Objectives:Fish are hypothesized to act as paratenic hosts for the zoonotic nematode Angiostrongylus cantonensis,which causes human eosinophilic meningitis.There is a lack of data confirming the relevance of fish in A...Objectives:Fish are hypothesized to act as paratenic hosts for the zoonotic nematode Angiostrongylus cantonensis,which causes human eosinophilic meningitis.There is a lack of data confirming the relevance of fish in A.cantonensis life cycle and their contribution to human infection.Materials and Methods:We conducted a series of experiments to investigate the survival and infectivity of A.cantonensis larvae in Clarias gariepinus(catfish;n=30)and Oreochromis niloticus(tilapia;n=24).Each fish was inoculated with 10000 third-stage larvae(L3).Larval survival was assessed through artificial digestion of fish tissues 1 week,2 weeks,and 3 weeks post-infection.To investigate the early stages of infection,four catfish were inoculated with 10000 L3 each and sacrificed 3 d post-infection.Quantitative polymerase chain reaction(qPCR)analysis and histopathological examination were performed to evaluate larval distribution and tissue reactions.Two infected catfish,sacrificed 1 week post-infection,were used to feed Wistar rats.Results:After 45 d,the rats did not shed first-stage larvae(L1),indicating the absence of infection.One week post-infection,dead larvae were present in the digested tissues of both fish species,and the same was observed 2 weeks and 3 weeks after exposure.qPCR analysis revealed that the intestine was the most heavily infected organ.Histopathological examination identified dead larvae within granulomas in both the intestines and liver.Early-stage infection experiment showed that fish sacrificed 3 d post-inoculation contained viable L3,which was infective to Wistar rats.Conclusions:While A.cantonensis L3 can survive and remain infective in fish for a short period,they typically die within first few days postinfection.This suggests that fish may not be significant long-term paratenic hosts for A.cantonensis but may play a temporary role in its transmission to mammals(including humans)and birds.These results are consistent with previous studies on freshwater shrimps and highlight the importance of understanding aquatic host interactions in the epidemiology of this zoonotic foodborne pathogen.展开更多
基金supported by the Southeast Asia-Europe Joint Funding Scheme for Research and Innovation(SEAEUROPEJFS19IN-053)the Czech Science Foundation(No.22-26136S)Elena Izquierdo-Rodriguez was supported by the M-ULL scholarship(M-ULL,convocatoria 2019),Czech Republic.The work of Lucia Anettováwas also supported by the Czech Academy of Sciences,ABERA Project.
文摘Objectives:Fish are hypothesized to act as paratenic hosts for the zoonotic nematode Angiostrongylus cantonensis,which causes human eosinophilic meningitis.There is a lack of data confirming the relevance of fish in A.cantonensis life cycle and their contribution to human infection.Materials and Methods:We conducted a series of experiments to investigate the survival and infectivity of A.cantonensis larvae in Clarias gariepinus(catfish;n=30)and Oreochromis niloticus(tilapia;n=24).Each fish was inoculated with 10000 third-stage larvae(L3).Larval survival was assessed through artificial digestion of fish tissues 1 week,2 weeks,and 3 weeks post-infection.To investigate the early stages of infection,four catfish were inoculated with 10000 L3 each and sacrificed 3 d post-infection.Quantitative polymerase chain reaction(qPCR)analysis and histopathological examination were performed to evaluate larval distribution and tissue reactions.Two infected catfish,sacrificed 1 week post-infection,were used to feed Wistar rats.Results:After 45 d,the rats did not shed first-stage larvae(L1),indicating the absence of infection.One week post-infection,dead larvae were present in the digested tissues of both fish species,and the same was observed 2 weeks and 3 weeks after exposure.qPCR analysis revealed that the intestine was the most heavily infected organ.Histopathological examination identified dead larvae within granulomas in both the intestines and liver.Early-stage infection experiment showed that fish sacrificed 3 d post-inoculation contained viable L3,which was infective to Wistar rats.Conclusions:While A.cantonensis L3 can survive and remain infective in fish for a short period,they typically die within first few days postinfection.This suggests that fish may not be significant long-term paratenic hosts for A.cantonensis but may play a temporary role in its transmission to mammals(including humans)and birds.These results are consistent with previous studies on freshwater shrimps and highlight the importance of understanding aquatic host interactions in the epidemiology of this zoonotic foodborne pathogen.
