Open AccessI chthyophthirius multifiliis as a potential vector of E dwardsiella ictaluri in channel catfish
Author(s) -
Xu DeHai,
Shoemaker Craig A.,
Klesius Phillip H.
Publication year - 2012
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.2012.02518.x
Subject(s) - edwardsiella ictaluri , ichthyophthirius multifiliis , catfish , biology , microbiology and biotechnology , bacteria , fish <actinopterygii> , veterinary medicine , ictalurus , fishery , medicine , genetics
There is limited information on whether parasites act as vectors to transmit bacteria in fish. In this trial, we used I chthyophthirius multifiliis and fluorescent E dwardsiella ictaluri as a model to study the interaction between parasite, bacterium, and fish. The percentage (23–39%) of theronts fluorescing after exposure to E . ictaluri was significantly higher than control theronts (~ 6%) using flow cytometry. Theronts exposed to E . ictaluri at 4 × 10 7 CFU mL −1 showed a higher percentage (~ 60%) of fluorescent theronts compared to those (42%) exposed to 4 × 10 3 CFU mL −1 at 4 h. All tomonts (100%) carried the bacterium after exposure to E . ictaluri . E dwardsiella ictaluri survived and replicated during tomont division. Confocal microscopy demonstrated that E . ictaluri was associated with the tomont surface. Among theronts released from tomonts exposed to E . ictaluri , 31–66% were observed with attached E . ictaluri . Sixty percent of fish exposed to theronts treated with 5 × 10 7 E . ictaluri mL −1 were positive for E . ictaluri at 4 h as determined by qPCR or fluorescent microscopy. Fluorescent E . ictaluri were observed on trophonts in skin and gill wet mounts of dead fish. This study demonstrated that Ich could vector E . ictaluri to channel catfish.