Spirometra Species Research Articles

Using the small subunit of nuclear ribosomal DNA to reveal the phylogenetic position of the plerocercoid larvae of Spirometra tapeworms

Although medically important, the systematics of Spirometra and the taxonomic position of S. erinaceieuropaei remain unclear. In this study, the 18S rDNA gene of S. erinaceieuropaei sparganum from naturally infected frogs caught in 14 geographical locations of China was sequenced. In addition, all available 18S sequences of the family Diphyllobothriidae in the Genbank database were included to reconstruct the phylogeny of diphyllobothriid tapeworms. The secondary structure model of the 18S rDNA was also predicated to further explore the sequence variation. Phylogenetic analyses were performed using maximum parsimony (MP), maximum likelihood (ML) and Bayesian inference (BI) methods. The intraspecific divergences of 18S rDNA in Chinese sparganum isolates ranged from 0.0 to 0.4%. Regions of V2, V4 and V7 were the most variable regions in the secondary structure of 18S rDNA. With the exception of genera Duthiersia and Probothriocephalus, other genera (i.e., Adenocephalus, Diphyllobothrium, Diplogonoporus, Duthiersia, Schistocephalus and Spirometra) selected in the Diphyllobothriidae shared similar topologies of V2, V4 and V7 structures. The topology of generated phylogenetic trees revealed close relationships among Adenocephalus, Digramma, Diphyllobothrium, Diplogonoporus, Ligula, Sparganum and Spirometra. The exact phylogenetic position of Spirometra species should be further analyzed with more sampling and more useful molecular markers.

Rapid identification of nine species of diphyllobothriidean tapeworms by pyrosequencing.

The identification of diphyllobothriidean tapeworms (Cestoda: Diphyllobothriidea) that infect humans and intermediate/paratenic hosts is extremely difficult due to their morphological similarities, particularly in the case of Diphyllobothrium and Spirometra species. A pyrosequencing method for the molecular identification of pathogenic agents has recently been developed, but as of yet there have been no reports of pyrosequencing approaches that are able to discriminate among diphyllobothriidean species. This study, therefore, set out to establish a pyrosequencing method for differentiating among nine diphyllobothriidean species, Diphyllobothrium dendriticum, Diphyllobothrium ditremum, Diphyllobothrium latum, Diphyllobothrium nihonkaiense, Diphyllobothrium stemmacephalum, Diplogonoporus balaenopterae, Adenocephalus pacificus, Spirometra decipiens and Sparganum proliferum, based on the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene as a molecular marker. A region of 41 nucleotides in the cox1 gene served as a target, and variations in this region were used for identification using PCR plus pyrosequencing. This region contains nucleotide variations at 12 positions, which is enough for the identification of the selected nine species of diphyllobothriidean tapeworms. This method was found to be a reliable tool not only for species identification of diphyllobothriids, but also for epidemiological studies of cestodiasis caused by diphyllobothriidean tapeworms at public health units in endemic areas.

Molecular Detection of Spirometra decipiens in the United States.

The genus Spirometra belongs to the family Diphyllobothriidae and order Pseudophyllidea, and includes intestinal parasites of cats and dogs. In this study, a plerocercoid labeled as Spirometra mansonoides from the USA was examined for species identification and phylogenetic analysis using 2 complete mitochondrial genes, cytochrome c oxidase I (cox1) and NADH dehydrogenase subunit 3 (nad3). The cox1 sequences (1,566 bp) of the plerocercoid specimen (USA) showed 99.2% similarity to the reference sequences of the plerocercoid of Korean Spirometra decipiens (GenBank no. KJ599679), and 99.1% similarity in regard to nad3 (346 bp). Phylogenetic tree topologies generated using 4 analytical methods were identical and showed high confidence levels with bootstrap values of 1.00, 100%, 100%, and 100% for Bayesian inference (BI), maximum-likelihood (ML), neighbor-joining (NJ), and maximum parsimony (MP) methods, respectively. Representatives of Diphyllobothrium and Spirometra species formed a monophyletic group, and the sister-genera status between these species was well supported. Trapezoic proglottids in the posterior 1/5 region of an adult worm obtained from an experimentally infected cat were morphologically examined. The outer uterine loop of the uterus coiling characteristically consisted of 2 complete turns. The results clearly indicated that the examined Spirometra specimen from the USA matched to S. decipiens very well, and indicated possible presence of the life cycle of this species in this region.

