[Efficacy of the pyrethroid permethrin on the control of Psoroptes ovis (Hering, 1838) (Acari:Psoroptidae) in naturally infested rabbits (Oryctolagus cuniculus)]

The goal of the present study was to evaluate the efficacy of a spray formulation containing 2% of the pyrethroid permethrin on the control of Psoroptes ovis in naturally infested rabbits. Ten rabbits, presenting clinical signs of psoroptic mange in both ear canals. The animals were divided into two groups of five: control, without treatment (GI) and a second group (GII) treated with a single application of 2% permethrin. The diagnosis was realized by collecting fragments of crusts from both ear canals and submitting to stereomicroscopy for the presence and evaluation of mites' motility. On day 0 the animals from GII were treated topically with 2mg of 2% permethrin in each ear canal. No other treatment or environmental decontamination was performed during the trial. The rabbits were evaluated daily for observation of possible side effects. To evaluate the efficacy, collections of material were undertaken on days: +7, +14, +21. The formulation containing 2% permethrin was 100% effective in the control of P. ovis in naturally infested rabbits, along all days of observation. No adverse reactions were observed in the treated animals.

Morphological changes in the salivary glands of Amblyomma cajennense females (Acari: Ixodidae) in different feeding stages on rabbits at first infestation

This study examined salivary glands of unfed, partially engorged, and engorged females of the tick Amblyomma cajennense on rabbits at first infestation using histological and histochemical techniques. In type I acini, no significant changes were observed among the three feeding conditions. In type II acini of unfed females, c1, c2, and c4 cells were described for the first time in this species. In a comparison among the three feeding conditions, an increase in this acinus was observed, due to the increase in secretion in c1, c2, and c4 cells and the appearance of c3 cells. In engorged females, some cells were still active. Type III acini presented cells d, e, and f containing secretion in unfed females. In partially engorged females, these cells were devoid of secretion. In engorged females, type III acini exhibited a reduced lumen. After engorgement, all acini underwent a degenerative process, as observed in females after two to five days post-engorgement.

[Cultivation of the clothes lice adapted to feeding on rabbits]

A race of clothes lice adapted to feeding on rabbits is kept at a laboratory longer than 50 years. For this period, more than 850 insect generations undergoing no change in a number of biological tests and morphological indices have been obtained. They have retained a high susceptibility to Provacheck rickettsia infection. All infected lice die, partially with the signs of hemolytic imbibition. Their rickettsial accumulation is as high as 10(5.0) ID50 per insect for albino rats.

[Psoroptes cuniculi infestation in four rabbits and treatment with ivermectin]

Psoroptes cuniculi for treatment and in 10 rabbits in contact with the infested animals for protection. The efficacy of the drug was evaluated based on the clinical signs, the absence of live mites and new clinical cases during a period of least two weeks. Elimination of clinical signs and mites were seen in three rabbits seven days after the ivermectin injection, but one rabbit, which had meningitis-like signs, died. Also, no new cases occurred in the other ten rabbits. These results suggest that an application of ivermectin can completely eliminate mites from rabbits naturally infested with P. cuniculi and that it was also a sufficient method for protection from contact infestation.

Variation in host susceptibility and infectiousness generated by co-infection: the myxoma-Trichostrongylus retortaeformis case in wild rabbits

One of the conditions that can affect host susceptibility and parasite transmission is the occurrence of concomitant infections. Parasites interact directly or indirectly within an individual host and often these interactions are modulated by the host immune response. We used a free-living rabbit population co-infected with the nematode Trichostrongylus retortaeformis, which appears to stimulate an acquired immune response, and the immunosuppressive poxvirus myxoma. Modelling was used to examine how myxoma infection alters the immune-mediated establishment and death/expulsion of T. retortaeformis, and consequently affects parasite intensity and duration of the infection. Simulations were based on the general T_H1–T_H2 immunological paradigm that proposes the polarization of the host immune response towards one of the two subsets of T helper cells. Our findings suggest that myxoma infections contribute to alter host susceptibility to the nematode, as co-infected rabbits showed higher worm intensity compared with virus negative hosts. Results also suggest that myxoma disrupts the ability of the host to clear T. retortaeformis as worm intensities were consistently high and remained high in old rabbits. However, the co-infection model has to include some immune-mediated nematode regulation to be consistent with field data, indicating that the T_H1–T_H2 dichotomy is not complete. We conclude that seasonal myxoma outbreaks enhance host susceptibility to the nematode and generate highly infected hosts that remain infectious for a longer time. Finally, the virus–nematode co-infection increases heterogeneities among individuals and potentially has a large effect on parasite transmission.

