Folia Parasitologica最新文献

Toxoplasma gondii Nicolle et Manceaux, 1909, the etiologic agent of toxoplasmosis, was considered a clonal population with three distinct genetic lineages (I, II and III); however, sequence analysis of different strains has revealed distinct atypical genotypes. Macrophages are essential for immunity against toxoplasmosis and differential cell regulation may affect the course of the disease. In this context, our study aims to investigate the infection by TgChBrUD2, a highly virulent atypical Brazilian strain of T. gondii, on the activation and polarisation of human macrophages. Human macrophage-like cells obtained from THP-1 cells were infected with TgChBrUD2, RH or ME49 strains of T. gondii to evaluate the impact of parasite infection on macrophage polarisation. Our results indicate that the TgChBrUD2 and ME49 strains of T. gondii induced a classic activation of human macrophages, which was confirmed by the high rate of spindle-shaped macrophages, low amount of urea and increase in the levels of nitrite, as well as the down-regulation of M2-markers. In contrast, RH strain promoted an alternative activation of macrophages. The polarisation of human macrophages towards an M1 subtype mediated by TgChBrUD2 and ME49 strains resulted in a low parasite burden, with high levels of IL-6 and MIF. Finally, the M2 subtype triggered by the RH strain culminated in a lower intracellular proliferation index. We concluded that the atypical (TgChBrUD2) and clonal (ME49) strains are able to elicit an M1 subtype, which results in parasitism control, partially explained by the high levels of IL-6 and MIF produced during the infection by these genotypes. In contrast, the clonal (RH) strain promoted a macrophage polarisation towards an M2 subtype, marked by a high parasite burden, with a weak modulation of pro-inflammatory cytokines. Thus, atypical strains can present different mechanisms of pathogenicity and transmissibility compared to clonal strains, as well as they can use distinct strategies to evade the host's immune response and ensure their survival.

Dactylogyrus Diesing, 1850 is the most species-rich genus in Platyhelminthes, with over 900 documented species, that are mostly strictly specific to freshwater cyprinoids. The morphological Dactylogyrus groups afrobarbae-type, carpathicus-type, pseudoanchoratus-type, and varicorhini-type are known to occur in Africa. This study describes a new species of Dactylogyrus of the varicorhini-type from the gills of the endemic smallmouth yellowfish Labeobarbus aeneus (Burchell) from the Vaal River, Free State Province, South Africa. Dactylogyrus matlopong sp. n. is unique among its varicorhini-type congeners mainly by the accessory piece of the male copulatory complex that presents a hook-shaped subunit with defined round base not reaching the male copulatory organ, combined with the presence of a conspicuous medial projection on the anterior margin of the ventral bar. Sequences of the partial 28S and 18S rRNA genes, together with entire ITS1 region, were generated for the first time for a species of Dactylogyrus from South Africa. Concatenated phylogenetic analyses of selected Dactylogyrus spp. showed that these parasites group according to their morphological types.

A three-year-old male South China tiger died in the tiger enclosure of the China Tiger Park in the Meihua Mountains on December 2018 after being bitten by a tick. This tiger presented clinical symptoms like whole-body severe jaundice, hepatosplenomegaly, kidney, and lymph node hemorrhages. The Colpodella sp.-specific 18S rRNA gene was detected using nested PCR. Interestingly, the DNA isolated from the blood of the tiger was found to be 100% similar to that of the tick by NCBI BLAST analysis. However, the DNA fragments isolated from the tiger's blood were 90.1% similar to the Colpodella sp. strain human erythrocyte parasite (HEP, MH208621) and 90.4% similar to the Colpodella sp. strain Heilongjiang (HLJ, KT364261). To investigate the species of ticks and ticks-carried Colpodella parasites in this region, the species of ticks obtained from the grasses outside the tiger enclosure and the species of Colpodella carried by ticks were identified. The DNA from ticks as well as that from the tick-borne Colpodella sp. were amplified from each tick using PCR followed by amplicon sequencing. In total 402 adult ticks samples were collected, among which 22 were positive for Colpodella sp. (5.5%), and the species were further determined by morphology, DNA sequencing and phylogenetic analyses. Interestingly, one Colpodella sp. was found to have 94.2% sequence similarities to the Colpodella sp. strain HEP (MH208621). This strain was previously reported to infect a woman in Yunnan, China. In addition, three Colpodella sp. showed 87-91% sequence similarities to the Colpodella sp. strain HLJ (KT364261), which was previously reported to infect human in Heilongjiang, China. This study disclosed the possibility of zoonotic transmission of Colpodella sp. by ticks in China. Finally, it provides a basis for urgently determining and monitoring the repertoire of ticks-borne piroplasmid pathogens, with the ultimate aim of strategic control.