Molecular identification of Spirometra spp. (Cestoda: Diphyllobothriidae) in some wild animals from Brazil

Species of the genus Spirometra are diphyllobothriid tapeworms with complex life cycles and are involved in human sparganosis, a neglected disease that affects individuals worldwide. Although some species were reported in wild felids and human cases of sparganosis were described in Brazil, the biology and taxonomy of these parasites are poorly understood. In the present study, samples of diphyllobothriids (eggs and/or proglottids) obtained from the stools of wild carnivores (Leopardus pardalis and Lycalopex vetulus) and plerocercoid larvae found in a snake (Crotalus durissus) from Brazil were analysed by amplifying a fragment of the gene cytochrome c oxidase subunit 1 (cox 1). The DNA sequences obtained here for the first time from the Spirometra spp. from Brazil were used to evaluate the phylogenetic relationships with other species. Molecular data identified two species in the Brazilian samples (evolutionary divergence of 17.8–19.2%). The species were identified as Spirometra sp. 1, found in Le. pardalis, and Spirometra sp. 2 found in Ly. vetulus and C. durissus, and they differed from Asian isolates of Spirometra erinaceieuropaei (17.5–20.2% and 12.2–15.6%, respectively), a species previously considered to be distributed worldwide. Moreover, Spirometra sp. 1 is genetically distinct from Sparganum proliferum from Venezuela (19.6–20.4%), while Spirometra sp. 2 is more closely related with the Venezuelan species (6.1–7.0%). Sequences of Spirometra sp. 2 revealed that it is conspecific with the Argentinean isolate of Spirometra found in Lycalopex gymnocercus (1.9–2.2%). Taxonomic and phylogenetic aspects related to New World species of Spirometra are briefly discussed.

Invaded Invaders: Infection of Invasive Brown Treesnakes on Guam by an Exotic Larval Cestode with a Life Cycle Comprised of Non-Native Hosts.

BackgroundMultiple host introductions to the same non-native environment have the potential to complete life cycles of parasites incidentally transported with them. Our goal was to identify a recently detected parasitic flatworm in the invasive Brown Treesnake (Boiga irregularis) on the remote Pacific island of Guam. We considered possible factors influencing parasite transmission, and tested for correlations between infection status and potential indicators of host fitness. We used genetic data from the parasite and information about the native ranges of other possible non-native hosts to hypothesize how it arrived on Guam and how its life cycle may be currently supported.MethodsWe identified the parasite by comparing larval morphology and mtDNA sequences with other Pseudophyllid tapeworms. We assessed probability of infection in individual snakes using logistic regression and examined different factors influencing presence of parasites in hosts.ResultsWe identified the parasite as the pseudophyllid cestode Spirometra erinaceieuropaei, with all sampled worms from multiple snakes sharing a single mtDNA haplotype. Infection appears to be limited to the only freshwater watershed on the island, where infection prevalence was high (77.5%). Larger snakes had a higher probability of being infected, consistent with the chronic nature of such infections. While infection status was positively correlated with body condition, infected snakes tended to have lower intra-peritoneal fat body mass, potentially indicating a negative effect on energy stores.ConclusionsWe discovered that B. irregularis inhabiting a small area of forested habitat in a freshwater watershed on Guam are often infected by a novel parasite of Asian origin. While further work is needed, this species of Spirometra, itself a non-native species, likely depends on a suite of recently introduced hosts from different parts of the world to complete the life cycle. This baseline study provides little evidence of any effects on host fitness, but additional data are needed to more thoroughly explore the consequences of infection in this invasive snake population.

Clinical Features of Pulmonary Sparganosis

Sparganosis is an infectious disease caused by the sparganum of Spirometra species, which seldom invades the respiratory system. The aim was to describe the clinical features and outcomes of pulmonary sparganosis. A total of 40 patients with pulmonary sparganosis were reviewed, including 12 cases known from this experience and 28 cases reported in the literature. Among these 40 patients at an average age of 45.4 ± 11.1 years (men 29), 34 (85%) had a history of ingesting raw or undercooked meat (mainly frogs or snakes). The top 3 symptoms were coughing (60.0%), fever (57.5%) and chest pain (42.5%). Peripheral blood eosinophilia was found in 30 cases (75%). Lesions were located in lung parenchyma, airway, pleura and pulmonary vessels of the patients. Thirty-one patients (77.5%) had pleural effusion. The diagnosis was established by antisparganum antibody test in 30 cases (75%) and by pathology in 9 cases (22.5%); 1 case was not mentioned. Among the 35 cases with follow-up information, 2 treated with complete surgical removal and 31 with oral administration of praziquantel had no recurrence; the remaining 2 died without effective treatments. As an extremely rare and life-threatening parasitic zoonosis, pulmonary sparganosis should be diagnosed by combining the epidemiology, patient history, eosinophilia and the positive antisparganum antibody test result together if no worm was detected. Oral praziquantel is considered to be an effective treatment.