The helminth parasites of the wild rabbit Oryctolagus cuniculus and their effect on host condition in Dunas de Mira, Portugal

The present study focuses on the helminth parasite community of the wild rabbit in a sand dune area in Portugal over a 5-year period. The influence of host sex and year on the composition of the helminth community is assessed, along with the potential effect of the detected helminths on host body condition. The basic structure of the helminth community comprises Mosgovoyia ctenoides, Graphidium strigosum, Trichostrongylus retortaeformis, Nematodiroides zembrae and Passalurus ambiguus. Mean intensities of G. strigosum varied between years. General G. strigosum intensities were also found to vary according to both year and host sex, but not according to the interaction of both factors. When assessing the effect of helminths on rabbit body condition (expressed by the kidney fat index), higher burdens of M. ctenoides, a cestode that presents a relatively large body mass, were found to induce a reduction in rabbit condition.

Detection of Babesia and Anaplasma species in rabbits from Texas and Georgia, USA

Rabbits have been shown to harbor a suite of zoonotic organisms, including a Babesia species, Borrelia burgdorferi, and Anaplasma phagocytophilum. In this study, we conducted a molecular survey for various tick-borne pathogens in three species of rabbits from Texas and Georgia. Of 18 black-tailed jackrabbits (Lepus californicus) tested from Texas, six (28%) were polymerase chain reaction (PCR) positive for Babesia, and nucleotide sequencing revealed two distinct species or strains. Two jackrabbits were infected with a Babesia species or strain (Babesia sp. A) that was nearly identical (99.9%) to a piroplasm previously detected in humans from Washington state, and the remaining four jackrabbits were infected with a Babesia species (Babesia sp. B) that was most similar (99.7%) to a Babesia species detected in cottontail rabbits from Massachusetts and humans from Kentucky and Missouri. Eleven (61%) black-tailed jackrabbits were positive for A. bovis, and one was positive for A. phagocytophilum. Two of four desert cottontails (Sylvilagus audubonii) from Texas were positive for the Babesia sp. B, and one desert cottontail each was positive for A. bovis and A. phagocytophilum. One of these desert cottontails was coinfected with the Babesia sp. B and A. phagocytophilum, and five jackrabbits were coinfected with Babesia species and A. bovis. Of 19 eastern cottontails (S. floridanus) from Georgia, only one (5.3%) was positive for A. phagocytophilum, and three (15.8%) were positive for A. bovis. No rabbits from Texas or Georgia were positive for Borrelia species. The only tick species detected on the Texas and Georgia rabbits was the rabbit tick, Haemaphysalis leporispalustris. These data extend the geographic and host range of these pathogens, and because both the Babesia species and A. phagocytophilum are potential zoonotic pathogens, it is important to be aware that these organisms are enzootic in parts of the southern United States.

Phylogenetic and biologic evidence that Babesia divergens is not endemic in the United States

The causative agent of human babesiosis in a Kentucky case, which was first identified as Babesia divergens, is identical to a parasite of eastern cottontail rabbits on Nantucket Island, Massachusetts based on piroplasm size, morphology, and ribosomal RNA sequence analysis. Studies showing differential infectivity for cattle, host erythrocyte specificity in vitro, parasite size and morphology in vitro, and ribosomal RNA sequences clearly demonstrate that the parasite from the rabbit (conspecific with the human Kentucky agent) is not the same organism as B. divergens.

