Objective: To investigate the efficacy of pomegranate(Punica granatum) peel extract as an alternative treatment on the white laboratory mice against giardiasis.Methods: Experimental animals were divided into five grou...Objective: To investigate the efficacy of pomegranate(Punica granatum) peel extract as an alternative treatment on the white laboratory mice against giardiasis.Methods: Experimental animals were divided into five groups, including Group A:control(infected untreated), Group B: infected and fed with pectin 7 days before infection, Group C: infected and fed with pectin starting from 7th day of infection,Group D: infected and fed with pomegranate peel extract 7 days before infection, and Group E: infected and fed with pomegranate peel extract starting from 7th day of infection.Results: Results from this study revealed that the prevention rate in the experimental groups reached approximately 50% by the 10 th day of using pomegranate peel extract.Moreover, stool cyst counts of groups showed a significant reduction in the shedding of cysts approximately 75.6% by day 20 post-infection. ELISA test showed a reduction in Giardia antigen in the stools of the experimental groups which received pomegranate peel extract. The cure rate of these groups was approximately 97.4% by 28 th day of infection.Conclusions: Our present findings indicated that the pomegranate peel extract proved to be valuable in prevention and treatment of Giardia lamblia infection. Further studies are required to determine the effective dose of pomegranate peel extract against Giardia lamblia infection.展开更多
Objective:To construct rapidly a full-length cDNA library from nanogram amounts total RIMA of Giardia lamblia(G.lamblia) trophozoites stocked in RNA stabilization reagent.Methods:Total RNA of Giardia was extracted usi...Objective:To construct rapidly a full-length cDNA library from nanogram amounts total RIMA of Giardia lamblia(G.lamblia) trophozoites stocked in RNA stabilization reagent.Methods:Total RNA of Giardia was extracted using Trizol reagent.A full-length cDNA library of G.lamblia trophozoites was constructed by a long-distance PCR(LD-PCR) method.The recombinant rate and the coverage rate of full-length clones of the library were evaluated.The inserted fragments were identified and sequenced by PCR amplification.Results:The titer of cDNA library was 3.85×10~7 pfu/mL.The length of inserted fragments ranged from 0.4 to 2.5 kb,and the recombination efficiency accounted for 100%(20/20).The coverage rate of full-length clones is high(17/20). Conclusions:The RNA stabilization reagent may be used to fix the cells and prevent the RNA in cells even though delivered under normal atmospheric temperature.The long-distance PCR can be used to construct a full-length cDNA library rapidly and it needs less RNA than the traditional method from mRNA.展开更多
Objective:To compare the genotype frequencies of HLA class-ⅡDRB1 alleles in Giardia(G.)lamblia-infected children.Methods:A total of 490 Egyptian children aged 2-16 years were subjected to microscopic stool examinatio...Objective:To compare the genotype frequencies of HLA class-ⅡDRB1 alleles in Giardia(G.)lamblia-infected children.Methods:A total of 490 Egyptian children aged 2-16 years were subjected to microscopic stool examination to detect G.lamblia infection,and to exclude other intestinal pathogens.On the basis of their microscopic findings,a group of 80 children were chosen as giardiasis cases,another 80 children were confirmed as Giardia free control group by immunochromatographic test,and the remaining children were excluded.Both giardiasis and control groups were then subjected to blood examination to identify their genetic type of HLA-DRB1 alleles.Results:HLA class-ⅡDRB1*03:01 and DRB1*13:01 alleles were significantly associated with G.lamblia infection(P<0.001 for each variable).On the other hand,HLA class-ⅡDRB1*04:02,DRB1*10:01,DRB1*14:01 and DRB1*15:01 alleles were significantly demonstrated in Giardia free children.However,other HLA-DRB1 alleles did not show any significant association with giardiasis.Conclusions:HLA class-ⅡDRB1*03,DRB1*13,DRB1*04,DRB1*10,DRB1*14 and DRB1*15 alleles may be involved in the establishment of host immune response to G.lamblia infection.展开更多
