Is Gastric Involvement by Strongyloides stercoralis in an Immunocompetent Patient a Common Finding? A Case Report and Review of the Literature.

PURPOSE: Gastric infection with Strongyloides stercoralis (SS) usually occurs in immunocompromised patients. The unexpected observation of this parasite in an otherwise healthy young lady who had undergone upper endoscopy and biopsy sampling of the gastro-duodenal mucosa, prompted us to review the literature to ascertain the conditions favouring gastric colonization by SS. METHODS: Pathology files of gastroduodenal biopsies received at St. Mary's hospital, Northern Uganda, between 2007 and 2017 were reviewed. Pubmed search was performed under the headings "Strongyloides stercoralis", "Gastric parasitosis". RESULTS: Histology of the only gastroduodenal biopsy with SS infection showed parasite eggs, immature rhabditiform larvae, and numerous adult worms in gastric pits and rhabditiform larvae in interepithelial parasitic tunnels, causing reactive changes of the glandular epithelium. There was no significant acute inflammatory cell infiltrate surrounding the parasites. Literature review showed that gastric SS infection appears to be very uncommon and was, as expected, largely prevalent in immunodeficient individuals (84.2% of published cases). The rare gastric SS infection is a complication of systemic strongyloidiasis, either hyperinfective, or disseminated form. It is also commonly associated with duodenal infection at microscopical examination. CONCLUSION: Involvement of gastric mucosa in the absence of duodenal strongyloidiasis appears to be quite rare and false-negative histopathological exams are reported if only the stomach is biopsied.

Cryptobia iubilans Infections in Discus Fish in Trinidad and Tobago.

Discus (Symphysodon spp.) are costly and prized specimens in the international ornamental fish trade. The majority of discus submitted to the Aquatic Animal Health Unit at the University of the West Indies School of Veterinary Medicine for necropsy between September 2010 and September 2015 had lesions consistent with Cryptobia iubilans infection, thus prompting this study. To determine the prevalence of the flagellated gastrointestinal protozoan C. iubilans in discus fish, 32 discus were sourced from 10 suppliers, including breeders, importers, and hobbyists across Trinidad. Fish were euthanized, and the internal organs, particularly the stomach and intestine, were observed under a light microscope for characteristic granulomatous lesions and/or live C. iubilans parasites. All wet-mount slides on which granulomas were observed were also Ziehl-Neelsen acid-fast stained to presumptively exclude the presence of Mycobacterium spp., the main differential when diagnosing C. iubilans-associated granulomatous gastritis or to determine the presence of dual infections. Further histological analyses were performed on stomach and intestinal sections, and transmission electron microscopy was used to confirm the parasite in stomach sections. The prevalence of C. iubilans infection was found to be 81.3%, and the prevalence of presumptive dual infections with Mycobacterium spp. was found to be 21.9%. To the best of our knowledge, this is the first documented study of C. iubilans infections in the wider Caribbean region.

First report of Spirocerca vulpis in red foxes (Vulpes vulpes) in Portugal.

Recent studies have described Spirocerca lupi-like nematodes in the stomach of red foxes (Vulpes vulpes) in Europe. A phylogenetic analysis of those specimens using mitochondrial DNA and their morphological reexamination allowed their characterization as a different species, Spirocerca vulpis. Between the years of 2010 and 2017, roundworms were collected from seven red foxes of northeastern Portugal found at necropsy with nodular lesions on their stomach wall. Histopathological analysis of four foxes revealed granulomatous lesions of the gastric nodules. On morphological assessment, by light microscopy, nematodes revealed the presence of six triangular teeth-like buccal capsule structures, which are absent in S. lupi. Polymerase chain reaction was run to amplify a 551 bp partial fragment of the cytochrome c oxidase subunit 1 gene. Sequences were 99% similar to S. vulpis (85% coverage) of red foxes from Spain and Bosnia and Herzegovina, 99% similar (99% coverage) to sequences of Spirocerca sp. of red foxes from Denmark and 93% similar (99% coverage) to S. lupi from South Africa. This is the first report of S. vulpis in foxes or any other host from Portugal.

Strongyloides stercoralis infection in San Marino Republic: first epidemiological data from an observational study.