Climate disruption and parasite-host dynamics: patterns and processes associated with warming and the frequency of extreme climatic events

Levels of parasitism and the dynamics of helminth systems is subject to the impact of environmental conditions such that we may expect long term increases in temperature will increase the force of infection and the parasite's basic reproduction number, R0. We postulate that an increase in the force of infection will only lead to an increase in mean intensity of adults when adult parasite mortality is not determined by acquired immunity. Preliminary examination of long term trends of parasites of rabbits and grouse confirm these predictions. Parasite development rate increases with temperature and while laboratory studies indicate this is linear some recent studies indicate that this may be non-linear and would have an important impact on R0. Warming would also reduce the selective pressure for the development of arrestment and this would increase R0 so that in systems like the grouse and Trichostrongylus tenuis this would increase the instability and lead to larger disease outbreaks. Extreme climatic events that act across populations appear important in synchronizing transmission and disease outbreaks, so it is speculated that climate disruption will lead to increased frequency and intensity of disease outbreaks in parasite populations not regulated by acquired immunity.

Passalurus ambiguus: new insights into copromicroscopic diagnosis and circadian rhythm of egg excretion

The present paper reports a study on the in vivo diagnosis and egg excretion rhythm of the pinworm Passalurus ambiguus in domesticated rabbits. Three copromicroscopic techniques were compared: the cellophane tape test, the McMaster technique, and the FLOTAC technique. Out of the 51 New Zealand White rabbit does examined, 42 (82.3%) resulted positive when examined with the FLOTAC technique, 39 (76.5%) with the cellophane tape test, and 29 (56.9%) with the McMaster technique. The agreement between the FLOTAC technique and the cellophane tape test was almost perfect (greater than 0.8); only moderate were the agreements (0.4) between the FLOTAC and the McMaster techniques and between the McMaster technique and the cellophane tape test. The results showed that the FLOTAC technique can be used for the quali-quantitative coprological diagnosis of P. ambiguus in rabbits due to its great sensitivity, as already shown for parasites of other animal species. The circadian rhythm of egg excretion by P. ambiguus was studied utilizing 42 individually caged rabbit does; fecal samples were collected from each cage every 6 h, i.e., at 6:00-12:00 hours, 12:00-18:00 hours, 18:00-24:00 hours, and 24:00-6:00 hours, and were analyzed by the FLOTAC technique. A circadian rhythm of P. ambiguus egg excretion was found, with significant lower values at 6:00-12:00 hours. In conclusion, the present study showed that the FLOTAC technique is the best copromicroscopic method for assessing P. ambiguus prevalence and intensity in rabbits and that the afternoon and evening hours are the best times for fecal sampling to perform the pinworm diagnosis.

The responses of a tropical breed of domestic rabbit, Oryctolagus cuniculus, to experimental infection with Trichostrongylus colubriformis

Clinical, parasitological and pathological responses of a tropical out-bred domestic rabbit to experimental Trichostrongylus colubriformis infection were used to evaluate its suitability as a laboratory host and model for studying the host–parasite relationships of T. colubriformis. In the first experiment, three groups each of 16, predominantly juvenile male, 8- to 10-week-old rabbits were given a single pulse infection with 500, 5000 or 25000 infective larvae (L3) of T. colubriformis, to represent low, medium and high levels of infection, respectively. A fourth group of 16 rabbits of similar age formed the uninfected controls. In the second experiment, two groups of 10 juvenile (8- to 10-week-old) and 10 adult (8- to 10-month-old) rabbits were similarly infected with 20000 L3, with appropriate naïve controls. Prepatency was 14 and 16 days and peak faecal egg counts occurred on days 24 and 20 after infection in young and adult rabbits respectively. Peak worm counts occurred on day 14 in both age groups and at all levels of infection. Subsequently, parasite burdens declined in a highly significantly dose- and age-dependent manner. At low and moderate levels of infection, approximately 83–98% of worms were recovered from the first 60 cm of the small intestine. Worm fecundity was also significantly influenced by host age and larval dose. Host age also had a significant effect on worm length. Infections with T. colubriformis were associated with a highly significant loss of body weight, accompanied by anorexia, diarrhoea and 25% mortality at high dose levels during the patent period of infection. There were no significant changes in packed cell volume and eosinophil counts at all ages and levels of infection but significant lymphocytosis occurred at the high dose level between days 7 and 21. Parasite-specific serum IgG responses were not related to worm burden. Overall, data showed that this miniature, docile and relatively inexpensive breed of rabbit is a potentially valuable laboratory host for studying T. colubriformis infections. The larval dose, duration of infection and host age were major determinants of host responsiveness to primary infections in this rabbit genotype.

