AIM: To provide scientific evidence for prevention and controlling of cryptosporidiosis, the infection of Cryptosporidium parvum and its epidemiological characteristics were studied in some areas of Anhui Province. ME...AIM: To provide scientific evidence for prevention and controlling of cryptosporidiosis, the infection of Cryptosporidium parvum and its epidemiological characteristics were studied in some areas of Anhui Province. METHODS: The oocyst of Cryptosporidium parvum in 5421 fresh stool samples from eleven areas of Anhui Province was tested by auramine-phenol stain and improved anti-acid stain respectively. The specific antibody of IgG, IgM and T subsets of 41 patients with positive Cryptosporidium parvum in stools were detected by ELISA and biotin-streptavidin (BSA) respectively. RESULTS: The total infective rate of Cryptosporidium parvum was 1.33% (74/5421). Among them, the positive rates of oocyst in the areas of Huaibei (1.82%) and Fuyang (1.80%) were higher. The positive rates of oocyst in stools of infants, pupils, middle school students, college students, adults, patients with diarrhea, and those with immunodeficiency were 3.15%(28/889), 0.82% (9/1098), 0.82%(9/1092), 0.83%(8/969), 0.85% (9/1095), 2.88%(8/278) and 8.33%(3/36)% respectively. The positive rates of oocyst in infants and the patients with diarrhea and immunodeficiency were significantly higher than those in controls (P【0.01). The positive rate of oocyst in males was similar to that in females (P】0.05). The positive rate of oocyst in urban areas (1.13%) was significantly lower than those in rural areas (1.72%, P【0.01). The positive rates of specific IgG, IgM and IgG+IgM in sera of the patients with positive oocyst in stool were 63.4% (26/41), 17.1% (7/41), 19.5% (8/41) respectively. The number fractions of T subsets of CD(3)(+), CD(4)(+), CD(8)(+) and CD(4)(+)/CD(8)(+) of the patients were 0.66+/-0.07, 0.44+/-0.06, 0.28+/-0.04 and 1.58+/-0.32 respectively. The difference between the patients and the controls was significant (P【0.05). The main manifestations of the patients were subclinical infection, in forms of slight abdominal pain, mild diarrhea, and loose stool. CONCLUSION: There are two infection peaks in infection of Cryptosporidium 展开更多
Cankered, dying seedlings of Juglans regia were observed in Shaanxi province in the northwest region of China. Neofusicoccum parvum was isolated from these cankered tissues, with the identification based on mor- pholo...Cankered, dying seedlings of Juglans regia were observed in Shaanxi province in the northwest region of China. Neofusicoccum parvum was isolated from these cankered tissues, with the identification based on mor- phology and an ITS-nrDNA sequence. In order to demonstrate how cultures of N. parvum could cause the expected symptoms, artificial infection, using these isolates and re-isolation of the pathogen, was used. This is the first report on this taxon as a walnut canker pathogen in China.展开更多
The CP15/60 gene encoding the CP15/60 surface protein of sporozoites in Cryptosporidiumparvum was obtained by PCR so as to research the nucleic vaccine against C.parvum. Theeukaryotic expressing vector pcDNA3-15/60 wa...The CP15/60 gene encoding the CP15/60 surface protein of sporozoites in Cryptosporidiumparvum was obtained by PCR so as to research the nucleic vaccine against C.parvum. Theeukaryotic expressing vector pcDNA3-15/60 was constructed by inserting CP15/60 gene intopcDNA3 (+) in XhoⅠand EcoRⅠ. A vaccination protocol was the adult pregnant goatsinoculated intranasally with the pcDNA3-15/60 plasmid and their offspring were infectedwith C.parvum oocysts. The results showed that the pcDNA3-15/60 plasmid can induce theimmune response of goats and the vaccinated goats can transfer the immunity to offspringconferring protection against C.parvum infection. These suggested that the recombinantplasmid could be a DNA vaccine candidate.展开更多
