Parasitology Research (Parasitol Res)

Publications in this journal

• Article: Neospora caninum NC-6 Argentina induces fetopathy in both serologically positive and negative experimentally inoculated pregnant dams.

  D Bacigalupe, W Basso, S G Caspe, G Moré, L Lischinsky, M L Gos, M Leunda, L Campero, D P Moore, G Schares, C M Campero, M C Venturini
  [show abstract] [hide abstract]
  ABSTRACT: Neospora caninum infection is a major cause of abortion in cattle. The objectives of this study were to genetically characterize the N. caninum NC-6 Argentina isolate using a multilocus microsatellite analysis approach and to study its biological behavior by experimental inoculations into seronegative and seropositive pregnant cattle, evaluating the humoral and cellular immune response elicited and the occurrence of transplacental transmission and fetopathy. Pregnant cows (65 days of gestation) seropositive and seronegative to N. caninum were intravenously inoculated with tachyzoites of the NC-6 Argentina N. caninum strain and slaughtered at 108 ± 2 days of gestation. Serum samples were analyzed for N. caninum antibodies by indirect fluorescent antibody test. The cellular immune response was analyzed by detection of gamma interferon (γIFN) production in blood cells. Tissue samples from dams, fetuses, and placental cotyledons were processed by histopathological and immunohistochemical techniques and examined for N. caninum DNA by PCR. Positive DNA samples were further analyzed by multilocus microsatellite typing for N. caninum. Inoculated animals had significantly higher N. caninum antibody titers and γIFN production than control animals. One seropositive inoculated cow aborted, one seronegative cow had a non-viable fetus, and the remaining fetuses from the experimentally inoculated dams had histopathologic lesions. The PCR was positive in 3/4 fetuses from seronegative inoculated cows and in 2/3 fetuses from seropositive inoculated cows. Multilocus microsatellite analysis revealed that the N. caninum DNA present in fetuses and placentas had an identical pattern to NC-6 Argentina strain. The NC-6 Argentina strain proved to be able to cross the placenta and to induce fetopathy in both the seropositive and seronegative dams.
  Parasitology Research 05/2013;
• Article: Serological and molecular detection of Strongyloides stercoralis infection among an Orang Asli community in Malaysia.

  Arine Fadzlun Ahmad, Faizah Hadip, Romano Ngui, Yvonne A L Lim, Rohela Mahmud
  [show abstract] [hide abstract]
  ABSTRACT: Detection of Strongyloides stercoralis infection particularly in asymptomatic individuals is often hampered due to the lack of standard diagnostic tools. In this study, the use of serological and molecular approaches were investigated for the detection of S. stercoralis infection among an Orang Asli (indigenous) community following a preliminary detection by microscopic examination of faecal samples. Out of 54 individuals studied, 17/54 (31.5 %) were detected to be positive for S. stercoralis infection by enzyme-linked immunosorbent assay (ELISA), compared to 0/54 (0 %) by faecal examination. Further confirmation performed by a nested polymerase chain reaction (PCR) using DNA extracted from faecal samples of these 17 individuals yielded 3/17 (17.6 %) positives for S. stercoralis DNA amplification. No amplification was seen with the other 37 faecal samples, which were negative by microscopy and ELISA. As the high ELISA positive results were suspected to be false-positives, ELISA is not recommended for use as a detection tool but may be beneficial for evaluating the effectiveness of anti-Strongyloides drugs. The present finding indicated that PCR should be considered as an alternative diagnostic tool for the detection of S. stercoralis infection.
  Parasitology Research 05/2013;
• Article: Hematological alterations caused by high intensity of L3 larvae of Contracaecum sp Railliet & Henry, 1912 (Nematoda, Anisakidae) in the stomach of Hoplias malabaricus in lakes in Pirassununga, São Paulo.

