First Report of Cryptosporidium molnari-Like Genotype and Cryptosporidium parvum Zoonotic Subtypes (IIaA15G2R1 and IIaA18G3R1) in Brown Trout ( Salmo trutta).

This study reports for the first time the molecular characterization of Cryptosporidium spp. in Salmo trutta. A total number of 613 brown trout was captured by local anglers in 44 Galician rivers within 10 river basins (NW Spain) during the 2015 fishing season (March-August) and classified into groups according to their size. The gastrointestinal tracts were dissected and differentiated in pyloric ceca and intestine, which were homogenized and concentrated in phosphate-buffered saline 0.04 M pH 7.2/diethyl ether (2:1). Cryptosporidium oocysts were observed by immunofluorescence microscopy in 103 of 613 specimens (16.8%), with a mean intensity of 326.7 oocysts/trout. The highest prevalence rate was detected in specimens <2 yr (23.1%). Considering the anatomical location, Cryptosporidium oocysts were observed in pyloric ceca (72 trout, 69.9%), intestine (15 trout, 14.6%), or in both locations (16 trout, 15.5%), showing statistically significant differences between the 2 locations ( P < 0.01). The prevalence rate in the pyloric ceca increased with the age/size of the fish (62.2% vs. 70.8% vs. 83.3% for trout <2, 2-3, and >3 yr, respectively). By contrast, the prevalence rate in the intestinal location decreased with the age/size of specimens (21.6% vs. 12.5% vs. 7.7% for trout <2, 2-3, and >3 yr, respectively), but statistically significant differences were not determined. The microscopic observation of clusters of 4-20 oocysts in the pyloric ceca from 5 specimens of 20-28-cm body length is remarkable. By polymerase chain reaction amplification and sequencing of fragments of small-subunit ribosomal DNA ( SSU-rDNA), GP60, hsp70, and actin loci, Cryptosporidium molnari-like genotype was identified in 1 trout and Cryptosporidium parvum (subtypes IIaA15G2R1 and IIaA18G3R1) in 47 fish, including those specimens in which oocyst clusters were observed. This finding may indicate a true infection by C. parvum, as the homogenization process would break the epithelial cells, releasing oocysts, free or in clusters. Cryptosporidium oocysts were detected in wild trout captured from 27 of 44 rivers sampled in Galicia (61.4%), belonging to 9 of the 10 river basins considered, confirming the presence of this protozoan parasite in Galician rivers and proving their wide dispersion in aquatic freshwater environments. The identification of the zoonotic species C. parvum in brown trout may indicate a risk to public health as trout may be a potential source of infection to humans. Thus, edible wild fish extend the range of foodstuffs involved in the transmission of cryptosporidiosis.

Redescription of Physaloptera praeputialis von Linstow, 1889 (Nematoda: Spirurida) infecting stray cats (Felis catus Linnaeus, 1758) in Qena, Egypt and overview of the genus taxonomy.

Members of the family Physalopteridae are small or large worms parasitic in various regions of the alimentary tract of amphibians (3 species), reptiles (45 species), birds (24 species), mammals (more than 90 species) and humans (more than 82 reported cases). This study estimated the prevalence of Physalopteridae in stray cats in Qena and identify the encountered species and to overview the taxonomic features of different species of the family from which more than 200 species were recovered besides the unnamed species. The gastrointestinal tracts of 39 necropsied stray cats were examined for Physaloptera spp. The encountered species was mounted and prepared to be studied by ordinary and scanning electron microscopy. Ph. praeputialis adults and larvae were recovered from the pyloric region of the stomach of 28 (71.2%) of 39 necropsied stray cats (Felis catus). Species was redescribed by light and scanning electron microscopy, compared with the other related species of the same genus and larval stages are described for the first time. SEM examination of the parasite revealed that oral aperture is surrounded by 2 massive rounded lateral pseudolabia; pseudolabium roughly rectangular in apical view bearing 2 large sub- median (dorsolateral and ventrolateral) cephalic papillae.

