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Einleitung: Eimeria (E.) spp. und Toxoplasma (T.) gondii sind intrazelluläre Protozoen aus dem Phylum Apicomplexa und stellen bedeutende Pathogene dar. Infektionen mit Eimeria spp. sind Auslöser der Kokzidiose, welche eine der ökonomisch bedeutsamsten Erkrankungen in der Geflügelproduktion darstellt. Die Toxoplasmose des Huhnes hingegen verläuft in der Regel subklinisch. Da beide Parasiten, Eimeria spp. und Toxoplasma gondii, weltweit verbreitet sind, können natürliche Koinfektionen auftreten. Prävalenzstudien mit Hilfe molekularer und serologischer Untersuchungsmethoden sind geeignet, um die Vorkommen, Verbreitung, und Speziesidentität von einzelnen Apicomplexa zu untersuchen, was zu besserer Diagnose, Kontrolle, und Bestandsüberwachung beiträgt. Trotz vorliegender Hinweise, dass bei Koinfektionen zu einer Interaktion zwischen Eimeria und Toxoplasma kommt, existieren Erkenntnislücken hinsichtlich der Häufigkeit und der Bedeutung von natürlichen Koinfektionen des Huhnes unter Feldbedingungen, insbesondere mit Augenmerk auf verschiedene Nutzungstypen, Produktions- und Haltungsbedingungen. Ziele der Untersuchungen: Die Ziele der Untersuchungen waren die Erhebung der Prävalenzen von verschiedenen Eimeria spp. und von T. gondii bei Hühnern, sowie die Häufigkeit ihres Auftretens als Einzel- und Koinfektionen unter Feldbedingungen unter Berücksichtigung verschiedener Nutzungstypen und Haltungsbedingungen in Griechenland. Tiere, Material und Methoden: Die Auswahl der für diese Feldstudie untersuchten Hühnerbestände erfolgte auf Basis der Anzahl von kommerziellen Hühnerhaltungen in drei Hauptregionen Griechenlands. Nach offiziellen Angaben des griechischen Ministeriums für Ländliche Entwickung und Lebensmittel konzentriert sich die griechische Geflügelindustrie hauptsächlich auf Epirus (im Nordwesten), Zentralmazedonien, und Zentralgriechenland. Die Probenentnahme erfolgte in kommerziellen und Hinterhofhaltungen, wobei die Probenanzahl proportional zur Anzahl entsprechender, Introduction: Eimeria spp. and Toxoplasma gondii are intracellular Apicomplexan protozoa and represent important pathogens for chickens. Coccidiosis, caused by Eimeria spp. is one of the most notable diseases in chickens having a high economic impact on the poultry industry worldwide, while toxoplasmosis is usually subclinical in these hosts. As both Eimeria spp and Toxoplasma gondii have a broad worldwide distribution, natural co-infections in chickens can occur. Prevalence studies using molecular and serological techniques have proven a very useful approach to study the diversity and distribution of these parasites’ mono-infections, further contributing to more efficient diagnosis, control and monitoring. Despite existing indications that these two parasites interact when the host is infected simultaneously, there are still knowledge gaps regarding the frequency and impact of naturally occurring co-infections under field conditions, particularly in different types of poultry, production and housing systems. Objective: Determination of the level of occurrence of Eimeria spp. and Toxoplasma gondii mono- and co-infections under field conditions, in different types of chickens and farm profiles in Greece. Animals, materials and methods: Selection of poultry operations was based on the number of commercial farms in three major Greek regions, as poultry farms in Greece are highly concentrated in Epirus (in North-Western Greece), Central Macedonia, and Central Greece, based on the data from the Hellenic Ministry of Rural Development and Food. Sampling from both commercial operations and backyard farms was conducted proportionately to their frequency (n=50) and type of flocks included in the study were layers (n=21), slow-growing broilers (n=15) and backyard chickens (n=14), under different production and housing systems (enriched cages, floor-housed in litter, free-range and organic systems). Conventional intensively reared broilers were not included in the study. To rec

