Field Evaluation of Recombinant Antigen ELISA in Detecting Zoonotic Schistosome Infection Among Water Buffaloes in Endemic Municipalities in the Philippines

In this study, we investigated the use of recombinant antigens thioredoxin peroxidase-1 (rSjTPx-1) and tandem repeat rSj1TR in evaluating the antibody positivity rates of Schistosoma japonicum infection among water buffaloes from four endemic areas in the Philippines, two municipalities with high endemicity (Calatrava, Negros Occidental and Catarman, Northern Samar) and two municipalities nearing elimination with no cases of human schistosomiasis (Talibon and Trinidad, Bohol). These recombinant antigen ELISA assays were compared with other diagnostic tests including SEA-ELISA, FECT, and fecal-based PCR. Results showed that rSj1TR-ELISA has the highest agreement with PCR in all study areas. Furthermore, significant positivity rates among water buffaloes were seen in Talibon and Trinidad, indicating that water buffaloes are maintaining the schistosome parasites in transmission areas even in the absence of human infection. Hence, serological assay using a more sensitive and specific rSj1TR-ELISA can be used for animal surveillance to prevent emergence and re-emergence of human schistosomiasis

The evaluation of control measures against Schistosoma mekongi in Cambodia by a mathematical model

We constructed a mathematical model for the transmission of Schistosoma mekongi in Cambodia. The simulation of the model will be instrumental in planning schistosomiasis control measures. The model includes two definitive hosts, humans and dogs, as animal reservoirs. Dogs are recognized to play an important role in schistosomiasis transmission in Cambodia. For the purpose of dealing with age-specific prevalence and intensity of infection, the human population was classified into eight age categories in the model. To describe the seasonal fluctuation of the intermediate host population of S. mekongi, the "Post-Spate Survival" hypothesis was adopted for the population dynamics of Neotricula aperta present in the Mekong River. We carried out simulations to evaluate the effect of universal treatment (UT) and targeted mass treatment (TT) with praziquantel on the reduction in prevalence of S. mekongi. The simulations indicated that biyearly UT for 8 years or yearly TT for 5 years after three courses of yearly UT could reduce the prevalence to below 5% when a UT or TT coverage of 85% of inhabitants was achieved. The simulation suggested that the suppression of S. mekongi in Cambodia would be possible by UT or TT with a high coverage rate.</p

Analyses of the Expression, Immunohistochemical Properties and Serodiagnostic Potential of Schistosoma japonicum Peroxiredoxin-4

Background Schistosoma japonicum, which inhabits the mesenteric vein of the mammalian hosts for about 20 to 30 years, is subjected to the oxidative stresses from the host defense mechanism during their intra-mammalian stages. To counteract this host immune attack, the parasite utilizes their antioxidant system for survival inside the host. Peroxiredoxins (Prxs), thiol-specific antioxidant proteins, play an essential role for protecting the parasite against oxidative stress by reducing hydrogen peroxide to water. Only three types of 2-Cys Prxs have been previously characterized in S. japonicum whereas a fourth Prx has been identified for Schistosoma mansoni as Prx-4. A sequence coding homologous to this gene in the S. japonicum database was identified, characterized and expressed as recombinant SjPrx-4 protein (rSjPrx-4). Furthermore, rSjPrx-4 was evaluated in this study for its diagnostic potentials in detecting S. japonicum infection in humans. Results The gene found in the parasite genome contained 2 active-site cysteines with conserved sequences in the predicted amino acid (AA) sequence and showed 75% identity with that of the previously characterized Prx (TPx-1) of S. japonicum. The gene was expressed in different stages of schistosome life-cycle with highest transcription level in the adult male. The gene was cloned into a plasmid vector and then transfected into Escherichia coli for expression of rSjPrx-4. Anti-rSjPrx-4 mouse sera recognized native SjPrx-4 in egg and adult worm lysate by western blotting. The result of a mixed function oxidation assay in which rSjPrx-4 prevented the nicking of DNA from hydroxyl radicals confirmed its antioxidant activity. Subsequently, immunolocalization analysis showed the localization of SjPrx-4 inside the egg, on the tegument and in the parenchyma of the adult worm. Enzyme-linked immunosorbent assay results showed that rSjPrx-4 has 83.3% sensitivity and 87.8% specificity. Its diagnostic potential was further evaluated in combination with recombinant SjTPx-1 protein, yielding an improved sensitivity and specificity of 90% and 92.7%, respectively. Conclusions These results suggest that SjPrx-4 plays a role as an antioxidant dealing with oxidative stresses of S. japonicum, and its diagnostic potential improved by coupling it with SjTPx-1 is a proof for developing a serological test with better diagnostic performance for human schistosomiasis

Origin of a novel protein-coding gene family with similar signal sequence in Schistosoma japonicum