  Lincoln L Corrêa, Letícia C Karling, Ricardo M Takemoto, Paulo S Ceccarelli, Marlene T Ueta
  [show abstract] [hide abstract]
  ABSTRACT: The objective of the present study was to discover the hematological indices of Hoplias malabaricus infected by larvae of Contracaecum sp. A total of 105 fish were collected from two lakes located in the municipal district of Pirassununga, São Paulo, Brazil, of which 95.2 % were infested by L3 larvae of Contracaecum sp., with an average intensity of 348.7 ± 231.55 helminths/fish. A total of 76 fish were analyzed to establish hematological parameters. Following analysis, it was found that there was a significant difference between hematological parameters Hct, erythrocytes (Er), thrombocytopenia (p = 0.01), and Hb (p = 0.02) in lakes A and B, while there was no significant difference for leukocyte (p = 0.68), mean corpuscular volume, mean corpuscular hemoglobin (p = 0.06), and mean corpuscular hemoglobin concentration (p = 0.47). The intensity of infection correlated negatively with Er (r s = -0.42; p < 0.01) and positively for (r s = 0.48; p < 0.01). The high intensity of infection by Contracaecum sp. in H. malabaricus did not affect the health of the fish despite causing alterations in hematological variables.
  Parasitology Research 05/2013;
• Article: Applicability of partial characterization of cytochrome oxidase I in identification of forensically important flies (Diptera) from China and Egypt.

  Sanaa Mohamed Aly, Jifang Wen
  [show abstract] [hide abstract]
  ABSTRACT: Precise species identification of every insect sample collected from criminal scenes play an essential role in the accurate estimation of postmortem interval. The morphological similarity poses a great challenge for forensic entomologists. DNA-based method can be used as a supplemental means of morphological method. In the present study, we demonstrate the applicability of the 304-bp cytochrome oxidase I gene fragment in molecular identification of forensically important Diptera. We analyzed 75 specimens belonging to 19 species of 3 families originating from China (Calliphoridae: Chrysomya megacephala, Chrysomya albiceps, Chrysomya rufifacies, Chrysomya nigripes, Aldrichina grahami; Lucilia bazini, Lucilia caesar, Lucilia cuprina, Lucilia sericata, Lucilia porphyrina; Muscidae: Musca autumnalis, Musca domestica, Fannia canicularis, Stomoxys calcitrans; Sarcophagidae: Sarcophaga albiceps, Sarcophaga dux, Helicophagella melanura) and Egypt (Calliphoridae: C. megacephala, C. albiceps, L. sericata; Muscidae: M. domestica, F. canicularis, S. calcitrans, Synthesiomyia nudiseta; Sarcophagidae: Sarcophaga argyrostoma). This region was amplified using polymerase chain reaction followed by direct sequencing of the amplification products. Nucleotide sequence divergences were calculated using the Kimura two-parameter distance model and a neighbor-joining phylogenetic tree generated. Intraspecific variation ranged from 0-0.8 % and interspecific variation occurred between 1-19 %. Although all examined specimens were assigned to the correct species and formed distinct monophyletic clades, the data of the phylogenetic analysis were not completely in accordance with the traditional morphological classification. As both C. nigripes and A. grahami unexpectedly joined with Muscidae and Sarcophagidae groups respectively. Moreover, both Calliphorinae and Luciliinae clades failed to represent Calliphoridae as a separate group. Therefore, although molecular methods are beneficial especially if the available evidence are immature stage or degraded fragments of insect, we suggest using this fragment only in addition to other identification methods.
  Parasitology Research 05/2013;
• Article: In vivo anthelmintic activity of Anogeissus leiocarpus Guill & Perr (Combretaceae) against nematodes in naturally infected sheep.

  Dramane Soro, Witabouna Mamidou Koné, Bassirou Bonfoh, Bernadin Dro, Kassédo Bénédicte Toily, Kagoyire Kamanzi
  [show abstract] [hide abstract]
  ABSTRACT: The identification of new anthelmintic drugs becomes a priority because of the availability of a handful of drugs, cost of treatments, and recent emergence of drug resistance. Medicinal plants are a good source of bioactive compounds for development of drugs. In this study, in vivo efficacy of Anogeissus leiocarpus was assessed in sheep naturally infected with gastrointestinal nematodes. Fecal examination, serological analyses, and necropsy were carried out to determine the egg and worm-burden reduction. The administration of ethanolic extract (single oral dose of 80 mg/kg) of A. leiocarpus induced a moderate fecal egg reduction (81 %) and adult worm-burden reduction (87 %) against Haemonchus contortus and Trichostrongylus colubriformis (82 %). The plant exhibited high efficacy against adult Strongyloïdes papillosus (100 %), Gaigeria pachyscelis (90 %), Cooperia curticei (100 %), and Oesophagostomum columbianum (95 %) but low efficacy against Trichostrongylus axei (67 %) and Trichuris globulosa (79 %). All these helminthes were sensitive to fenbendazole, except O. columbianum which showed a decrease susceptibility (17 %). The plant extract also improved certain biological parameters by increasing bodyweight from 0.7 ± 2.9 to 3.3 ± 1.9 % and improving hematocrit of 6.9 ± 1.6 % 3-week posttreatment. It emerges from the results that the plant possesses significant effectiveness on diarrhea; all treated animals gave normal feces. This study has shown that A. leiocarpus could find an application in the control of multiparasitism in small ruminants.
  Parasitology Research 05/2013;
• Article: Expression of Tim-1 and Tim-3 in Plasmodium berghei ANKA infection.