Strongyloides stercoralis is a neglected parasite that can cause death in immunocompromised individuals. There were no data on the epidemiology of S. stercoralis infection in San Marino Republic until two patients (one of whom died) were diagnosed with severe strongyloidiasis (hyperinfection) between September 2016 and March 2017. A serology test for Strongyloides spp. was introduced in routine practice in the laboratory of the State Hospital to test patients considered to be at risk for strongyloidiasis. Between August 2017 and August 2018, of 42 patients tested with serology, two (4.8%) were positive. An additional case was found by gastric biopsy. Two of the positive cases were presumably autochthonous infections (elderly people with no significant travel history), while the other was a probable imported case (young man born in Nigeria and settled in Europe since 2003). Epidemiology of strongyloidiasis in San Marino might be similar to Northern Italy, where a relevant proportion of cases was diagnosed in immigrants (mainly from sub-Saharan Africa) and in elderly Italians with eosinophilia. Screening for strongyloidiasis might be worthwhile in inhabitants of San Marino in the same categories of individuals, particularly those at risk of immune suppression.

A New Species of Ascarophis (Nematoda: Cystidicolidae) Parasitizing Clinocottus analis (Pisces: Cottidae) from Baja California, Mexico.

A new species of nematode, Ascarophis morronei n. sp. (Cystidicolidae), is described from the stomach wall of the woolly sculpin Clinocottus analis (Cottidae) collected in the rocky intertidal from northwestern Baja California, Mexico. Collected nematodes were studied using both light and scanning electron microscopy. Sequence fragments for 18S rDNA molecular markers were obtained from the new nematode species, in order to test its position within the family Cystidicolidae under a phylogenetic context. Main characters distinguishing this new species include the reduced labia and the morphology of the eggs, distances of nerve ring and excretory pore from the anterior end, and left spicule of males. The new species described here is the second for the genus Ascarophis reported as adult in the Southern California Bight, and the first one recorded for the fish genus Clinocottus.

Concomitant Infection of S. mansoni and H. pylori Promotes Promiscuity of Antigen-Experienced Cells and Primes the Liver for a Lower Fibrotic Response.

Helicobacter pylori chronically colonizes the stomach and is strongly associated with gastric cancer. Its concomitant occurrence with helminths such as schistosomes has been linked to reduced cancer incidence, presumably due to suppression of H. pylori-associated pro-inflammatory responses. However, experimental evidence in support of such a causal link or the mutual interaction of both pathogens is lacking. We investigated the effects of co-infection during the different immune phases of S. mansoni infection. Surprisingly, co-infected mice had increased H. pylori gastric colonization during the interferon gamma (IFNγ) phase of schistosome infection but reduced infiltration of T cells in the stomach due to misdirection of antigen-experienced CXCR3+ T cells to the liver. Unexpectedly, H. pylori co-infection resulted in partial protection from schistosome-induced liver damage. Here, we demonstrate that an increase in fibrosis-protective IL-13Ra2 is associated with H. pylori infection. Thus, our study strongly points to an immunological interaction of anatomically isolated pathogens, eventually resulting in altered disease pathology.

Anthelmintic effect of Cassia fistula and Combretum leprosum protein fractions against goat gastrointestinal nematodes / Efeito antihelmíntico das frações proteicas de Cassia fistula e Combretum leprosum contra nematodeos gastrintestinais de caprinos

Abstract In this study, we evaluated the ovicidal and larvicidal activity of protein preparations obtained from Cassia fistula L. and Combretum leprosum Mart. leaves on the gastrointestinal parasites of goats. Protein preparations were obtained after the extraction of C. fistula L. and C. leprosum Mart. leaves, followed by protein fractionation (with ammonium sulfate saturation percentages of 30%, 30%-60%, and 60%-90%) and dialysis, which resulted in protein fractions (called F1, F2, and F3, respectively). The fractions were evaluated by egg hatching (the eggs were recovered in stool samples from naturally infected goats) and larval development tests. The results reveled that the inhibition of hatching of eggs caused by the protein fractions of C. fistula (38%) were similar to that of the control drug, thiabendazole. In addition, the fractions of C. fistula caused significant inhibition (61-69%) of larval development also. However, C. leprosum did not reveal significant inhibition of egg hatching and larval development. We conclude that C. fistula L. showed better ovicidal and larvicidal activity against endoparasites.