Human Infections with Spirometra decipiens Plerocercoids Identified by Morphologic and Genetic Analyses in Korea.

Tapeworms of the genus Spirometra are pseudophyllidean cestodes endemic in Korea. At present, it is unclear which Spirometra species are responsible for causing human infections, and little information is available on the epidemiological profiles of Spirometra species infecting humans in Korea. Between 1979 and 2009, a total of 50 spargana from human patients and 2 adult specimens obtained from experimentally infected carnivorous animals were analyzed according to genetic and taxonomic criteria and classified as Spirometra erinaceieuropaei or Spirometra decipiens depending on the morphology. Morphologically, S. erinaceieuropaei and S. decipiens are different in that the spirally coiled uterus in S. erinaceieuropaei has 5-7 complete coils, while in S. decipiens it has only 4.5 coils. In addition, there is a 9.3% (146/1,566) sequence different between S. erinaceieuropaei and S. decipiens in the cox1 gene. Partial cox1 sequences (390 bp) from 35 Korean isolates showed 99.4% (388/390) similarity with the reference sequence of S. erinaceieuropaei from Korea (G1724; GenBank KJ599680) and an additional 15 Korean isolates revealed 99.2% (387/390) similarity with the reference sequences of S. decipiens from Korea (G1657; GenBank KJ599679). Based on morphologic and molecular databases, the estimated population ratio of S. erinaceieuropaei to S. decipiens was 35: 15. Our results indicate that both S. erinaceieuropaei and S. decipiens found in Korea infect humans, with S. erinaceieuropaei being 2 times more prevalent than S. decipiens. This study is the first to report human sparganosis caused by S. decipiens in humans in Korea.

Sparganosis –a rare case report

Sparganosis is a parasitic infection caused by the plercercoid larvae of diphyllobothroid tapeworms belonging to the genus Spirometra. It is a rare disease of human as man is not a natural host of spirometra species. Diagnosis of latter is difficult as it mimics other conditions that commonly cause subcutaneous or visceral fluid collection. Here we report a case of Sparganosis in a man who presented with a swelling over left cheek. It was confirmed by pathological and microbiological examination. To the best of our knowledge, this is the first case from Central India where sparganum was isolated from a swelling.

The morphological characteristics of the sparganum stage of the Malaysian Spirometra species

The morphological characteristics of the sparganum stage of the Malaysian Spirometra species

Subcutaneous Sparganosis: A Rare Case Report

Human sparganosis is a rare parasitic disease as a result of infection by plerocercoid larva (sparganum) of Spirometra species. In this case report, a 31-year-old man presented as a subcutaneous nodule in the axilla for 5 months, which was excised. Characteristic plerocercoid larvae accompanied by sinus tract and abscess in the subcutaneous tissue were discovered under microscopic examination of the excised tissue. This report aims to highlight the existence and presentation of sparganum infection which is considered to be rare in Indian subcontinent. Also this case report reveals an atypical picture where the larval forms was not identified on gross examination of the excised tissue and the diagnosis was confirmed on the basis of microscopy.

The occurrence of zoonotic parasites in rural dog populations from northern Portugal

A survey of intestinal parasites in dogs was carried out in a rural region around Cantanhede, in northern Portugal, where 301 dog faecal samples were collected from small-ruminant farms. Saturated salt flotation and formol-ether sedimentation techniques were used. An enquiry was conducted in 234 farms and a risk factor evaluation for zoonotic helminths was determined among the 195 farmers who owned dogs. The overall parasite prevalence in faecal samples of dogs was 58.8%, with specific prevalences for Ancylostomidae being 40.9% followed by species of Trichuris (29.9%), Toxocara (8%), Isospora (4%), Capillaria (0.7%) and Spirometra (0.3%). Taeniidae eggs were present in five samples (1.7%) which were analysed with the polymerase chain reaction (PCR) technique and revealed to be from Taenia sp., and not Echinococcus granulosus. This rural region has a traditional small-farm system, in which farm products are mainly for in-house consumption and home slaughtering is a current practice (57%). Analysis showed home slaughtering to be a statistically significant risk factor for the presence of Ancylostomidae (P= 0.007) and Toxocara sp. (P= 0.049). Owning cattle was found to be a significant risk factor for Taenia sp. (P= 0.031).