  Bo Huang, Man Liu, Shiguang Huang, Bin Wu, Hong Guo, Xin-Zhuan Su, Fangli Lu
  [show abstract] [hide abstract]
  ABSTRACT: Cerebral malaria (CM) is a serious and often fatal complication of Plasmodium falciparum infections; however, the precise mechanisms leading to CM is poorly understood. Mouse malaria models have provided insight into the key events in pathogenesis of CM. T-cell immune response is known to play an important role in malaria infection, and members of the T-cell immunoglobulin- and mucin-domain-containing molecule (Tim) family have roles in T-cell-mediated immune responses. Tim-1 and Tim-3 are expressed on terminally differentiated Th2 and Th1 cells, respectively, and participate in the regulation of Th immune response. Until now, the role of Tim family proteins in Plasmodium infection remains unclear. In the present study, the mRNA levels of Tim-1, Tim-3, and some key Th1 and Th2 cytokines in the spleen of Kunming outbred mice infected with Plasmodium berghei ANKA (PbANKA) were determined using real-time polymerase chain reaction (qRT-PCR). Compared with uninfected controls, Tim-1 expression was significantly decreased in infected mice with CM at day 10 postinfection (p.i.) but significantly increased in infected mice with non-CM at day 22 p.i.; in contrast, Tim-3 expression was significantly increased in infected mice both with CM at day 10 p.i. and with non-CM at day 22 p.i. The expressions of IFN-γ, TNF-α, IL-10, and IL-12 were significantly increased but IL-4 was significantly decreased in infected mice with CM at days 10 p.i., whereas the expressions of IFN-γ, TNF-α, IL-4, IL-10, and TGF-β were significantly increased but IL-12 was significantly decreased in infected mice with non-CM at days 22 p.i. Furthermore, the expression of Tim-1 and Tim-3 could reflect Th2 and Th1 immune response in the spleen of PbANKA-infected mice, respectively. Our data suggest that PbANKA infection could inhibit the differentiation of T lymphocytes toward Th2 cells, promote the Th1 cell differentiation, and induce Th1-biased immune response in the early infective stage, whereas the infection could promote Th2 cell differentiation and induce Th2-biased immune response in the late infective stage. Our data indicate that both Tim-1 and Tim-3 may play a role in the process of PbANKA infection, which may represent a potential therapeutic target.
  Parasitology Research 05/2013;
• Article: Detection of Anaplasma marginale in Hyalomma asiaticum ticks by PCR assay.

  Limei Zhang, Yong Wang, Dongjie Cai, Gaoming He, Ziqiang Cheng, Jianzhu Liu, Kai Meng, Dubao Yang, Shujing Wang
  [show abstract] [hide abstract]
  ABSTRACT: A polymerase chain reaction (PCR) assay was performed in this study to amplify the major surface protein 5 (msp5) gene from the genomic DNA of Anaplasma marginale in Hyalomma asiaticum ticks by species-specific primers. Sequence analysis showed that the msp5 gene was 643 bases long and that the PCR products from the samples had an identical sequence (JX507127). Moreover, the BLAST showed that the sequence was identical to the msp5 sequences of A. marginale and most closely related to the A. marginale msp5 gene (AB704328) and the Liangdang strain of the A. marginale msp5 gene (EF546443) with similarity of 99 % (differing only by two bases). An epidemiological survey was performed in several dairy farms: a total of 68 ticks were collected from 49 cattle. As a result, 14 of the 49 (28.57 %) blood smears stained with Wright-Giemsa and 22 of the 68 (32.35 %) ticks examined by PCR assay exhibited A. marginale infection. The results of the PCR assay were mostly consistent with the results of the microscopic examination. A number of results were negative in blood smear but positive in PCR, which is important for the early diagnosis of anaplasmosis.
  Parasitology Research 05/2013;
• Article: Comparative analysis of midgut bacterial communities of Aedes aegypti mosquito strains varying in vector competence to dengue virus.

