Experimental transmission of Cystoisospora felis-like coccidium from bobcat (Lynx rufus) to the domestic cat (Felis catus)

Detection of Sarcocystis albifronsi, Eimeria alpacae, and Cystoisospora felis in Eurasian lynx (Lynx lynx) in northwestern China

Eurasian lynx (Lynx lynx) is widely distributed in various habitats in Asia and Europe, and it may harbor multiple pathogens. Currently, the information on protozoan infection in Eurasian lynx is scarce. In this study, we performed nested polymerase chain reaction (nPCR) analysis to detect intestinal protozoan infection in three dead Eurasian lynxes, in northwestern China. Three dead Eurasian lynxes, an adult female (#1), an adult male (#2), and a cub male (#3), were sampled in West Junggar Mountain, the northwestern region of Xinjiang Uyghur Autonomous Region. The intestine samples were analyzed using nPCR. We used primers targeting the cytochrome C oxidase subunit I gene (COI) for detection of Sarcocystis and Eimeria species and targeting the small subunit 18 S ribosomal RNA gene (18S rRNA) for detection of Cystoisospora species. The nPCR-positive products were sequenced, aligned, and phylogenetically analyzed. Three intestinal protozoa, Sarcocystis albifronsi, Eimeria alpacae, and Cystoisospora felis, were found in three Eurasian lynxes. The intestine sample of Eurasian lynx #2 was detected with S. albifronsi and E. alpacae. In addition, C. felis was only found in the intestine sample of Eurasian lynx #3. To the best of our knowledge, S. albifronsi and E. alpacae were detected in Eurasian lynx for the first time. In addition, C. felis was firstly found in Eurasian lynx in China. These findings extend our knowledge of the geographical distribution and host range of intestinal protozoa.

SARCOCYSTIS AND OTHER PARASITES IN FECES OF BOBCATS (LYNX RUFUS) FROM MISSISSIPPI

Rectal contents of 56 adult bobcats (Lynx rufus) in 2014 and 2017 from remote areas of Mississippi were examined microscopically for parasite stages after the sugar flotation method. Among the helminths, eggs/larvae found were: Paragonimus sp. in 12, Toxocara cati-like in 16, trichurid-capillarid-like in 3, hookworms in 27, and lungworms in 28. Among the protozoa, oocysts/cysts found were: Cystoisospora felis-like in 2, Cystoisospora rivolta-like in 4, Cryptosporidium sp. in 1, and Giardia sp. in 1. Additionally, numerous Sarcocystis sporocysts were detected in the feces of 12 bobcats; sporocysts were described morphologically. The status of C. felis derived from the bobcat and other wild felids is reviewed and compared with C. felis from the domestic cat. It is the first record of C. rivolta from the bobcat. The presence of eggs of Paragonimus sp. and T. cati in feces of 21.4% and 28.5%, respectively, suggests a role for the bobcat in the dissemination of these zoonotic helminths in the environment in the wild. Taxonomy of coccidia of wild Felidae is discussed and Isospora lyncisLevine and Ivens, 1981 from the Lynx is now regarded as a species inquirenda.

The detection and phylogenetic characterization of Cryptosporidium, Cystoisospora, and Giardia duodenalis of cats in South Korea

Introduction

Cryptosporidium, Cystoisospora, and Giardia duodenalis are gastrointestinal protozoa parasites that cause diarrhea in various animals. However, information regarding the detection and phylogenetic characterization of gastrointestinal protozoa parasites in cats is limited throughout South Korea. Therefore, this study aimed to determine the detection and identify subspecies of gastrointestinal protozoa parasites in cats from South Korea.

Methods

A total of 290 fecal samples were collected from stray, companion, and shelter cats in six provinces. Cryptosporidium, Cystoisospora, and G. duodenalis were identified by PCR. All positive samples were subtyped by PCR and sequencing of gp60, ITS-1, tpi, bg, and gdh.

Results

The overall detection of gastrointestinal protozoan parasitic infection was 17.93%. G. duodenalis was the most prevalent, with 7.93%, followed by Cystoisospora spp. (7.24%) and Cryptosporidium spp. (4.48%). In addition, C. felis (n=10), C. parvum (n=2), C. ryanae (n=1), Cystoisospora felis (n=14), Cystoisospora suis (n=5), Cystoisospora ohioensis (n=1), Cystoisospora spp. were identified in subspecies analysis of positive samples. C. felis showed a significant association with diarrhea (7.81%) and living condition (6.04%), and Cystoisospora felis in diarreha (9.38%) according to detection. Through phylogenetic analysis of the tpi, bg, and gdh genes from 23 G. duodenalispositive samples, it was confirmed that the samples of present study belonged to assemblage A, B, C, and D.

