An Emerging Innovative UV Disinfection Technology (Part II): Virucide Activity on SARS-CoV-2

The coronavirus SARS-CoV-2 pandemic has become a global health burden. Surface sanitation is one of the key points to reduce the risk of transmission both in healthcare and other public spaces. UVC light is already used in hospital and laboratory infection control, and some recent studies have shown its effectiveness on SARS-CoV-2. An innovative UV chip technology, described in Part I of this study, has recently appeared able to overcome the limits of old lamps and is proposed as a valid alternative to LEDs. This study was designed to test the virucidal activity on SARS-CoV-2 of a device based on the new UV chip technology. Via an initial concentration of virus suspension of 107.2 TCID50/mL, the tests revealed a viral charge reduction of more than 99.9% after 3 min; the maximum detectable attenuation value of Log10 = 5.7 was measured at 10 min of UV exposure.

ULTRASONIC PROCESSING OF RABIES VIRUS SUSPENSION FOR OBTAINING ANTIGEN-CONTAINING PREPARATIONS FOR DIAGNOSTIC TEST SYSTEMS

The effect of ultrasonic treatment of a virus-containing suspension on the purity of the rabies virus antigenic preparations was studied. It was found that the maximum yield of free of tissue and culture proteins virus is observed when processing 10-20% of the virus-containing suspension at a temperature not exceeding 8-10°C, processing time 3-5 min and a frequency of 30-40 kHz.

Peste des petits ruminants pathogenesis on experimental infected goats by the Moroccan 2015 isolate

Background Peste des petits ruminants (PPR) is a viral disease of major economic importance on small ruminants. Goats are usually known to be more susceptible to the disease. Infection chronology, virus circulation, and the disease early detection need to be better understood. This study evaluates the tissue tropism and pathogenesis of PPR following experimental infection of goats using a lineage IV virus, the most dominant in the world originated from Asia. PPRV infection was experimentally induced in 4 six-month-old goats by intra-nasal and intravenous route of cell virus suspension and from infectious mashed tissue. The clinical signs were observed and goats were euthanized at predetermined clinical score level for post-mortem examinations and PPRV detection by RT-PCR. Clinical signs of infection were present, pyrexia, serous-mucopurulent nasal discharges, coughing, diarrhea and asthenia, for both cell virus suspension and infectious mashed tissue. PPRV genome was highly detected in swabs and tissues with clinical signs dominated by pulmonary attack and digestive symptoms secondary. Results Results of this study indicates that PPRV is an invasive infection in animals that in a short period, less than 10 days, invade all vital organs. On live animals, early diagnostic may be easily done on lacrimal and rectal swabs. Conclusion The experimental PPRV-infection model using the cell virus suspension is suitable for vaccine evaluation as a standard model.

Phenoloxidase activity and haemolymph cytology in honeybees challenged with a virus suspension (deformed wings virus DWV) or phosphate buffered suspension (PBS)

ABSTRACT: The innate immune system of honeybees mainly consists in antimicrobial peptides, cellular immunity and melanisation. In order to investigate the immune response of honeybees to immune stressors, three stress degrees were tested. Newly emerged bees naturally DWV-infected were collected from a Varroa mite-free apiary and divided into three experimental groups: naturally DWV infected bees, PBS injected bees, and artificially DWV super infected bees. Phenoloxidase activity and haemolymph cellular subtype count were investigated. Phenoloxidase activity was highest (P<0.05) in DWV-superinfected bees, and the haemocyte population differed within the three observed groups. Although, immune responses following DWV infection have still not been completely clarified, this investigation sheds light on the relation between cell immunity and the phenoloxidase activity of DWV-naturally infected honeybees exposed to additional stress such as injury and viral superinfection.

Transmission of different nucleopolyhedroviruses by two ectoparasitoids: Bracon hebetor say (Hymenoptera: Braconidae) and Euplectrus plathypenae (Howard) (Hymenoptera: eulophidae)

The transmission of nucleopolyhedroviruses (NPVs) of Autographa gamma (AgNPV), Mamestra brassicae (MbNPV), Lacanobia oleraceae (LoNPV), Helicoverpa armigera (HaNPV) and Xantia c-nigrum (XnNPV) to their relevant larvae by the ectoparasitoid Bracon hebetor and the transmission of the multiple-enveloped NPVs of Spodoptera exigua (SeMNPV) and Spodoptera frugiperda (SfMNPV) by the ectoparasitoid Euplectrus plathypenae was examined. Two methods of contamination of the both parasitoids (exposure to infected hosts and total body surface) and two subsequent transmissions of the viruses by Bracon hebetor to healthy hosts were tested. The results showed that both parasitoids were capable to be mechanical vectors of the tested NPVs. Every Bracon hebetor female was able to transmit subsequently twice the virus in 27% to 52.2% of the five Noctuidae species by preliminary exposing to infected larvae. The second method of contamination (applying virus suspension to the total body surface of the parasitoid) was also efficient causing virus infection in between 29.4% and 54.15% of the larvae. The parasitoid E. plathypenae transmited the virus from infected to noninfected larvae in 20% and 25.57% of the S. frugiperda and S. exigua larvae, and 6.43% and 11.10%, respectively of them died from the virus infection. The same observation was established by the second method of contamination - respectively 33.33% and 40% infection and between 13.23% and 16.67% mortality. The mortality of all tested larvae exposed to virus contaminated parasitoids was higher when the parasitoid entire body surface had been artificially contaminated with the virus than when the parasitoid itself was previously allowed to oviposit the larvae.