  Shakti S Charan, Kiran D Pawar, David W Severson, Milind S Patole, Yogesh S Shouche
  [show abstract] [hide abstract]
  ABSTRACT: Differences in midgut bacterial communities of Aedes aegypti, the primary mosquito vector of dengue viruses (DENV), might influence the susceptibility of these mosquitoes to infection by DENV. As a first step toward addressing this hypothesis, comparative analysis of bacterial communities from midguts of mosquito strains with differential genetic susceptibility to DENV was performed. 16S rRNA gene libraries and real-time PCR approaches were used to characterize midgut bacterial community composition and abundance in three Aedes aegypti strains: MOYO, MOYO-R, and MOYO-S. Although Pseudomonas spp.-related clones were predominant across all libraries, some interesting and potentially significant differences were found in midgut bacterial communities among the three strains. Pedobacter sp.- and Janthinobacterium sp.-related phylotypes were identified only in the MOYO-R strain libraries, while Bacillus sp. was detected only in the MOYO-S strain. Rahnella sp. was found in MOYO-R and MOYO strains libraries but was absent in MOYO-S libraries. Both 16S rRNA gene library and real-time PCR approaches confirmed the presence of Pedobacter sp. only in the MOYO-R strain. Further, real-time PCR-based quantification of 16S rRNA gene copies showed bacterial abundance in midguts of the MOYO-R strain mosquitoes to be at least 10-100-folds higher than in the MOYO-S and MOYO strain mosquitoes. Our study identified some putative bacteria with characteristic physiological properties that could affect the infectivity of dengue virus. This analysis represents the first report of comparisons of midgut bacterial communities with respect to refractoriness and susceptibility of Aedes aegypti mosquitoes to DENV and will guide future efforts to address the potential interactive role of midgut bacteria of Aedes aegypti mosquitoes in determining vectorial capacity for DENV.
  Parasitology Research 05/2013;
• Article: Nyctanthes arbor-tristis positively affects immunopathology of malaria-infected mice prolonging its survival.

  Jyoti Agrawal, Karuna Shanker, Debabrata Chanda, Anirban Pal
  [show abstract] [hide abstract]
  ABSTRACT: In order to search for new products that display antimalarial and immunomodulatory mechanisms that complement direct antiparasitic activity, a set of in vitro and in vivo experiments were designed to evaluate the effect of Nyctanthes arbor-tristis in Plasmodium berghei infected mice. Three extracts of N. arbor-tristis leaves from varying concentrations of alcohol and water were considered for their potential to suppress expression of pro-inflammatory mediators from macrophages primed with lipopolysaccharide. The ethanolic extract, which lowered the pro-inflammatory mediators [tumour necrosis factor (TNF), 13.52-55.83 %; interleukin-6 (IL-6), 0-17.29 %; and NO, 39.37-81.63 %], was selected to be examined in malaria (P. berghei) infected mice. Corroborating the in vitro results, it was observed that the extract could normalise the TNF (78 %) and IL-6 (70.35 %) optimally at 1 g/kg, thus retarding the pathological process in infected mice and increasing the mean survival time from 10.6 to 15.6 days. There were no signs of toxicity in the acute oral toxicity test up to 2 g/kg. (1)H NMR of the biologically active extract was obtained to ensure the presence of the compound of interest, i.e., iridoid glycoside. The quality and the reproducibility of results were ensured by means of achieving characteristic high-performance liquid chromatography fingerprint of the extract.
  Parasitology Research 04/2013;
• Article: First identification of four trypanorhynchid cestodes: Callitetrarhynchus speciouses, Pseudogrillotia sp. (Lacistorhynchidae), Kotorella pronosoma and Nybelinia bisulcata (Tentaculariidae) from Sparidae and Mullidae fish.