Objective: To investigate the efficacy of (Commiphora molmol(Myrrh)) extract as alternative treatment in hamsters against giardiasis. This study was conducted to evaluate the effect of the new compound (Commiphora mol...Objective: To investigate the efficacy of (Commiphora molmol(Myrrh)) extract as alternative treatment in hamsters against giardiasis. This study was conducted to evaluate the effect of the new compound (Commiphora molmol(Myrrh)), as agent a natural product extracted from the roots of Zingiber officinal, on Giardia lamblia infection as anti-protozoal and to study the parasitological and Histopathological impact of this treatment on the duodenal mucosa of infected hamsters. Fifty hamsters were divided into five groups: Group (A): normal control. Group (B): Giardia lamblia infected and untreated hamsters served as control. Group (C): infected with Giardia lamblia and treated with metronidazole in dose (120 μg/kg body weight twice daily for 7 successive days). Group (D) Giardia lamblia infected and orally treated with Myrrh (500 mg/Kg for 1 week). Group (E): Giardia lamblia infected and orally treated with combination 1/3 dose of (120 μg/kg body weight) metronidazole and Myrrh (250 mg/Kg) for 1 week). After 2 weeks of the treatment, hamsters were sacrificed. The highest percentages of reduction in the number of Giardia lamblia cysts and trophozoites were in the group receiving combined metronidazole and myrrh. Histopathological examination revealed complete healing of intestinal mucosa after the combined treatment, while partial healing of the lining epithelium of the intestine was noticed after metronidazole and either myrrh plant treatment.展开更多
The prevalence of two gastrointestinal parasites the Entamoeba histolytica and Giardia lamblia parasites and their impact on some blood parameters, i.e. packed cell volume (PCV), hemoglobin (Hb%) and total protein (TP...The prevalence of two gastrointestinal parasites the Entamoeba histolytica and Giardia lamblia parasites and their impact on some blood parameters, i.e. packed cell volume (PCV), hemoglobin (Hb%) and total protein (TP) of a total 780 patients (children and adults) admitted to Samarra General Hospital were assessed. Samples of fresh feces were collected in normal physiological saline and examined using Olympic microscopes. The frequency of the parasite E. histolytica was 12.8% (46.3% male and 53.6% female). The highest frequency of infection of E. histolytica (13.8%) was found at age group (1 - 5 years old) followed by <1 year old children while the lowest (7.4%) was at ages (>41 years old). The highest rate of infection (33.9%) was found in September and the lowest (2.2%) in January. Similarly, the general infection frequency of the parasite G. lamblia was 3.9% with the highest rate at ages 1 - 20 years old and the lowest rate was 7.3% for >50 years old. The monthly, highest rate of infection (5.2%) was in August and least (2.2%) in January (2.2%). The frequency of total protein (TPD) in the blood relevant to the presence of parasite E. histolytica and G. lamblia was 4.6% and 1%, respectively. It is concluded that the above two parasites are the most common gastrointestinal parasite in Iraq whose pathogenesis to be which is likely to escalate during the summer seasons and at low hygienic services environment. There has been an irrelevance neither to anemia nor total protein deficiency. It is recommended that Ministry of Health in Iraq should not share the global idea of defining the giardiasis as a neglected disease.展开更多
AIM: To evaluate whether a higher prevalence of Giardia lamblia infection is associated with an increase in irritable bowel syndrome (IBS) prescriptions at the county level in Michigan. METHODS: The Michigan Disease S...AIM: To evaluate whether a higher prevalence of Giardia lamblia infection is associated with an increase in irritable bowel syndrome (IBS) prescriptions at the county level in Michigan. METHODS: The Michigan Disease Surveillance System (MDSS) was used to ascertain both the numbers of Giardia lamblia infections as well as the total number of foodborne illnesses per population by county in Michigan during 2005. This was compared with Blue Cross Blue Shield (BCBS) of Michigan numbers of drug prescriptions for IBS per