Resumo Neste estudo, foram avaliadas as atividades ovicida e larvicida de preparações proteicas de Cassia fistula L. e Combretum leprosum Mart. em parasitas gastrointestinais de caprinos. As preparações proteicas foram obtidas por extração das folhas de C. fistula L. e C. leprosum Mart. seguido pelo fracionamento proteico (com porcentagens de saturação de sulfato de amônio de 30%, 30-60%, 60-90%) e diálise, resultando nas frações proteicas (intituladas F1, F2 e F3, respectivamente). As frações foram avaliadas nos testes de eclosão de ovos (os ovos foram recuperados em amostras de fezes de cabras naturalmente infectadas) e de desenvolvimento larvar. Os resultados revelaram que a inibição da eclosão de ovos causada pelas frações proteicas de C. fistula (38%) foi semelhante à do fármaco controle, o tiabendazol. Além disso, as frações de C. fistula também causaram inibição significativa (61-69%) do desenvolvimento larvar. No entanto, C. leprosum não revelou inibição significativa na eclosão dos ovos e no desenvolvimento larvar. Concluiu-se que C. fistula L. mostrou uma melhor atividade ovicida e larvicida contra endoparasitas.

Redescription and genetic characterization of Cystidicoloides vaucheri, including first description of male and current status on the phylogeny of Cystidicolidae (Nematoda: Habronematoidea).

Cystidicoloides vaucheri collected in the stomach of the redtail catfish Phractocephalus hemioliopterus from River Acre, State of Acre, Brazil is redescribed, including the first description of males and the first genetic characterization based upon 18S and 28S genes of the rRNA. Newly collected females were biometrically smaller than those reported in the original description, but similar morphology shared by the two samples revealed that they belong to the same species. Scanning electron micrographs showed the accurate structure of the cephalic region, described here in detail. Furthermore, the morphology of males completed the specific diagnosis, strengthening the validity of the species. The three other congeners differ from C. vaucheri mainly as follows: in C. dlouhyi the area rugosa is absent, the cephalic structures in C. fischeri are completely distinct, and in both species the spicules have membranous outgrowths, absent in C. vaucheri. Despite the dubious generic assignment of C. izecksohni, it differs from C. vaucheri in several biometrical and morphological features. Because of data availability, only sequences of the 18S were used for phylogenetic reconstructions. Results showed that the genus Ascarophis and the families Cystidicolidae and Physalopteridae are not monophyletic. Cystidicoloides vaucheri formed an independent branch clustering with representatives of Cystidicolidae, confirming its validity. The inclusion of Salmonema and Spinitectus within Cystidicolidae should be reviewed, since they formed an assemblage with species from Rhabdochonidae. In fact, current classification of some taxa belonging to Habronematoidea, Physalopteroidea and Thelazioidea need to be re-evaluated, mainly based on molecular data from different genes.

Spirocercosis in red fox (Vulpes vulpes) in a natural reserve located in a meso-Mediterranean area.

Spirocerca lupi Rudolphi 1809 (Nematoda Spirocercidae) has an indirect cycle involving intermediate and paratenic hosts, having domestic or wild canids as the main definitive hosts. The most frequent pathology affecting dogs is a granulomatous tumor-like growth containing adults in the oesophagus and aorta. There are very few references about the presence of nodules in the stomach. There is scant information about the epidemiology of this disease in wild red foxes in meso-Mediterranean areas. In this work we report on the natural infection of wild red foxes by Spirocerca lupi and the damage produced in the stomach wall in an area where contact with other potential definitive hosts (canids) is very rare. From July 2015 to November 2016, 61 red foxes were sampled. 18.03% of the stomach walls examined had nodules containing Spirocerca lupi adults and eggs. The prevalence of infection was similar for young and adult groups (23.81 and 18.18%; χ2 = 0.25; df = 1; P = 0.6171) and it was higher in females than in males (25.81 versus 10.00%, χ2 = 2.58; df = 1; P = 0.1082). The red fox population in the area seems to be well established judging from their age distribution and the fact that they could be captured all year round. It would appear that in the absence of other main definitive host S. lupi population is able to survive just parasitizing red foxes. Pathologic effects of this parasite on red foxes seems to show some differences related to domestic dogs. These results also indicates as predator control programs can maintain suitable host populations with reduced level of infection.