  Kareem Morsy, Abdel-Rahman Bashtar, Fathy Abdel-Ghaffar, Saleh Al Quraishy, Ali Al Ghamdi, Nesma Mostafa
  [show abstract] [hide abstract]
  ABSTRACT: Four previously unrecognized trypanorhynchids are described based on fish specimens from Sparidae and Mullidae host fish of the Red Sea. From September 2010 to June 2011, 66 specimens of the sea bream Pagrus pagrus (F: Sparidae) and 43 of the red mullet Mullus barbatus (F: Mullidae) were purchased from markets in the Suez and Hurghada cities of the Red Sea. The fishes were measured, and their organs investigated for helminth infections. Forty-one (37.6 %) out of the 109 fish specimens investigated were parasitized with Trypanorhyncha metacestodes, identified as Callitetrarhynchus speciouses Linton 1897, Pseudogrillotia sp. Dollfus 1969, Kotorella pronosoma Stossich 1901 from P. pagrus, and Nybelinia bisulcata Linton 1889 from M. barbatus in the mesentery and peritoneal cavity, with prevalences of 16.5, 11.0, 6.0, and 12.0 %. All of these larval stages were encapsulated larvae in blastocysts. C. speciouses is characterized by an elongated scolex, two bothria, a long postbulbosa, and four elongated bulbs. Pseudogrillotia sp. possesses a scolex with two lateral patelliform bothridia; posterior margins are free, not notched. A long sheath was observed, which was irregularly coiled when tentacles invaginated. N. bisulcata possesses an acraspedote scolex with four bothridia, which are broad, bean-shaped. The tentacles are spirally coiled, supplied with hooks with abruptly turned points. The four tentacles sheaths rose from scolex as two anterior (front) and two posterior (back) which overlap at the apices of bulbs. K. pronosoma is characterized by a short body with a craspedote scolex and four bothridia. The tentacles are short and emerge pairwise. The presence of Trypanorhyncha metacestodes in the muscles does not represent a risk of infection for humans. They have a negative effect on fish esthetics. The repugnant aspect and the prohibition for commercial use by sanitary inspectors, however, cause consumer rejection. Parasites of the order Trypanorhyncha have been recorded in these host fishes for the first time.
  Parasitology Research 04/2013;
• Article: Developmental stages of Hepatozoon seurati (Laveran and Pettit 1911) comb. nov., a parasite of the corned viper Cerastes cerastes and the mosquito Culex pipiens from Egypt.

  Kareem Morsy, Abdel Rahman Bashtar, Fathy Abdel Ghaffar, Saleh Al Quraishy, Salam Al Hashimi, Ali Al Ghamdi, Mohammed Shazly
  [show abstract] [hide abstract]
  ABSTRACT: Developmental stages of Hepatozoon seurati (Laveran and Pettit 1911) comb. nov. are described from the tissues of the corned viper Cerastes cerastes, and from the vector Culex pipiens. The parasite described in the present study is firstly recorded as Haemogregarina seurati (Laveran and Pettit 1911) in the same host. After demonstration of the sporogonous development in the mosquito vector (C. pipiens) which showed all characteristics of the genus Hepatozoon (large oocysts containing many sporocysts producing numerous sporozoites), the parasite should be transferred into the genus Hepatozoon. The infected erythrocytes measured 20 ± 0.95 × 7.3 ± 0.85 μm; while uninfected cells measured 13.3 ± 1.04 × 7.5 ± 0.16 μm. Hypertrophy and faintly stained cytoplasm are mostly occurred in infected erythrocytes. Blood stages of the parasite were found exclusively in the erythrocytes in two forms: (1) small trophozoites (10.0 ± 0.52 × 3.0 ± 0.4 μm) and (2) long (mature) sausage-shaped (16.5 ± 1.5 × 3.5 ± 0.4 μm). Merogony occurred in the endothelial cells of the blood capillaries of lung, liver, and spleen. Mature meronts was 27.6 ± 0.7 × 17.5 ± 0.5 μm in diameter and contained 20-35 merozoites (averaged in 26). These merozoites measured 16.5 ± 1.5 × 3.5 ± 0.4 μm. Syzygy and gamogony occurred in the mosquito myxocoel till the 5th day post-infection (p.i.) while sporogony took place after 15 days p.i. On the third day p.i., a large spherical macrogamete of 29.0 ± 0.8 × 20.5 ± 0.6 μm containing a distinct nucleus in association with a single microgamete were observed. The microgamete was pyriform measured 8 ± 02 μm in length. It had a prominent nucleus and a long flagellum of at least 20.4 ± 1.3 μm in length. Fertilization occurred on the 3rd to the 4th days p.i. and the formed zygote developed into an oocyst in which repeated mitotic divisions with centripetal invaginations occurred producing sporoblasts. After sporulation, each sporoblast termed as sporocyst, and contained 18 banana-shaped sporozoites measured 14.0 ± 1.6 × 3.2 ± 0.6 μm. Experimental transmission was successful by intraperitoneal inoculation of the infective stages (sporozoites) to uninfected vipers and led to the appearance of blood stages after 5-6 weeks.
  Parasitology Research 04/2013;
• Article: Histopathology of the tegument of rabbits infested by Rhipicephalus sanguineus (ACARI: IXODIDAE) ticks and exposed to selamectin (active principle of acaricide Revolution®, Pfizer).

