Combined effects of Chinese medicine feed and ginger extract bath on co-infection of Ichthyophthirius multifiliis and Dactylogyrus ctenopharyngodonid in grass carp

Authors: FU, YAO-WU - Jinan University; WANG, BIN - Jinan University; ZHANG, QI-ZHONG - Jinan University; Xu, Dehai; LIN, DE-JIE - Jinan University; YANG, XING-YA - Jinan University; ZHU, SHU-QUN - Jinan University; PAN, JING-YANG - Jinan University; DENG, QIAN - Jinan University; LIU, YAN_MENG - Jinan University; ZHOU, SHENG-YU - Jinan University

Submitted to: Parasitology Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/10/2017
Publication Date: 7/30/2017
Citation: Fu, Y., Wang, B., Zhang, Q., Xu, D., Lin, D., Yang, X., Zhu, S., Pan, J., Deng, Q., Liu, Y., Zhou, S. 2017. Combined effects of Chinese medicine feed and ginger extract bath on co-infection of Ichthyophthirius multifiliis and Dactylogyrus ctenopharyngodonid in grass carp. Parasitology Research. 116(7):2017-2025.

Interpretive Summary: Ichthyophthirius multifiliis and Dactylogyrus ctenopharyngodonid are two important parasites in skin and gill of freshwater fish. Co-infection by these parasites leads to high fish mortality and results in heavy economic loss. Hematological changes of fish co-infected with two parasites have never been studied and effective drugs to treat two parasites in fish need to be explored. This study investigated the hematological response of fish co-infected with two parasites and evaluated the efficacy of medicated feed and ginger extract bath against these parasites on fish. Results demonstrated that the infection intensity of both parasites was significantly decreased after grass carp fed medicated feed containing 4% medicinal plant extracts. All parasites were eliminated during 21 days when grass carp treated with medicated feed and 4 mg/L ginger extract bath. The trial results demonstrated that the combined treatment of ginger extract bath and medicated feed containing medicine plant mixtures was an effective way to control D. ctenopharyngodonid and I. multifiliis on fish. The results also demonstrate that red blood cells significantly decrease after fish co-infected with two parasites. The white blood cells significantly increased with the increment of parasite infection intensities. The study results are important to the aquaculture and pharmaceutical industry and will help researchers to develop effective parasiticides and control strategies against D. ctenopharyngodonid and I. multifiliis on fish.

Technical Abstract: Dactylogyrus ctenopharyngodonid and Ichthyophthirius multifiliis are two important ectoparasites of freshwater fish. Co-infection by the two parasites leads to high fish mortality and results in heavy economic losses. This study aimed to evaluate the efficacy of medicated feed and a ginger extract bath against D. ctenopharyngodonid and I. multifiliis on grass carp and investigate the hematological response of grass carp co infected by the two parasites. These results demonstrated that red blood cell (RBC) and thrombocyte percentage among leucocytes significantly decreased after grass carp were co-infected by D. ctenopharyngodonid and I. multifiliis. The monocyte and neutrophil percentages significantly increased with the increment of parasite mean intensities, while the lymphocyte percentage decreased. The activities of serum acid phosphatase (ACP), alkaline phosphatase (AKP), lysozyme (LZM), and superoxide dismutase (SOD) significantly increased after co-infection. When grass carp treated with medicated feed containing 4% of Astragalus membranaceus, Allium sativum, Morus alba, and Glycyrrhiza uralensis, the activities of ACP, AKP, LZM, and SOD were significantly enhanced, and the mean intensities of D. ctenopharyngodonid and I. multifiliis were significantly decreased. When grass carp was treated with medicated feed and a 4-mg/L ginger extract bath, all parasites were eliminated during 28 days. The bath of ginger extract at a concentration of 4 mg/L kept a low mean intensity of I. multifiliis and D. ctenopharyngodonid, then the two parasites were eliminated by oral administration of the medicated feed with an immunostimulant (Chinese medicine compound).