Discussion

South Korean cats have a high rate of gastrointestinal protozoan parasites infection with cat-specific Cryptosporidium and Cystoisospora, which are associated with living conditions and diarrhea symptoms. Moreover, zoonotic and other animal-specific subtype of protozoan parasites have been detected in cat feces.

New Insights into Gastrointestinal and Pulmonary Parasitofauna of Wild Eurasian lynx (Lynx lynx) in the Harz Mountains of Germany

The Eurasian lynx (Lynx lynx) represents an endangered wild felid species. In Germany, it currently occurs in three isolated populations in and around the Harz Mountains, the Palatinate Forest and the Bavarian Forest. Lynx parasitic infections affect animal health and might have an influence on population performance. Therefore, we investigated the protozoan and helminth fauna of free-ranging Eurasian lynx of the Harz population with emphasis on zoonotic parasites. Individual scat samples (n = 24) were collected from wild animals between 2019 and 2021 in the Harz National Park and surrounding areas. In total, 15 taxa of endoparasites were detected, including seven nematodes (i.e., Aelurostrongylus abstrusus, Angiostrongylus spp., Uncinaria stenocephala, Toxascaris leonina, Toxocara cati, Cylicospirura spp. and Capillaria spp.), one cestode (Diphyllobothriidae) and one trematode (Heterophylidae) as well as six protozoans (i.e., Cystoisospora rivolta, Cystoisospora felis, Toxoplasma gondii/Hammondia spp., Sarcocystis spp., Giardia intestinalis and Cryptosporidium spp.). Moreover, first-stage larvae (L1) of spurious lungworm, Protostrongylus pulmonalis, originating from lagomorph preys were identified. This work represents the first report on patent A. abstrusus and Angiostrongylus spp. infections in wild German Eurasian lynxes. Some of the identified parasites represent relevant pathogens for lynxes, circulating between these carnivorous definitive hosts and a variety of mammalian and invertebrate intermediate hosts, e.g., Sarcocystis spp., T. gondii/Hammondia spp., T. cati, T. leonina, A. abstrusus and Angiostrongylus spp., while others are considered exclusively pathogenic for wild felids (e.g., Cylicospirura spp., C. rivolta, C. felis). This study provides insights in the occurrence of zooanthroponotically relevant metazoan (i.e., T. cati and U. stenocephala) and protozoan (i.e., G. intestinalis) species in free-ranging lynx. The present work should be considered as a baseline study for future monitoring surveys on endoparasites circulating in wild Eurasian lynx for appropriate management practices in lynx conservation strategies in Europe.

An initial coprological survey of parasitic fauna in the wild Amur leopard (Panthera pardus orientalis)

The Amur leopard, one of nine recently recognized subspecies of leopard, is still the most threatened by a stochastic procession of extinction. Evaluation of the potential danger to the conservation of the Amur leopard originating from disease urgently needs to be studied. Unfortunately, research on the potential risk to Amur leopards caused by disease is rare. In terms of parasitic diseases that affect this species, even basic data for parasitic fauna are absent. The aim of this study is to acquire this knowledge to improve the general understanding of Amur leopard parasites. Seven parasite species, including 3 nematodes (Toxocara cati, a capillarid-type parasite, and a Metastrongyloidea-type parasite), 2 cestodes (Spirometra sp. and Taenia sp.), 1 trematode (Paragonimus sp.), and 1 protozoan (Cystoisospora felis), were found in this research. Toxocara cati occurred most frequently, followed by Spirometra sp.

Development of Cystoisospora felis in Cell Culture and in vitro Formation of Monozoic Tissue Cysts

Cystoisospora felis is a coccidian parasite commonly found in feces of domestic cats. Infection in cats occurs by ingestion of sporulated oocysts or consumption of rodents infected by the parasite. Scarce information is available about extraintestinal stages of C. felis in naturally infected intermediate hosts, as well as in cell culture. The aim of the current work was to investigate the development of C. felis in Vero cells (African green monkey kidney) and MDCK cells (Madin-Darby canine kidney). Cell monolayers were inoculated with mechanically released sporozoites of C. felis, and parasite growth was daily examined using light microscopy. After cell invasion, only parasitophorous vacuoles containing a single zoite were observed. Five days post-inoculation with sporozoites, unstained cell monolayers were evaluated by differential interference contrast (DIC), and also by Romanovsky stain using conventional light microscopy. Single zoites, each surrounded by a cyst wall, were observed by both methods. Multiplication by endodyogeny did not occur in any cell monolayer. Treatment of encysted parasites with HCl-pepsin for 15 min led to dissolution of the cyst wall and release of intact and motile zoites. To our knowledge, this is the first demonstration of in vitro production of monozoic tissue cysts of C. felis. As kittens commonly shed C. felis in their feces, oocysts are easily available for in vitro production of monozoic tissue cysts of the parasite. Development of C. felis in cell culture may be employed as a model on tissue cyst formation of Cystoisospora spp. and closely related coccidia.

