Objective:To study the incidence of encysted progenetic metacercariae of Clinostomum complanatum(C. complanatum) in Channa punctatus(C. punctatus), associated histopathology and the experimental infection to laborator...Objective:To study the incidence of encysted progenetic metacercariae of Clinostomum complanatum(C. complanatum) in Channa punctatus(C. punctatus), associated histopathology and the experimental infection to laboratory chicken to obtain ovigerous adult worms.Methods:Live C. punctatus were brought from local fish market of Aligarh, India, dissected and examined on a monthly basis for the presence of C. complanatumcysts. For histochemistry, infected tissue sections with attached cysts were processed for haematoxylene and eosin staining. Cysts were aseptically fed to 4 day old leghorn chicken to obtain adult worms. Mechanically excysted metacercaria and the ovigerous adult worms were stained in carmine to prepare permanent slides.Results:One year survey for the infection of encysted progenetic metacercaria of C.complanatuminC. punctatusrevealed the prevalence, intensity and abundance of 24.7%, 2.27and 0.608, respectively. Histopathology showed heavy infiltration of immune cells at the site of cyst attachment and some tissue damage was also evident. Following feeding to experimental chicken, about 41.07% of the encysted metacercariae were able to excyst and migrate back to bucco-pharyngeal region where they tenaciously attached and fed on blood, and transformed into ovigerous adult worms from 62 hours onwards of post infection.Conclusions:The parasite is potentially pathogenic to the host, and the availability of a suitable intermediate host can be a contributing factor for the occurrence of C. complanatummetacercaria either in the excysted or encysted form, indicating loose host specificity and zoonotic potential.展开更多
Objective:To analyze the prevalence of echinostome metacercariae in Filopaludina dorliaris(F.dorliaris)and Filopaludina martensi martensi(F.martensi martensi)and genotype variation of echinostome metacercariae by usin...Objective:To analyze the prevalence of echinostome metacercariae in Filopaludina dorliaris(F.dorliaris)and Filopaludina martensi martensi(F.martensi martensi)and genotype variation of echinostome metacercariae by using random amplified polymorphic DNA(RAPD)analysis.Methods:Filopaludina sp.snails were collected from eight localities of Lamphun Province,Northern Thailand and examined for echinostome metacercariae.RAPD-PCR was used lo analyze genotype variation of echinostome metacercariae.Results:A total of 3 226 F.dorliaris and F.martensi martensi snails were collected from eight localities.The overall prevalences of echinostome metacercariae in F.dorliaris and F.martensi martensi were 40.89%and 36.27%,while the intensity of infection was 20.37 and 12.04,respectively.The dendrogram constructed base on RAPD profiles,4 well supported domains were generated;(i)group of metacercariae from Ban Hong,Mae Ta,Meaung,Pa Sang,Toong Hua Chang,and Weang Nong that were clustered in the group of E.revolutum,(ii)Ban Thi,(iii)Lee,and(iv)3 adults of an out group.Condusioiis:This research demonstrated RAPD profiling has been a useful tool to detect DNA polymorphisms to determine genetic relationship between echinostome metacercariae in Lamphun Province,Northern Thailand.展开更多
Aim To explore if Echinochasmus liliputanus cercariae can develop into metacercariae both invivo and in vitro and biological activity of the metacercariae,then to determine the effects of silver ni-trate on eereariae ...Aim To explore if Echinochasmus liliputanus cercariae can develop into metacercariae both invivo and in vitro and biological activity of the metacercariae,then to determine the effects of silver ni-trate on eereariae encystation in vitro.Methods Cereariae of Echinochasmus liliputanus from Bellamyaaeruginosa snails treated with or without silver nitrate were used to infected goldfish,the second inter-mediate host,or to incubated in many different solutions for 24 h to record the encystation rates.Themetacercariae formed both in vivo and in vitro were then used to infected New