one thousand members per county in 2005. These data were also analyzed for associations with per capita income by county and the number of refugees entering each county in 2005. RESULTS: There were a total of 786 confirmed cases of Giardia lamblia reported to MDSS in 2005. During the same time period, the number of prescriptions for IBS varied from 0.5 per 1000 members up to 6.0 per 1000 members per month. There was no trend towards higher numbers of IBS prescriptions in the counties with more Giardia lamblia infections. Per capita income was not associated with either IBS prescriptions or Giardiasis. There was a significant linear association between the number of refugees entering each county, and the number of Giardia lamblia cases per 100 000 population. CONCLUSION: In this ecological study, there was no association found between BCBS prescriptions for IBS and Giardia lamblia infections in Michigan counties. Our findings may have been influenced by the disparate number of refugees admitted per county.展开更多
The genes encoding type II DNA topoisomerases were investigated in Giardia lamblia genome, and a type IIA gene,GlTop 2 was identified. It is a single copy gene with a 4476 bp long ORF without intron. The deduced amino...The genes encoding type II DNA topoisomerases were investigated in Giardia lamblia genome, and a type IIA gene,GlTop 2 was identified. It is a single copy gene with a 4476 bp long ORF without intron. The deduced amino acid sequence shows strong homology to eukaryotic DNA Top 2. However, some distortions were found, such as six insertions in the ATPase domain and the central domain, a -100 aa longer central domain; a ~200 aa shorter C-terminal domain containing rich charged residues. These features revealed by comparing with Top 2 of the host, human, might be helpful in exploiting drug selectivity for antigiardial therapy. Phylogenetic analysis of eukaryotic enzymes showed that kinetoplastids, plants, fungi, and animals were monophyletic groups, and the animal and fungi lineages shared a more recent common ancestor than either did with the plant lineage; microsporidia grouped with fungi. However, unlike many previous phylogenetic analyses, the ''amitochondriate'' G. lamblia was not the earliest branch but diverged after mitochondriate kinetoplastids in our trees. Both the finding of typical eukaryotic type IIA topoisomerase and the phylogenetic analysis suggest G, lamblia is not possibly as primitive as was regarded before and might diverge after the acquisition of mitochondria. This is consistent with the recent discovery of mitochondrial remnant organelles in G. lamblia.展开更多
The nuclear matrix of diplomonad Giardia lamblia was detected for the first time with DGD embedmentsectioning- embedment free electron microscopy after a series of specific extractions. The result showed that archaezo...The nuclear matrix of diplomonad Giardia lamblia was detected for the first time with DGD embedmentsectioning- embedment free electron microscopy after a series of specific extractions. The result showed that archaezoa Giardia lamblia already possessed nuclear matrix within its two nuclei. The finest fibrils of the nuclear matrix of Giardia lamblia were measured to be about 11 to 13 nm in thickness. However, the nuclear lamina and nucleolus have never been observed. These results seem to suggest that nuclear matrix is an indispensable intranuclear structural component even in the primitive nucleus.展开更多
Background:Access to clean and safe drinking water that is free from pathogenic protozoan parasites,especially Cryptosporidium parvum and Giardia lamblia that cause gastrointestinal illness in humans,is still an issue...Background:Access to clean and safe drinking water that is free from pathogenic protozoan parasites,especially Cryptosporidium parvum and Giardia lamblia that cause gastrointestinal illness in humans,is still an issue in Southeast Asia(SEA).This study is the first attempt to detect the aforementioned protozoan parasites in water samples from countries in SEA,using real-time polymerase chain reaction(qPCR)assays.Methods:A total of 221 water samples of 10 l each were collected between April and October 2013 from Malaysia(53),Thailand(120),the Philippines(33),and Vietnam(15).A physicochemical