Detection and genetic characterization of Toxoplasma gondii in market-sold mussels (Mytilus edulis) in certain provinces of China.

Mussels, randomly collected from fish markets in China, were analyzed by a semi-nested PCR to detect B1 gene of Toxoplasma gondii. Out of the 2215 samples, fifty-five (2.48%) were detected T. gondii-positive. The prevalence in Shandong province, Liaoning province and Zhejiang province were 2.51%, 2.26% and 2.69%, respectively. T. gondii oocysts were more frequently detected in digestive glands (1.04%) and haemolymph (1.49%) when compared with gills (0.23%). Of the 55 positive DNA, only two samples showed complete genotype at 11 locus and were authenticated as ToxoDB Genotype #9. To our knowledge, the present study is the first to confirm the presence of T. gondii in market-sold mussels in China. The findings point to the risk of humans acquiring T. gondii infection by consuming mussels bought in the aquatic product market.

Cystic echinococcosis and other helminth infections of wild boar in northeastern and northwestern regions of Tunisia.

This study identified helminth species of wild boar (Sus scrofa) originating from northeastern and northwestern regions of Tunisia using 297 lungs, 297 livers, 264 intestinal tracts, 120 samples of muscle tissue (tongue, masseter, diaphragm, inter-costal) and 232 faecal samples derived from a total of 591 animals. Host gender was registered for the lung and liver wild boar group, which included 163 males and 134 females. All animals, excluding those used to retrieve muscular samples, were classified into three age classes, <2 (n = 212), 2-3 (n = 208) and ⩾4 years old (n = 141). Helminth fauna of the examined wild boar included 14 parasite species: one trematode (adult, Brachylaemus suis), three cestodes (metacestodes of Echinococcus granulosus, Taenia hydatigena cysticercus, adult, Hymenolepis diminuta), nine nematodes (adults of Metastrongylus apri, Metastrongylus pudendotectus, Ascarops strongylina, Globocephalus urosubulatus, Physocephalus sexalatus, Gnathostoma hispidum, Gongylonema pulchrum and eggs of Strongyloides ransoni and Capillaria spp.) and one acanthocephalan (adult, Macracanthorhynchus hirudinaceus). Trichinella larvae were not recovered from any of the 30 wild boar examined. Results showed a 73.5% global prevalence of infection with visceral helminths, 67.3% of which were lung and hepatic infections and 80.3% of helminths were recovered from the gastrointestinal tract. The most prevalent parasite was M. hirudinaceus (61.7%) while the highest intensity of infection was observed for Metastrongylus spp. The most prevalent cestode was E. granulosus (18.9%). This is the first detailed study on helminth infections of wild boar from a North African country.

Epizootic Infection by Trypanosoma vivax in Cattle from the State of Minas Gerais, Brazil.

Trypanosomiasis is caused by a pathogenic protozoan of the genus Trypanosoma, being Trypanosoma vivax the most important agent for cattle. The aim of the present study was to demonstrate the expansion of T. vivax infection in different mesoregions of Minas Gerais, Brazil, and describe the clinicopathological findings of trypanosomiasis in cattle. The diagnosis was based on visualization of the parasite in blood smears and DNA detection of T. vivax in the blood of live cows and tissues of necropsied animals by the polymerase chain reaction (PCR). Thirty suspected herds were tested, of which 11 were positive for T. vivax. The most frequent clinical signs were anemia, apathy, drop in milk production, weight loss, reproductive disorders, and nervous signs. Concomitant diseases, such as malignant edema, pneumonia and increased cases of mastitis were associated with T. vivax infection. Three cows were necropsied and the most significant findings were low body condition score, pale mucous and spleen with white pulp hyperplasia. The results demonstrated the expansion of T. vivax infection in Minas Gerais, that PCR-associated blood smears are promising for diagnosis, and that other diseases often occur concomitantly to T. vivax infection in regions with trypanosomiasis in cattle.

Dendrorchis pampae sp. n. (Digenea: Gorgoderidae) from Cynopoecilus melanotaenia (Cyprinodontiformes: Cynolebiidae) a killifish from southern Brazil, with an emended diagnosis of Dendrorchis.