Prevalence of faecal-borne parasites in colony stray cats in northern Italy.

Endoparasitic infections are common in stray cats. Many of these parasites are responsible for zoonoses, and stray cats can be a source of environmental contamination. The prevalence of parasites in 139 stray colony cats in the city of Milan, northern Italy, was investigated by faecal examination. The overall prevalence of endoparasites was 50.4%, with 11 different parasites found. Parasites with zoonotic potential were detected in 49.6% of cats. Concurrent infections with two or more zoonotic parasites were recorded in 14.3% of cats. Among the parasites found, the most common was Toxocara cati (33.1%; P <0.0001). The other species found by coproscopic examination were: Ancylostoma tubaeformae (7.2%), Isospora species (4.3%), Trichuris vulpis (2.9%), Dipylidium caninum (2.9%), Aelurostrongylus abstrusus (2.9%), Eucoleus aerophilus (syn Capillaria aerophila) (1.4%), Spirometra species (1.4%), Taenia pisiformis (0.7%) and Hymenolepis nana (0.7%). Coproantigen specific for Giardia duodenalis was detected in 2.9% of the samples. Pseudoparasites (eggs of mites) were found in 4.3% of the samples. No sample contained Toxoplasma gondii oocysts, despite the fact that 70 cats tested positive for T gondii-specific IgG antibodies, and none of the diarrhoetic samples tested positive for Cryptosporidium species oocysts. Variables linked to infection were body condition score (BCS), the presence of diarrhoea and infection with G duodenalis. Cats infected with G duodenalis were more likely to have a low BCS (odds ratio (OR) = 11.5, P = 0.02) and diarrhoea (OR = 30.7, P = 0.0007). The results of the present study confirm that endoparasitic infections, most of which have zoonotic potential, are distributed in stray colony cats of Milan.

Prevalence of fecal-borne parasites detected by centrifugal flotation in feline samples from two shelters in upstate New York

Over a 3.5-year period, fecal samples from 1322 cats from two shelters and affiliated foster homes in upstate New York were processed for parasite detection by both 1.18spg zinc sulfate and 1.3spg sugar double centrifugal flotation. In 50.9% of the samples at least one parasite was detected. Overall, 18 different parasites ranging in prevalence from 0.2% to 21% were recovered. The most prevalent parasites of foster and shelter cats in this study were Cystoisospora species and Toxocara cati (21% prevalence, each). In order of percentage of positive samples, other findings were: Giardia species (8.9%), Aelurostrongylus abstrusus (6.2%), taeniid eggs (3.9%), Cryptosporidium species (3.8%), Aonchotheca species (3.7%), Eucoleus species (2.3%), Ancylostoma species (2.2%), Cheyletiella species (2.0%), Dipylidium caninum (1.1%), Otodectes species, Toxoplasma-like oocysts and Sarcocystis species (0.8% each), Demodex and Spirometra species (0.4% each), and Alaria species and Felicola subrostratus (0.2% each).

Diphyllobothriasis and sparganosis in Indonesia

Food-borne zoonotic cestode infections by Diphyllobothrium spp. and Spirometra spp. are relatively uncommon in Indonesia. So far, only one case of diphyllobothriasis was confirmed in 2004 in Jakarta, whereas there were 4 sparganosis cases in Indonesia. Morphology of eggs and gravid proglottids revealed the first case to be caused by Diphyllobothrium species. However, molecular identification of the species was not successful. Sparganosis may not be particularly rare in Indonesia, since Spirometra species have often been found in cats and other animals. These topics in Indonesia are briefly overviewed with reference to historical records and socio-cultural background information.

IS THE HUMAN-INFECTING DIPHYLLOBOTHRIUM PACIFICUM A VALID SPECIES OR JUST A SOUTH AMERICAN POPULATION OF THE HOLARCTIC FISH BROAD TAPEWORM, D. LATUM?