BackgroundEvolution of novel protein-coding genes is the bedrock of adaptive evolution. Recently, we identified six protein-coding genes with similar signal sequence from Schistosoma japonicum egg stage mRNA using signal sequence trap (SST). To find the mechanism underlying the origination of these genes with similar core promoter regions and signal sequence, we adopted an integrated approach utilizing whole genome, transcriptome and proteome database BLAST queries, other bioinformatics tools, and molecular analyses.ResultsOur data, in combination with database analyses showed evidences of expression of these genes both at the mRNA and protein levels exclusively in all developmental stages of S. japonicum. The signal sequence motif was identified in 27 distinct S. japonicum UniGene entries with multiple mRNA transcripts, and in 34 genome contigs distributed within 18 scaffolds with evidence of genome-wide dispersion. No homolog of these genes or similar domain was found in deposited data from any other organism. We observed preponderance of flanking repetitive elements (REs), albeit partial copies, especially of the RTE-like and Perere class at either side of the duplication source locus. The role of REs as major mediators of DNA-level recombination leading to dispersive duplication is discussed with evidence from our analyses. We also identified a stepwise pathway towards functional selection in evolving genes by alternative splicing. Equally, the possible transcription models of some protein-coding representatives of the duplicons are presented with evidence of expression in vitro.ConclusionOur findings contribute to the accumulating evidence of the role of REs in the generation of evolutionary novelties in organisms\u27 genomes

Usefulness of Environmental DNA for Surveillance and Control of Schistosomiasis: Detection and Tracking Schistosoma mansoni and Its Intermediate Host Biomphalaria glabrata in Low Endemic Areas of Minas Gerais, Brazil

Poster Session

Analysis of the effectiveness of control measures against Schistosoma mekongi using an intra- and inter-village model in Champasak Province, Lao PDR

Schistosomiasis mekongi is prevalent in the Khong district of Lao PDR, made up of one big island. Khong, and numerous small islands in the Mekong River. Schistosoma mekongi is spread by Neotricula aperta as the intermediate host along the Mekong River. Therefore, even if an epidemic of S. mekongi were stamped out in a certain village, infection may recur if the source of infection is a village located in the upper reaches of the Mekong River. The purpose of this study was to construct a mathematical model for the transmission of S. mekongi among villages from the upper to lower Mekong River to estimate the effect of control measures against it. The chief characteristic of the present model is competence in dealing with the spread of infection among villages through the Mekong River in consideration of the reduction in longevity of cercariae and miracidia and their diffusion in the river. The model also takes into account seasonal fluctuation in the water level of the Mekong River, which affects human behavior in terms of water contact. The results of simulations indicated that the prevalence of schistosomiasis mekongi would be suppressed to a low level for a long time in a village further downstream when universal mass treatment is performed in villages further upstream simultaneously

ナマ シラス ノ セイ ショク ニヨル カンセン ガ ウタガワレタ クジラ フクショクモンジョウチュウ ショウ ノ 1レイ

埼玉県在住の男性・64 歳.2012 年11 月初旬,近医で日本海裂頭条虫症の診断を受け,駆虫目的で本院消化器内科を紹介受診.外来で駆虫治療したところ,全長約250 cm の白色紐状で,全体的に肉厚感のある虫体を排出した.虫体は形態学的特徴より日本海裂頭条虫ではなく,クジラ複殖門条虫が強く疑われたため,遺伝子解析を行った.PCR によって増幅されたcytochrome c oxidase subunit 1 遺伝子(cox1)の全長塩基配列を解析したところ,既知のクジラ複殖門条虫の塩基配列と99%の相同性を示したことから,本症例はクジラ複殖門条虫症と確定した.該当患者は,便に白色紐状物が混入する2&#12316;3 か月前に,生シラスを生食しており,これが感染源となった可能性が高いと考えられた.We have reported a case of infection with whale tapeworm,Diplogonoporus balaenopterae, in Dokkyo MedicalUniversity Hospital. The patient, a 64-year-old Japanesemale, living in Saitama Prefecture was admitted to our hospitalon Nov. 1st 2012, owing to pieces of tapeworm beingdischarged. He was treated with Biltricide&reg; (20 mg/kg)and Magcorol P&reg;( 100 g) in the hospital and he expelled atapeworm about 250 cm, in length along with the scolex afterabout 2 hours of treatment. Based on the morphologicalfeatures of the strobila and the scolex we strongly suspectedthat the tapeworm belongs to the genus Diplogonoporus.To identify the species of the discharged tapeworm, thecomplete cox1 gene was amplified by PCR and the nucleotidesequence was analyzed. The sequence showed 99 %homology against those from D. balaenopterae. From theseresults the patient was diagnosed as a diplogonoporiasiscaused by D. balaenopterae, whale tapeworm. We could notfind any proglottides of tapeworm nor eggs in stools whenwe performed follow up medical examinations three monthsafter treatment. Therefore it can be concluded that the patientwas cured of this disease. In most cases the infectionsource of the whale tapeworm to humans is reported ascoming from marine fish such as sardines and bonitos. Thepatient had frequently consumed various kinds of raw marinefish, and we suspect that the infection source can beattributed to eating raw whitebait