A new species of Dendrorchis is described and compared with others in the genus. The parasites were found in the swim bladder of the annual killifish Cynopoecilus melanotaenia. Hosts were collected from a seasonal wetland in southern Brazil. The main characteristics of D. pampae are: genital pore in the intestinal bifurcation region elongate and lobed vitellaria uterine loops limited to the acetabular region and to the rear end of the body; and wide intestinal caeca. An emended diagnosis of the genus Dendrorchis includes the characteristics of the new species. This is the first record of an adult digenean in an annual killifish from South America.

Parasitic causes of organ condemnation in cattle slaughtered in Fako abattoirs, South-West region of Cameroon, and estimate of financial losses.

An abattoir study was carried out between May and October 2016 to determine the parasitic causes of organ condemnation during meat inspection and to evaluate the attendant financial losses in Fako abattoirs, in the South-West region of Cameroon. Organs (liver, lungs, heart, tongue, kidney, spleen and intestine) were examined at meat inspection following standard procedures and the financial loss was estimated by considering the total weight of condemned organs and the price per kilogram of marketable organs, obtained from the local market. The organs of 1472 cattle were examined, of which 357 (24.38%) were condemned. The organs condemned because of parasitic infestations were the liver (333) and small intestine (24), and the infections were caused by flukes of Fasciola sp. and proglottids of Moniezia sp., respectively. Hydatid cysts and cysticerci were absent. The prevalence of fasciolosis and monieziosis was 22.62% and 1.63%, respectively. Condemnation deprived the region of 665.457 kg of meat, with an associated financial loss of CFA 1,330,902 (USD 2505), during the study period. Parasitic diseases worsen the food insecurity situation as they result in the withdrawal of a considerable amount of meat from the food chain. Fasciolosis, the leading parasitic cause of meat condemnation in Fako, is also zoonotic. It is therefore important that effective control measures are implemented countrywide against this parasitosis.

Helminth parasites of the endangered hooded grebe, Podiceps gallardoi, from Patagonia Argentina, with the description of two new digenean species.

In March 2011, a predator killed 33 hooded grebes, Podiceps gallardoi Rumboll (Podicipedidae), a critically endangered species, in a nesting colony at El Cervecero Lake, Santa Cruz Province, Argentina. The viscera of ten birds were examined for helminths. Two new species of Trematoda were recovered from the intestines. The plagiorchid Plagiorchis patagonensis n. sp. is mainly characterized by the larger size of the oral sucker relative to the ventral sucker, and by the distribution of the vitellarium in two lateral fields, confluent between the caecal bifurcation and the ventral sucker. The echinostomatid Euparyphium tobianum n. sp. is mainly characterized by possessing a head collar with 37-39 spines (4 angle spines on each ventral lappet, 4 lateral spines in a single row on each side, and 21-23 dorsal spines in a double row). An unidentified cestode, a tetramerid nematode and a notocotylid trematode were also recovered from the birds. This is the first record of helminths parasitizing the hooded grebe.

Morphometric and molecular analyses of two digenean species from the mullet: Skrjabinolecithum spinosum n. sp. from the Russian southern Far East and Unisaccus tonkini n. sp. from Vietnam.

