Tavares Camila Prestes Dos Santos, Dal Pont Giorgi, Stica Paula Valeska, da Silva Ubiratan de Assis Teixeira, Westphal Gisela Geraldine Castilho, Schott Eric J, Ostrensky Antonio
Integrated Group for Aquaculture and Environmental Studies, Federal University of Paraná, Curitiba, Paraná, Brazil.
Graduate Program in Zoology of the Federal University of Paraná, Curitiba, Paraná, Brazil.
J Fish Dis. 2025 Sep;48(9):e14035. doi: 10.1111/jfd.14035. Epub 2024 Nov 4.
Understanding the pathogenicity of viral infections in aquatic organisms is vital due to their substantial impact on aquaculture and wild populations. This study assessed the pathogenicity of Callinectes sapidus Reovirus 2 in Callinectes danae and its effects on the metabolic, immunological and behavioural parameters. CsRV2-negative specimens were divided into CsRV2 inoculum (n = 10) and saline injection (n = 15). After 14 days, all the crabs that received the inoculum tested positive for CsRV2. However, 11 crabs from the control group also tested positive and were subsequently considered an additional experimental group. The cumulative mortality in the group challenged reached 70% after 14 days. RT-PCR revealed Callinectes danae Portunibunyavirus 1 presence in CsRV2-injected crabs, explaining heightened mortality. Ammonia flow remained unaffected, but oxygen consumption was significantly impacted (p < 0.05) by CsRV2 and coinfection, suggesting increased metabolic energy expenditure. The coinfection caused an increase in the proportion of crabs with reflex impairment as a likely consequence of physiological exhaustion. Additionally, there was a trend toward reducing the number of granulocytes in coinfected crabs, indicating that granulocytes may be more affected by coinfection. These findings demonstrate the pathogenicity of CsRV2 in C. danae, with coinfection exacerbating metabolic, behavioural and immunological changes, increasing mortality.
了解病毒感染对水生生物的致病性至关重要，因为它们对水产养殖和野生种群有重大影响。本研究评估了锯缘青蟹呼肠孤病毒2对达纳青蟹的致病性及其对代谢、免疫和行为参数的影响。将CsRV2阴性标本分为CsRV2接种组（n = 10）和生理盐水注射组（n = 15）。14天后，所有接种的螃蟹CsRV2检测呈阳性。然而，对照组的11只螃蟹检测也呈阳性，随后被视为另一个实验组。14天后，受挑战组的累积死亡率达到70%。RT-PCR显示，在注射CsRV2的螃蟹中存在达纳青蟹港布尼亚病毒1，这解释了死亡率的升高。氨流量未受影响，但CsRV2和共感染显著影响了耗氧量（p < 0.05），表明代谢能量消耗增加。共感染导致反射受损的螃蟹比例增加，这可能是生理疲惫的结果。此外，共感染的螃蟹中粒细胞数量有减少的趋势，表明粒细胞可能更容易受到共感染的影响。这些发现证明了CsRV2对达纳青蟹的致病性，共感染加剧了代谢、行为和免疫变化，增加了死亡率。