With the discovery that the coccidian parasite Cryptosporidium sp. can cause severe symptoms in humans, many diagnostic techniques were quickly implemented such as microscopic visualization, immunofluorescence and PCR...With the discovery that the coccidian parasite Cryptosporidium sp. can cause severe symptoms in humans, many diagnostic techniques were quickly implemented such as microscopic visualization, immunofluorescence and PCR. Currently, there is no effective drug treatment and none of the current diagnostic methods is 100% accurate. In this study, a BALB/C mouse was subcutaneously immunized with Cryptosporidium parvum oocysts extract. The spleen was removed and the splenocytes were fused with SP2/0 myeloma cells in order to obtain hybridoma cells secreting antibodies specific to C. parvum antigens. Human and cattle fecal samples previously characterized by microscopy [Ziehl-Neelsen staining (ZN) and Lugol] and PCR for the presence of C. parvum and Giardia duodenalis, were analyzed by indirect immunofluorescence, using the developed hybridomas supernatants. The study shows that the selected hybridomas supernatants identify C. parvum oocysts in fecal samples in correlation with C. parvum oocysts identified using ZN/PCR. No false positive results were obtained and the two best supernatants gave 20% -30% of false negative results. No cross reaction with G. duodenalis was observed. By comparing our results with those obtained with an immunofluorescence commercial kit, it suggests the potential use of the monoclonal antibodies present in two of the hybridomas supernatants as a detection tool of C. parvum. With a reliability of 80.8% and 73.1% versus ZN and PCR methods for IFI, compared with a reliability of 76.9% and 92.3% versus ZN and PCR for commercial DIF kit, the supernatant 4.1D5 seems to be the most promising subject to further study its usefulness for C. parvum detection.展开更多
Three new mycophenolic acid derivatives, penicacids E-G(1-3), together with three known analogues, mycophenolic acid(4), 4′-hydroxy-mycophenolic acid(5) and mycophenolic methyl ester(6), were isolated from a marine-d...Three new mycophenolic acid derivatives, penicacids E-G(1-3), together with three known analogues, mycophenolic acid(4), 4′-hydroxy-mycophenolic acid(5) and mycophenolic methyl ester(6), were isolated from a marine-derived fungus Penicillium parvum HDN17-478 from a South China Sea marine sediment sample. The structures of compounds 1-3 were elucidated by HRMS, NMR, and Mosher’s method. Among them, compounds 1 and 2 were the first examples of mycophenolic acid analogs with a double bond at C-3′/C-4′ position. The cytotoxicity of 1-6 was evaluated against the HCT-116, BEL-7402, MGC-803, SH-SY5 Y, HO-8910 and HL-60 cell lines, and compounds 4 and 6 showed potent cytotoxicity with IC50 values ranging from 1.69 to 12.98 μmol·L–1.展开更多
[Objectives]The study was to identify the causal agent of leaf spots of Camellia drupifera in Hainan Province,China.[Methods]Phylogenetic analyses,spore morphology and pathogenicity tests were adopted to identify the ...[Objectives]The study was to identify the causal agent of leaf spots of Camellia drupifera in Hainan Province,China.[Methods]Phylogenetic analyses,spore morphology and pathogenicity tests were adopted to identify the pathogen.[Results]The fungus was identified as Neofusicoccum parvum.The colonies were initially pale to white on PDA,with diffuse yellow pigment around the colonies in the agar after 5 d.After 10 d,the aerial mycelium became gray,and the substrate mycelium became black.Thirty days later,a large number of conidia were generated on OMA.Conidia were hyaline,nonseptate,and fusiform.The mean size of 100 conidia was(13.6-25.4)×(6.2-10.3)μm;the mean length/width ratio was(2.5±0.3)μm.[Conclusions]N.parvum was the causal agent of leaf spots of C.drupifera observed in Hainan Province,China.展开更多