Adults of Skrjabinolecithum spinosum n. sp. were discovered in Mugil cephalus from the Gulf of Peter the Great in southern Far-East Russia. Additionally, adults of Unisaccus tonkini n. sp. were found in the intestine of Moolgarda cunnesius and Moolgarda seheli from the coastal waters of Cat Ba Island, Tonkin Bay, northern Vietnam. Skrjabinolecithum spinosum n. sp. possesses a larger body, and ventral and oral sucker size in comparison with Skrjabinolecithum vitellosum, a smaller pharynx size and body length/width rate ratio in comparison to Skrjabinolecithum pyriforme, a smaller body length and prepharynx size in comparison to Skrjabinolecithum lobolecitum and a smaller pharynx length and egg size in comparison to Skrjabinolecithum indicum and S. lobolecitum. The new species also differs from S. indicum, S. lobolecitum and S. vitellosum by the form of the testis, and from the last two species by the presence of a two-branched intestine. The morphometric parameters of S. spinosum n. sp. are similar to those of Skrjabinolecithum spasskii. However, S. spinosum n. sp., unlike S. spasskii, has an armed hermaphroditic duct. Unisaccus tonkini n. sp. is similar to Unisaccus spinosus (Martin, 1973), Unisaccus brisbanensis (Martin, 1973) and Unisaccus overstreeti (Ahmad, 1987) in body size but differs in oral sucker, pharynx and hermaphroditic sac size from U. spinosus, and in ventral sucker and ovary size from U. brisbanensis and U. overstreeti. Bayesian phylogenetic analysis, based on combined data of internal transcribed spacer 2 (ITS2) and partial 28S rRNA gene sequences, confirmed the validity of S. spinosum n. sp. and U. tonkini n. sp. Analysis of interrelationships of the family Haploporidae, including molecular data on new species, showed that the Waretrematinae subfamily is more heterogeneous in comparison with Haploporinae and Forticulcitinae, and includes U. tonkini n. sp.

Interleukin-17A-Deficient Mice Are Highly Susceptible to Toxoplasma gondii Infection Due to Excessively Induced T. gondii HSP70 and Interferon Gamma Production.

Interleukin17A (IL-17A) is known to be involved in the host defense against pathogens and the pathogenesis of autoimmune diseases. Previously, we showed that excessive amounts of interferon gamma (IFN-γ) play an important role in the pathogenesis of the lethal effects of Toxoplasma gondii by inducing anaphylactic responses. In the study described in this report, we examined the effects of IL-17A deficiency on murine host defense against oral T. gondii infection. IL-17A-deficient C57BL/6 (B6) mice exhibited higher rates of mortality than wild-type (WT) mice during the acute phase of T. gondii infection. CD4+ T cells in the mesenteric lymph nodes (mLNs) and ileum of T. gondii-infected IL-17A-deficient mice produced higher levels of IFN-γ than did those of WT mice. In addition, the level of T. gondii HSP70 (T.gHSP70) expression was also significantly increased in the ileum, mLNs, liver, and spleen of infected IL-17A-deficient mice compared with that in WT mice. These elevated levels of expression of T.gHSP70 and IFN-γ in infected IL-17A-deficient mice were presumably linked to the IL-17A defect since they decreased to WT levels after treatment with recombinant IL-17A. Furthermore, IL-17A-deficient mice were highly susceptible to the anaphylactic effect of T.gHSP70, and the survival of IL-17A-deficient mice during the acute phase was improved by treatment with an anti-T.gHSP70 monoclonal antibody. These results suggest that IL-17A plays an important role in host survival against T. gondii infection by protecting the host from an anaphylactic reaction via the downregulation of T.gHSP70 and IFN-γ production.

The occurrence of Toxocara species in naturally infected broiler chickens revealed by molecular approaches.

Consuming raw and undercooked meat is known to enhance the risk of human toxocariasis because Toxocara species have a wide range of paratenic hosts, including chickens. The aim of this study was to identify species of Toxocara in naturally infected broiler chickens using molecular approaches. A polymerase chain reaction (PCR) method was used for the differentiation of Toxocara canis and Toxocara cati larvae recovered from tissues and organs, and identified by microscopic observations. Thirty-three 35- to 47-day-old broiler chickens were used for examination of Toxocara larvae. The duodenum, liver, lungs, heart, kidneys, skeletal muscles and brain of each chicken were examined using the pepsin method, and DNA from each tissue was extracted as the template for PCR assay. The findings revealed that 5 of 33 (15.2%) broiler chickens were infected with Toxocara larvae. Larvae were recovered from the liver (n = 19), duodenum (n = 8), skeletal muscles (n = 8) and brain (n = 2) of broiler chickens naturally infected with Toxocara spp. The results showed that the frequencies of the species in the chickens were T. canis larvae (n = 5, 83.3%) and T. cati larvae (n = 1, 16.7%). Our data from the present study demonstrated the importance of broiler chickens as a paratenic host for the parasite's life cycle in the environment. The implementation of DNA amplification as a routine diagnostic technique is a specific and alternative method for identification of Toxocara larvae, and allowed the observation of specific species under field conditions within the locations where broiler chickens are typically raised and exposed to Toxocara spp. eggs or larvae.