Efectos producidos por spinitectus jamundensis, nematoda cystidicolidae, en el estómago del sábalo prochilodus lineatus pisces prochilodidae / Effects produced by spinitectus jamundensis, nematoda cystidicolidae, in the stomach of the shad prochilodus lineatus pisces prochilodidae

The presence of the nematode spinitectus jamundensis in cardial and pyloric regions of the stomach of prochilodus lineatus is observed. Samples of the parasitized stomach were analyzed by histological techniques using hematoxilin eosin and mallory (azan) Heidenhainïs stainnigs. The macroscopical description of the inner surface of th stomach showing damages in the parasites penetration sites, were observed. Histological observations show that the parasite enters the mucous membrane reaching muscular mucous membrane of the cardial region or the epithelial plaits in the pyloric region reaching up to the muscular layer without crossing it. In this way, the parasite remains confined by a thin layer of connective tissue and in almost direct contact with tissue liquids. Sometimes, in host tissues as response to the parasite presence, an increased level in the amount of lymphocytes in the surrounding tissues is observed

[Effects produced by Spinitectus jamundensis (Nematoda, Cystidicolidae) in the stomach of the shad, Prochilodus lineatus (Pisces, Prochilodidae)]. / Efectos producidos por Spinitectus jamundensis (Nematoda, Cystidicolidae) en el estómago del sábalo, prochilodus lineatus (Pisces, Prochilodidae).

The presence of the nematode Spinitectus jamundensis in cardial and pyloric regions of the stomach of Prochilodus lineatus is observed. Samples of the parasitized stomach were analyzed by histological techniques using Hematoxilin-Eosin and Mallory (Azan) Heidenhain's stainnigs. The macroscopical description of the inner surface of the stomach showing damages in the parasites penetration sites, were observed. Histological observations show that the parasite enters the mucous membrane reaching muscular mucous membrane of the cardial region or the epithelial plaits in the pyloric region reaching up to the muscular layer without crossing it. In this way, the parasite remains confined by a thin layer of connective tissue and in almost direct contact with tissue liquids. Sometimes, in host tissues as response to the parasite presence, an increased level in the amount of lymphocytes in the surrounding tissues is observed.

Infection of sheep with adult and larval Ostertagia circumcincta: abomasal morphology.

The infection of parasite-naive sheep with approximately 15,000 adult Ostertagia circumcincta via abomasal cannulae resulted in marked changes in the structure and function of the abomasum. The functional changes, which have been characterised previously, included elevated abomasal pH and increased serum concentrations of pepsinogen and gastrin. Eight days after the transplant of adult worms, the abomasa of recipient animals were significantly heavier than those of controls (P < 0.001), the thickness of the fundic mucosa was greater (P < 0.01), there were fewer parietal cells (P < 0.01) and increases in the numbers of mitotic figures and mucus-producing cells. Mucous cell hyperplasia was also evident in the fundic mucosae of sheep receiving a trickle infection of infective, third-stage O. circumcincta larvae and was prominent within nodules associated with larval development. In non-nodular mucosa, there was hyperplasia of mucous cells and changes in the distribution of parietal cells. Decreases in the number of parietal cells at the gland base were offset by increases at a mid-gland level, probably due to chronic hypergastrinaemia, so that, overall, total parietal cell number was unaffected. Mucous cell hyperplasia and the diminution of parietal cell number are seen in a diverse range of disease states and may be mediated by host growth factors such as Transforming growth factor-alpha. Alternatively, the cellular and/or the secretory changes in response to the presence of adult worms are mediated by chemicals that are cytotoxic/inhibitory for parietal cells, and released by the parasites themselves.

Gastritis caused by Aonchotheca putorii in a domestic cat.

Aonchotheca putorii is a parasitic nematode of the stomach and small intestines of many wild mammals. Although A putorii has been found in domestic cats in Iowa, it has not been reported to be pathogenic. The parasite caused severe gastric and was associated with a gastric ulcer and secondary anemia in a 10-year-old domestic shorthair cat from Ohio. The source of infection was not determined. Surgical resection of the affected tissue resolved clinical signs. The importance of postoperative administration of an anthelmintic in the resolution of any remaining A putorii is unknown. Ivermectin was given empirically to this cat. It is not known whether, or at what dosage, ivermectin or any other anthelmintic is effective against A putorii.