Neofusicoccum parvum,an endophytic fungus isolated from Elaeocarpus serratus(Ceylon Olive;family Elaeocarpaceae),was grown for 3 weeks in potato dextrose broth.Chromatographic separation of the ethyl acetate extracts ...Neofusicoccum parvum,an endophytic fungus isolated from Elaeocarpus serratus(Ceylon Olive;family Elaeocarpaceae),was grown for 3 weeks in potato dextrose broth.Chromatographic separation of the ethyl acetate extracts from the culture filtrate and mycelium over silica gel,Sephadex LH-20 and preparative thin layer chromatography furnished(R)-7-hydroxymellein(1),(3R,4R)-4-hydroxymellein(2),(3R,4S)-4-hydroxymellein(3),(R)-5-hydroxymellein(4),(R)-mellein(5),(3R,4R)-4,7-dihydroxymellein(6),(6R,7S)-dia-asperlin(7),CJ-14445(8)and 13,14,15,16-tetranorlabd-7-ene-19,6β:12,17-diolide(9).The structures of known compounds 1–9 were determined by spectroscopic methods and comparison with reported data.This is the first report of the isolation of an endophytic fungus from E.serratus,and the isolation of compounds 1,4,6,8 and 9 from N.parvum.It is important to note that compounds 1–7 are small molecules with an oxygen heterocyclic ring system.These compounds can be used as starting materials in the synthesis of pharmaceutically important large molecules with oxygen heterocyles.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 st展开更多
Typical harmful micro-algal species constantly occurred in high density in marine aquaculture ponds in Xiangshan and Sanmen Bay, Zhejiang Province. Fates of the microalgal cells influenced by activity of the cultured ...Typical harmful micro-algal species constantly occurred in high density in marine aquaculture ponds in Xiangshan and Sanmen Bay, Zhejiang Province. Fates of the microalgal cells influenced by activity of the cultured animals largely determined the ef fects of the harmful microalgae. However, it is difficult to detect the in situ process. In this paper, toxic activities of three harmful microalga, namely P rymnesium parvum, Pleurochrysis elongata, Karlodinium veneficum, which were isolated from the local ponds, were comparatively studied based on brine shrimp toxic bioassays. Diff erent lethal activities of live cells, cell debris, cellular extracts, and cell free mediums prepared by different process were analyzed. The results showed that,(1) all of the three microalgal species had density and time dependent lethal ef fects on A rtermia nauplii, while P. parvum was the most toxic one and had acute lethal eff ects in 5 h. No such acute lethal eff ects were observed in P. elongata or K. veneficum;(2) live cells, cell debris and cellular extracts of P. parvum had the same lethal pattern. Prymnesins, toxin from P. parvum, is probably not exotoxic active; For P. elongata, toxic activity mainly came from live cells and cell debris; For K. veneficum, toxic activity was relatively lower compared with the other two species. However, Karlotoxin, toxin from K. veneficum, is exotoxic active. Physical disturbance triggered K. veneficum cells actively releasing toxins, which made it an active predator.展开更多
Objective: To investigate U parvum (previously Ureaplasmaurealyticum biovar 1) and U urealyticum (previouslyUreaplasma urealyticum biovar 2) and their subtypes andserovars in urine specimens of pregnant women. Methods...Objective: To investigate U parvum (previously Ureaplasmaurealyticum biovar 1) and U urealyticum (previouslyUreaplasma urealyticum biovar 2) and their subtypes andserovars in urine specimens of pregnant women. Methods: After collecting 151 specimens and inoculatingbroth, all broth culture positive (urease positive) specimenswere amplified, species were identified and subtyped by usinggeneral primers, species-specific, and type-specific primerstargeting the multiple banded antigen (MBA) gene sequence. Results: U parvum was identified in 58 of 151 specimens andU. urealyticum in 18 (both were present in 5, and neither werefound in 6). Serovars 3, 1, and 6 were the most commonamong U parvum isolates and subtypes l and 3 were the mostcommon among U urealyticum. Multiple serovars amongclinical isolates were found. Conclusion: This PCR-based typing system could facilitatestudies of the relationship between individual ureaplasmaspecies or subtypes and human diseases.展开更多