Pathogenesis of mixed infection by Spironucleus sp. and Citrobacter freundii in freshwater angelfish Pterophyllum scalare.

The present study was carried out to identify and describe the pathology of the freshwater angelfish Pterophyllum scalare during chronic mortality in an in-door aquaculture system. Scraping of the integument and gills and the collection of intestinal contents to search for external and internal parasites were performed. Kidneys were collected aseptically for the microbiological analysis and the isolates were subjected to antibiotics to test for susceptibility. Subsequently, necropsy for macroscopic assessment and collection of internal organs for histopathology were performed. The fish exhibited lethargy, lip tumor, hemorrhage and liver granuloma. No ectoparasites were diagnosed. Endoparasites of the genus Spironucleus were found in large numbers in the intestine of the affected fish. In the microbiological analysis, Citrobacter freundii was isolated from the kidney and identified by colony PCR. This bacterium showed susceptibility to three of the eight antibiotics evaluated: ciprofloxacin, cefoxitin and tetracycline. For the pathological analysis, liver and spleen granulomas were present. In the intestinal tissue, a large and unusual amount of mast cells and their free granules were described and discussed in detail. The present study showed that mast cells play an important role during the chronic infection of freshwater angelfish.

Establishment of a murine model of cerebral malaria in KunMing mice infected with Plasmodium berghei ANKA.

Malaria remains one of the most devastating diseases. Cerebral malaria (CM) is a severe complication of Plasmodium falciparum infection resulting in high mortality and morbidity worldwide. Analysis of precise mechanisms of CM in humans is difficult for ethical reasons and animal models of CM have been employed to study malaria pathogenesis. Here, we describe a new experimental cerebral malaria (ECM) model with Plasmodium berghei ANKA infection in KunMing (KM) mice. KM mice developed ECM after blood-stage or sporozoites infection, and the development of ECM in KM mice has a dose-dependent relationship with sporozoites inoculums. Histopathological findings revealed important features associated with ECM, including accumulation of mononuclear cells and red blood cells in brain microvascular, and brain parenchymal haemorrhages. Blood-brain barrier (BBB) examination showed that BBB disruption was present in infected KM mice when displaying clinical signs of CM. In vivo bioluminescent imaging experiment indicated that parasitized red blood cells accumulated in most vital organs including heart, lung, spleen, kidney, liver and brain. The levels of inflammatory cytokines interferon-gamma, tumour necrosis factor-alpha, interleukin (IL)-17, IL-12, IL-6 and IL-10 were all remarkably increased in KM mice infected with P. berghei ANKA. This study indicates that P. berghei ANKA infection in KM mice can be used as ECM model to extend further research on genetic, pharmacological and vaccine studies of CM.

Mechanisms of mortality in Culicoides biting midges due to Haemoproteus infection.

We examined the effects of Haemoproteus infection on the survival and pathology caused in the biting midges. Forty-six females of Culicoides impunctatus were exposed experimentally by allowing them to feed on a naturally infected red-backed shrike infected with Haemoproteus lanii (lineage hRB1, gametocytaemia 5·2%). Seventeen females were fed on an uninfected bird (controls). Dead insects were collected, counted and used for dissection, histological examination and polymerase chain reaction-based testing. Parasites were present in all experimentally infected biting midges, but absent from control insects. Survivorship differed significantly between the control and infected groups. Twelve hours post-exposure (PE), 45 (98%) experimentally infected midges were dead, but all control midges remained alive, and many of them survived until 7 day PE. The migrating ookinetes of H. lanii overfilled midgut, markedly damaged the midgut wall, entered the haemocoel and overfilled the abdomen and thorax of exposed biting midges. Massive infection by migrating ookinetes led to damage of abdomen and thorax of biting midges. The parasites often present in large clumps in the haemocoel in abdomen and thorax, leading to the interruption of the haemolymph circulation. These are the main reasons for rapid death of biting midges after feeding on high-intensity infections of Haemoproteus parasites.