Chronic emesis caused by a nematode-induced gastric nodule in a cat.

A spirurid nematode-induced gastric nodule was believed to be responsible for chronic gastric irritation and vomiting in a domestic short-hair cat. Clinical improvement was noticed following surgical removal of the parasitic nodule in the wall of the pylorus. Morphologic characteristics of the parasite were most consistent with Spirocerca lupi. Infection with Spirocerca lupi is most commonly reported in Canids, often resulting in chronic granulomatous disease of the distal portion of the esophagus. In some animals, the lesions transform into fibrosarcomas and osteogenic sarcomas.

Refractory barriers in the sand fly Phlebotomus papatasi (Diptera: Psychodidae) to infection with Leishmania panamensis.

The life cycle of Leishmania panamensis in Phlebotomus papatasi was studied to characterize barriers limiting parasite colonization, differentiation, migration, and attachment in an unnatural sand fly host. The insects were fed a suspension of L. panamensis-infected macrophages and human erythrocytes, and were examined up to 16 days post-infection by light and electron microscopy. Histologic examination of 401 flies showed the peritrophic membrane to be the first important barrier to parasite establishment in the gut lumen. In most flies, parasites were unable to escape from the closed peritrophic sac, which was either excreted or retained intact in the midgut. After five days, only 31% of the flies were infected; attached parasites colonized the pylorus-ileum and/or colon regions of the hindgut. Anterior migration into the cardia region of the midgut occurred in less than 1% of infected flies; no parasites colonized the foregut. In the bloodmeal and residual bloodmeal, five morphologic forms developed from ingested amastigotes: stumpy, spatulate, elongate, short nectomonad promastigotes, and paramastigotes. Abnormal retention of amastigotes in macrophages and delayed development of promastigote stages was observed. The primary form attached in the hindgut was a pear-shaped haptomonad promastigote. Differentiation of L. panamensis in Ph. papatasi appeared to be similar to that described in natural hosts, except that metacyclic infective forms were not observed, and some forms developed in unusual locations. Phlebotomus papatasi was a partly refractory biological host for L. panamensis. The peritrophic membrane adversely affected the infection rate; rare anterior migration and a lack of metacyclic promastigotes may preclude transmission by bite.

The establishment and development of Haemonchus contortus in goats.

Twelve goats were inoculated with 40,000 third-stage Haemonchus contortus larvae and two were killed on each of Days 4, 7, 11, 14, 18 and 21 after inoculation (DAI). The number of worms that established, and the site of development were recorded. More worms established in the fundic, than in the middle or pyloric thirds of the abomasum. Early development occurred within the mucosa; emergence into the lumen started between 7 and 11 days after infection. By 4 DAI, all worms had completed the third moult to the L4 stage. At 11 DAI the majority of the worms were adults. A mean of 13.2% of the female worms had eggs in their uteri at 18 DAI; by 21 DAI more than half of the female worms had eggs in their uteri. The development of H. contortus was essentially similar to that described in sheep.

The development of extra-intestinal cycle of Trypanosoma cruzi in Triatoma infestans and Panstrongylus megistus.

By applying various histological techniques the results obtained were similar to those in Lacombe's previous publications referring to the development of Trypanosoma cruzi in haemolymph, the later penetration in the Malpighian tubes and their return to the digestive tract. Trypomastigotes and sphaeromastigotes are found in the promesenteron after two hours of feeding the insect with mice blood containing numerous Trypanosoma cruzi. Some parasites move to the promesenteron from postmesenteron and others from the haemolymph of the insect. The amastigotes form inside the haemocytes, multiply, occupying nearly all the cells of the haemolymph. The parasites liberated inside the Malpighian tubes move to the ampullae where they begin their growth. The parasites in epimastigote and trypomastigote forms cross the pyloric valve and adhere to the folds of the rectum.