An Italian case of intestinal anisakiasis with a presurgical diagnosis: Could this parasite represent an emerging disease?

Anisakiasis is a parasitic infection caused by the consumption of raw fish containing larvae of the Anisakis species. Since the first description in 1960 of a patient suffering from this pathogen, in the Netherlands, most of the cases have been reported in Japan, where consumption of raw fish is common, but the number of cases is increasing worldwide. The first case identified in Italy dates back to 1996 and a few cases have been reported since then. In Italy the intestinal form occurs almost as frequently as the gastric form, which is far more frequent in Japan. Intestinal Anisakiasis represents a diagnostic challenge as it is clinically misdiagnosed and most of the patients require surgery due to the occurrence of complications such as bowel occlusion or perforation. Practically no cases of the intestinal form are diagnosed preoperatively. We report the first case, to our knowledge, of intestinal Anisakiasis in which surgery was avoided, due to a prompt diagnosis suspected on intestinal biopsies. A literature review of Anisakiasis cases reported in Italy is also carried out.

Gastric Strongyloidiasis: Report of 2 Cases and Brief Review of the Literature.

Strongyloides stercoralis is an intestinal nematode with a complicated lifecycle and auto-infection. In healthy individuals, this parasite usually does not cause any symptoms. But in immunocompromised patients, the symptoms vary from abdominal pain and discomfort to sepsis and death.Gastric infection and involvement by this nematode are rare and uncommon. Here we report 2 cases of Strongyloides stercoralis hyperinfection that were discovered in gastric biopsies in 2 immunocompromised patients. A gastric biopsy was taken for each patient and both showed cross sections of adult worms, eggs, and rhabditiform larvae of S. stercoralis embedded within gastric crypts. This short report describes these 2 immunocompromised patients with disseminated infection by S. strecoralis with gastric involvement with emphasis on recognition of the histological findings in gastric biopsies.

Hydatid Cyst Diagnosed by Endoscopic Ultrasound.

A 69-year-old female with unremarkable past history underwent endoscopy for dyspepsia. She denied weight loss or anorexia. Upper endoscopy revealed a bulge in the lesser curvature and posterior wall of the stomach with 4-5 cm. Endoscopic ultrasound was performed which showed a heterogeneous lesion, anechogenic in the major part, with a floating membrane inside, the greatest diameter of 90.8 × 17.2 mm, originated in the left liver lobe. Surgical resection was performed. Pathologic examination revealed a cystic lesion with an acellular thick fibrous wall, surrounded by a conspicuous inflammatory reaction. The cyst wall revealed a characteristic lamellar pattern of the fibers. In the internal surface of the lesion, there were remains of membranous structures, amidst which a vestigial Protoscolex was noted. In the presented case, a floating membrane was observed, which is a pathognomonic feature, establishing the diagnosis of hydatid cyst type 3. Fine needle aspiration guided by ultrasound was not performed due to the certainty in the diagnosis. To the authors' knowledge, these are the first images by endoscopic ultrasound of hydatid cyst of liver presented as a bulge in the stomach with pathognomonic features, which allowed the definitive diagnosis with no need for further diagnostic tests.

Aspirin treatment exacerbates oral infections by Trypanosoma cruzi.

Oral transmission of the protozoan parasite Trypanosoma cruzi, the etiological agent of Chagas disease, has been documented in Latin American countries. The reported cases of infection were due to the ingestion of contaminated fresh fruit, juices, or sugar cane juice. There have been few studies on the physiopathology of the disease in oral transmission cases. Gastritis is a common ailment that can be caused by poor dietary habits, intake of alcohol or other gastric irritants, bacterial infection, or by the widespread use of non-steroidal anti-inflammatory drugs (NSAIDs). This study investigated in a mouse model whether gastric mucosal injury, induced by aspirin, would affect the course of disease in animals infected with T. cruzi by the oral route. The CL14 and G strains of T. cruzi, both of low infectivity, were used. To this end, groups of BALB/c mice were treated during 5 days with aspirin (100 mg kg(-1)) before oral infection with T. cruzi metacyclic forms (4 × 10(5) or 5 × 10(7) parasites/mouse). Histological analysis and determination of nitric oxide and TNF-α were performed in gastric samples obtained 5 days after infection. Parasitemia was monitored from the thirteenth day after infection. The results indicate that aspirin treatment of mice injured their gastric mucosa and facilitated invasion by both CL14 and G strains of T. cruzi. Strain CL14 caused more severe infection compared to the G strain, as larger numbers of amastigote nests were found in the stomach and parasitemia levels were higher. Our study is novel in that it shows that gastric mucosal damage caused by aspirin, a commonly used NSAID, facilitates T. cruzi infection by the oral route.