Larval migration of the ascarid nematode Toxocara canis following infection and re-infection in the gerbil Meriones unguiculatus.

A morphological and immunohistochemical study of larval migration patterns was performed in gerbils that were infected once (primary infected group) or twice (secondary infected group) with 1500 eggs of Toxocara canis. Animals from the primary infected and the re-infected group were killed at different times after infection, and larvae were counted in the intestines, liver, lungs and brain. Fragments of all organs were formalin fixed and paraffin embedded for histology and immunohistochemistry analyses (using polyclonal anti-Toxocara serum raised in rabbits infected with T. canis). In the primary infected group, larvae were more abundant in the intestine at 24 h, in the liver and lungs between 24 and 72 h and in the brain after 96 h; larvae predominated in the brain for up to 60 days after infection. In the re-infected group, an increase in the number of larvae in the liver and a reduction in the number of larvae in the brain was observed up to 60 days after re-infection. Inflammatory reactions were absent or limited. Eosinophils and loose granulomata were observed around the larvae and their antigens in the primary infected group and were more severe. Many eosinophils and typical epithelioid granulomata were observed around larvae in the re-infected group. These results demonstrate that the migration pattern of T. canis larvae in gerbils is similar to that in mice and rats, exhibiting a late neurotropic stage. In the re-infected group, there was histological evidence of an adaptive T-helper 2 (Th-2) response, and larvae were apparently retained within granulomata in the liver, without obvious signs of destruction.

Sequestration and histopathology in Plasmodium chabaudi malaria are influenced by the immune response in an organ-specific manner.

Infection with the malaria parasite, Plasmodium, is associated with a strong inflammatory response and parasite cytoadhesion (sequestration) in several organs. Here, we have carried out a systematic study of sequestration and histopathology during infection of C57Bl/6 mice with Plasmodium chabaudi AS and determined the influence of the immune response. This parasite sequesters predominantly in liver and lung, but not in the brain, kidney or gut. Histopathological changes occur in multiple organs during the acute infection, but are not restricted to the organs where sequestration takes place. Adaptive immunity, and signalling through the IFNγ receptor increased sequestration and histopathology in the liver, but not in the lung, suggesting that there are differences in the adhesion molecules and/or parasite ligands utilized and mechanisms of pathogenesis in these two organs. Exacerbation of pro-inflammatory responses during infection by deletion of the il10 gene resultsin the aggravation of damage to lung and kidney irrespective of the degree of sequestration. The immune response therefore affected both sequestration and histopathology in an organ-specific manner. P. chabaudi AS provides a good model to investigate the influence of the host response on the sequestration and specific organ pathology, which is applicable to human malaria.

Predilection sites for Toxoplasma gondii in sheep tissues revealed by magnetic capture and real-time PCR detection.

Undercooked lamb and mutton are common sources of Toxoplasma gondii infection for humans. A sequence specific magnetic capture technique in combination with quantitative real-time PCR targeting the 529 bp repeat element of T. gondii was used for estimation of the parasite burdens in various sheep tissues (n = 6) three months after peroral experimental inoculation with 10,000 T. gondii oocysts. Brain was the most frequently affected organ (positive in all 6 sheep) and showed the highest estimated parasite loads (0.5-30,913 parasites/g tissue). Lung samples were positive in three sheep, with load estimates of 36.3 to <1 parasite/g tissue. Heart tissue was positive in three sheep and kidney only in one animal with low parasite loads (<1 parasite/g tissue). Only few skeletal muscle samples in 2 animals showed positive results, with very low parasite burdens, while samples from further internal organs (i.e. liver and spleen) were negative in all animals. This study identified the brain as the most important predilection site and therefore the most appropriate tissue for T. gondii detection.