Ligula intestinalis (Linnaeus, 1758) is a tapeworm parasite with a worldwide distribution that uses a wide variety of fish species as its second intermediate host. In the present study, we investigated the prevalence and population genetic structure of plerocercoids of L. intestinalis in five common cyprinoid species, roach Rutilus rutilus (Linnaeus), freshwater bream Abramis brama (Linnaeus), white bream Blicca bjoerkna (Linnaeus), bleak Alburnus alburnus (Linnaeus), and rudd Scardinius erythrophthalmus (Linnaeus), collected in six water bodies of the Czech Republic (Milada, Most, Medard, Jordán, Římov and Lipno). Of the six study sites, the highest frequency of parasitism was recorded in Lake Medard (15%). The overall prevalence rate among the species was as follows: roach > rudd ≥ freshwater bream > bleak > white bream. Two mitochondrial genes (cytb and COI) were used to compare the population genetic structure of parasite populations using selected samples from the five fish species. The results of the phylogenetic analysis indicated that all populations of L. intestinalis were placed in Clade A, previously identified as the most common in Europe. At a finer scale, haplotype network and PCoA analyses indicated the possible emergence of host specificity of several mtDNA haplotypes to the freshwater bream. Moreover, pairwise Fixation indices (F_ST) revealed a significant genetic structure between the parasite population in freshwater bream and other host species. Parasite populations in roach not only showed the highest rate of prevalence but also depicted a maximum number of shared haplotypes with populations from bleak and rudd. Our results suggest that recent ecological differentiation might have influenced tapeworm populations at a fine evolutionary scale. Thus, the differences in prevalence between fish host species in different lakes might be influenced not only by the parasite's ecology, but also by its genetic diversity.

Multivalvulid myxosporeans of the genera Kudoa Meglitsch, 1947 and Unicapsula Davis, 1924 (Cnidaria: Myxozoa) are often the cause of unsightly cyst formation or postmortem myoliquefaction in the trunk muscle of commercial marine fish, which reduces the market value of infected individuals. Twenty species (18 Kudoa spp. and two Unicapsula spp.) have been recorded from carangid fish, although the majority of them, excluding polyxenous species, such as K. amamiensis Egusa et Nakajima, 1980, K. iwatai Egusa et Shiomitsu, 1983, K. nova Naidenova, 1975, K. quadratum (Thélohan, 1895) and K. yasunagai (Hsieh et Chen, 1984), are limited to a single or a few fish species. We report the occurrence of macroscopic cysts of Kudoa trachuri Matsukane, Sato, Tanaka, Kamata et Sugita-Konishi, 2011 in the trunk muscle of four new host fish species, i.e., Pseudocaranx dentex (Bloch et Schneider), Decapterus akaadsi Abe, D. muroadsi (Temminck et Schlegel) and Decapterus tabl Berry, fished from the Philippine Sea (Northwest Pacific Ocean), off southwestern of Japan. Myxospore morphology and genetic characteristics of the ribosomal RNA gene (rDNA) of these isolates were consistent with previous records of K. trachuri from Trachurus japonicus (Temminck et Schlegel) from around Japan. In addition, a new species of Kudoa that forms long filamentous pseudocysts in trunk myofibres was found in four of the six D. tabl collected in this study. We describe Kudoa longichorda sp. n. for this new isolate, based on its morphology of subquadrate myxospores with four shell valves and polar capsules and with small dimensions (length 4.3-5.5 µm, width 6.0-6.8 µm, thickness 4.8-6.3 µm, polar capsule length 2.3-3.1 µm, polar capsule width 1.1-1.7 µm), as well as 18S and 28S rDNA sequences distinct from those of known species.