A review of Cystoisospora felis and C. rivolta-induced coccidiosis in cats

Until the discovery of Toxoplasma gondii oocysts in cat feces in 1970, little was known of coccidiosis in cats. Until 1970, three coccidian parasites based on different sized oocysts were recognized, the parasite with large oocysts (∼40 μm long and called Isospora felis), medium sized oocysts (∼25 μm long, called Isospora rivolta), and small sized oocysts (14 μm or less, called Isospora bigemina) were known and they were considered not host-specific. Later, it was demonstrated that these parasites were host-specific and had also extra-intestinal stages. The Isospora bigemina turned out to be more than 25 organisms belonging to T. gondii, Hammondia spp., Sarcocystis spp., Besnoitia spp., and Neospora spp.; these subjects have been reviewed previously in detail. The present paper summarizes biology of Isospora felis, and I. rivolta (now transferred to genus Cystoisospora), including taxonomy, life cycle, diagnosis, and treatment. Re-excretion of T. gondii oocysts from chronically infected cats after superinfection with Cystoisospora felis oocysts is discussed. There are only two species of Cystoisospora species in cats, C. felis and C. rivolta; Isospora novocati and Cystoisospora frenkeli named for I. rivolta-like parasites of cats are considered synonym of C. rivolta. Clinical coccidiosis occurs more commonly in recently weaned kittens and C. felis infections are more prevalent than C. rivolta.

Morphological and molecular characterization of Cystoisospora sp. from Asian small-clawed otters Aonyx cinereus

In this study, we provide the first description of Cystoisospora infection in Asian small-clawed otters (Aonyx cinereus). In July 2017, three juvenile otters recently imported from the Republic of Indonesia showed severe diarrhea and were diagnosed with coccidial infection; two of them eventually died. Fecal examination revealed the presence of numerous oocysts. Sporulated oocysts showed typical Cystoisospora features, measuring 24.6 ± 1.6 (22.0–27.0) × 21.8 ± 1.4 (19.0–25.0) μm, with an oocyst length/width ratio of 1.1 ± 0.1 (1.0–1.3). Each sporocyst contained four sporozoites in a head-to-tail arrangement. The Stieda body was absent, and the sporocyst residuum was present. These morphological characteristics differentiated this species from the other valid Cystoisospora species described from mustelids. Molecular analysis was conducted at two loci: the nuclear 18S ribosomal RNA and mitochondrial cytochrome c oxidase subunit I genes. The 18S sequence showed high similarity with canine Cystoisispora ohioensis (1-bp difference, 1422/1423 [99.9%]). At the cytochrome c oxidase subunit I gene locus, the sequence from otters was identical to that of feline Cystoisospora rivolta (847/847 [100%]). Phylogenetic analyses using concatenated data demonstrated that Cystoisospora sp. from otters and C. rivolta grouped together in the same Cystoisospora clade. Based on these data, we concluded that Cystoisospora sp. detected from otters appeared to be highly similar to C. rivolta.

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We characterized Cystoisospora infection in three Asian small-clawed otters.

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Two otters showed anorexia, green diarrhea, and vomiting.

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Fecal examination revealed numerous oocysts with typical Cystoisospora features.

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Sporulated oocysts were morphologically differentiated from those of other Cystoisospora spp. from mustelids.

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Molecular and morphological features were highly similar to feline C. rivolta.

Parasite prevalence survey in shelter cats in Citrus County, Florida

Free-roaming cat population estimates within the United States currently range from 10 to 114million individual cats. Zoonotic parasites of free-roaming cats are public health concerns; therefore, it is important to investigate the parasite prevalence in these populations. Seventy-six fecal samples from shelter cats in Citrus County, FL were surveyed for parasites using the Sheather's sugar centrifugal flotation method. The objective was to determine the prevalence of patent gastrointestinal parasitism in the sampled shelter cats as a proxy for parasite prevalence in the free-roaming cat populations in the area. Parasites identified with zoonotic potential include Toxocara cati, Ancylostoma sp., Spirometra sp., Mesocestoides sp., Cryptosporidium sp., and Giardia sp. Both tapeworms detected can infect humans, but are not directly transmissible from cats to people. Other parasite diagnostic stages found included Aonchotheca putorii eggs, Cystoisospora felis and Cystoisospora rivolta oocysts, and Sarcocystis sp. sporocysts. The mites Lynxacarus radovskyi and Notoedres cati were detected in feces likely from ingestion while grooming.