Using ITS2 gene sequences, the validity of the tapeworm Diphyllobothrium pacificum (Nybelin, 1931), infecting humans on the Pacific coast of South America and in Japan, was assessed. ITS2 sequences of this cestode differed markedly (sequence similarity 79.0-80.2%) from those of the most common human-infecting cestode, the broad fish tapeworm Diphyllobothrium latum (L.), as well as other four species of Diphyllobothrium, including potential human parasites (D. cordatum, D. dendriticum, and D. lanceolatum) and two species of Spirometra (sequence similarity 77.5-81.9%). Interspecific sequence similarity between all but one (D. pacificum) species was 86.1-99.6%, whereas individual isolates of D. dendriticum and D. ditremum exhibited intraspecific sequence similarity of 97.0-98.0% and 98.2-99.9%, respectively. Phylogenetic trees constructed from ITS2 sequences show a markedly distant position of D. pacificum from other species analyzed and also indicate the possible paraphyly of Spirometra.

Sparganosis in wild‐caught baboons (Papio cynocephalus anubis)

Sparganosis is the infection of a paratenic host with the plerocercoid metacestode of Spirometra spp. A 12-year-old captive, pregnant, wild-caught baboon from Tanzania had multiple subcutaneous nodules. Examination of the biopsied nodules revealed the presence of viable metacestodes. The histological morphology of the metacestodes was consistent with the genus Spirometra and other pseudophyllidean cestodes. Since species of Spirometra produce growth hormones that are active in mammals, we measured fetal and placental growth and hormone levels. Blood samples were taken from the mother and the cesarean-derived fetus for hematological, biochemical, and hormonal analyses and to test for the presence of antispargana antibodies. Baboon placental weight and fetal hematological, biochemical, and morphometric parameters were within normal ranges. Antibody titers to spargana did not differ significantly between mother (1.08 OD(405)) and fetus (0.91 OD(405)). Baboon maternal insulin-like growth factor and growth hormone values were also within the normal range. Estradiol and progesterone analysis in four of these animals (antibody titers ranged from 0.71 to 1.7 OD(405)) showed no statistically significant difference with age- or phase-matched cycle parameters compared with antibody-negative females. Based on the results that have been obtained, sparganosis did not appear to affect the endocrinological profile of pregnant and cycling female baboons.

Proteinases and Associated Genes of Parasitic Helminths

Many parasites have deployed proteinases to accomplish some of the tasks imposed by a parasitic life style, including tissue penetration, digestion of host tissue for nutrition and evasion of host immune responses. Information on proteinases from trematodes, cestodes and nematode parasites is reviewed, concentrating on those worms of major medical and economical importance. Their biochemical characterization is discussed, along with their putative biological roles and, where available, their associated genes. For example, proteinases expressed by the various stages of the schistosome life-cycle, in particular the well-characterized cercarial elastase which is involved in the penetration of the host skin and the variety of proteinases, such as cathepsin B (Sm31), cathepsin L1, cathepsin L2, cathepsin D, cathepsin C and legumain (Sm32), which are believed to be involved in the catabolism of host haemoglobin. The various endo- and exoproteinases of Fasciola hepatica, the causative agent of liver fluke disease, are reviewed, and recent reports of how these enzymes have been successfully employed in cocktail vaccines are discussed. The various proteinases of cestodes and of the diverse superfamilies of parasitic nematodes are detailed, with special attention being given to those parasites for which most is known, including species of Taenia, Echinococcus, Spirometra, Necator, Acylostoma and Haemonchus. By far the largest number of papers in the literature and entries to the sequence data bases dealing with proteinases of parasitic helminths report on enzymes belonging to the papain superfamily of cysteine proteinases. Accordingly, the final section of the review is devoted to a phylogenetic analysis of this superfamily using over 150 published sequences. This analysis shows that the papain superfamily can be divided into two major branches. Branch A contains the cathepin Bs, the cathepsin Cs and a novel family termed cathepsin Xs, while Branch B contains the cruzipains, cathepsin Ls, papain-like and aleurain/cathepsin H-like proteinases. The relationships of the helminth proteinases, and similar proteinases from protozoan parasites and other organisms, within these groups are discussed.

Growth Stimulating Effect of Experimental Sparganosis in Thyroidectomized and Hypophysectomized Rats, and Comparative Activity of Different Species of Spirometra

Growth Stimulating Effect of Experimental Sparganosis in Thyroidectomized and Hypophysectomized Rats, and Comparative Activity of Different Species of Spirometra