analysis was conducted.The water samples were processed in accordance with the US Environmental Protection Agency’s methods 1622/1623.1,microscopically observed and subsequently screened using qPCR assays.Results:Cryptosporidium oocysts were detected in treated water samples from the Philippines(1/10),with a concentration of 0.06±0.19 oocyst/L,and untreated water samples from Thailand(25/93),Malaysia(17/44),and the Philippines(11/23),with concentrations ranging from 0.13±0.18 to 0.57±1.41 oocyst/L.Giardia cysts were found in treated water samples from the Philippines(1/10),with a concentration of 0.02±0.06 cyst/L,and in untreated water samples from Thailand(20/93),Vietnam(5/10),Malaysia(22/44),and the Philippines(16/23),with concentrations ranging from 0.12±0.3 to 8.90±19.65 cyst/L.The pathogens C.parvum and G.lamblia were detected using using qPCR assays by targeting the 138-bp fragment and the small subunit gene,respectively.C.parvum was detected in untreated water samples from the Philippines(1/23)and Malaysia(2/44),whilst,G.lamblia detected was detected in treated water samples from the Philippines(1/10)and in untreated water samples from Thailand(21/93),Malaysia(12/44),and the Philippines(17/23).Nitrate concentration was found to have a high positive correlation with(oo)cyst(0.993).Conclusion:The presence of(oo)cysts in the water samples means that there is potential risk for zoonotic disease transmission in the studied countries.Detection using qPCR is feasible for quantifying both pathogenic C.parvum and G.lamblia in large water samples.展开更多
Rapid and sensitive pathogen detection methods are essential for the effective functioning of the water treatment industry, yet for many pathogens, effective detection and removal methods are still lacking. Cryptospor...Rapid and sensitive pathogen detection methods are essential for the effective functioning of the water treatment industry, yet for many pathogens, effective detection and removal methods are still lacking. Cryptosporidium parvum oocysts and Giardia lamblia cysts are two of the most common waterborne pathogens currently infecting the water supply. In this study, a new method was developed for the detection of Cryptosporidium parvum oocysts and Giardia lamblia cysts. The method includes multi-steps as coagulation concentration of （oo）cysts in water, the dissolution of the resulting flocs into a small volume using acid, filtration of the （oo）cysts solution, and DNA extraction, purification, and examination using real-time PCR. The method was tested using spiked tap water and reservoir water as references, and the mean recovery ranged from 19.6% to 97.6% for oocysts, and from 51.4% to 98.7% for cysts. The method is economical and convenient, and is especially suitable for relatively high turbidity surface water.展开更多
From a specialized cDNA library, four novel box H/ACA snoRNAs, named GLsR22, GLsR23, GLsR24 and GLsR25, were identified from the primitive eukaryote, Giardia lamblia. Bioinformat- ics analyses indicated that all of th...From a specialized cDNA library, four novel box H/ACA snoRNAs, named GLsR22, GLsR23, GLsR24 and GLsR25, were identified from the primitive eukaryote, Giardia lamblia. Bioinformat- ics analyses indicated that all of them can be poten- tially folded into double hairpins, the typical secon- dary structures of box H/ACA snoRNAs. GLsR24 and GLsR25 are predicted to guide the site-specific pseudouridylation at U1753 and U2396 on 23S rRNA, respectively, while GLsR22 and GLsR23 belong to the family of “orphan” snoRNAs. All of the four novel snoRNAs are encoded by single copy genes and located in small intergenic regions. Interestingly, compared with the counterparts previously reported in Archaea and other unicellular protozoan, the box H/ACA snoRNAs identified from G. lamblia have unique structural features, implying that snoRNAs evolved from prokaryotes to eukaryotes in different ways.展开更多
目的了解皖浙两省部分城镇地区宠物犬蓝氏贾第鞭毛虫和隐孢子虫感染情况,及聚集体类型或虫种。方法在安徽多地和浙江杭州共采集315份新鲜宠物犬粪样,分别采用基于蓝氏贾第鞭毛虫谷氨酸脱氢酶(GDH)基因的半巢式PCR和隐孢子虫核糖体小亚基...目的了解皖浙两省部分城镇地区宠物犬蓝氏贾第鞭毛虫和隐孢子虫感染情况,及聚集体类型或虫种。方法在安徽多地和浙江杭州共采集315份新鲜宠物犬粪样,分别采用基于蓝氏贾第鞭毛虫谷氨酸脱氢酶(GDH)基因的半巢式PCR和隐孢子虫核糖体小亚基(SSU r RNA)基因的巢式PCR方法对所有粪样进行扩增,并对获得的阳性扩增产物进行测序和生物信息学分析,确定蓝氏贾第鞭毛虫的聚集体和隐孢子虫的虫种类型。结果 315份犬粪样中,蓝氏贾第鞭毛虫和隐孢子虫的阳性率分别为3.2%(10/315)和1.6%(5/315)。幼龄犬(≤12个月)蓝氏贾第鞭毛虫阳性率(17.8%)和隐孢子虫阳性率(11.1%)均显著高于成年犬(0.7%和0)(P<0.05)。雌性犬和雄性犬蓝氏贾第鞭毛虫和隐孢子虫阳性率差异均无统计学意义(P>0.05)。发现蓝氏贾第鞭毛虫两种聚集体类型,即聚集体B(n=6)和聚集体D(n=4)。从5份阳性犬粪中分离的隐孢子虫经巢式PCR SSU r RNA基因检测,均为犬隐孢子虫(Cryptosporidium canis)。结论皖浙两省部分地区宠物犬蓝氏贾第鞭毛虫和犬隐孢子虫的阳性率分别为3.2%和1.6%。发现的蓝氏贾第鞭毛虫聚集体类型为聚集体B和聚集体D。展开更多
