Enteroviruses belong to the Picornaviridae family and infect a wide range of mammals including cattle. Bovine enterovirus (BEV) has recently been reclassified into E and F serotypes. BEV was first isolated in Egypt in 1966 although it has been known in other countries since the 1950s. In this study, BEV-F2 was isolated from calves with severe diarrhea and the isolated viruses were subjected to molecular characterization. Illumina sequencing of one of the isolates revealed the presence of a complete BEV-F genome sequence. The phylogenetic analysis revealed nucleotide substitutions along the genome in comparison with other known strains of BEV-F (HQ663846, AY508697 and DQ092795). Two primer sets were designed from the 3D and 5'NTR regions and used for the examination of the remaining isolates, which were confirmed to be of the BEV-F2 serotype. The availability of the complete genome sequence of this virus adds to the sequence database of the members of Picornaviridae and should be useful in future molecular studies of BEV.

Sheeppox virus (SPPV) is one of the listed and notifiable disease affect sheep production with major effect on the trade of new breed of sheep. This study was conducted to identify sheep pox by using cell culture, electron microscope (EM) and open reading frame (ORF) 103 gene during an outbreak of local breed of sheep occurred in Sharkia Governorate, Egypt in April 2017. Affected adult sheep showed typical skin pox lesion on face, the inner side of lips, inner aspect of the thigh and under the tail. The incidence rate of infection was 23.5% and the mortality rate in young lambs aged 3 to 6 months old was 8.2%. Forty-three scabs and tissue samples from clinically diseased adult sheep and dead lambs were collected and subjected to culture on Vero cell. The cytopathic effect (CPE) was observed within 3 to 7 days in 40 samples. A typical Poxvirus was a brick-like shape with round ends by negative staining of EM and ovoid like structure with dumb-bell shaped DNA core with concave bodies sides by positive staining of EM. By conventional PCR utilizing ORF103 gene and obtained bands of about 570 bp referred to SPPV. The sequence amplicon was analyzed by NCBI-BLAST and register in GeneBank under accession N. MG873537 and phylogentic tree was designed which revealed that the isolated strain of SPPV was resembled with other strains of SPPV isolated in Egypt, India, China, and USA. Finally, both EM and PCR are considered as sensitives, rapids, and powerful methods to identify SPPV from tissue and scab's samples without the need of further culture in addition to the useful and easily use of ORF103 gene to differentiate SPPV from other Capripoxvirus.

Parainfluenza virus type 3 (PIV-3) can infect a wide variety of mammals including humans, domestic animals, and wild animals. In the present study, bovine parainfluenza virus type 3 (BPIV-3) was isolated from nasal swabs of Egyptian cattle presenting with clinical signs of mild pneumonia. The virus was isolated in Madin-Darby bovine kidney (MDBK) cells and confirmed by reverse transcription-polymerase chain reaction (RT-PCR). The complete genome of Egyptian BPIV-3 strain was sequenced by using next generation (Illumina) sequencing. The new isolate classified with genotype A of BPIV-3 and was closely related to the Chinese NM09 strain (JQ063064). Subsequently in 2015–16, a molecular surveillance study was undertaken by collecting and testing samples from cattle and buffaloes with respiratory tract infections. The survey revealed a higher rate of BPIV-3 infection in cattle than in buffaloes. The infection was inversely proportional to the age of the animals and to warm weather. This report should form a basis for further molecular studies on animal viruses in Egypt.

This study was applied on a cattle farm of Holstein cows at Sharkia Governorate for the isolation and identification of Bovine herpesvirus type-1 (BoHV-1) and to examine its effect on T lymphocytes. The results of clinical examination revealed that there were respiratory disorders in 30 out of 150 (20%) of cattle including elevated body temperature (40 to 42°C), nasal and ocular discharges, some animals developed severe rhinitis, conjunctivitis, corneal opacity, cough and diarrhea. Out of 30 nasal swabs, 15 swabs were positive for virus isolation as indicated by cytopothic effect (CPE) on MDBK cells. Only 11 of the 15 isolates were confirmed by virus neutralization test (VNT) as BoHV-1 isolates. In addition, only 3 out of 4 BoHV-1 isolates were detected by PCR. Peripheral blood T lymphocytes (PBTL) were analyzed using electron microscopy and comet assay to examine the effect of BoHV-1 on lymphocytes. Electron micrographs of T lymphocytes revealed peripheral condensation of chromatin and fragmentation of the nucleus end of the cell leading to the formation of apoptoic bodies. Comet assay denoted fragmentation of cellular DNA. It could be concluded that BoHV-1 can infect T lymphocytes of cattle, causing directly and indirectly apoptosis which subsequently lead to suppression of cellmediated immunity, enhancing establishment of latency and increasing the probability for secondary bacterial infection.

Bovine herpes virus type 1 (BoHV-1) is an economically important, worldwide distributed pathogen of domestic and wild Bovidae. It causes respiratory tract manifestations and/or abortion. The present study was achieved to study seroprevalence and isolate BoHV-1 from suspected cattle, buffaloes, sheep and goats collected from three governorates in Egypt (Menofya, Kalubeya and Dakahlia) during the years 2017 and 2018. Serum and milk samples obtained from apparently healthy non-vaccinated animals were tested for detection of BoHV-1 specific antibodies by indirect ELISA method. A total of 78 (22.5%) serum samples and 46 (13.3%) milk samples out of 346 and 300 samples, respectively, were positive. Virus was isolated from nasal swabs and lung tissue samples on chorio-allantoic membrane (CAM) of 11-day-old specific pathogen free embryonated chicken eggs. It showed pin-point small foci, scattered on CAM membrane. Examination by electron microscope using positive staining methods showed the characteristic morphology of the herpes virion (an enveloped virus with 120 to 200 nm diameter). The viral isolate was confirmed to be BoHV-1 in a PCR assay using specific primers produced a fragment (575 bp) of gC encoding gene in the viral DNA genome.