文摘AIM: To provide scientific evidence for prevention and controlling of cryptosporidiosis, the infection of Cryptosporidium parvum and its epidemiological characteristics were studied in some areas of Anhui Province. METHODS: The oocyst of Cryptosporidium parvum in 5421 fresh stool samples from eleven areas of Anhui Province was tested by auramine-phenol stain and improved anti-acid stain respectively. The specific antibody of IgG, IgM and T subsets of 41 patients with positive Cryptosporidium parvum in stools were detected by ELISA and biotin-streptavidin (BSA) respectively. RESULTS: The total infective rate of Cryptosporidium parvum was 1.33% (74/5421). Among them, the positive rates of oocyst in the areas of Huaibei (1.82%) and Fuyang (1.80%) were higher. The positive rates of oocyst in stools of infants, pupils, middle school students, college students, adults, patients with diarrhea, and those with immunodeficiency were 3.15%(28/889), 0.82% (9/1098), 0.82%(9/1092), 0.83%(8/969), 0.85% (9/1095), 2.88%(8/278) and 8.33%(3/36)% respectively. The positive rates of oocyst in infants and the patients with diarrhea and immunodeficiency were significantly higher than those in controls (P【0.01). The positive rate of oocyst in males was similar to that in females (P】0.05). The positive rate of oocyst in urban areas (1.13%) was significantly lower than those in rural areas (1.72%, P【0.01). The positive rates of specific IgG, IgM and IgG+IgM in sera of the patients with positive oocyst in stool were 63.4% (26/41), 17.1% (7/41), 19.5% (8/41) respectively. The number fractions of T subsets of CD(3)(+), CD(4)(+), CD(8)(+) and CD(4)(+)/CD(8)(+) of the patients were 0.66+/-0.07, 0.44+/-0.06, 0.28+/-0.04 and 1.58+/-0.32 respectively. The difference between the patients and the controls was significant (P【0.05). The main manifestations of the patients were subclinical infection, in forms of slight abdominal pain, mild diarrhea, and loose stool. CONCLUSION: There are two infection peaks in infection of Cryptosporidium
基金supported by the program for tacking key problem of Shaanxi agricultural scientific and technological extent(2015NY124)Project NSFC(31270690)+1 种基金Project PCSIRT(NO.IRT1035)special funding for basic S&T work of Ministry of Science and Technology(2009FY210100)of China
文摘Cankered, dying seedlings of Juglans regia were observed in Shaanxi province in the northwest region of China. Neofusicoccum parvum was isolated from these cankered tissues, with the identification based on mor- phology and an ITS-nrDNA sequence. In order to demonstrate how cultures of N. parvum could cause the expected symptoms, artificial infection, using these isolates and re-isolation of the pathogen, was used. This is the first report on this taxon as a walnut canker pathogen in China.
基金supported by Natural Science Foundation of Jilin Province for Outstanding Young scientists Award,China(2002).
文摘The CP15/60 gene encoding the CP15/60 surface protein of sporozoites in Cryptosporidiumparvum was obtained by PCR so as to research the nucleic vaccine against C.parvum. Theeukaryotic expressing vector pcDNA3-15/60 was constructed by inserting CP15/60 gene intopcDNA3 (+) in XhoⅠand EcoRⅠ. A vaccination protocol was the adult pregnant goatsinoculated intranasally with the pcDNA3-15/60 plasmid and their offspring were infectedwith C.parvum oocysts. The results showed that the pcDNA3-15/60 plasmid can induce theimmune response of goats and the vaccinated goats can transfer the immunity to offspringconferring protection against C.parvum infection. These suggested that the recombinantplasmid could be a DNA vaccine candidate.
