acyclovir and Fish-Diseases

Topics: Acyclovir; Animals; Carps; Fish Diseases; Herpesviridae; Herpesviridae Infections

To evaluate the effect of a multidose acyclovir protocol on koi herpesvirus (KHV) viral load and mortality in a cohabitation challenge.. 180 koi fish.. Forty fish (shedders) were immersed in a 0.5 KHV plaque-forming units/mL static bath for 8 hours. Mock shedders were treated similarly but exposed to cell culture media. KHV shedders were then transferred into 8 tanks (5 shedders per tank) containing 10 naïve fish (cohabitants) each. Fish in the acyclovir group (AT) received a 10 mg/kg acyclovir intracoelomic injection 1, 3, and 6 days after the first confirmed KHV mortality. Positive controls (PC) were treated similarly but received sterile saline injections. Negative controls (NC) were exposed to mock shedders. Morbidity and mortality were evaluated daily for 50 days post-challenge. Quantitative PCR was used to determine viral load in the gill biopsies of shedders and cohabitants collected at days 19 (T1), 22 (T2), 25 (T3), 34 (T4), and 50 (T5) post-challenge.. Survival curves analyzed by the Gehan-Breslow-Wilcoxon method revealed a delayed onset of mortalities and a significantly lower KHV load at T2 and T3 detected in AT cohabitant fish (P = .042) compared to PC group. However, there were no significant differences in overall mortality or viral loads at T5.. The acyclovir protocol used in this study did not control viral infection or mortality at the end of the 50-day trial. Shorter intervals between injections could improve outcomes, but the additional stress inflicted by handling should be considered. Exploring other therapeutic alternatives and doses is warranted.

Topics: Acyclovir; Animals; Carps; Fish Diseases; Herpesviridae; Herpesviridae Infections

The channel catfish virus (CCV) can cause lethal hemorrhagic infection in channel catfish, resulting in significant economic losses in the fish industry. Effective drugs for the virus are still lacking. Acyclovir is known as a potent antiviral agent against human herpes viruses and some animal DNA viruses. The present study was undertaken to explore the antiviral response and mechanism of acyclovir against CCV in channel catfish ovary (CCO) cells. Acyclovir was able to significantly inhibit the expression of viral genes related to CCV viral DNA synthesis and suppress viral replication at a safe concentration. Furthermore, acyclovir blocked the cytopathic effects and apoptosis induced by CCV, thereby maintaining the normal cellular morphological structure, as shown by the protection of CCO cells from the formation of apoptotic bodies or nuclear fragmentation. Moreover, reverse transcript quantitative polymerase chain reaction (RT-qPCR) demonstrated that acyclovir suppressed the expression of caspase 3, caspase 8 and caspase 9, while there was no significant impact on the expression of the apoptosis-inhibiting gene bcl-2 in CCV-infected cells. In addition, acyclovir did not promote the expression of immune-related genes such as MyD88, Mx1, IRF3, IRF7, IFN-I, NF-kB and IL-1β, suggesting that the antiviral activity of acyclovir to CCV infection is not achieved by facilitating the expression of immune-related genes in CCO cells. Taken together, the results from this study suggest that acyclovir could effectively regulate CCV-induced infection, and thus is a promising therapeutic agent against CCV. Our results will aid our understanding of the pharmacological mechanisms of antiviral agents.

Topics: Acyclovir; Animals; Antiviral Agents; Apoptosis; Catfishes; Cytopathogenic Effect, Viral; Female; Fish Diseases; Fish Proteins; Gene Expression Regulation, Viral; Ictalurivirus; Ovary; Viral Proteins; Virus Replication

The therapeutic efficacy of 9-(2-hydroxyethoxymethyl) guanine (Acyclovir, ACV) was evaluated using Oncorhynchus masou virus (OMV) and chum salmon fry. The fish, which were experimentally infected with OMV, were treated with ACV either orally or by the immersion method. Daily immersion of fish into ACV solution (25 microgram/ml, 30 min/day, 15 times) reduced mortality of the infected fish. Oral administration of the drug (25 microgram/fish per day, 60 times) did not affect survival of the chum salmon. On the contrary, the group administered 5-iodo-2'-deoxyuridine (IUdR) by the oral route showed a higher survival than the ACV-administered group. This suggested that an effective level of ACV was not maintained in fish given the drug by the oral route. Daily immersion of infected fish into ACV solution (25 microgram/ml, 30 min/day, 60 times) considerably suppressed the development of tumors induced by OMV.

Topics: Acyclovir; Animals; Fish Diseases; Herpesviridae Infections; Neoplasms; Salmon