Hamdi M O H A M E D Sallam

ABSTRACT:
Infectious bronchitis (IB) is considered to be one of the major causes of
economic loss in the chicken production sector in many countries including Egypt, even in vaccinated flocks. In the present study, tracheal swabs and different organs (trachea, paranasal sinuses , bronchi , lung and kidney) were collected from 30 broiler farms showing respiratory signs and variable mortalities in different localities of Behira governorate at the period from January 2017 to March 2020 in order to determine the genetic changes occurred in hypervariable region I and II of S1 gene of IBV and also the pathological changes associated its infection. The virus was isolated then detected by real-time RT-PCR in the fore mentioned samples. About 56.7% (17/30) from the investigated farms were positive for IBV infection. S1 gene has been partially sequenced for three recent isolates and phylogenetic analysis revealed close relatedness with each other. These isolates belong to genotype 1- lineage 23 (G1- 23), and shared less than 84.4% and 79.5% nucleotide and amino acid identities, respectively, with the commercial vaccine strains used in Egypt. The study also showed similar pattern of viral evolution to IBV at Egypt and Israel. Pathological examination of paranasal sinuses, trachea and bronchi revealed the presence of mucous exudate, epithelial erosion in some cases and hyperplasia in others. Lung showed severe interstitial pneumonia while kidneys showed multiple focal areas of necrosis with lymphocyte aggregation. It can be concluded that IBV strains isolated from
Beheira governorate are distinct from vaccine strains and should be included  in vaccine production that will help in improving IBV control.

Key words:foot and-mouth disease; quarantine measures; epidemiological state; ELISA Although it was the first animal disease to be attributed to a virus, which was the second virus to be discovered, foot-and-mouth disease (FMD) is still one of the most important animal diseases causing many economic losses. Many outbreaks of the disease have been occurred worldwide after introduction of new animals into the herd. Therefore, a high attention should be done during animal importation from areas in which the disease has been recorded. During this study, three groups of cattle were quarantined and examined for the presence of anti-3ABC antibody which indicates previous infection in order to evaluate the efficiency of the quarantine measures; applied during cattle importation; for detection of infected animals. Serum samples were collected and examined three times for both group (A) and (B), and four times for group (C) along a period of 34, 48 and 46 days respectively. Positive results obtained from all serum examinations except from the third serum examination of group (A). This study showed that one time examination of cattle for detection of FMD infection during 30 days quarantine period isn't enough for detection of all infected animals, and clarified the crucial role of the quarantine period in detection of FMD infected animals that delay in the response to the infection.

Newcastle disease (ND) is a highly contagious viral disease that causing high economic losses among poultry farms. The disease is caused by Newcastle disease virus (NDV) that frequently reported in Egypt although of intensive vaccination. Continuous genetic characterization of the virus along with detection of genetic variations in relation to the vaccine strains, are important for proper disease control. Clinical samples were collected from broiler farms in six Egyptian governorates during 2020−2022. NDV was isolated on embryonated chicken egg and identified by real time reverse transcriptase-PCR. Nineteen NDV isolates namely (HS1NDV−HS19NDV) were identified by RT-PCR and deposited on GeneBank database under the accession nos. (OP588159−OP588177). All the isolates found to be velogenic according to the amino acid sequences of the cleavage sits (GRRQKRF). In addition these strains were assigned under genotype VII and sub-genotype VII.1.1. In relation to vaccine strains, comparison o...

Adeno-associated viruses (AAVs) are defective members of the genus Dependoparvovirus. Waterfowl parvoviruses, another member of the Dependoparvovirus, were found to be the closest relative of AAVs. This study was performed to identify the genetic changes that may occur to goose parvovirus (GPV) in one Muscovy duck flock that was observed for 12 weeks after the virus was isolated. Persistent watery diarrhea and wing deformity were the common signs. Cloacal swabs were collected from diseased ducks. Unexpectedly, the identified virus was an AAV. The closest strains were duck AAVs at the nucleotide level, identified in Australia and China. Meanwhile, only 52.3% of nucleotide identity was shared with the GPV strain, previously identified from this flock. Duck adenovirus (DAdV) could not be identified in the samples. This study is one of the first studies in which genetic changes of GPV were tracked. In addition, emerging duck AAV from GPV is suggested, which will be useful for future vir...