文摘With the discovery that the coccidian parasite Cryptosporidium sp. can cause severe symptoms in humans, many diagnostic techniques were quickly implemented such as microscopic visualization, immunofluorescence and PCR. Currently, there is no effective drug treatment and none of the current diagnostic methods is 100% accurate. In this study, a BALB/C mouse was subcutaneously immunized with Cryptosporidium parvum oocysts extract. The spleen was removed and the splenocytes were fused with SP2/0 myeloma cells in order to obtain hybridoma cells secreting antibodies specific to C. parvum antigens. Human and cattle fecal samples previously characterized by microscopy [Ziehl-Neelsen staining (ZN) and Lugol] and PCR for the presence of C. parvum and Giardia duodenalis, were analyzed by indirect immunofluorescence, using the developed hybridomas supernatants. The study shows that the selected hybridomas supernatants identify C. parvum oocysts in fecal samples in correlation with C. parvum oocysts identified using ZN/PCR. No false positive results were obtained and the two best supernatants gave 20% -30% of false negative results. No cross reaction with G. duodenalis was observed. By comparing our results with those obtained with an immunofluorescence commercial kit, it suggests the potential use of the monoclonal antibodies present in two of the hybridomas supernatants as a detection tool of C. parvum. With a reliability of 80.8% and 73.1% versus ZN and PCR methods for IFI, compared with a reliability of 76.9% and 92.3% versus ZN and PCR for commercial DIF kit, the supernatant 4.1D5 seems to be the most promising subject to further study its usefulness for C. parvum detection.
基金supported by the National Key R&D Program of China (No. 2018YFC0310800)the National Science and Technology Major Project for Significant New Drugs Development (No. 2018ZX09735004)+3 种基金the Marine S&T Fund of Shandong Province for Pilot National Laboratory for Marine Science and Technology (Qingdao)(Nos. 2018SDKJ0401-2 and 2016ASKJ05-04)the NSFC-Shandong Joint Fund (No. U1906212)the Fundamental Research Funds for the Central Universities (No. 201941001)the Taishan Scholar Youth Expert Program in Shandong Province (No. tsqn201812021)。
文摘Three new mycophenolic acid derivatives, penicacids E-G(1-3), together with three known analogues, mycophenolic acid(4), 4′-hydroxy-mycophenolic acid(5) and mycophenolic methyl ester(6), were isolated from a marine-derived fungus Penicillium parvum HDN17-478 from a South China Sea marine sediment sample. The structures of compounds 1-3 were elucidated by HRMS, NMR, and Mosher’s method. Among them, compounds 1 and 2 were the first examples of mycophenolic acid analogs with a double bond at C-3′/C-4′ position. The cytotoxicity of 1-6 was evaluated against the HCT-116, BEL-7402, MGC-803, SH-SY5 Y, HO-8910 and HL-60 cell lines, and compounds 4 and 6 showed potent cytotoxicity with IC50 values ranging from 1.69 to 12.98 μmol·L–1.
基金Hainan Provincial Natural Science Foundation of China(319MS081)Central Finance Forestry Science and Technology Extension Project(Qiong[2020]TG06).
文摘[Objectives]The study was to identify the causal agent of leaf spots of Camellia drupifera in Hainan Province,China.[Methods]Phylogenetic analyses,spore morphology and pathogenicity tests were adopted to identify the pathogen.[Results]The fungus was identified as Neofusicoccum parvum.The colonies were initially pale to white on PDA,with diffuse yellow pigment around the colonies in the agar after 5 d.After 10 d,the aerial mycelium became gray,and the substrate mycelium became black.Thirty days later,a large number of conidia were generated on OMA.Conidia were hyaline,nonseptate,and fusiform.The mean size of 100 conidia was(13.6-25.4)×(6.2-10.3)μm;the mean length/width ratio was(2.5±0.3)μm.[Conclusions]N.parvum was the causal agent of leaf spots of C.drupifera observed in Hainan Province,China.