Zealand rabbits to testtheir infectivity to its definitive hosts or to exeyst in 0.1% sodium deoxycholate excystation medium at37℃ for 1 h.Results In vivo encystment of cercariae occurred in the gills of goldfish.However,thecercariae were also able to encyst in vitro in Locke’s solution,NaCl solution,artificial gastric juice orhuman gastric juice with eneystation rates of 74.28 %,44.94 %,8.37 % and 10.79 %.0.7×-1.2×Locke’s or 0.7%-1.2% NaCl solution was shown to be appropriate for in vitro encystment to occurwithin 24 hour,however,full- strength Locke’s solution was shown to be optimal.The one- day- oldencysted metacereariae formed in vivo showed 88.53 % exeystation when treated in 0.1% sodium de-oxycholate exeystation medium at 37℃ for 1h.The metacercariae formed in vitro,however,showed88.60% and 84.95% excystation for normal and abnormal ones respectively.While abnormal cysts atroom temperature usually die within 10 days,about 70% normal cyst,both in vivo and in vitro,canstill excyst after stored in 0.5×Locke’s at 4℃ for 3 mouths.Cysts formed in vivo and in vitro were e-qually infective to rabbits.1 uM silver nitrate had a dramatic effect on the cercariae encysting in vitro.When treated with silver nitrate,the cereariae encystation rates decreased to 16.25% in Locke’s solu-tion and 6.69% in NaCl solution,however,the encystment was largely restored wben the cercariaewere washed to remove Ag+.Conclusion The finding of E.liliputanus cercariae encysting in vitro,especially in human gastric juice,might be helpful in elucidating mechanisms of the definitive hosts in-fected by the cercariae directly.The encystment of the cercariae in vitro could be inhibited when thecercariae were treated with 1 uM silver nitrate.As silver nitrate binds to the papillae,especially to theciliated papillae,on the cercarial surface,it is suggested that papillar chemoreceptors may be involved inencystment of the cercariae.展开更多
2008年3月～2009年3月,在广西柳江河段上的三江县、融安县、融水县、柳城县、柳州市和象州县设点,采集各地河道内的鱼类,用直接压片法和消化法检查其感染华支睾吸虫的情况。共捕获鱼16204尾,经鉴定分属9科27属35种,其中32种不同程度感...2008年3月～2009年3月,在广西柳江河段上的三江县、融安县、融水县、柳城县、柳州市和象州县设点,采集各地河道内的鱼类,用直接压片法和消化法检查其感染华支睾吸虫的情况。共捕获鱼16204尾,经鉴定分属9科27属35种,其中32种不同程度感染华支睾吸虫,感染率为10.5%,感染度为4.6个/g。麦穗鱼(Pseudoras bora parva)的感染率(21.5%)和感染度(9.9个/g)最高,其次为宽鳍鱲(Zacco platypus),感染率为17.8%,感染度为8.9个/g。各河段感染率间的差异有统计学意义,象州县河段感染率(12.3%)较高,三江县河段(9.1%)和柳州市区河段(9.7%)感染率较低。统计学分析表明,夏、秋两季鱼的感染率较高,春、冬两季较低;中、上水层鱼类的感染率较高,下水层鱼类较低;杂食性和草食性鱼类的感染率较高,肉食性鱼类较低。展开更多
基金financially supported by Aligarh Muslim University(grant No.09PHDL128)
文摘Objective:To study the incidence of encysted progenetic metacercariae of Clinostomum complanatum(C. complanatum) in Channa punctatus(C. punctatus), associated histopathology and the experimental infection to laboratory chicken to obtain ovigerous adult worms.Methods:Live C. punctatus were brought from local fish market of Aligarh, India, dissected and examined on a monthly basis for the presence of C. complanatumcysts. For histochemistry, infected tissue sections with attached cysts were processed for haematoxylene and eosin staining. Cysts were aseptically fed to 4 day old leghorn chicken to obtain adult worms. Mechanically excysted metacercaria and the ovigerous adult worms were stained in carmine to prepare permanent slides.Results:One year survey for the infection of encysted progenetic metacercaria of C.complanatuminC. punctatusrevealed the prevalence, intensity and abundance of 24.7%, 2.27and 0.608, respectively. Histopathology showed heavy infiltration of immune cells at the site of cyst attachment and some tissue damage was also evident. Following feeding to experimental chicken, about 41.07% of the encysted metacercariae were able to excyst and migrate back to bucco-pharyngeal region where they tenaciously attached and fed on blood, and transformed into ovigerous adult worms from 62 hours onwards of post infection.Conclusions:The parasite is potentially pathogenic to the host, and the availability of a suitable intermediate host can be a contributing factor for the occurrence of C. complanatummetacercaria either in the excysted or encysted form, indicating loose host specificity and zoonotic potential.