Intraspecific and interspecific genetic variation of Gongylonema pulchrum and two rodent Gongylonema spp. (G. aegypti and G. neoplasticum), with the proposal of G. nepalensis n. sp. for the isolate in water buffaloes from Nepal.

The gullet worm (Gongylonema pulchrum) has been recorded from a variety of mammals worldwide. In an earlier study, we demonstrated two separate transmission cycles in cattle (Bos taurus) and wild mammals in Japan based on nucleotide sequences of the ribosomal RNA gene (rDNA) and cytochrome c oxidase subunit I (cox-1) region of mitochondrial DNA of multiple isolates of different origins. Our earlier study additionally demonstrated two major cox-1 haplotypes of G. pulchrum prevalent in cattle in Japan. In the present study, we collected G. pulchrum from cattle and goats (Capra hircus) in Alashan League, Inner Mongolia, China; Gongylonema aegypti from spiny mice (Acomys dimidiatus) in the Sinai Peninsula, Egypt; and Gongylonema neoplasticum from a black rat (Rattus rattus) in Okinawa Island, Japan, to analyze their genetic relationships with G. pulchrum in Japan. The gullet worms from Alashan League had almost identical rDNA nucleotide sequences and two cox-1 haplotypes as seen in G. pulchrum from the cattle in Japan. The two rodent Gongylonema spp. had distinct rDNA nucleotide sequences compared with those of G. pulchrum; only the 18S and 5.8S rDNA sequences showed high identities at 97.2-98.7%, while the remaining sequences were less than 75% identical. The 18S, 5.8S, and 28S rDNA sequences of the two rodent Gongylonema spp. showed nucleotide identities of 99.8% (1811/1814), 100% (158/158), and 98.9% (3550/3590), respectively. The cox-1 regions showed 91.6% (338/369)-92.1% (340/369) identities, with completely identical amino acid sequences. The genetic diversities of three distinct Gongylonema spp. and their possible intraspecific genetic variation may allow us to resolve the taxonomic position of Gongylonema spp. which display few obvious morphological differences from their congeners. Consequently, the Gongylonema isolate from water buffaloes (Bubalus bubalis) in Nepal reported in our previous study is concluded to be a new species, and Gongylonema nepalensis n. sp. is erected for it.

Histozoic myxosporeans infecting the stomach wall of elopiform fishes represent a novel lineage, the Gastromyxidae.

BACKGROUND: Traditional studies on myxosporeans have used myxospore morphology as the main criterion for identification and taxonomic classification, and it remains important as the fundamental diagnostic feature used to confirm myxosporean infections in fish and other vertebrate taxa. However, its use as the primary feature in systematics has led to numerous genera becoming polyphyletic in subsequent molecular phylogenetic analyses. It is now known that other features, such as the site and type of infection, can offer a higher degree of congruence with molecular data, albeit with its own inconsistencies, than basic myxospore morphology can reliably provide. METHODS: Histozoic gastrointestinal myxosporeans from two elopiform fish from Malaysia, the Pacific tarpon Megalops cyprinoides and the ten pounder Elops machnata were identified and described using morphological, histological and molecular methodologies. RESULTS: The myxospore morphology of both species corresponds to the generally accepted Myxidium morphotype, but both had a single nucleus in the sporoplasm and lacked valvular striations. In phylogenetic analyses they were robustly grouped in a discrete clade basal to myxosporeans, with similar shaped myxospores, described from gill monogeneans, which are located at the base of the multivalvulid clade. New genera Gastromyxum and Monomyxum are erected to accommodate these myxosporean taxa from fish and gill monogeneans respectively. Each are placed in a new family, the Gastromyxidae with Gastromyxum as the type genus and Monomyxidae with Monomyxum as the type genus. CONCLUSIONS: To improve modern systematics of the myxosporeans it is clear that a combination of biological, ecological, morphological and molecular data should be used in descriptive studies, and the naming and redistribution of taxa and genera is going to be necessary to achieve this. Here we demonstrate why some Myxidium-shaped myxospores should not be included in the family Myxidiidae, and create two new families to accommodate them based on their site of infection, host biology / ecology, DNA sequence data and morphological observations. Subsequent descriptive works need to follow a similar course if we are going to create a prevailing and workable systematic structure for the Myxosporea.

