responses to the parasitisation as well as in chronology of pathological changes of gastric tissue induced by the parasite. The sequence of individual changes during the acute phase of parasitisation, however, corresponded in both hosts. At the beginning, the gastric tissues of both hosts were irregularly affected by cryptosporidia invading the tissue in an island-like manner and thus sporadic foci of parasitisation localized within gastric pits were surrounded by large areas of healthy tissue. The first alterations of hosts' gastric surface were noticed after 5 DPI. Some pits were slightly open and enlarged. At 8-10 DPI, the cryptosporidiosis affected a majority of the glandular part in both hosts, whereas the non-glandular part exhibited no changes. Pathological chnages of the tissue included an intensive epithelial hyperplasia and a mucosal hypertrophy without inflammatory exudates. The pathological changes of gastric tissue in BALB/c mice gradually retreated from 21 DPI onwards and the complete regeneration of epithelial cells was observed at 28 DPI. In contrast, in M. coucha, the cryptosporidiosis entered a chronic phase after 18 DPI and all the above-described pathological alterations of parasitised tissue became even much more obvious. Moreover, a massive increase in the volume of the lamina propria caused an enlarged distance between individual affected gastric glands.

Břetislav Koudela - One of the best experts on this subject based on the ideXlab platform.

  • Life cycle of Cryptosporidium muris in two rodents with different responses to parasitization.
    Parasitology, 2013
    Co-Authors: Janka Melicherová, Martin Kvac, Břetislav Koudela, Bohumil Sak, Jana Ilgová, Andrea Bardůnek Valigurova
    Abstract:

    This study focuses on mapping the life cycle of Cryptosporidium muris in two laboratory rodents; BALB/c mice and the southern multimammate rat Mastomys coucha , differing in their prepatent and patent periods. Both rodents were simultaneously experimentally inoculated with viable oocysts of C. muris (strain TS03). Animals were dissected and screened for the presence of the parasite using a combined morphological approach and nested PCR (SSU rRNA) at different times after inoculation. The occurrence of first developmental stages of C. muris in stomach was detected at 2·5 days post-infection (dpi). The presence of Type II merogony, appearing 36 h later than Type I merogony, was confirmed in both rodents. Oocysts exhibiting different size and thickness of their wall were observed from 5 dpi onwards in stomachs of both host models. The early phase of parasitization in BALB/c mice progressed rapidly, with a prepatent period of 7·5–10 days; whereas in M. coucha , the developmental stages of C. muris were first observed 12 h later in comparison with BALB/c mice and prepatent period was longer (18–21 days). Similarly, the patent periods of BALB/c mice and M. coucha differed considerably, i.e. 10–15 days vs chronic infection throughout the life of the host, respectively.

  • LIFE CYCLE OF Cryptosporidium muris IN TWO RODENTS EXHIBITING A DIFFERENT RESPONSE TO THE PARASITIZATION
    2012
    Co-Authors: Janka Melicherová, Martin Kvac, Břetislav Koudela, Jana Ilgová, Andrea Bardůnek Valigurova
    Abstract:

    Genus Cryptosporidium belongs to the phylum Apicomplexa comprising numerous important human and animal pathogens. Considering their unique epicellular location on the surface of host epithelial cells as well as molecular analyses pointing out their phylogenetic affinity with gregarines, cryptosporidia are recently often excluded from the typical coccidia. Cryptosporidium muris is a gastrointestinal pathogen parasitizing epithelial cells within crypts of the gastric glands and exhibiting a monoxenous life cycle. Main aim of this study was to map the in vivo development of C. muris using a combined microscopic approach and molecular tool (nested PCR amplifying SSU rRNA.Experimental inoculations with infective oocysts were performed simultaneously in two species of laboratory rodents, BALB/c mice and the southern multimammate rat Mastomys coucha, differing in their prepatent and patent period. Emphasis was given to the existence and the chronology of particular developmental stages that are generally described throughout the literature related to cryptosporidia. The presence of merozoites Type II and the thin walled oocysts, that are thought to be responsible for autoinfection, was confirmed in both rodent models; nevertheless, they occurred in these hosts at different time after inoculation and in different abundance. The initial phase of the infection of BALB/c mice progressed rapidly with a prepatent period of 7-10 days, while in M. coucha the developmental stages of C. muris were observed later and its prepatent period was longer (18-21 days). Similarly, the patent periods of BALB/c mice and M. coucha differed significantly, i.e. 10-15 days and chronic infection throughout the life of host respectively. We focused on pathological alterations of the affected gastric tissue. In M. coucha, the first pathological modifications were observed in a chronic phase of infection, while the gastric tissue of BALB/c mice exhibited no observable changes induced by the parasite.

