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Objective To compare the complete mitochondrial genome sequences of two phenotypes of Paragonimus westermani isolated from Fujian Province with different sizes of metacercariae, and perform a phylogenetic analysis of various geographical isolates of P. westermani from Asia, so as to identify the possible genetic characteristics associated with the P. westermani phenotypes. Methods P. westermani metacercariae with different sizes (large metacercariae, 380–420 μm in diameter; small metacercariae, 320–340 μm) isolated from freshwater crabs were used to infect dogs, and the eggs and adult worms of P. westermani were collected from the dog stool samples and lung tissues. Then, the egg size and morphology were compared. In addition, genomic DNA was extracted from the adult worms of the two phenotypes of P. westermani and used for the PCR amplification to yield the complete mitochondrial genome sequence. Sequence structure and phylogenetic analyses were performed based on the complete mitochondrial genome of P. westermani. Results Following infection with large and small P. westermani metacercariae, the adult worms recovered from the dog lung had a thick body, and had oral and ventral suckers. The ventral sucker was located slightly in front of the midline of the body, and testes, ovary and vitelline gland were seen in the adult worms. Following fixation, the adults appeared oval, with an approximately 1.7∶1 of the length-width ratio. The length and width of the eggs isolated from the fecal samples of dogs infected with large and small P. westermani metacercariae varied significantly, and the large metacercariae produced bigger eggs than the smaller metacercariae. Based on the morphological features of adults and eggs and the ITS2 sequences, both phenotypes were identified as P. westermani. The complete mitochondrial genome sequence analysis of adults showed almost consistent sequences in the protein-coding region of the mitochondrial genome of adult worms derived from large and small metacercariae, with a major variation seen in the former non-coding region. Sliding window analysis revealed the most polymorphic region within the ND4 gene across the mitochondrial genome from various geographical isolates of P. westermani, and phylogenetic analysis showed that both phenotypes were clustered into the Chinese branch of P. westermani, which was close to the Japanese branch and distinct from the South/Southeast Asian branch. Conclusions The genetic distance between the phenotypes of P. westermani isolated from Fujian Province is near at a mitochondrial genome level, with no remarkable genetic differentiation seen; however, the mutation and structural changes in the non-coding region may result in the phenotypic variations. In addition, there is a distinct variation of the evolutionary rate in the mitochondrial coding genes, suggesting the selection of appropriate molecular markers during the phylogenic researches.
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Exosomes are tiny vesicles secreted by most endogenous cells, and the extracellular vesicles (EVs) are specifically secreted by cells. Recently, it was found that exosomes contain a large quantity of important substances such as proteins, nucleic acids, and lipids, which play important roles in material exchange and information transmission in cell-cell communication, and in modulating the immune response, metabolism, and expansion, metastasis, and drug resistance of tumors. This paper summarizes the recent researches on exosomes in parasites and parasitic diseases and hopes to be helpful for improving the researches of parasites and parasitic diseases.
ABSTRACT
Exosomes are tiny vesicles secreted by most endogenous cells, and the extracellular vesicles (EVs) are specifically secreted by cells. Recently, it was found that exosomes contain a large quantity of important substances such as proteins, nucleic acids, and lipids, which play important roles in material exchange and information transmission in cell-cell communication, and in modulating the immune response, metabolism, and expansion, metastasis, and drug resistance of tumors. This paper summarizes the recent researches on exosomes in parasites and parasitic diseases and hopes to be helpful for improving the researches of parasites and parasitic diseases.
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Objective To investigate the infection status of intestinal nematodes and their risk factors in rural residents of Jiangxia District, Wuhan City, so as to provide the reference for the establishment of targeted prevention and control measures. Methods According to the requirements of cross-sectional study of the national human key parasitic diseases, the residents in Shanpo Sub-district, Jiangxia District were randomly selected as the objects for the investigation of the infection status of Ascaris lumbricoides, hookworm and Trichuris trichiura. A questionnaire survey was performed simultaneously. Results Totally 236 residents received the stool tests, and only the hookworm eggs were found, with an infection rate of 7.63% (18 cases). The survey of intestinal parasitic infection status and their risk factors in 600 residents found 397 cases of suspected roundworm infection, 355 cases of suspected hookworm larvae dermatitis, 295 cases of suspected hookworm infection, and 145 cases of suspected whipworm infection, respectively. The Logistic regression analysis found that the risk factors of suspected roundworm infection included not always washing hands after toilet, using manure and fertilizer, and not often wearing shoes when doing farm work; the protective factors included knowing how roundworm infection was gained, and not using fresh dung for fertilization. The risk factors of suspected hookworm infection included using well water and pond water as the source of drinking water, eating food off the ground, using manure and fertilizers, and not washing when there was only one cutting board, and its protective factors included using tap water and well water as drinking water source, knowing how the roundworm infection was gained, and sometimes or not suing fresh feces for fertilization. The risk factors for suspected whipworm infection included eating food off the ground. Conclusions The intestinal parasite prevalence in the residents of the Shanpo Sub-district, Jiangxia District in Wuhan City is relatively high, and some risk factors associated with their infection indeed exist. Therefore, the regional government and health department should strengthen the health education to improve the residents’ knowledge about parasitic diseases and selfprotection awareness. At the same time, the residents should take physical examination regularly and take necessary deworming treatment to effectively control the prevalence and spread of intestinal parasitic diseases.
