SARS-CoV-2 seroprevalence determination in pets and camels in Egypt using multispecies enzyme-linked immunosorbent assay.

The coronavirus disease 2019 (COVID-19) pandemic has translated into a worldwide economic recession and public health crisis. Bats have been incriminated as the main natural host for the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is the causative agent of the COVID-19 pandemic. However, the reservoir and carrier hosts of the virus remain unknown. Therefore, a cross sectional serosurvey study was performed to estimate antibodies to SARS-CoV-2. To assess IgM antibodies to SARS-CoV-2 nucleocapsid protein (NP), a SARS-CoV-2 Double Antigen Multispecies diagnostic enzyme-linked immunosorbent assay kit was used. The seropositive samples were confirmed and validated by measuring IgG antibody titers in sera. The enrolled animals were from different locations in the Giza governorate, Egypt, and were sampled at the time of the pandemic; they comprised 92 companion animals and 92 domestic camels. The study established that 4.76% (1/21 clinical samples) of dogs, 7.69% of cats (1/13 shelter samples) and 1.08% (1/92) of camels, had measurable SARS-CoV-2 NP IgM antibodies. All IgM-seropositive samples were IgG positive with a measurable titer of 34.5, 28.6, and 25.8 UI/mL for dog, cat, and camels, respectively. According to our best knowledge, this study was the first to assess SARS-CoV-2 seroprevalence in the specific animals investigated in Egypt. These results may herald a promising epidemiological role for pet animals and camels in SARS-CoV-2 virus maintenance. Thus, our study's results ought to be confirmed with a nationwide seroprevalence study, and further studies are required to clarify whether these animals act as active or passive carriers.

Decision tree risk analysis for FMD outbreak prevention in Egyptian feedlots.

Foot and Mouth Disease (FMD) is one of the most contagious and economically influential viral diseases on animal health and productivity. Introduction of newly purchased animals to beef farms constitutes a greater risk for the FMD outbreaks in endemic countries. Physical examination of newly purchased animals in live animal markets and/or at the receiving farm, and the timing of preventative FMD vaccination may reduce the risk of FMD outbreaks under endemic conditions. Small (< 50 animals) and medium (50-500 animals) sized beef farms in Egypt constitute more than 60% of the country's beef industry where protocols for receiving newly purchased animals vary widely between farms. The current risk analysis aimed to build a decision tree model to reduce FMD outbreaks associated with introduction of replacement cattle on Egypt's medium sized beef farms. Management practices explored were the use of physical examinations and FMD vaccination and their timing for replacements with the goal of reducing losses due to FMD outbreaks. A producer survey revealed that more than 50% of the study herds relied on live animal markets as a source for replacements and reported more FMD outbreaks (P-value=0.09), FMD herd morbidity > 50% (p-value=0.05), and weight loss > 15 kg/animal in FMD clinical cases (P-value=0.01) in comparison to herds that received replacements from other farms, imported, or purchased from small stakeholders. More than 70% of the surveyed farms received replacements ≤ 1year old and reported significantly higher FMD outbreaks (P-value=0.02) in comparison to farms that received older animals. More than 80% of the surveyed farms performed physical examination of newly purchased animals before arrival at their premises. Of the surveyed farms, 73% reported FMD outbreaks with 67% of the outbreaks being reported during the Fall and Winter seasons. The decision tree identified physical examination of newly purchased animals prior to arrival and mixing with a premises beef herd followed by vaccination against FMD upon arrival as the intervention resulting in the lowest probability of FMD outbreak (8.9%). In contrast, herds that did not perform physical examination and delay the FMD vaccination for two or more weeks had the highest probability of FMD outbreaks (33.5%).

The Role of Silver Nanoparticles in a Treatment Approach for Multidrug-Resistant Salmonella Species Isolates.

PURPOSE: The main objective of this study is to investigate the antibacterial activity of silver nanoparticles (AgNPs) against multidrug-resistant Salmonella isolates recovered from diarrheic  sheep and goats. METHODS: This study used chemical reduction synthesis of AgNPs to evaluate their antimicrobial effects by estimation of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) for each isolate using the microplate dilution method and tetrazolium salt reduction test to detect the viability percentage. In vivo treatment efficacy was assessed in mice by determining the viable count of Salmonella Enteritidis recovered from feces and by hematologic, biochemical and histopathologic examinations to confirm that use of AgNPs has no toxic or pathologic effects and to evaluate its ability in tissue regeneration following treatment. RESULTS: All recovered strains were identified as MDR with a prevalence of 4% and 3.6% in sheep and goats, respectively. The results of TEM, DLS, Zeta potential, and FTIR revealed typical characteristics of the synthesized AgNPs. Silver nanoparticles showed antibacterial activity against all recovered strains with MIC of ≤0.02-0.313 µg/mL (mean average 0.085±0.126 µg/mL) and MBC of 0.078-1.250 µg/mL (average 0.508±0.315 µg/mL). In vivo efficacy of AgNPs was observed by a reduction in the number of viable S. Enteritidis recovered from feces in an S. Enteritidis infected mouse model, with complete shedding stopping between treatment days 4 and 6. Hematologic, serum biochemical, and histopathologic analyses proved the ability of AgNPs to suppress inflammatory reaction caused by S. Enteritidis infection. CONCLUSION: The study proved the effective ability of AgNPs to fight MDR Salmonella spp. in vitro and in vivo without adverse effects.