Acta Parasitologica最新文献

Purpose: Leishmania RNA viruses (LRV) are double-stranded RNA viruses (dsRNA viruses) that play a role in the pathogenesis of Leishmania parasites. Cutaneous leishmaniasis (CL) is endemic in various parts of Iran. Our aimed was to investigate presence of LRV among the Leishmania major isolates in four endemic regions of Iran.

Methods: In a cross-sectional study, we assessed the presence of LRV1 and LRV2 in 181 clinical isolates of L. major from four endemic cities in Iran using reverse transcription polymerase chain reaction (RT-PCR). After RNA extraction and cDNA synthesis, RT-PCR tests were conducted with LRV1 and LRV2 specific primers. Human beta-actin and kmp genes served as internal and external controls, respectively, and the Allele ID software was used to optimize melting curves.

Results: LRV2 was detected in 27.6% (50 out of 181) of L. major isolates, while no LRV1 was found. We did not observe a statistically significant difference in the presence of LRV2 based on age group, number, or location of lesions.

Conclusion: This study confirms the presence of LRV2 in clinical isolates of L. major from endemic regions of Iran. Further researches with larger sample sizes is recommended to explore the association between LRV and clinical symptoms as well as treatment response.

Purpose: The infection of brown trout (Salmo trutta) by the acanthocephalan parasite Echinorhynchus truttae is initiated by the ingestion of gammarid crustaceans harbouring the cystacanth form. Gammarus pulex has been reported as the common intermediate host of this parasite species. The absence of G. pulex in the rivers of Spain suggests that native gammarid species may play the role of intermediate host for E. truttae, which is the only acanthocephalan species reported in salmonids in this country. The aim of the present study was to investigate whether native gammarid species of Galician rivers can act as intermediate hosts of E. truttae.

Methods: A total of 263 gammarid specimens were collected from rivers in Galicia and fixed in 70% ethanol. They were examined under stereomicroscope for the presence of acanthocephalan larval stages.

Results: In one gammarid specimen identified as Echinogammarus lusitanicus, one cystacanth of Echinorhynchus truttae was observed.

Conclusion: The presence of a cystacanth of E. truttae in the gammarid E. lusitanicus indicates that this species play a role as an intermediate host in the life-cycle of this parasite in Galicia, where G. pulex (the most frequently reported intermediate host of this parasite species) is lacking.

Background: Allocreadiids are relatively small digeneans that appear to be restricted to freshwater systems distributed across the world. Allocreadiids are highly diverse in the Americas, particularly in the Neotropical biogeographical region. Their taxonomic history has been rather controversial, with several taxonomic reassessments and the description of new genera and species.

Methods: We sampled Creptotrematina specimens from a characid collected in the Pardo River, Paranapanema River basin in Brazil, and specimens of C. aguirrepequenoi, from Astyanax spp. in several localities between northern Mexico and Costa Rica. The specimens were studied through integrative approaches using morphological and molecular analyses of the 28S rDNA gene and two different regions of the COI mtDNA gene.

Results: We describe a new species of Creptotrematina which is differentiated from other congeners by the overall body size, but in particular by the size and position of the cirrus-sac, distribution of the vitelline follicles, and extension of uterine loops in the posterior end of body. Phylogenetic analyses of the 28S rDNA and COI mtDNA genes placed the new species in a monophyletic clade together with all other sequenced species of Creptotrematina, and as a sister species of C. batalhensis. Genetic divergences between the new species and other Creptotrematina spp. varied from 1.1 to 1.2% for the 28S rDNA and 12.4-14.3% for the COI mtDNA. Phylogenetic analysis based on COI mtDNA showed the isolates of C. aguirrepequenoi grouped in four monophyletic clades representing populations geographically separated along a wide geographical range spanning between northern Mexico and Costa Rica, with an estimated genetic divergence between 3.9% and 8.9%.

Conclusions: Our findings based on integrative analyses recognize Creptotrematina saltograndensis n. sp. from a characid collected in the Pardo River, Paranapanema River basin in Brazil and provide validation of the wide geographical distribution of C. aguirrepequenoi across Middle-America parasitizing Astyanax spp.; the genetic divergence of the species through the analysis of two regions of COI mtDNA points towards considering it represent a species complex, although we refrain at the moment on describing a new species, awaiting for further verification using other molecular markers, and obtaining fresh material for a more detailed taxonomic analyses. This study increases the known diversity of allocreadiids and contributes to the understanding of evolutionary relationships, host-parasite relationships, and biogeographic history of the group.

Purpose: Cystic echinococcosis (CE) is a neglected tropical disease prevalent worldwide, particularly in rural areas. Previous studies evaluated immune responses in patients with hepatic CE, however none had assessed Th1, Th2 and Th17 levels simultaneously in pulmonary CE patients. This study aimed to fill this gap in literature by using flow cytometry analysis.