基金supported by the Ministry of Science and Technology and the Graduate School,Chiang Mai Univeraity
文摘Objective:To analyze the prevalence of echinostome metacercariae in Filopaludina dorliaris(F.dorliaris)and Filopaludina martensi martensi(F.martensi martensi)and genotype variation of echinostome metacercariae by using random amplified polymorphic DNA(RAPD)analysis.Methods:Filopaludina sp.snails were collected from eight localities of Lamphun Province,Northern Thailand and examined for echinostome metacercariae.RAPD-PCR was used lo analyze genotype variation of echinostome metacercariae.Results:A total of 3 226 F.dorliaris and F.martensi martensi snails were collected from eight localities.The overall prevalences of echinostome metacercariae in F.dorliaris and F.martensi martensi were 40.89%and 36.27%,while the intensity of infection was 20.37 and 12.04,respectively.The dendrogram constructed base on RAPD profiles,4 well supported domains were generated;(i)group of metacercariae from Ban Hong,Mae Ta,Meaung,Pa Sang,Toong Hua Chang,and Weang Nong that were clustered in the group of E.revolutum,(ii)Ban Thi,(iii)Lee,and(iv)3 adults of an out group.Condusioiis:This research demonstrated RAPD profiling has been a useful tool to detect DNA polymorphisms to determine genetic relationship between echinostome metacercariae in Lamphun Province,Northern Thailand.
文摘Aim To explore if Echinochasmus liliputanus cercariae can develop into metacercariae both invivo and in vitro and biological activity of the metacercariae,then to determine the effects of silver ni-trate on eereariae encystation in vitro.Methods Cereariae of Echinochasmus liliputanus from Bellamyaaeruginosa snails treated with or without silver nitrate were used to infected goldfish,the second inter-mediate host,or to incubated in many different solutions for 24 h to record the encystation rates.Themetacercariae formed both in vivo and in vitro were then used to infected New Zealand rabbits to testtheir infectivity to its definitive hosts or to exeyst in 0.1% sodium deoxycholate excystation medium at37℃ for 1 h.Results In vivo encystment of cercariae occurred in the gills of goldfish.However,thecercariae were also able to encyst in vitro in Locke’s solution,NaCl solution,artificial gastric juice orhuman gastric juice with eneystation rates of 74.28 %,44.94 %,8.37 % and 10.79 %.0.7×-1.2×Locke’s or 0.7%-1.2% NaCl solution was shown to be appropriate for in vitro encystment to occurwithin 24 hour,however,full- strength Locke’s solution was shown to be optimal.The one- day- oldencysted metacereariae formed in vivo showed 88.53 % exeystation when treated in 0.1% sodium de-oxycholate exeystation medium at 37℃ for 1h.The metacercariae formed in vitro,however,showed88.60% and 84.95% excystation for normal and abnormal ones respectively.While abnormal cysts atroom temperature usually die within 10 days,about 70% normal cyst,both in vivo and in vitro,canstill excyst after stored in 0.5×Locke’s at 4℃ for 3 mouths.Cysts formed in vivo and in vitro were e-qually infective to rabbits.1 uM silver nitrate had a dramatic effect on the cercariae encysting in vitro.When treated with silver nitrate,the cereariae encystation rates decreased to 16.25% in Locke’s solu-tion and 6.69% in NaCl solution,however,the encystment was largely restored wben the cercariaewere washed to remove Ag+.Conclusion The finding of E.liliputanus cercariae encysting in vitro,especially in human gastric juice,might be helpful in elucidating mechanisms of the definitive hosts in-fected by the cercariae directly.The encystment of the cercariae in vitro could be inhibited when thecercariae were treated with 1 uM silver nitrate.As silver nitrate binds to the papillae,especially to theciliated papillae,on the cercarial surface,it is suggested that papillar chemoreceptors may be involved inencystment of the cercariae.
文摘2008年3月～2009年3月,在广西柳江河段上的三江县、融安县、融水县、柳城县、柳州市和象州县设点,采集各地河道内的鱼类,用直接压片法和消化法检查其感染华支睾吸虫的情况。共捕获鱼16204尾,经鉴定分属9科27属35种,其中32种不同程度感染华支睾吸虫,感染率为10.5%,感染度为4.6个/g。麦穗鱼(Pseudoras bora parva)的感染率(21.5%)和感染度(9.9个/g)最高,其次为宽鳍鱲(Zacco platypus),感染率为17.8%,感染度为8.9个/g。各河段感染率间的差异有统计学意义,象州县河段感染率(12.3%)较高,三江县河段(9.1%)和柳州市区河段(9.7%)感染率较低。统计学分析表明,夏、秋两季鱼的感染率较高,春、冬两季较低;中、上水层鱼类的感染率较高,下水层鱼类较低;杂食性和草食性鱼类的感染率较高,肉食性鱼类较低。