Taenia spp.: 18S rDNA microsatellites for molecular systematic diagnosis

The 18S rDNA gene of adult worms of Taenia parva found in Genetta genetta in the Iberian Peninsula and larval stages of T. pisiformis from the wild rabbit (Oryctolagus cuniculus) in Tenerife (Canary Islands) were amplified and sequenced. The sequences of the 18S rDNA gene of T. parva (1768 bp) and T. pisiformis (1760 bp) are reported for the first time (GenBank accession nos. AJ555167–AJ555168 and AJ555169–AJ555170, respectively). In 168 alignment positions microsatellites in the 18S rDNA of both taxa were detected for the first time (TGC in T. parva and TGCT in T. pisiformis) and differences in their sequences with different repetition numbers were observed. The use of nucleotide sequences of this gene in the resolution of systematic problems in cestodes is discussed with reference to the systematic status of Taenia spp. and mainly in human taeniids such as T. solium, T. saginata, and Asian human isolates of Taenia.

Immunocytochemistry of Psoroptes cuniculi stained by sera from naive and infested rabbits: preliminary results

Immunocytochemistry was used to identify possible target antigens in the digestive system of Psoroptes cuniculi. Sera from three recently acutely infested rabbits, from rabbits with a mild long lasting infestation, and from a rabbit with repeated mite infestations and no longer able to maintain a population of P. cuniculi were used to determine any antibody specificity to the mite digestive system. The reactivity of these sera was compared with sera from three un-infested animals. The different pool of sera targeted different mite antigens; in particular, sera from the resistant rabbit and the chronically infested rabbits reacted with gut cells, faecal material and cuticle, while sera from the recently infested rabbits reacted with gut contents, faecal material and cuticle of the parasites but not with gut cells. Finally, sera from un-infested rabbits did not demonstrate any specificity to P. cuniculi antigens reacting only with mite gut contents in a weak manner. These preliminary data suggest the presence of antibodies induced in the host blood by infection, which act against the parasite by binding to antigen at the surface of its gut.

[Biochemical changes in rabbits experimentally infected by Trypanosoma evansi]

The purpose of the present paper has been evaluating the biochemical changes in rabbits experimentally infected by Trypanosome evansi. Six male rabbits, separated in two groups, were used with the group A, the control group, being composed by non-infected animals and the group B composed by rodents infected with a T. evansi stump. The animals were maintained at room temperature and they have been analyzed during 120 days through 5 blood collections on days 1, 20, 40, 60 and 120. The biochemical changes observed in the infected rabbits were hyperproteinemia, hyperglobulinemia, increase on the urea levels, and significant decrease on ALT and albumin. The creatinine remained within the normality parameters. The rodents belonging to the group B have shown biochemical changes even after 80 days when the protozoon was not observed in the circulation anymore.

Periurban Trypanosoma cruzi-infected Triatoma infestans, Arequipa, Peru

Simple interventions may facilitate vector control and prevent periurban transmission of Chagas disease.