Methods: Peripheral blood mononuclear cells (PBMCs) were isolated from blood samples collected from healthy control (HC) volunteers and patients with active pulmonary CE cysts. The PBMCs were analysed to evaluate Th1, Th2, and Th17 cell levels within the CD3 + CD4 + T-cell population, using antibodies against interferon (IFN)-γ, interleukin (IL)-4, and IL-17, respectively.

Results: Our analysis revealed elevated Th2 levels in CE patients, while Th1 and Th17 cell counts showed no significant difference between HC volunteers and patients with pulmonary CE.

Conclusion: The results indicate an imbalanced Th1/Th2/Th17 cell regulation in the pathogenesis of pulmonary CE. Future studies are recommended to compare immune responses between pulmonary and hepatic CE to confirm these findings and evaluate any potential difference in the immunopathology associated with the two clinical forms of CE.

Purpose: The identification of the external attaching fish parasitic cymothoid, Nerocila phaiopleura Bleeker 1857, is still based on the brief description of Australian specimens provided by Bruce (1987). The present study aimed to provide a redescription and molecular characterisation of Indian specimens of N. phaiopleura.

Materials and methods: Morphological identification was carried out based on microscopic examinations and taxonomic drawings. mitochondrial DNA cox1 was selected as the target gene for sequencing and molecular identification. Nucleotide genetic divergence (p-distance) and base-pair differences among the different species were determined using MEGA11.

Results: Nerocila phaiopleura can be well separated from its congeners by the following combination of characteristics: Body about 2.4 times as long as wide, cephalon broadly rounded anteriorly; coxae posteriorly directed, acute and extending beyond their corresponding pereonite; pereonite 7 posterior angle produced, extending to the pleonite 1; pleonites 1 and 2 ventrolateral process posteriorly directed; uropod exopod straight and elongate, 1.7-2.0 times longer than endopod; uropod endopod lateral margin not serrate, no notch on medial margin; pereopods with short ischium; pleotelson triangular. The p-distance among N. phaiopleura and other available Nerocila spp. ranged from 21 to 19%.

Conclusion: This study represents the first detailed taxonomic redescription of Indian specimens of N. phaiopleura. Key taxonomic features of the life stages and molecular data are provided here to identify the species properly. Interspecific genetic divergence between N. phaiopleura and other Nerocila spp. is assessed for the first time. Studies in cymothoid life histories, genetics, and morphology are necessary to understand one of the least understood parasite families.

Purpose: The study aimed to identify Clogmia (Telmatoscopus) albipunctata larva recovered from the urinary tract of a four-year-old female Siberian Husky dog in India using morphological assessment and molecular techniques.

Methods: Larval specimen obtained from the dog urine underwent preliminary morphological assessments followed by polymerase chain reaction (PCR) to selectively amplify segments of the Cytochrome b (Cytb), NADH1 genes, and the tRNA-Ser gene within mitochondrial DNA. Species identification was achieved through sequence analysis of the amplified product and subsequent phylogenetic analysis.

Results: Larva recovered from dog urine underwent morphological examination, revealing notable features characteristic of Clogmia genus. The primers targeting the mitochondrial DNA gene region of fly larva, amplified a distinct product of approximately 788 bp. Integration of morphological and molecular biology techniques confirmed the identification of the C. albipunctata larva in the dog urinary tract.

Conclusion: This study elucidates the initial molecular evidence of C. albipunctata presence in a four-year-old female Siberian Husky dog exhibiting symptoms of haematuria and frequent micturition in India. It reveals an instance of a domestic dog in India contracting a C. albipunctata larva infection in its urinary tract, emphasizing the importance of clinical vigilance towards this infection.

Purpose: Cryptosporidium spp. and Giardia duodenalis are two important foodborne human and animal parasites that can be disseminated through both food and water, leading to diarrheal disease. Nevertheless, available information on the circumstances of Cryptosporidium and Giardia duodenalis from Ningxia is limited.

Methods: A total of 208 stool samples of dairy calves derived from large-scale farms (> 1000 heads) of five cities randomly in Ningxia were gathered randomly, were amplified and analyzed by nested PCR based on the three target genes (18S rRNA, gp60 and tpi)and phylogenetic systematics.

Results: The prevalence of cryptosporidiosis and giardiasis in dairy calves in Ningxia were 13.0% (27/208 samples, 95% CI 9.1-18.2%) and 1.9% (4/208, 95% CI 0.8-4.9%) respectively. Three Cryptosporidium species appeared in this study which are Cryptosporidium parvum (C. parvum), Cryptosporidium andersoni (C. andersoni) and Cryptosporidium ryanae (C. ryanae) based on the 18S rRNA gene sequence. IIdA15G1 and IIdA13G1 belonging to the subtypes of Cryptosporidium were detected by the gp60 PCR. The genotypes of Giardia duodenalis were only assemblage E through the amplification of the triosephosphate-isomerase gene (tpi gene).

