Impact of Pseudomonas H6 surfactant on all external life cycle stages of the fish parasitic ciliate Ichthyophthirius multifiliis

TY - JOUR

T1 - Impact of Pseudomonas H6 surfactant on all external life cycle stages of the fish parasitic ciliate Ichthyophthirius multifiliis

AU - Al-Jubury, Azmi

AU - Lu, C.

AU - Kania, Per Walter

AU - Jørgensen, Louise von Gersdorff

AU - Liu, Y.

AU - de Bruijn, I.

AU - Raaijmakers, J.

AU - Buchmann, Kurt

PY - 2018

Y1 - 2018

N2 - A bacterial biosurfactant isolated from Pseudomonas (strain H6) has previously been shown to have a lethal effect on the oomycete Saprolegnia diclina infecting fish eggs. The present work demonstrates that the same biosurfactant has a strong in vitro antiparasitic effect on the fish pathogenic ciliate Ichthyophthirius multifiliis. Three life cycle stages (the infective theront stage, the tomont and the tomocyst containing tomites) were all susceptible to the surfactant. Theronts were the most sensitive showing 100% mortality in as low concentrations as 10 and 13 μg/ml within 30 min. Tomonts were the most resistant but were killed in concentrations of 100 μg/ml. Tomocysts, which generally are considered resistant to chemical and medical treatment, due to the surrounding protective cyst wall, were also sensitive. The surfactant, in concentrations of 10 and 13 μg/ml, penetrated the cyst wall and killed the enclosed tomites within 60 min. Rainbow trout fingerlings exposed to the biosurfactant showed no adverse immediate or late signs following several hours incubation in concentrations effective for killing the parasite. This bacterial surfactant may be further developed for application as an antiparasitic control agent in aquaculture.

AB - A bacterial biosurfactant isolated from Pseudomonas (strain H6) has previously been shown to have a lethal effect on the oomycete Saprolegnia diclina infecting fish eggs. The present work demonstrates that the same biosurfactant has a strong in vitro antiparasitic effect on the fish pathogenic ciliate Ichthyophthirius multifiliis. Three life cycle stages (the infective theront stage, the tomont and the tomocyst containing tomites) were all susceptible to the surfactant. Theronts were the most sensitive showing 100% mortality in as low concentrations as 10 and 13 μg/ml within 30 min. Tomonts were the most resistant but were killed in concentrations of 100 μg/ml. Tomocysts, which generally are considered resistant to chemical and medical treatment, due to the surrounding protective cyst wall, were also sensitive. The surfactant, in concentrations of 10 and 13 μg/ml, penetrated the cyst wall and killed the enclosed tomites within 60 min. Rainbow trout fingerlings exposed to the biosurfactant showed no adverse immediate or late signs following several hours incubation in concentrations effective for killing the parasite. This bacterial surfactant may be further developed for application as an antiparasitic control agent in aquaculture.

KW - biological control

KW - Ichthyophthirius multifiliis

KW - parasiticide

KW - Pseudomonas

KW - surfactant

U2 - 10.1111/jfd.12810

DO - 10.1111/jfd.12810

M3 - Journal article

C2 - 29671884

AN - SCOPUS:85048362462

SN - 0140-7775

VL - 41

SP - 1147

EP - 1152

JO - Journal of Fish Diseases

JF - Journal of Fish Diseases

IS - 7

ER -