Examinations of nematodes collected from some marine fishes off the southwestern coast of Java, Indonesia in 2000 and 2001 revealed the presence of the following six species: ascaridoids Ichthyascaris grandis sp. n. from the intestine of Lophiomus setigerus (Vahl), I. cf. longispicula Li, Liu, Liu et Zhang, 2012 from the intestine of Conger cinereus Rüppel, Ichthyascaris sp. from the body cavity of Lobotes surinamensis (Bloch), and Raphidascaroides halieutaeae Yin, 1983 from the intestine of Halieutaea stellata (Vahl), and philometrids Philometra ivaschkini Parukhin, 1976 from the stomach wall of Trichiurus lepturus Linnaeus and P. psettoditis Moravec, Walter et Yuniar, 2012 from the body cavity (liver) of Psettodes erumei (Bloch et Schneider). Descriptions of these nematodes based on light and scanning electron microscopical studies are provided. The new species I. grandis sp. n. is mainly characterised by large body measurements (males and females up to 41.8 mm and 73.6 mm long, respectively), the length of spicules (0.99-1.05 mm), the tail tip usually without rudimentary spines and by the presence of 44-53 pairs of caudal papillae, eight to twelve of which being postanals. In addition to new data on the morphology of R. halieutaeae and other nematodes recorded, the 11 species of Raphidascaroides Yamaguti, 1941 poorly described from marine fishes in South Asia and reviewed in the monograph of Sood (2017) are considered species inquirendae and incertae sedis.

Buffaloes represent an important economic resource for several regions of the world including Romania. In the present study, we examined 104 faecal samples collected from 38 buffalo calves (2-11 weeks old) from household rearing systems in Romania for gastrointestinal parasites. All samples were tested using the saturated salt flotation, McMaster and modified Ziehl-Nielsen staining methods. PCR coupled with sequencing isolates were used to identify assemblages of Giardia lamblia (Kunstler, 1882) and species of Cryptosporidium Tyzzer, 1907. Overall, 33 out of 38 examined buffalo calves were infected with different gastrointestinal parasites: 16 had single infections and 17 had mixed infections with two or three parasites. Species of Eimeria Schneider, 1875 (32/38; 84%) were the most prevalent parasites; eight species were identified according to the oocyst morphology, including the pathogenic E. bareillyi (Gill, Chhabra et Lall, 1963) which was detected for the first time in buffaloes from Romania. The nematodes Toxocara vitulorum (Goeze, 1782) (11/38; 37%) and Strongyloides papillosus (Wedl, 1856) (6/38; 16%) were also detected. Cryptosporidium spp. were found in four (11%) buffalo calves; two of them were molecularly identified as C. ryanae Fayer, Santin et Trout, 2008, and another one clustered in the same clade with C. ryanae, C. bovis Fayer, Santin et Xiao, 2005, and C. xiaoi Fayer et Santin, 2009. Giardia duodenalis assemblage E was also molecularly detected in a single (2.6%) buffalo calf. The presence of other buffaloes in the same barn was identified as a risk factor for infection with T. vitulorum. Our results indicate extensive parasitic infections in buffalo calves from northwestern Romania and underline the necessity of prophylactic treatments for T. vitulorum and E. bareillyi.