In Arequipa, Peru, vectorborne transmission of Chagas disease by Triatoma infestans has become an urban problem. We conducted an entomologic survey in a periurban community of Arequipa to identify risk factors for triatomine infestation and determinants of vector population densities. Of 374 households surveyed, triatomines were collected from 194 (52%), and Trypanosoma cruzi–carrying triatomines were collected from 72 (19.3%). Guinea pig pens were more likely than other animal enclosures to be infested and harbored 2.38× as many triatomines. Stacked brick and adobe enclosures were more likely to have triatomines, while wire mesh enclosures were protected against infestation. In human dwellings, only fully stuccoed rooms were protected against infestation. Spatially, households with triatomines were scattered, while households with T. cruzi–infected triatomines were clustered. Keeping small animals in wire mesh cages could facilitate control of T. infestans in this densely populated urban environment.

Enzymatic activity in extracts of allergy-causing astigmatid mites

Many of the previously characterized allergens of house dust mites are known to be proteases, and this enzymatic activity is thought to contribute to their allergenicity. Other astigmatid mites, including stored-product mites and the ectoparasitic itch mite, Sarcoptes scabiei De Geer, are also known to be allergenic, but little or nothing is known about their enzymatic activities. The purpose of this study was to characterize the enzymatic activities present in extracts of the parasitic itch mite and from eight other species of free-living astigmatid mites. Extracts were prepared from one parasitic mite (S. scabiei), five stored-product mites (Chortoglyphus arcuatus (Troupeau), Lepidoglyphus destructor (Schrank), Blomia tropicalis Bronswijk, Cock, Oshima, Tyrophagus putrescentiae (Schrank), and Acarus siro L.), and three house dust mites [Dermatophagoidesfarinae Hughes, Dermatophagoides pteronyssinus (Troussart), and Euroglyphus maynei (Cooreman) ]. ApiZym strips were used to screen for the presence of 19 individual enzyme activities. Digestion of nine other substrates was evaluated by spectrophotometric or electrophoretic methods. All mite extracts exhibited some form of phosphatase, esterase, aminopeptidase, and glycosidase activity, although their substrate specificities varied considerably. Itch mite extract did not possess detectable serine peptidase activity nor was it able to hydrolyze gelatin or casein, whereas all other mite extracts exhibited these activities. Storage mite extracts possessed enzymes capable of degrading the widest range of substrates, whereas itch mite extract had the most limited proteolytic capacity. Extracts of nine species of allergy-causing astigmatid mites contain wide and diverse repertoires of enzymatic activities. These catalytic activities may be important contributors to the induction and manifestation of inflammatory and immune responses to mites in patients.

[Species from genus Eimeria observed in domestic rabbit (Oryctolagus cuniculus) feces raised at the Municipality of Campos dos Goytacazes in the State of Rio de Janeiro, Brazil]

This study was designed to identify species of the genus Eimeria from eleven rabbit meat breeders from Campos dos Goytacazes. Fecal samples were collected from rabbits with different health conditions and consintence of feces. The following species of Eimeria were identified: E. perforans; E. magna; E. coecicola; E. irresidua; E. media; E. flavescens; E. nagpurensis; E. intestinalis, E. exigua and E. stiedae. Parasites from this genus were detected in 81.82% (9) of the rabbit meat production sites, regardless of the management and hygiene conditions. In all cases the infection was always caused from more than one species of Eimeria.

Spermiogenesis and spermatozoon ultrastructure of the cestode Mosgovoyia ctenoides (Cyclophyllidea: Anoplocephalidae), an intestinal parasite of Oryctolagus cuniculus (Lagomorpha: Leporidae)