文摘Neofusicoccum parvum,an endophytic fungus isolated from Elaeocarpus serratus(Ceylon Olive;family Elaeocarpaceae),was grown for 3 weeks in potato dextrose broth.Chromatographic separation of the ethyl acetate extracts from the culture filtrate and mycelium over silica gel,Sephadex LH-20 and preparative thin layer chromatography furnished(R)-7-hydroxymellein(1),(3R,4R)-4-hydroxymellein(2),(3R,4S)-4-hydroxymellein(3),(R)-5-hydroxymellein(4),(R)-mellein(5),(3R,4R)-4,7-dihydroxymellein(6),(6R,7S)-dia-asperlin(7),CJ-14445(8)and 13,14,15,16-tetranorlabd-7-ene-19,6β:12,17-diolide(9).The structures of known compounds 1–9 were determined by spectroscopic methods and comparison with reported data.This is the first report of the isolation of an endophytic fungus from E.serratus,and the isolation of compounds 1,4,6,8 and 9 from N.parvum.It is important to note that compounds 1–7 are small molecules with an oxygen heterocyclic ring system.These compounds can be used as starting materials in the synthesis of pharmaceutically important large molecules with oxygen heterocyles.
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 st
基金Supported by the Earmarked Fund for Modern Agro-industry Technology Research System,China(No.CARS-49)the Ningbo Science and Technology Research Projects,China(No.2017C110003)+2 种基金the Li Dak Sum Yip Yio Chin Kenneth Li Marine Biopharmaceutical Development Fundthe National 111 Project of Chinathe K.C.Wong Magna Fund of Ningbo University
文摘Typical harmful micro-algal species constantly occurred in high density in marine aquaculture ponds in Xiangshan and Sanmen Bay, Zhejiang Province. Fates of the microalgal cells influenced by activity of the cultured animals largely determined the ef fects of the harmful microalgae. However, it is difficult to detect the in situ process. In this paper, toxic activities of three harmful microalga, namely P rymnesium parvum, Pleurochrysis elongata, Karlodinium veneficum, which were isolated from the local ponds, were comparatively studied based on brine shrimp toxic bioassays. Diff erent lethal activities of live cells, cell debris, cellular extracts, and cell free mediums prepared by different process were analyzed. The results showed that,(1) all of the three microalgal species had density and time dependent lethal ef fects on A rtermia nauplii, while P. parvum was the most toxic one and had acute lethal eff ects in 5 h. No such acute lethal eff ects were observed in P. elongata or K. veneficum;(2) live cells, cell debris and cellular extracts of P. parvum had the same lethal pattern. Prymnesins, toxin from P. parvum, is probably not exotoxic active; For P. elongata, toxic activity mainly came from live cells and cell debris; For K. veneficum, toxic activity was relatively lower compared with the other two species. However, Karlotoxin, toxin from K. veneficum, is exotoxic active. Physical disturbance triggered K. veneficum cells actively releasing toxins, which made it an active predator.
文摘Objective: To investigate U parvum (previously Ureaplasmaurealyticum biovar 1) and U urealyticum (previouslyUreaplasma urealyticum biovar 2) and their subtypes andserovars in urine specimens of pregnant women. Methods: After collecting 151 specimens and inoculatingbroth, all broth culture positive (urease positive) specimenswere amplified, species were identified and subtyped by usinggeneral primers, species-specific, and type-specific primerstargeting the multiple banded antigen (MBA) gene sequence. Results: U parvum was identified in 58 of 151 specimens andU. urealyticum in 18 (both were present in 5, and neither werefound in 6). Serovars 3, 1, and 6 were the most commonamong U parvum isolates and subtypes l and 3 were the mostcommon among U urealyticum. Multiple serovars amongclinical isolates were found. Conclusion: This PCR-based typing system could facilitatestudies of the relationship between individual ureaplasmaspecies or subtypes and human diseases.