Parasitism among individuals in a population often varies more than expected by chance only, leading to parasite aggregation, which is a parameter of paramount importance in parasite population dynamics and particularly in vector-borne epidemiology. However, the origin of this phenomenon is yet not fully elucidated. An increasing body of literature has demonstrated that individuals vary consistently in their behaviour, which is referred to as animal personality. Such behavioural variation could potentially lead to different encounter rates with parasites. To test this hypothesis, the relationship between personality and burden with ticks (Ixodes spp.) in the bank vole, Myodes glareolus (Schreber), was assessed. Wild rodents (eight females and 18 males) were live-trapped, identified, sexed, weighted, and inspected for ticks. Behavioural profiling was then performed using standardised tests measuring activity/exploration and boldness with a combination of automatically and manually recorded behavioural variables summarised using multivariate analyses. The resulting personality descriptors and questing tick variables were used as explanatory variables in negative binomial generalised linear models of tick burden and Bayesian simulations were performed to better estimate coefficients. Tick burden was associated to body mass and sex, but not to personality descriptors, which was mainly associated to activity/exploration. These results are discussed regarding the complex relationships among individual personality, physiological status, space use and health status.

In recent years, an emerging dermocystidiosis caused by Dermocystidium anguillae Spangenberg, 1975 has been found to pose a threat to the culture of American eel, Anguilla rostrata (Lesueur), as well as Chinese perch, Siniperca chuatsi (Basilewsky), in China. Dermocystidium anguillae was originally described from European eel, Anguilla anguilla (Linnaeus), and it is thus important to identify the possible source of this pathogen. In the present study, we compared D. anguillae from European eels cultured in China with those from American eels. Molecular analysis showed that the SSU rDNA of D. anguillae infecting European eels was identical to that of D. anguillae infecting American eels, suggesting their conspecificity. To investigate the source of D. anguillae causing dermocystidiosis in American eels cultured in China, a specific PCR assay for the detection of D. anguillae was developed with high sensitivity (10^-6 ng/µl of D. anguillae genomic DNA). Using the present molecular detection method, the water and sediment of culture ponds, fish feed and American eel elvers imported from America were screened for the presence of D. anguillae. No amplicons were detected from the water, sediment and fish feed samples. However, positive amplicons were found in American eel elvers, indicating that D. anguillae has been introduced from American eel elvers to China. It is suggested that American eel elvers imported from America should be examined for the presence of D. anguillae before their exportation abroad to prevent the spread of this pathogen.

Entamoeba moshkovskii Tshalaia, 1941 is prevalent in developing countries and it is considered to be primarily a free-living amoeba, which is morphologically indistinguishable, but biochemically and genetically different from the human infecting, pathogenic Entamoeba histolytica Schaudinn, 1903. The pathogenic potential of this organism is still under discussion. Entamoeba moshkovskii in human stool samples has been reported in different countries such as the United States, Italy, Australia, Iran, Turkey, Bangladesh, India (Pondicherry), Indonesia, Colombia, Malaysia, Tunisia, Tanzania and Brazil, but no data are available about the occurrence of E. moshkovskii in farm animals. This study provides data on the occurrence of E. moshkovskii in pigs in a total of 294 fresh faecal samples collected from five different regions in Kolkata, West Bengal, India. Stool samples were tested by nested PCR using primers targeting SSU rDNA of E. moshkovskii. The amplified PCR products were further confirmed by RFLP technique. Purified nested PCR products were also sequenced and identified via BLAST program run on the NCBI website to confirm species along with their genetic characteristics of the E. moshkovskii isolates. Overall 5.4 % samples were identified as E. moshkovskii positive. Results of this study demonstrate that swine can host E. moshkovskii and should be considered as a potential natural reservoir for E. moshkovskii. However, the occurrence of E. moshkovskii infection in pigs was not statistically associated with their faecal consistency, sex and developmental stage.