Ultrastructural characters in spermiogenesis and spermatozoa are considered important tools to elucidate the phylogenetic relationships within the Platyhelminthes. In the Anoplocephalidae, ultrastructural data refer to the spermatozoon of 14 species, whereas data on spermiogenesis refer to only 7 species. The present study focused on the spermiogenesis and spermatozoon of the anoplocephalid cestode Mosgovoyia ctenoides, as revealed by transmission electron microscopy. Type IV spermiogenesis was detected, beginning with the formation of a differentiation zone containing 2 centrioles, with a centriolar adjunct and vestigial striated rootlets. Different forms of the latter character have been described in other anoplocephalids. This study supports spermiogenesis of type IV as the most frequent in the Anoplocephalidae and confirms the presence of a centriolar adjunct in yet another type IV spermiogenesis species. The spermatozoon of M. ctenoides possesses 1 axoneme of the 9+ '1' trepaxonematan type, 2 crestlike bodies, dense plates, and granules of electron-dense cytoplasmic material, nucleus, and twisted cortical microtubules. It was again confirmed that the presence of granular material and the absence of both a periaxonemal sheath and intracytoplasmic walls are constant characters in the spermatozoa of all the Anoplocephalinae.

Blowfly strike prevalence in domestic rabbits in southwest England and Wales

The prevalence of blowfly strike in rabbits in southwest England and Wales was investigated using a retrospective postal survey of small animal and mixed veterinary practices. Questionnaires were sent to 474 practices; 219 were returned completed, giving a response rate of 46.2%. The prevalence of blowfly strike was estimated as the percentage of veterinary practices that reporting having treated at least one rabbit for strike between May and September 2005. Overall, 94.5% (+/-2.21) of practices treated at least one case of rabbit strike. Almost half, 49.3% (+/-11.3) of practices reported treating only 1-5 rabbits for blowfly strike in the study period; 32.8% (+/-4.56), 13% (+/-3.27) and 4.8% (+/-2.08) treated 6-10, 11-15 and more than 15 struck rabbits, respectively. In 46.3% (+/-4.84) of the practices most infested rabbits survived. For 40.4% (+/-4.77) of practices, about half the struck rabbits survived. However, for 13.3% (+/-3.30) of practices most struck rabbits were reported to have died. The practices reporting that most animals died were those that saw significantly fewer rabbits and fewer struck rabbits than practices where more animals survived. This suggests that training and experience in the appropriate care of infested rabbits may be critical in ensuring a favorable outcome.

Evaluation of some coagulation parameters in hepatic coccidiosis experimentally induced with Eimeria stiedai in rabbits

The objective of this study was to evaluate some coagulation parameters in hepatic coccidiosis experimentally induced with Eimeria stiedai in rabbits. Fourteen healthy New Zealand rabbits were equally divided into two groups. One group received no treatment, the other group was orally inoculated with 40 000 sporulated oocysts of E. stiedai in a 1 ml inoculum using a catheter. At day 24 after inoculation, blood samples were collected into sodium citrate-containing tubes to evaluate some coagulation parameters. Although statistically not significant, infected rabbits had prolonged prothrombin time and activated partial thromboplastin time compared with rabbits in the control group. A significant reduction (P < 0.05) was observed in the level of fibrinogen of infected rabbits compared with that of the controls. A slight decrease in thrombocyte counts of infected rabbits was not statistically significant.

Prevalence of Toxoplasma gondii antibodies in rabbits (Oryctolagus cuniculus) from Mexico

Antibodies to Toxoplasma gondii were determined by indirect enzyme-linked immunosorbent assay in serum samples from domestic rabbits from 3 rabbit farms in Mexico. Antibodies to T. gondii were found in 77 (26.9%) of 286 animals. On the farm with the higher rearing standards, the seroprevalence was 18.7%, whereas on the farm with medium standards and another managed by a family, seroprevalence was 39.7 and 33.3%, respectively. This report is the first report concerning the prevalence of antibodies to T. gondii in rabbits from Mexico. Although the prevalence found in the present study is within the range reported for other countries, 2 of the farms revealed a relatively high prevalence, which was probably associated with the presence of cats inside rabbit houses.