Larval Gnathostoma spinigerum Detected in Asian Swamp Eels, Monopterus albus, Purchased from a Local Market in Yangon, Myanmar.

The present study was performed to determine the infection status of swamp eels with Gnathostoma sp. larvae in Myanmar. We purchased total 37 Asian swamp eels, Monopterus albus, from a local market in Yangon in June and December 2013 and 2014. All collected eels were transferred with ice to our laboratory and each of them was examined by the artificial digestion technique. A total of 401 larval gnathostomes (1-96 larvae/eel) were detected in 33 (89.2%) swamp eels. Most of the larvae (n=383; 95.5%) were found in the muscle. The remaining 18 larvae were detected in the viscera. The advanced third-stage larvae (AdL3) were 2.3-4.4 mm long and 0.25-0.425 mm wide. The characteristic head bulb (0.093 × 0.221 mm in average size) with 4 rows of hooklets, muscular long esophagus (1.025 mm), and 2 pairs of cervical sacs (0.574 mm) were observed by light microscopy. The average number of hooklets in the 1st, 2nd, 3rd, and 4th rows was 41, 45, 48, and 51, respectively. As scanning electron microscopic findings, the characteristic 4-5 rows of hooklets on the head bulb, a cervical papilla, tegumental spines regularly arranged in the transverse striations, and an anus were well observed. Based on these morphological characters, they were identified as the AdL3 of Gnathostoma spinigerum. By the present study, it has been confirmed for the first time that Asian swamp eels, M. albus, from Yangon, Myanmar are heavily infected with G. spinigerum larvae.

Comparative evaluation of lesion development, tissue damage, and cytokine expression in golden hamsters (Mesocricetus auratus) infected by inocula with different Leishmania (Viannia) braziliensis concentrations.

The golden hamster (Mesocricetus auratus) is a susceptible model to Leishmania (Viannia) spp.; however, available studies employ different infection protocols, which account for clinical and pathological presentation differences. Herein, L. (V.) braziliensis preparations were standardized to contain 10(4), 10(5), or 10(6) parasites to determine an optimal inoculum that ensured cutaneous lesions without causing a disseminated infection in hamsters. Lesion development was followed for 105 days by size measurements, and skin, draining lymph node, spleen, and sera were investigated to check parasite load, spleen visceralization, cytokine expression, histopathological changes, and anti-Leishmania IgG levels. The lesion emergence time was inversely proportional to the parasite concentration in the inocula. Animals infected by 10(4) parasites presented nodular lesions, while those infected with 10(6) parasites often exhibited ulcerated lesions. The differences in the final lesion sizes were observed between 10(4) and 10(5) inocula or 10(4) and 10(6) inocula. High IFNG expression, anti-Leishmania IgG levels, and parasite load occurred independently of the inoculum used. A mild inflammatory skin involvement was observed in animals infected with 10(4) parasites, while extensive tissue damage and parasite spleen visceralization occurred with 10(5) and 10(6) parasites. These results indicate that inocula with different concentrations of parasites generate differences in the time of lesion emergence, clinical presentation, and systemic commitment, despite high and similar IFNG expression and parasite load. This suggests that a modulation in the immune response to different parasite numbers occurs in an early phase of the infection, which could dictate the establishment and magnitude of the chronic phase of the disease.

Efficacy of voriconazole in a murine model of acute Trypanosoma cruzi infection.

OBJECTIVES: Antifungal triazole derivatives have been studied as possible alternatives for the treatment of Chagas' disease. Voriconazole has demonstrated in vitro activity against Trypanosoma cruzi, but its efficacy in vivo has not yet been tested. We aimed to determine the effect of voriconazole in a murine model of acute T. cruzi infection. METHODS: Treatment efficacy was evaluated by comparing parasitaemia, mortality and organ involvement (by histological examination) of infected mice. RESULTS: Treatment with voriconazole significantly lowered parasitaemia and mortality compared with controls, reduced the percentage of mice with amastigote nests in heart and skeletal muscle and moderately decreased myocardial inflammation. CONCLUSIONS: Our findings support the potential of voriconazole for the treatment of acute Chagas' disease and motivate future animal studies using varying doses and treatment schemes. Further evaluation of voriconazole for clinical use in human Chagas' patients is warranted.