Conclusion: There is a risk of transmission to humans in Ningxia because of zoonotic genotypes (C. parvum, C. andersoni, assemblage E) and subtypes (IId) of Cryptosporidium spp. and G. duodenalis in dairy calves, and it is necessary to pay attention to the disease to prevent a widespread epidemic of the disease with the purpose to protect human and livestock health.

Purpose: The purpose of the present study is to contribute to the knowledge on the diversity of cestodes of the genus Paroniella Fuhrmann, 1920 parasitising passerine birds of the family Pycnonotidae (bulbuls) in the Afrotropical Region. The only known species of this groups, Paroniella perreti (Mahon, 1954) from Pycnonotus tricolor (Hartlaub) in the Democratic Republic of the Congo, is poorly described. Therefore, it needed a detailed redescription in order to make a reliable comparison and provide differentiation among this species and newly-collected davaineid specimens. Based on new materials collected from Neolestes torquatus Cabanis in Gabon, Paroniella neolestes n. sp. is described.

Methods: The type series of P. perreti from the collection of the Natural History Museum of Geneva is redescribed and figured using conventional light microscopy and interference-contrast microscopy. The specimens of the new species were stained by iron acetocarmine and mounted in Canada balsam.

Results: The present study provided more detailed and accurate data on P. perreti (compared to its original description) in relation mostly to the armament of suckers (not mentioned in the original description), the structure of the copulative apparatus, the number of rostellar hooks and the number of testes. The morphological comparison of the specimens from Neolestes torquatus from Gabon with the known 53 species of the genus Paroniella (presented in a table format) characterised them as belonging to a new species. The new combination Paroniella oitaensis (Kugi, 1990) n. comb. was proposed.

Conclusions: Based on the present state of knowledge, P. perreti and P. neolestes seem to be specific each to a single host species, i.e. Pycnonotus tricolor and Neolestes torquatus, respectively. Further studies of davaineid cestodes from pycnonotids from Africa as well as from South and Southeast Asia may result in discovering much greater diversity of this group than currently known.

Purpose: Artemisinin combination therapies, the first-line antimalarials in Nigeria, have reportedly suffered multiple failures in malaria treatment, hence the search for novel combination of other compounds. Methyl gallate and palmatine have been reported to exhibit antiplasmodial activities but the antimalarial activity of their combination has not been evaluated. Therefore, the evaluation of the combination of methyl gallate and palmatine for antimalarial activity in vitro and in vivo in the presence of piperine was carried out.

Materials and methods: The inhibitory potential of methyl gallate and palmatine combination on β-hematin (hemozoin) formation was studied in vitro. Also, the antimalarial activity of methyl gallate and palmatine combination with/without a bioenhancer (piperine) was evaluated in Plasmodium berghei NK65-infected mice.

Results: Methyl gallate and palmatine in the ratio 3:2 acted synergistically in vitro and had the highest inhibitory effect (IC₅₀ = 0.73 µg/mL) on β-hematin (hemozoin) formation. The 3:2 combination of methyl gallate and palmatine exhibited no antimalarial activity in vivo in the absence of piperine but caused reduction in parasitemia that exceeded 40% in the presence of piperine at the dose of 25 mg/kg body weight on days 6 and 8 post-inoculation in mice.

Conclusion: The 3:2 combination of methyl gallate and palmatine in the presence of piperine exhibited antimalarial activity in vivo, possibly by synergistic inhibition of hemozoin formation which may cause accumulation of haem within the food vacuole of Plasmodium spp. and its death.

Purpose: Animal hoarding has been associated with unhealthy human, animal and environmental conditions that predispose such individuals to serious life-threatening risks such as arson, malnutrition, cruelty and zoonosis. The study aimed to evaluate the presence of anti-Toxocara spp. antibodies among individuals with animal hoarding disorder in Curitiba, Brazil.

Methods: 65 residences with register of animal hoarder behavior were visited and 11 residences were included in the study, with a total of 19 individuals consenting participation. A short questionnaire was applied to gather information regarding hoarders and their dogs/cats, and serum samples were screened to detect antibodies (IgG) against antigens of Toxocara spp.

Results: Overall, 14/19 individuals (73.7%) presented anti-Toxocara spp. antibodies. In 8/11 (72.7%) households at least one person was seropositive. Seropositivity was higher among women (10/13; 76.9%) than men (4/6; 66.7%). A total of 442 dogs (14-30 dogs; average = 23.3 per household) and 31 cats (1-20 cats; average = 4.8 per household) were observed. To the authors' knowledge, this was the first study to survey occurrences of toxocariasis among animal hoarders. The high population densities of dogs observed during visits, in conjunction with absence of veterinary care and unsanitary conditions, may indicate that situations of high levels of animal infection and soil contamination were present.

Conclusion: In summary, the seroprevalence observed in this study indicated that there was a high risk of Toxocara spp. infection among individuals with animal hoarding disorder. Provision of educational programs to reduce the risk of infection in this population is warranted.