  • Life cycle of Cryptosporidium muris in experimental conditions
    2012
    Co-Authors: Andrea Bardůnek Valigurova, Martin Kvac, Janka Melicherová, Jana Ilgová, Břetislav Koudela
    Abstract:

    Cryptosporidia (Apicomplexa) have been recently recognized as one of the most ubiquitous parasites infecting gastrointestinal and respiratory tract of vertebrates. Localization of cryptosporidian developmental stages in the host epithelium has been the subject of extensive speculation for many years. Our published data support the term epicellular to reflect the cryptosporidian localization, rather than the term intracellular extracytoplasmic, used throughout the literature. Due to its peculiar localization, Cryptosporidium can derive nutrition while minimizing immunologic recognition and there is currently no effective treatment for cryptosporidiosis. In presented study, the life cycle of Cryptosporidium muris parasitizing gastric glands of experimentally infected laboratory rodents, Mastomys natalensis and BALB/c mice, has been analysed in detail. The main aim was to map the development of C. muris in hosts exhibiting different response to the parasitization. We have focused on the endogenous development of C. muris, during which the parasite was attached to the host epithelium and its development included both asexual and sexual developmental stages. Animals were dissected and screened for the presence of parasite using combined morphological approach and nested PCR (SSU rRNA) at different time after inoculation with infective oocysts. The study has revealed possible difficulties in detecting C. muris developmental stages in gastric glands during the first days of parasitization. In addition to experiments in vivo, we attempt to culture C. muris in vitro using the HCT-8 and HT-29 human adenocarcinoma cell lines.

  • Effects of low and high temperatures on infectivity of Cryptosporidium muris oocysts suspended in water.
    Veterinary Parasitology, 2008
    Co-Authors: Helena Neumayerová, Břetislav Koudela
    Abstract:

    Abstract Cryptosporidium muris oocysts suspended in 200 μl of water were pipetted into plastic microcentrifuge tubes which were stored at 4 °C or frozen at −5 °C for 1, 3, 5, 7, and 10 days and at −20 °C for 1, 3, 5, and 8 h, respectively. Other samples of C. muris oocysts suspended in water were heated in the metal block of a thermal DNA cycler. Block temperatures were set at 5 °C incremental temperatures from 40 to 70 °C. At each high temperature setting microcentrifuge tubes containing C. muris oocysts were exposed for 1 min. Both, frozen and heated oocyst suspensions as well as untreated control oocyst suspensions were then inoculated into each of four ICR mice by gastric intubation. Untreated, freeze-thawed or heated oocysts were considered infectious when oocysts of C. muris were found microscopically in the faeces of mice after inoculation. All inoculated mice that received oocysts frozen at −5 °C for 3, 5, 7, and 10 days and −20 °C for 1, 3, 5, and 8 h had no oocysts in faeces. In contrast, C. muris oocysts frozen at −5 °C for 1 day remained infective for inoculated mice. Our results also indicated that when water containing C. muris oocysts was exposed at a temperature of 55 °C or higher for 1 min, the infectivity of oocysts was lost.

  • fine structure of invasion and development of Cryptosporidium muris in experimentally infected host
    2007
    Co-Authors: Andrea Bardůnek Valigurova, Břetislav Koudela
    Abstract:

    Studovaný bol proces invazie a vývoja žaludocneho parazita Cryptosporidium muris na urovni ultrastruktury.