Abortive long-lasting sporogony of two Haemoproteus species (Haemosporida, Haemoproteidae) in the mosquito Ochlerotatus cantans, with perspectives on haemosporidian vector research.

Haemoproteus spp. are cosmopolitan vector-born haemosporidian parasites, some species of which cause diseases in non-adapted birds. Recent polymerase chain reaction (PCR)-based studies have detected mitochondrial cytochrome b gene lineages of these Haemoproteus parasites in blood-sucking mosquitoes and speculated about possible involvement of these insects in transmission of avian haemoproteids. However, development of Haemoproteus lineages has not been documented in mosquitoes. We infected 304 individuals of Ochlerotatus cantans, a widespread Eurasian mosquito, with Haemoproteus tartakovskyi (lineage hSISKIN1) and Haemoproteus balmorali (lineage hROBIN1). Mosquitoes were allowed to take non-infected and infected blood meals and maintained in the laboratory until 17 days post-infection (dpi). They were tested for presence of sporogonic stages by microscopic and PCR-based methods. Microscopic examination revealed partial development of both parasites in the infected insects. Numerous ookinetes were seen in the gut area and adjacent tissues located in the head, thorax and abdomen of mosquitoes between 1 and 5 dpi. Numerous oocysts were seen in the midgut wall between 4 and 15 dpi; they were also present in the head and thorax of infected mosquitoes testifying to the active movement of ookinetes throughout the body. Oocysts degenerated between 11 and 17 dpi. Sporozoites were not seen in oocysts or mosquito salivary glands, indicating abortive sporogonic development at the oocyst stage. In accordance with microscopy data, PCR and sequencing revealed presence of the lineages hSISKIN1 and hROBIN1 in experimental mosquitoes as long as 15 and 17 dpi, respectively, demonstrating relatively long survival of Haemoproteus parasites in the resistant insects without DNA degeneration. The present study shows that PCR-based diagnostics should be carefully used in vector studies of haemosporidians because it detects parasites in insects for several weeks after initial infection, but does not distinguish abortive parasite development. Demonstration of infective sporozoites in insects is essential for definitively demonstrating the insects are vectors.

New host and locality records of two nematode parasites Dujardinnascaris mujibii (Heterocheilidae) and Hysterothylacium aduncum (Anisakidae) from the common seabream Pagrus pagrus: a light and scanning electron microscopic study.

In the present study, the morphology and morphometric characterization of Dujardinnascaris mujibii (Heterocheilidae) and Hysterothylacium aduncum (Anisakidae), new nematode parasites infecting the sea bream Pagrus pagrus (Osteichthyes, Sparidae), were described for the first time from the Gulf of Suez and Hurghada City of the Red Sea, Egypt. Ninety-eight (70 %) and 62 (44.2 %) out of 140 of the examined fish were naturally infected with these nematodes, respectively. The infection was investigated macroscopically by the occurrence of these parasites in the flesh, stomach, intestines, as well as their body cavities as adult and larval stages. D. mujibii is characterized by an elongated body with a length of 36.4 ± 3 (23-38) mm (female) and 20 ± 3.0 (17-24) mm (males); the head is provided with three prominent lips each with four teeth like structures and the apical lip is embossed with a regular zigzag pattern as revealed by SEM. Interlabia were present, with prominent grooves. Juvenile stage is smaller than adults and provided with a spiny mucron. H. aduncum was small, measured 22.5 ± 2.0 (20.0-24.3) mm in length (female) and 16.3 ± 2.0 (14.5-17.4) mm (male). The head region bears three large lips which were clearly separated from each other, with the apical one having two rounded ends and the space between the two adjacent lips occupied by very prominent interlabia. The present study represents new host and locality records from P. pagrus fish in Egypt.