文摘Objective: To investigate the efficacy of pomegranate(Punica granatum) peel extract as an alternative treatment on the white laboratory mice against giardiasis.Methods: Experimental animals were divided into five groups, including Group A:control(infected untreated), Group B: infected and fed with pectin 7 days before infection, Group C: infected and fed with pectin starting from 7th day of infection,Group D: infected and fed with pomegranate peel extract 7 days before infection, and Group E: infected and fed with pomegranate peel extract starting from 7th day of infection.Results: Results from this study revealed that the prevention rate in the experimental groups reached approximately 50% by the 10 th day of using pomegranate peel extract.Moreover, stool cyst counts of groups showed a significant reduction in the shedding of cysts approximately 75.6% by day 20 post-infection. ELISA test showed a reduction in Giardia antigen in the stools of the experimental groups which received pomegranate peel extract. The cure rate of these groups was approximately 97.4% by 28 th day of infection.Conclusions: Our present findings indicated that the pomegranate peel extract proved to be valuable in prevention and treatment of Giardia lamblia infection. Further studies are required to determine the effective dose of pomegranate peel extract against Giardia lamblia infection.
基金supported by grants from the Education Department of Jilin Province(2010D532)the open grant from the State Key Laboratory of Genetic Resources and Evolution,Kunming Institute of Zoology(GREKF08-07)+2 种基金Natural Grant of Jilin City(201032243)Natural Foundation of Hainan Province of China(310043 and 811197)Key Project of Hainan Provincial Bureau of Health(No2010-41)
文摘Objective:To construct rapidly a full-length cDNA library from nanogram amounts total RIMA of Giardia lamblia(G.lamblia) trophozoites stocked in RNA stabilization reagent.Methods:Total RNA of Giardia was extracted using Trizol reagent.A full-length cDNA library of G.lamblia trophozoites was constructed by a long-distance PCR(LD-PCR) method.The recombinant rate and the coverage rate of full-length clones of the library were evaluated.The inserted fragments were identified and sequenced by PCR amplification.Results:The titer of cDNA library was 3.85×10~7 pfu/mL.The length of inserted fragments ranged from 0.4 to 2.5 kb,and the recombination efficiency accounted for 100%(20/20).The coverage rate of full-length clones is high(17/20). Conclusions:The RNA stabilization reagent may be used to fix the cells and prevent the RNA in cells even though delivered under normal atmospheric temperature.The long-distance PCR can be used to construct a full-length cDNA library rapidly and it needs less RNA than the traditional method from mRNA.
文摘Objective:To compare the genotype frequencies of HLA class-ⅡDRB1 alleles in Giardia(G.)lamblia-infected children.Methods:A total of 490 Egyptian children aged 2-16 years were subjected to microscopic stool examination to detect G.lamblia infection,and to exclude other intestinal pathogens.On the basis of their microscopic findings,a group of 80 children were chosen as giardiasis cases,another 80 children were confirmed as Giardia free control group by immunochromatographic test,and the remaining children were excluded.Both giardiasis and control groups were then subjected to blood examination to identify their genetic type of HLA-DRB1 alleles.Results:HLA class-ⅡDRB1*03:01 and DRB1*13:01 alleles were significantly associated with G.lamblia infection(P<0.001 for each variable).On the other hand,HLA class-ⅡDRB1*04:02,DRB1*10:01,DRB1*14:01 and DRB1*15:01 alleles were significantly demonstrated in Giardia free children.However,other HLA-DRB1 alleles did not show any significant association with giardiasis.Conclusions:HLA class-ⅡDRB1*03,DRB1*13,DRB1*04,DRB1*10,DRB1*14 and DRB1*15 alleles may be involved in the establishment of host immune response to G.lamblia infection.