HISTOPATHOLOGY OF GASTRIC WALL IN CHINESE ALLIGATOR ALLIGATOR SINENSIS INFECTED WITH ORTLEPPASCARIS SINENSIS (NEMATODA: ASCARIDOIDEA).

Crocodiles are susceptible to infection with a wide array of external and internal gastrointestinal helminths, yet little is known on the histopathology following infection or the effects of these parasites. The present study was aimed at evaluating the impact of infection by Ortleppascaris sinensis (Nematoda: Ascaridoidea) on the stomach of captive Alligator sinensis. The histological examination of the stomach revealed presence of superficial ulcer in mucous layer and granulomatous inflammation in submucous layer at entire gastric walls of the Alligator sinensis. Our findings also confirm that development of Ortleppascaris sinensis is in close association with the wall of the stomach.

Los cocodrilos son susceptibles a la infección con una amplia gama de helmintos gastrointestinales externos e internos; sin embargo, poco se sabe sobre la histopatología tras la infección o los efectos de estos parásitos. El presente estudio pretende evaluar el impacto de la infección por Ortleppascaris sinensis (Nematodos: Ascaridoidea) sobre el estómago del Alligator sinensis en cautividad. El examen histológico del estómago reveló la presencia de úlcera superficial en la capa mucosa e inflamación granulomatosa en la capa submucosa del conjunto de las paredes gástricas del Alligator sinensis. Nuestros resultados confirman también que el desarrollo de Ortleppascaris sinensis está estrechamente relacionado con la pared del estómago.

Genetically distinct isolates of Spirocerca sp. from a naturally infected red fox (Vulpes vulpes) from Denmark.

Spirocerca lupi causes formation of nodules that may transform into sarcoma in the walls of aorta, esophagus and stomach of infected canids. In February 2013, post mortem examination of a red fox (Vulpes vulpes) hunted in Denmark revealed the presence of several nodules containing adult worms of Spirocerca sp. in the stomach and the omentum. The nodules largely consisted of fibrous tissue with infiltration of mononuclear cells, neutrophilic granulocytes and macrophages with hemosiderin deposition. Parasitological examination by three copromicroscopic methods, sedimentation, flotation with saturated sugar-salt solution, and sieving failed to detect eggs of Spirocerca sp. in feces collected from the colon. This is the first report of spirocercosis in Denmark, and may have been caused by a recent introduction by migrating paratenic or definitive host. Analysis of two overlapping partial sequences of the cox1 gene, from individual worms, revealed distinct genetic variation (7-9%) between the Danish worms and isolates of S. lupi from Europe, Asia and Africa. This was confirmed by phylogenetic analysis that clearly separated the Danish worms from other isolates of S. lupi. The distinct genetic differences of the current worms compared to other isolates of S. lupi may suggest the presence of a cryptic species within Spirocerca.

Endoscopic (video) demonstration of hookworm infestation of the stomach.

Hookworm infestation is common in southern India. The adult worms normally reside in the duodenum, graze the intestinal mucosa with their large buccal cavities and ingest the intestinal epithelial cells and blood. Depending on the number of worms the infection may be either asymptomatic or can cause iron deficiency anaemia due to chronic blood loss. Adult worms live in the small intestine and are not usually seen in the stomach. There are only very few case reports in the literature reporting hookworm infestation of the stomach. In this case report we present an endoscopic (video) demonstration of hookworm infestation of the stomach in a woman who presented with chronic anaemia.