Cryptosporidiosis is an intestinal disease that affects a variety of hosts including animals and humans. Since no vaccines exist against the disease till date, drug treatment is the mainstay of disease control. Nitazoxanide (NTZ) is the only FDA-approved drug for the treatment of human cryptosporidiosis. However, its efficacy in immunocompromised people such as those with AIDS, in malnourished children, or those with concomitant cryptosporidiosis is limited. In the absence of effective drugs against cryptosporidiosis, improving the efficacy of existing drugs may offer an attractive alternative. In the present work, we have assessed the potential of the cell-penetrating peptide (CPP) octaarginine (R8) to increase the uptake of NTZ. Octaarginine (R8) was synthetically attached to NTZ in an enzymatically releasable manner and used to inhibit growth of Cryptosporidium parvum in an in vitro culture system using human ileocecal adenocarcinoma (HCT-8) cell line. We observed a significant concentration-dependent increase in drug efficacy. We conclude that coupling of octaarginine to NTZ is beneficial for drug activity and it represents an attractive strategy to widen the repertoire of anti-cryptosporidial therapeutics. Further investigations such as in vivo studies with the conjugate drug will help to further characterize this strategy for the treatment of cryptosporidiosis

Background. Cryptosporidiosis is a parasitic disease associated with potentially fatal diarrhea. The most used method in Cryptosporidium subtyping is based on the glycoprotein gene gp60. Each infection can represent a parasite population, and it is important to investigate the influence on transmission and virulence, as well as any impact on public health investigations. However, an easy-to-use method for detection is lacking. Methods. Here we report on the use of the bioinformatic program TIDE for deconvolution of gp60 chromatograms. A combination of single oocyst analysis and cloning successfully confirmed the within-sample parasite population diversity. Retrospective sample analysis was conducted on archived chromatograms. Results. For Cryptosporidium parvum, 8.6% multistrain infections (13 of 152) obscured by currently used consensus base calling were detected. Importantly, we show that single oocysts can harbor a mixed population of sporozoites. We also identified a striking dominance of unappreciated polymerase stutter artefacts in all 218 chromatograms analyzed, challenging the uncritical use of gp60 typing. Conclusions. We demonstrate the value of a new, easy-to-use analytical procedure for critical characterization of C. parvum and Cryptosporidium hominis in epidemiological investigations, also applicable retrospectively. Our findings illuminate the hidden parasite diversity with important implications for tracing zoonotic and person-to-person transmissions.

Cryptosporidium parvum is an important diarrhoea-associated protozoan, which is difficult to propagate in vitro. In 2017, a report described a continuous culture of C. parvum Moredun strain, in the oesophageal squamous cell carcinoma cell line COLO-680N, as an easy-to-use system for C. parvum propagation and continuous production of oocysts. Here, we report that—using the Köllitsch strain of C. parvum—even though COLO-680N cells, indeed, allowed parasite invasion and early asexual parasite replication, C. parvum proliferation decreased after the second day post infection. Considering recurring studies, reporting on successful production of newly generated Cryptosporidium oocysts in the past, and the subsequent replication failure by other research groups, the current data stand as a reminder of the importance of reproducibility of in vitro systems in cryptosporidiosis research. This is of special importance since it will only be possible to develop promising strategies to fight cryptosporidiosis and its ominous consequences for both human and animal health by a continuous and reliable methodological progress.

The protozoan Cryptosporidium parvum is one of the major causative pathogens of diarrhoea in young ruminants; therefore, it causes economic losses and impairs animal welfare. Besides C. parvum, there are many other non-infectious and infectious factors, such as rotavirus, Escherichia coli, and Giardia duodenalis, which may lead to diarrhoeic disease in young livestock. Often, more than one infectious agent is detected in affected animals. Little is known about the interactions bet-ween simultaneously occurring pathogens and their potential effects on the course of disease. In this review, a brief overview about pathogens associated with diarrhoea in young ruminants is presented. Furthermore, information about coinfections involving Cryptosporidium is provided.