文摘Objective: To investigate the efficacy of (Commiphora molmol(Myrrh)) extract as alternative treatment in hamsters against giardiasis. This study was conducted to evaluate the effect of the new compound (Commiphora molmol(Myrrh)), as agent a natural product extracted from the roots of Zingiber officinal, on Giardia lamblia infection as anti-protozoal and to study the parasitological and Histopathological impact of this treatment on the duodenal mucosa of infected hamsters. Fifty hamsters were divided into five groups: Group (A): normal control. Group (B): Giardia lamblia infected and untreated hamsters served as control. Group (C): infected with Giardia lamblia and treated with metronidazole in dose (120 μg/kg body weight twice daily for 7 successive days). Group (D) Giardia lamblia infected and orally treated with Myrrh (500 mg/Kg for 1 week). Group (E): Giardia lamblia infected and orally treated with combination 1/3 dose of (120 μg/kg body weight) metronidazole and Myrrh (250 mg/Kg) for 1 week). After 2 weeks of the treatment, hamsters were sacrificed. The highest percentages of reduction in the number of Giardia lamblia cysts and trophozoites were in the group receiving combined metronidazole and myrrh. Histopathological examination revealed complete healing of intestinal mucosa after the combined treatment, while partial healing of the lining epithelium of the intestine was noticed after metronidazole and either myrrh plant treatment.
文摘The prevalence of two gastrointestinal parasites the Entamoeba histolytica and Giardia lamblia parasites and their impact on some blood parameters, i.e. packed cell volume (PCV), hemoglobin (Hb%) and total protein (TP) of a total 780 patients (children and adults) admitted to Samarra General Hospital were assessed. Samples of fresh feces were collected in normal physiological saline and examined using Olympic microscopes. The frequency of the parasite E. histolytica was 12.8% (46.3% male and 53.6% female). The highest frequency of infection of E. histolytica (13.8%) was found at age group (1 - 5 years old) followed by <1 year old children while the lowest (7.4%) was at ages (>41 years old). The highest rate of infection (33.9%) was found in September and the lowest (2.2%) in January. Similarly, the general infection frequency of the parasite G. lamblia was 3.9% with the highest rate at ages 1 - 20 years old and the lowest rate was 7.3% for >50 years old. The monthly, highest rate of infection (5.2%) was in August and least (2.2%) in January (2.2%). The frequency of total protein (TPD) in the blood relevant to the presence of parasite E. histolytica and G. lamblia was 4.6% and 1%, respectively. It is concluded that the above two parasites are the most common gastrointestinal parasite in Iraq whose pathogenesis to be which is likely to escalate during the summer seasons and at low hygienic services environment. There has been an irrelevance neither to anemia nor total protein deficiency. It is recommended that Ministry of Health in Iraq should not share the global idea of defining the giardiasis as a neglected disease.
文摘AIM: To evaluate whether a higher prevalence of Giardia lamblia infection is associated with an increase in irritable bowel syndrome (IBS) prescriptions at the county level in Michigan. METHODS: The Michigan Disease Surveillance System (MDSS) was used to ascertain both the numbers of Giardia lamblia infections as well as the total number of foodborne illnesses per population by county in Michigan during 2005. This was compared with Blue Cross Blue Shield (BCBS) of Michigan numbers of drug prescriptions for IBS per one thousand members per county in 2005. These data were also analyzed for associations with per capita income by county and the number of refugees entering each county in 2005. RESULTS: There were a total of 786 confirmed cases of Giardia lamblia reported to MDSS in 2005. During the same time period, the number of prescriptions for IBS varied from 0.5 per 1000 members up to 6.0 per 1000 members per month. There was no trend towards higher numbers of IBS prescriptions in the counties with more Giardia lamblia infections. Per capita income was not associated with either IBS prescriptions or Giardiasis. There was a significant linear association between the number of refugees entering each county, and the number of Giardia lamblia cases per 100 000 population. CONCLUSION: In this ecological study, there was no association found between BCBS prescriptions for IBS and Giardia lamblia infections in Michigan counties. Our findings may have been influenced by the disparate number of refugees admitted per county.
