Protection of animals against devastating RNA viruses using CRISPR-Cas13s.

The intrinsic nature of CRISPR-Cas in conferring immunity to bacteria and archaea has been repurposed to combat pathogenic agents in mammalian and plant cells. In this regard, CRISPR-Cas13 systems have proved their remarkable potential for single-strand RNA viruses targeting. Here, different types of Cas13 orthologs were applied to knockdown foot-and-mouth disease virus (FMDV), a highly contagious disease of a wide variety of species with genetically diverse strains and is widely geographically distributed. Using programmable CRISPR RNAs capable of targeting conserved regions of the viral genome, all Cas13s from CRISPR system type VI (subtype A/B/D) could comprehensively target and repress different serotypes of FMDV virus. This approach has the potential to destroy all strains of a virus as targets the ultra-conserved regions of genome. We experimentally compared the silencing efficiency of CRISPR and RNAi by designing the most effective short hairpin RNAs according to our developed scoring system and observed comparable results. This study showed successful usage of various Cas13 enzymes for suppression of FMDV, which provides a flexible strategy to battle with other animal infectious RNA viruses, an underdeveloped field in the biotechnology scope.

Marek's Disease Virus in Commercial Turkey Flocks, Iran.

Marek's disease is a significant illness in chickens and a potential threat to the poultry industry worldwide. Marek's disease virus (MDV) causes immunosuppression and lymphoproliferative disease in chickens, but the turkey is an unusual host for the virus, and tumors caused by MDV in turkeys are unique. This study sampled 15 asymptomatic commercial turkey flocks (five spleens from each flock) at slaughter. Gallid alphaherpesvirus 2 (GaHV-2) was identified by PCR of spleen samples of two flocks. A phylogenetic analysis of the Meq gene was also performed. Sequencing and phylogenetic analysis revealed that the turkey GaHV-2 had genetic similarity with GaHV-2 strains recently detected in the Iranian commercial layer and breeder turkey flocks. This is the first time MDV has been detected in turkey flocks of Iran, and therefore, further assays including experimental inoculation to demonstrate pathotype characteristics in vivo are needed.

Nota de investigación- Virus de la enfermedad de Marek en parvadas comerciales de pavos en Irán. La enfermedad de Marek es una enfermedad importante de los pollos y una amenaza potencial para la industria avícola en todo el mundo. El virus de la enfermedad de Marek (MDV) causa inmunosupresión y una enfermedad linfoproliferativa en pollos, pero el pavo es un huésped inusual para este virus y los tumores causados por el virus de la enfermedad de Marek en pavos son únicos. En este estudio se recolectaron muestras de 15 lotes de pavos comerciales asintomáticos (cinco bazos de cada lote) en el momento del sacrificio. El Gallid alphaherpesvirus 2 (GaHV-2) fue identificado por PCR de muestras de bazo de dos parvadas. También se realizó un análisis filogenético del gene Meq. La secuenciación y el análisis filogenético revelaron que el GaHV-2 de pavo tenía una similitud genética con las cepas de GaHV-2 detectadas recientemente en parvadas de postura comerciales y de pavos reproductores iraníes. Esta es la primera vez que se detecta el virus de Marek en parvadas de pavos de Irán y, por lo tanto, se necesitan más ensayos, incluida la inoculación experimental, para demostrar las características del patotipo in vivo.

Oral Abscess Caused by Chryseobacterium indologenes in Ball Python (Python regius); A Case Report.

Chryseobacterium indologenes is an opportunistic pathogen isolated from human infections and, rarely, from some aquatic animals. A 3-year-old male ball python (Python regius) was admitted to the veterinary clinic by a pet owner because of acute respiratory and swallowing failure. During physical examinations, oral secretions and abscesses were observed in the mouth cavity and throat of the animal. After microbiological analysis including isolation, identification, and 16s rRNA sequencing, C. indologenes was detected as the main cause of the oral abscess in this case. Phylogenetic relatedness analysis showed a close relationship between this isolate and other strains isolated from human infections. Antimicrobial susceptibility testing revealed that the isolate was multi-drug resistant. However, it was very sensitive to minocycline, ceftazidime, and tetracycline. The patient was treated by antibiotic therapy and completely recovered after two weeks. To the best of our knowledge, this is the first incidence of C. indologenes in an oral abscess in a ball python. As a result we would consider this organism as an opportunistic animal pathogen with zoonotic potentiality.