  Vlamir Bozzatto, Patrícia Rosa de Oliveira, Maria Izabel Camargo-Mathias
  [show abstract] [hide abstract]
  ABSTRACT: Ticks are hematophagous ectoparasites which can transmit several diseases to the host during their feeding process. When ticks mechanically damage the tissue, they eventually induce inflammatory responses on the skin spot where they are fixed. One of the alternatives to control these ectoparasites is the use of chemical substances like selamectin-the active principle of Pfizer's antiparasitic Revolution®-a macrocyclic lactone capable of doing neurotoxic damage to the tick and eventually eliminating infestation in dogs and cats. The purpose of this study was to analyze, using histological and histochemical techniques, the occurrence of morphophysiological alterations in the skin of the host rabbits exposed to selamectin and infested with Rhipicephalus sanguineus (Acari: Ixodidae). Histologically, the exposed and infested rabbits showed a partial and/or total decrease in the stratum corneum and the epithelium decreased in the number of cell layers, consequently reducing the stratification (thinning) and quite pronounced formations of sub-epidermal edemas with consequent disorganization of collagen fibers in the dermal layer's connective tissue. Histochemical tests showed strong periodic acid-Schiff-positive reaction in the hair follicle and some regions of the dermis, besides resynthesis of collagen fibers detected by Mallory's trichrome technique. The obtained results showed that selamectin acts like a toxicant agent when in contact with the skin of the rabbit infested with ticks, inducing morphophysiological alterations in the acute inflammatory process in the animal's tegument. Selamectin is a chemical substance which has a dose-dependent action since higher concentrations cause greater morphophysiological damage in the skin of rabbits.
  Parasitology Research 04/2013;
• Article: Blastocystis surface antigen is stable in chemically preserved stool samples for at least 1 year.

  Rick Gould, Kenneth Boorom
  [show abstract] [hide abstract]
  ABSTRACT: Blastocystis spp. refer to a group of prevalent enteric protists found in humans and animals. Detection of Blastocystis spp. in fecal samples is often performed by clinicians with direct microscopy, which provides low sensitivity, or with culture and polymerase chain reaction testing, a method which is problematic when used with formalin-preserved stool samples. Prior study of Blastocystis and other enteric protists suggests that immunofluorescence antibody (IFA) stain could provide sensitivity and compatibility with formalin, but no information is available on the longevity of Blastocystis sp.'s surface antigens in formalin. We collected fecal samples from animals at a country fair held in the summer of 2009 in Oregon, USA. Samples were tested for the presence of Blastocystis infection using an IFA stain shortly after collection, and again after 1 year, with samples stored refrigerated at 4-8 °C. Most samples collected from steer, pigs, and goats were found to be Blastocystis positive. All fecal samples that were Blastocystis positive initially remained positive after 1 year. Blastocystis-negative samples remained negative. Minimal degradation was observed in stained slides. Blastocystis surface antigens detected by a polyclonal stain remained stable in formalin for a period of at least 1 year.
  Parasitology Research 04/2013;
• Article: The origin of the giant liver fluke, Fascioloides magna (Trematoda: Fasciolidae) from Croatia determined by high-resolution melting screening of mitochondrial cox1 haplotypes.