基金supported by Grants (30070362, 30170135,30021004) the National Natural Science Foundationof China and Grants (KSCX2-SW-101C, STZ-00-23)the Chinese Academy of Sciences.
文摘The genes encoding type II DNA topoisomerases were investigated in Giardia lamblia genome, and a type IIA gene,GlTop 2 was identified. It is a single copy gene with a 4476 bp long ORF without intron. The deduced amino acid sequence shows strong homology to eukaryotic DNA Top 2. However, some distortions were found, such as six insertions in the ATPase domain and the central domain, a -100 aa longer central domain; a ~200 aa shorter C-terminal domain containing rich charged residues. These features revealed by comparing with Top 2 of the host, human, might be helpful in exploiting drug selectivity for antigiardial therapy. Phylogenetic analysis of eukaryotic enzymes showed that kinetoplastids, plants, fungi, and animals were monophyletic groups, and the animal and fungi lineages shared a more recent common ancestor than either did with the plant lineage; microsporidia grouped with fungi. However, unlike many previous phylogenetic analyses, the ''amitochondriate'' G. lamblia was not the earliest branch but diverged after mitochondriate kinetoplastids in our trees. Both the finding of typical eukaryotic type IIA topoisomerase and the phylogenetic analysis suggest G, lamblia is not possibly as primitive as was regarded before and might diverge after the acquisition of mitochondria. This is consistent with the recent discovery of mitochondrial remnant organelles in G. lamblia.
文摘The nuclear matrix of diplomonad Giardia lamblia was detected for the first time with DGD embedmentsectioning- embedment free electron microscopy after a series of specific extractions. The result showed that archaezoa Giardia lamblia already possessed nuclear matrix within its two nuclei. The finest fibrils of the nuclear matrix of Giardia lamblia were measured to be about 11 to 13 nm in thickness. However, the nuclear lamina and nucleolus have never been observed. These results seem to suggest that nuclear matrix is an indispensable intranuclear structural component even in the primitive nucleus.
基金study was supported by the University of Malaya High Impact Research Grant(UM.C/625/1/HIR/MoHE/MED/23 and UM.0000041/HIR.C3)from the Ministry of Higher Education,Malaysia+1 种基金postgraduate research grants(PV 049/2011B and PV 014/2012A)University Malaya Research Grants(UMRG 544/14HTM and UMRG 362/15AFR).
文摘Background:Access to clean and safe drinking water that is free from pathogenic protozoan parasites,especially Cryptosporidium parvum and Giardia lamblia that cause gastrointestinal illness in humans,is still an issue in Southeast Asia(SEA).This study is the first attempt to detect the aforementioned protozoan parasites in water samples from countries in SEA,using real-time polymerase chain reaction(qPCR)assays.Methods:A total of 221 water samples of 10 l each were collected between April and October 2013 from Malaysia(53),Thailand(120),the Philippines(33),and Vietnam(15).A physicochemical analysis was conducted.The water samples were processed in accordance with the US Environmental Protection Agency’s methods 1622/1623.1,microscopically observed and subsequently screened using qPCR assays.Results:Cryptosporidium oocysts were detected in treated water samples from the Philippines(1/10),with a concentration of 0.06±0.19 oocyst/L,and untreated water samples from Thailand(25/93),Malaysia(17/44),and the Philippines(11/23),with concentrations ranging from 0.13±0.18 to 0.57±1.41 oocyst/L.Giardia cysts were found in treated water samples from the Philippines(1/10),with a concentration of 0.02±0.06 cyst/L,and in untreated water samples from Thailand(20/93),Vietnam(5/10),Malaysia(22/44),and the Philippines(16/23),with concentrations ranging from 0.12±0.3 to 8.90±19.65 cyst/L.The pathogens C.parvum and G.lamblia were detected using using qPCR assays by targeting the 138-bp fragment and the small subunit gene,respectively.C.parvum was detected in untreated water samples from the Philippines(1/23)and Malaysia(2/44),whilst,G.lamblia detected was detected in treated water samples from the Philippines(1/10)and in untreated water samples from Thailand(21/93),Malaysia(12/44),and the Philippines(17/23).Nitrate concentration was found to have a high positive correlation with(oo)cyst(0.993).Conclusion:The presence of(oo)cysts in the water samples means that there is potential risk for zoonotic disease transmission in the studied countries.Detection using qPCR is feasible for quantifying both pathogenic C.parvum and G.lamblia in large water samples.