ABSTRACT
Objective To investigate the infection status of intestinal nematodes and their risk factors in rural residents of Jiangxia District, Wuhan City, so as to provide the reference for the establishment of targeted prevention and control measures. Methods According to the requirements of cross-sectional study of the national human key parasitic diseases, the residents in Shanpo Sub-district, Jiangxia District were randomly selected as the objects for the investigation of the infection status of Ascaris lumbricoides, hookworm and Trichuris trichiura. A questionnaire survey was performed simultaneously. Results Totally 236 residents received the stool tests, and only the hookworm eggs were found, with an infection rate of 7.63% (18 cases). The survey of intestinal parasitic infection status and their risk factors in 600 residents found 397 cases of suspected roundworm infection, 355 cases of suspected hookworm larvae dermatitis, 295 cases of suspected hookworm infection, and 145 cases of suspected whipworm infection, respectively. The Logistic regression analysis found that the risk factors of suspected roundworm infection included not always washing hands after toilet, using manure and fertilizer, and not often wearing shoes when doing farm work; the protective factors included knowing how roundworm infection was gained, and not using fresh dung for fertilization. The risk factors of suspected hookworm infection included using well water and pond water as the source of drinking water, eating food off the ground, using manure and fertilizers, and not washing when there was only one cutting board, and its protective factors included using tap water and well water as drinking water source, knowing how the roundworm infection was gained, and sometimes or not suing fresh feces for fertilization. The risk factors for suspected whipworm infection included eating food off the ground. Conclusions The intestinal parasite prevalence in the residents of the Shanpo Sub-district, Jiangxia District in Wuhan City is relatively high, and some risk factors associated with their infection indeed exist. Therefore, the regional government and health department should strengthen the health education to improve the residents’ knowledge about parasitic diseases and selfprotection awareness. At the same time, the residents should take physical examination regularly and take necessary deworming treatment to effectively control the prevalence and spread of intestinal parasitic diseases.
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Studies on the enzymology of snails are important in the study of molluscicidal mechanism.The alteration of activi-ties of enzymes after molluscicidal treatment was reported in large numbers of papers.This paper reviews the progress of studies on the enzymology of snails under the treatment of molluscicides.
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Objective To investigate the knowledge and practice of residents about schistosomiasis prevention and control in endemic areas of Jingzhou City,Hubei Province after the disease transmission being controlled,so as to provide the valuable in-formation for formulating an efficient health education and intervention strategy.Methods The residents were selected by using the cluster sampling method and investigated with questionnaires in Jiangling County and Gong'an County,Jingzhou City,Hu-bei Province,and the data were analyzed by using the descriptive analysis method,Chi-square tests and logistic regression.Re-sults In a total,826 available questionnaires were obtained with 100% of valid rate.Among them,97.0% of the interviewee knew schistosomiasis,and 86.3% knew that the infection happened by contacting water containing cercariae.The residents in el-der age(41-84 years)had higher awareness rates than the residents in lower age(6-17 years),about the regions of epidemic area(χ 2=57.860),infection route of schistosomiasis(χ 2=87.045),advanced schistosomiasis symptoms(χ 2=27.268)and On-comelania hupensis being as intermediate host(χ 2=55.856)(all P<0.05).The males had higher awareness rates of epidemic areas than the females(χ2=13.442,P<0.05).For personal behavior,36.6% of the interviewee had experience of contacting lake or pond water many times a day,and 66.5% had the willingness to participate in schistosomiasis health education.Conclu-sion In the investigation areas,Jiangling County and Gong'an County,the awareness rates of the residents about schistosomia-sis prevention and control are higher,and we should strengthen the health education and behavior intervention,especially in the students of middle and primary schools to help them have the self-protection ability efficiently.