The importance of collecting live fly larvae from a severely decomposed human cadaver in winter. Case report

Abstract: A severely decomposed cadaver was found in a snow-covered mountain forest on January 31, 2010. The cadaver, later identified as a 24-year-old Japanese man, was hanging from under a tree and consisted mainly of skeletal remains. At autopsy, dozens of larvae were observed around the inner cavity of the knee joint, and entomologically they were identified as the third instar larvae of the family Piophilidae (Diptera). It is interesting that the larvae were found alive at the autopsy in January when snow is present. The entomological information supports the information that the man had died around September 8 with the following reason: the location where the victim was found was too cold for the flies to have deposited their eggs; at the man&apos;s death, the ambient temperature was enough high for flies to deposit their eggs; according to the gradual decrease of the ambient temperature, the larvae penetrated into deep lesion with feeding. This is a valuable case demonstrating that live larvae can be obtained from a severely decomposed cadaver found in winter and can support the information about the time of death. This report also validated the importance of collecting Piophilidae flies of severely decomposed cadavers in winter. Key Words: fly larvae, winter, severely decomposed cadaver, forensic entomology, postmortem interval, autopsy. E ntomological information can often be useful in determining both the manner of death (insect activity can sometimes be concentrated around wound sites) and the post mortem interval (PMI) when medical parameters are no longer of value 1) Department of Legal For cadavers with short PMI, detailed information about the species and instars of collected larvae may provide entomological evidence for PMI estimation. Even if the cadavers had been restored for the long time, flies are often observed and provide useful information We report a case in which a victim was found in a snow-covered forest. Although the cadaver consisted mostly of skeletal remains due to postmortem changes, live fly larvae could be collected. As this entomological evidence was well accordance with the information obtained from police investigation, we suggest the importance of collecting live insects even in the severely decomposed cadavers in winter

Diagnostic performance of quantitative Ga-SPECT/CT for patients with lower-limb osteomyelitis

Abstract Background Patients with lower-limb osteomyelitis (LLOM) may experience major adverse events, such as lower-leg amputations or death; therefore, early diagnosis and risk stratification are essential to improve outcomes. Ga-scintigraphy is commonly used for diagnosing inflammatory diseases. Although the diagnostic performance of planar and SPECT imaging for localized lesions is limited, SPECT/CT, which simultaneously acquires functional and anatomical definition, has resulted in significant improvements to diagnostic confidence. While quantitative Ga-SPECT/CT is an emerging approach to improve diagnoses, its diagnostic performance has not been sufficiently evaluated to date. Therefore, this study aimed to evaluate the diagnostic performance of Ga-SPECT/CT with quantitative analyses for patients with LLOM. Methods A total of 103 consecutive patients suspected of LLOM between April 2012 and October 2016 were analyzed. All patients underwent Ga-scintigraphy with SPECT/CT imaging. Findings were assessed visually, with higher than background accumulation considered positive, and quantitatively, using Ga-SPECT/CT images to calculate the lesion-to-background ratio (LBR), the maximum standardized uptake value (SUVmax), and total lesion uptake (TLU). Diagnoses were confirmed using pathological examinations and patient outcomes, and diagnostic performances of planar, SPECT, and SPECT/CT images were compared. To evaluate prognostic performance, all patients were observed for 5 years for occurrences of major adverse events (MAE), defined as recurrence of osteomyelitis, major leg amputation, or fatal event. Multivariate Cox regression was performed to evaluate outcome factors. Results The overall diagnoses indicated that 54 out of 103 patients had LLOM. LBR, SUVmax, and TLU were significantly higher in patients with LLOM (12.23 vs. 1.00, 4.85 vs. 1.34, and 68.77 vs. 8.63, respectively; p < 0.001). Sensitivity and specificity were 91% and 96% for SPECT/CT with LBR, 89% and 94% for SPECT/CT with SUVmax, and 91% and 92% for SPECT/CT with TLU, respectively. MAE occurred in 23 of 54 LLOM patients (43%). TLU was found to be an independent prognostic factor (p = 0.047). Conclusions Ga-SPECT/CT using quantitative parameters, namely LBR and TLU, had better diagnostic and prognostic performances for patients with LLOM compared to conventional imaging. The results suggest that Ga-SPECT/CT is a good alternative for diagnosing LLOM in countries where FDG-PET/CT is not commonly available