文摘Rapid and sensitive pathogen detection methods are essential for the effective functioning of the water treatment industry, yet for many pathogens, effective detection and removal methods are still lacking. Cryptosporidium parvum oocysts and Giardia lamblia cysts are two of the most common waterborne pathogens currently infecting the water supply. In this study, a new method was developed for the detection of Cryptosporidium parvum oocysts and Giardia lamblia cysts. The method includes multi-steps as coagulation concentration of （oo）cysts in water, the dissolution of the resulting flocs into a small volume using acid, filtration of the （oo）cysts solution, and DNA extraction, purification, and examination using real-time PCR. The method was tested using spiked tap water and reservoir water as references, and the mean recovery ranged from 19.6% to 97.6% for oocysts, and from 51.4% to 98.7% for cysts. The method is economical and convenient, and is especially suitable for relatively high turbidity surface water.
基金the National Natural Science Foundation of China （Grant Nos. 30230200 ＆ 30370328） the funds from the Ministry of Education of China and Natural Science Foundation of Guangdong Province （Grant No. IRT0447, NSF-05200303） the National Basic Research Program （Grant No. 2005CB724600）.
文摘From a specialized cDNA library, four novel box H/ACA snoRNAs, named GLsR22, GLsR23, GLsR24 and GLsR25, were identified from the primitive eukaryote, Giardia lamblia. Bioinformat- ics analyses indicated that all of them can be poten- tially folded into double hairpins, the typical secon- dary structures of box H/ACA snoRNAs. GLsR24 and GLsR25 are predicted to guide the site-specific pseudouridylation at U1753 and U2396 on 23S rRNA, respectively, while GLsR22 and GLsR23 belong to the family of “orphan” snoRNAs. All of the four novel snoRNAs are encoded by single copy genes and located in small intergenic regions. Interestingly, compared with the counterparts previously reported in Archaea and other unicellular protozoan, the box H/ACA snoRNAs identified from G. lamblia have unique structural features, implying that snoRNAs evolved from prokaryotes to eukaryotes in different ways.
基金This work was supported by grants from the State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences （No. GREKF08-07）, the National Natural Science Foundation of China （No. 81301450） and the Jilin Provincial Science and Technology Department of China （No. 20130413035GH）
文摘目的了解皖浙两省部分城镇地区宠物犬蓝氏贾第鞭毛虫和隐孢子虫感染情况,及聚集体类型或虫种。方法在安徽多地和浙江杭州共采集315份新鲜宠物犬粪样,分别采用基于蓝氏贾第鞭毛虫谷氨酸脱氢酶(GDH)基因的半巢式PCR和隐孢子虫核糖体小亚基(SSU r RNA)基因的巢式PCR方法对所有粪样进行扩增,并对获得的阳性扩增产物进行测序和生物信息学分析,确定蓝氏贾第鞭毛虫的聚集体和隐孢子虫的虫种类型。结果 315份犬粪样中,蓝氏贾第鞭毛虫和隐孢子虫的阳性率分别为3.2%(10/315)和1.6%(5/315)。幼龄犬(≤12个月)蓝氏贾第鞭毛虫阳性率(17.8%)和隐孢子虫阳性率(11.1%)均显著高于成年犬(0.7%和0)(P<0.05)。雌性犬和雄性犬蓝氏贾第鞭毛虫和隐孢子虫阳性率差异均无统计学意义(P>0.05)。发现蓝氏贾第鞭毛虫两种聚集体类型,即聚集体B(n=6)和聚集体D(n=4)。从5份阳性犬粪中分离的隐孢子虫经巢式PCR SSU r RNA基因检测,均为犬隐孢子虫(Cryptosporidium canis)。结论皖浙两省部分地区宠物犬蓝氏贾第鞭毛虫和犬隐孢子虫的阳性率分别为3.2%和1.6%。发现的蓝氏贾第鞭毛虫聚集体类型为聚集体B和聚集体D。