  Eva Bazsalovicsová, Ivica Králová-Hromadová, Ján Radvánszky, Relja Beck
  [show abstract] [hide abstract]
  ABSTRACT: The high-resolution melting (HRM) method, recently optimized as a reliable technique for population study of the European Fascioloides magna populations, was applied to determine an origin of F. magna individuals from Croatia. The structure and frequency of mitochondrial cytochrome c oxidase subunit I (439 bp; cox1) haplotypes of 200 Croatian flukes coming from 19 red deer (Cervus elaphus elaphus) livers were screened and compared with recently determined reference samples of F. magna from all European foci-Italy, Czech Republic, and Danube floodplain forests. While the reference haplotypes Ha1 and Ha2 were specific for flukes from the first European focus of fascioloidosis, the Natural Park La Mandria in Italy, the remaining three haplotypes (Ha3, Ha4, and Ha5) represented parasites from the second focus, Czech Republic. Besides, Ha3 and Ha4 were found also in the third, latest, and still expanding European focus, the Danube floodplain forests. The HRM screening of cox1 haplotypes of Croatian F. magna individuals resulted in classification of samples into the two mitochondrial haplogroups characterized by well-distinguished melting curves. They corresponded to Ha3 and Ha4 reference haplotypes that confirmed the Danube origin of F. magna from Croatia. The results support the theory that the Danube floodplain forests population of F. magna represents uniform genetic pool of the parasite. The spread of F. magna alongside the Danube River down to Croatia was possible due to suitable ecological conditions for definitive and intermediate hosts present in this unique biotope.
  Parasitology Research 04/2013;
• Article: Molecular characterization and expression of Rab7 from Clonorchis sinensis and its potential role in autophagy.

  Feifei Jia, Ye Li, Yan Huang, Tingjin Chen, Shan Li, Yanquan Xu, Zhongdao Wu, Xuerong Li, Xinbing Yu
  [show abstract] [hide abstract]
  ABSTRACT: Accumulating evidences suggest that Rab7 GTPase is important for the normal progression of autophagy. However, the role of Rab7 GTPase in regulation of autophagy in Clonorchis sinensis is not known. In this study, a gene encoding Rab7 was isolated from C. sinensis adult cDNA. Recombinant CsRab7 was expressed and purified from Escherichia coli. CsRab7 transcripts were detected in the cDNA of adult worm, metacercaria, cercaria, and egg of C. sinensis, and were highly expressed in the metacercaria. Immunohistochemical localization results revealed that CsRab7 was specifically deposited on the vitellarium and eggs of adult worm. Furthermore, EGFP signal of CsRab7WT and the active mutant CsRab7Q67L were associated with autophagic vesicles in transiently transfected 293T cells. It is concluded from the present study that CsRab7 GTPase possibly contributes to the development of C. sinensis and that the autophagy pathway could be an important site of action with respect to the developmental role of CsRab7 in C. sinensis.
  Parasitology Research 04/2013;
• Article: Qualitative risk assessment for the endemisation of Dirofilaria repens in the state of Brandenburg (Germany) based on temperature-dependent vector competence.

  R Sassnau, C Genchi
  [show abstract] [hide abstract]
  ABSTRACT: Climate change with an increase in average temperature may be responsible for propagation of temperature-dependent vectors and/or vector-associated pathogens in regions that were previously not endemic. The analysis of climate data of Brandenburg state (Germany) had showed that the extrinsic development of Dirofilaria repens, the causative agent of canine subcutaneous dirofilariosis, was possible from the years 2001 to 2012. This finding, associated to the movement of infected dogs and their relocation from endemic European areas to Germany makes possible a rapid endemization of the infection and highlight the risk for human health, being D. repens a frequent cause of zoonotic infections.
  Parasitology Research 04/2013;
• Article: Variations in local adaptation of allopatric Fasciola hepatica to French Galba truncatula in relation to parasite origin.