DISPERSION AND FIXATION OF ADENO-ASSOCIATED VIRUS WITH GLUTARALDEHYDE FOR AFM STUDIES

Sample preparation is an important procedure for atomic force microscope (AFM) studies. However, flexible virus particles have a tendency to aggregate together and are easily compressed during sample preparation or by AFM tip that subsequently hamper studying of virus by AFM. Herein, low concentration chemical reagent of glutaraldehyde (2%, v/v) is pre-mixed in virus suspension that facilitates the dispersion and observation of recombinant serotype 2 adeno-associated virus particles deposited on mica surface with little deformation.

Potency of Garlic Extract Against Koi Herpesvirus (KHV) in Common Carp

<p>Prevention of koi herpesvirus (KHV) infection using chemicals or medicines was ineffective way. In this study garlic extract was used to prevent KHV infection. Virus suspension of 0.1 ml and garlic extract of 0.1 ml in different dosage, i.e., 100, 200 and 300 ppt, was injected into common carp body. Hemoglobin concentration, red and white blood cell numbers, and leukocyte number were counted. The results of study showed that administration of 300 ppt of garlic extract could produce higher survival rate (67.5%), good blood parameters and clinical symptoms compared to other treatments.</p> <p>Keywords: garlic, KHV, common carp</p> <p> </p> <p>ABSTRAK</p> <p>Upaya penanggulangan wabah Koi Herpesvirus (KHV) menggunakan bahan-bahan kimia atau obat-obatan adalah tidak efektif. Pada penelitian ini dilakukan pemberian ekstrak bawang putih untuk menanggulangi infeksi KHV. Suspensi virus sebanyak 0,1 ml ditambahkan dengan 0,1 ml ekstrak bawang putih dengan berbagai konsentrasi, yaitu 100, 200 dan 300 ppt, disuntikkan ke dalam tubuh ikan mas. Kadar hemoglobin, jumlah sel darah merah dan sel darah putih jenis dan jumlah leukosit diamati. Hasil penelitian menunjukkan bahwa pemberian ekstrak bawang putih sebanyak 300 ppt menghasilkan kelangsungan hidup (67,5%) yang lebih baik dibandingkan dengan perlakuan lainnya, dan begitu pula dengan gambaran darah serta gejala klinisnya. </p> <p>Kata kunci: bawang putih, KHV, ikan mas</p>

Effect of Ultraviolet Radiation on Pathogenity of White Spot Syndrome Virus in Giant Tiger Prawn (Penaeus monodon Fab.)

<p>This experiment was conducted to examine the effect of UV irradiation on pathogenity of white spot syndrome virus (WSSV) in black tiger shrimp (<em>Penaeus monodon</em> Fab.). A hundred ml of WSSV virus suspension (200 μg/ml) were placed at 30 cm under UV light 10 Watt. Radiation on WSSV virus was performed for 15, 30, 45, and 60 minutes. Black tiger sjrimp in density of 260 tails/L were immersed in 1000 ml of irradiated virus suspension (20 μg/ml) to test their pathogenities. The results of study showed that duration of UV irradiation on WSSV virus was reverse correlated to their pathogenities. In constrast, survival of black tiger shrimp was linear correlated to duration of UV inactivation of virus. Higher survival rate of shrimp (65.52%) after challenge test was obtained by irradiation of virus for 60 min.</p> <p>Keywords: WSSV, virus, pathogen, ultraviolet, black tiger prawn, <em>Penaeus monodon</em></p> <p> </p> <p>ABSTRAK</p> <p>Penelitian ini dilakukan untuk mengetahui pengaruh radiasi UV terhadap patogenitas virus <em>White Spot Syndrome Virus</em> (WSSV) pada udang windu (<em>Penaeus monodon </em>Fab). Suspensi virus WSSV dengan konsentrasi 200 μg/ml sebanyak 100 ml ditempatkan 30 cm diradiasi menggunakan UV 10 Watt. Radiasi dilakukan selama 15, 30, 45, dan 60 menit. Udang dengan kepadatan 260 ekor/L direndam dalam 1000 ml suspensi virus (20 μg/ml) hasil radiasi untuk menguji patogenitasnya. Hasil penelitian menunjukkan bahwa lama radiasi UV pada virus WSSV berbanding terbalik dengan tingkat patogenitasnya. Sementara itu, lama inaktivasi virus dengan UV berbanding lurus terhadap kelangsungan hidup udang. Kelangsungan hidup udang windu tertinggi (65,52%) setelah uji tantang diperoleh dengan meradiasi virus selama 60 menit.</p> <p>Kata kunci: WSSV, virus, patogen, ultraviolet, udang windu, <em>Penaeus monodon</em></p>