Real-time polymerase chain reaction as a rapid and efficient alternative to estimation of picornavirus titers by tissue culture infectious dose 50% or plaque forming units

Waterborne virus transport and the associated risks in a large lake

Waterborne enteric viruses in lakes, especially at recreational water sites, may have a negative impact on human health. However, their fate and transport in lakes are poorly understood. In this study, we propose a coupled water quality and quantitative microbial risk assessment (QMRA) model to study the transport, fate and infection risk of four common waterborne viruses (adenovirus, enterovirus, norovirus and rotavirus), using Lake Geneva as a study site. The measured virus load in raw sewage entering the lake was used as the source term in the water quality simulations for a hypothetical scenario of discharging raw wastewater at the lake surface. After discharge into the lake, virus inactivation was modeled as a function of water temperature and solar irradiance that varied both spatially and temporally during transport throughout the lake. Finally, the probability of infection, while swimming at a popular beach, was quantified and compared among the four viruses. Norovirus was found to be the most abundant virus that causes an infection probability that is at least 10 times greater than the other viruses studied. Furthermore, environmental inactivation was found to be an essential determinant in the infection risks posed by viruses to recreational water users. We determined that infection risks by enterovirus and rotavirus could be up to 1000 times lower when virus inactivation by environmental stressors was accounted for compared with the scenarios considering hydrodynamic transport only. Finally, the model highlighted the role of the wind field in conveying the contamination plume and hence in determining infection probability. Our simulations revealed that for beaches located west of the sewage discharge, the infection probability under eastward wind was 43% lower than that under westward wind conditions. This study highlights the potential of combining water quality simulation and virus-specific risk assessment for a safe water resources usage and management.

Potential of rosmarinic acid to ameliorate toxic effects of diethyl methoxy thio‑phosphoryl thio‑succinate on albino wistar rats' lung, mast cell infiltration inhibitory pathway

Malathion (MA) is a widely used pesticide in agriculture. It can cause toxicity in different organs of the body. Rosmarinic acid (RO) is found in rosemary extract that can be absorbed through gastrointestinal tract mucosa with potent antioxidant, and anti-inflammatory potential. The current study is designed to investigate the potential of RO to protect the lung after MA administration. Forty albino rats were allocated equally to four groups. C-group received corn oil. RO-group received RO orally. MA-group received MA. MA-RO-group received RO in addition to MA. After three weeks the lungs were dissected for histopathological and biochemical investigations. MA-group showed manifestations of severe inflammation with inflammatory cells infiltration in the lung. MA-RO-group showed limited inflammatory cell infiltration. C-group and RO-group appeared with weak anti-survivin immunoreactivity. MA-group showed strong positive immunoreactivity. The reactivity was weakly positive in MA-RO-group. MA-group showed a significant decrease in SP-D gene expression in comparison to the C-group, in addition, MA-RO-group showed a significant increase in SP-D expression. In conclusion, the current study approves that oral administration of MA causes lung injury as it has inflammatory effects, caused by oxidative stress and reports the potential of RO to protect lung tissue against toxic effects of MA through its anti-inflammatory, antioxidant, and anti-apoptotic potential.

Detection of Betanodavirus in experimentally infected European seabass (Dicentrarchus labrax, Linnaeus 1758) using non-lethal sampling methods

One of the major disease threats affecting the Mediterranean aquaculture industry is viral encephalopathy and retinopathy (VER). The target organs for Betanodavirus detection are the brain and eyes, obtained through lethal sampling. This study aimed to evaluate the efficacy and suitability of non-lethal samples for detecting Betanodavirus in European seabass (Dicentrarchus labrax). European seabass juveniles were infected with Betanodavirus, by either an intramuscular injection or immersion (10⁷ TCID₅₀ /ml and 10⁶ TCID₅₀ /ml, respectively), and samples collected 7, 15 and 30 days post-infection (dpi). The brain was collected as a lethal sample, and gills, caudal fin and blood as non-lethal tissues for detecting Betanodavirus by quantitative reverse transcription PCR (RT-qPCR). The presence of virus in non-lethal tissues was inconsistent, with lower viral loads than in the brain. For blood, higher viral loads were detected in intramuscular-infected fish at 15 dpi until the end of the challenge. Serum antibodies against Betanodavirus were assessed using an enzyme-linked immunosorbent assay (ELISA). Antibodies were detected as early as 7 dpi, with higher mean antibody titres at 15 and 30 dpi. The presence of Betanodavirus-specific antibodies indicates that this is a suitable evaluation method for detecting early stages of the infection.