  Y Dar, M Lounnas, F F Djuikwo Teukeng, R Mouzet, B Courtioux, S Hurtrez-Boussès, P Vignoles, G Dreyfuss, D Rondelaud
  [show abstract] [hide abstract]
  ABSTRACT: Two French populations of Galba truncatula were subjected to experimental infections with Egyptian and French isolates of Fasciola sp. miracidia, originating from cattle and sheep, to compare characteristics of snail infections in allopatric and sympatric groups. All sampled Egyptian isolates were identified as Fasciola hepatica using microsatellite markers. Compared to snails infected with French miracidia, snail survival at day 30 post-exposure was significantly greater in the Egyptian groups, while prevalence of infection was significantly lower (in an Egyptian group infected with cattle-derived miracidia) or did not show any significant differences in the other three cases. The total number of metacercariae was significantly higher in the four Egyptian groups. However, snail population and the mammalian origin of F. hepatica had also a significant effect on this parameter. The dissection of snail cadavers showed a significantly higher number of free rediae in the Egyptian groups, even if snail population also had a significant effect on the redial burden. Both Egyptian isolates of F. hepatica could easily develop in French snails, causing a low mortality in snails and inducing a metacercarial production higher than that noted in sympatric infections. However, the mammalian origin of F. hepatica eggs and the quality of snail populations as intermediate hosts had to be taken into account for studying local adaptation in reason of their effects on this process.
  Parasitology Research 04/2013;
• Article: Larvicidal activity against Aedes aegypti of pacharin from Bauhinia acuruana.

  Roberto Wagner da Silva Góis, Leôncio Mesquita de Sousa, Gilvandete Maria Pinheiro Santiago, Nirla Rodrigues Romero, Telma Leda Gomes Lemos, Angela Martha Campos Arriaga, Raimundo Braz-Filho
  [show abstract] [hide abstract]
  ABSTRACT: The aim of the present study was to evaluate the activity of pacharin isolated from the ethanol extract from roots of Bauhinia acuruana on third-instar larvae of Aedes aegypti Linn. (Diptera: Culicidae). The crude ethanol extract showed larvicidal activity at the concentration of 500 μg/mL. Given this larvicidal activity, this extract was submitted to chromatographic fractionation on a silica gel column eluted with n-hexane, dichloromethane, ethyl ether, ethyl acetate, and methanol in order to isolate the active compound(s). Pacharin, obtained in pure form from fraction eluted with ethyl ether, was evaluated for their larvicidal effects against A. aegypti. In these bioassays, the larvae were exposed at concentrations of 500, 250, 100, 50, and 25 μg/mL of the crude ethanol extract or pacharin. After 24 h, the number of dead larvae was counted and the LC50 values for larval mortality were calculated. Pacharin showed LC50 value of 78.9 ± 1.8 μg/mL. The structure of isolated compound was identified on the basis of their spectral data (IR, 1D- and 2D-NMR) and by comparison with literature spectral data. The results indicate pacharin as a potential natural larvicide.
  Parasitology Research 04/2013;
• Article: Molecular characterization of the carbon dioxide receptor in the oriental latrine fly, Chrysomya megacephala (Diptera: Calliphoridae).

  Xiang Wang, Ming Zhong, Qinlai Liu, Sanaa Mohamed Aly, Chang Wu, Jifang Wen
  [show abstract] [hide abstract]
  ABSTRACT: The blowfly Chrysomya megacephala (Fabricius) (Diptera: Calliphoridae) cannot only act as a mechanical vector of various pathogens, but also infest man and animals causing human health problems and economic losses in the livestock and fish industries. As in other insects, olfaction of this species plays an important role in host location and is presumably mediated via transmembrane receptor signaling pathways. Here, we isolate and characterize CmegGr1 and CmegGr2, two new members of the chemosensory receptor gene family from C. megacephala. The open reading frames of CmegGr1 and CmegGr2 cDNA clones encode 453 and 486 amino acid residues, respectively. These two deduced proteins display high amino acid conservation with previously identified carbon dioxide (CO2) receptors, such as Drosophila melanogaster Gr21a/Gr63a and Anopheles gambiae s.s. Gr22/Gr24. Further sequence analysis showed that both proteins are consistent with their corresponding orthologs in the membrane topology prediction with some ambiguities in the location of N terminus and the number of transmembrane domains. The transcripts of CmegGr1 and CmegGr2 were detected in the major chemosensory organs including the antennae and proboscises with maxillary palps attached. These results suggest that CmegGr1 and CmegGr2 are likely to be the primary receptors for CO2 detection in C. megacephala. Knowledge of the molecular identity of the blowfly olfactory CO2 receptors may aid in the development of novel control strategies designed to take advantage of this unique and critical olfactory pathway.
  Parasitology Research 04/2013;