In vitro host erythrocyte specificity and differential morphology of Babesia divergens and a zoonotic Babesia sp. from eastern cottontail rabbits (Sylvilagus floridanus)

A Babesia sp. isolated from eastern cottontail rabbits (Sylvilagus floridanus) is morphologically similar and genetically identical, based on SSU rRNA gene comparisons, to 2 agents responsible for human babesiosis in the United States. This zoonotic agent is closely related to the European parasite, Babesia divergens. The 2 organisms were characterized by in vitro comparisons. In vitro growth of the rabbit Babesia sp. was supported in human and cottontail rabbit erythrocytes, but not in bovine cells. Babesia divergens was supported in vitro in bovine and human erythrocytes, but not in cottontail rabbit cells. Morphometric analysis classifies B. divergens as a small babesia in bovine erythrocytes, but the parasite exceeds this size in human erythrocytes. The rabbit Babesia sp. is large, the same size in both human or rabbit erythrocytes, and is significantly larger than B. divergens. Eight or more rabbit Babesia sp. parasites may occur within a single erythrocyte, sometimes in a floret array, unlike B. divergens. The erythrocyte specificity and morphological differences reported in this study agree with previous in vivo results and validate the use of in vitro methods for characterization of Babesia species.

Cryptosporidium infection in juvenile pet rabbits

Cryptosporidium infection was confirmed by fecal examination for the first time in pet rabbits in a wholesale store located in Kanagawa Prefecture, Japan. Fecal samples were obtained postmortem from juvenile rabbits (n=66), which had died after developing diarrhea. Feces from healthy rabbits (n=30) were also collected and examined as controls. Two types of Cryptosporidium oocysts distinctive in size and shape were found (Type A and B). Types A and B oocysts were detected from 16.7% and 13.6% of the diarrheic, and 3.3% and 0% of the normal feces, respectively. Since Cryptosporidium oocysts were detected at a higher rate in the diarrheic rabbits than in the healthy rabbits, special caution should be taken when handling a pet rabbit presenting with diarrhea.

New perspectives on host-parasite interplay by comparative transcriptomic and proteomic analyses of Schistosoma japonicum

Schistosomiasis remains a serious public health problem with an estimated 200 million people infected in 76 countries. Here we isolated ~ 8,400 potential protein-encoding cDNA contigs from Schistosoma japonicum after sequencing circa 84,000 expressed sequence tags. In tandem, we undertook a high-throughput proteomics approach to characterize the protein expression profiles of a number of developmental stages (cercariae, hepatic schistosomula, female and male adults, eggs, and miracidia) and tissues at the host-parasite interface (eggshell and tegument) by interrogating the protein database deduced from the contigs. Comparative analysis of these transcriptomic and proteomic data, the latter including 3,260 proteins with putative identities, revealed differential expression of genes among the various developmental stages and sexes of S. japonicum and localization of putative secretory and membrane antigens, enzymes, and other gene products on the adult tegument and eggshell, many of which displayed genetic polymorphisms. Numerous S. japonicum genes exhibited high levels of identity with those of their mammalian hosts, whereas many others appeared to be conserved only across the genus Schistosoma or Phylum Platyhelminthes. These findings are expected to provide new insights into the pathophysiology of schistosomiasis and for the development of improved interventions for disease control and will facilitate a more fundamental understanding of schistosome biology, evolution, and the host-parasite interplay.

Schistosomiasis remains a major public health problem in the developing world. Schistosoma japonicum, the Oriental blood fluke, causes intestinal schistosomiasis in China and the Philippines. Knowledge of the genome and proteome of this worm should improve understanding of biomedical aspects of schistosomiasis. This study represents the first major attempt to characterize the majority of the expressed genes and proteins of a human blood fluke through rigorous, high-throughput genomic and proteomic methodologies. The findings of this study provide a unique resource of numerous schistosome genes and information on protein profiles of the different developmental stages of S. japonicum. Many of the newly discovered proteins are localized on the surface of the worm and its eggs, and they are likely to be involved in the pathogenesis of schistosomiasis. Furthermore, genetic variants found in many of these new genes likely reflect the ability of this important human pathogen to adapt and respond to environmental pressures and the capacity of the parasite to respond to anti-schistosomal therapies. Comparison of these S. japonicum genes with those from mammals and other organisms will facilitate advances in the understanding of blood fluke biology and evolution.