For the aim of genotypic fingerprinting of Brucella melitensis bv3 isolated from different ruminant species in Kafrelsheikh governorate, Egypt, a multilocus variable-number tandem-repeat analysis (MLVA 16) has been approached. The MLVA 16 was performed on 41 B. melitensis bv3 isolates identified by bacteriological and molecular techniques. Thirty-one isolates originated from the preferential host (28 sheep and three goats), and ten isolates from atypical hosts (nine cattle and one buffalo). Recovering the same genotype in two different animal species suggests cross-species adaptation of B. melitensis bv3 to different atypical ruminant species in Egypt. Furthermore, the isolation of B. melitensis from aborted cows after the entry of a replacement cow from an unknown brucellosis status herd in cattle farms that had never reared small ruminants indicates that cows can be infected and spread the infection without the presence of the original host. Our results further showed that different genotypes of B. melitensis could be isolated from different samples of the same animal. The local geographic distribution of genotypes showed a very close genetic relatedness with previously reported genotypes outside the study area. Worldwide, all genotypes and strains identified in this study were mostly related to the Western Mediterranean lineage and were less likely to the Americas clonal lineage. In conclusion, uncontrolled animal movement and the ability of B. melitensis to spread among atypical hosts in the absence of the original hosts are potential causes for the failure of brucellosis control programs in endemic areas. The legal importation and illegal movement of cattle and sheep are the main factors for maintaining the infection of B. melitensis within the country. Further investigations are required to understand the reasons for the presence of more than one genotype of B. melitensis in the same animal and the efficacy of the current applied strategy for brucellosis control.

Newcastle disease (ND), caused by avian orthoavulavirus type-1 (NDV), is endemic in poultry in the Middle East causing continuing outbreaks in poultry populations despite efforts to vaccinate. In the past, genotype 2.XXI (former 2.VI) was present in poultry in Egypt but has been replaced by genotype 2.VII. We investigated whether virus evolution contributed to superseding, and focused on the antigenic sites within the Heamagglutinin-Neuramindase (HN) spike protein. Full length sequences of a NDV genotype 2.VII isolate currently circulating in Egypt was compared to a genotype 2.XXI isolate that was present as co-infection with vaccine type viruses (2.II) in an historical isolate of the year 2011. Amino acid differences in the HN glycoprotein for both 2.XXI and 2.VII viruses amounted to 11,7% and 11,9 % compared to LaSota vaccine type. However, mutations within the globular head (aa 126-570), bearing relevant antigenic sites, were underrepresented (aa divergence of 8,8% and 8,1 % compared to 22,4% and 25,6% within the fragment encompassing cytoplasmic tail, transmembrane part and stalk regions (aa 1-125) for genotypes 2.XXI and 2.VII, respectively. Nevertheless, reaction patterns of HN-specific monoclonal antibodies revealed differences between vaccine type viruses and genotype 2.XXI and 2.VII viruses for specific epitopes. Accordingly, compared to Egyptian vaccine type isolates and the LaSota vaccine reference strain, single aa substitutions in 6 of 10 described neutralizing epitopes were found within the attachment protein. However, the same alterations in neutralization sensitive epitopes were present in old genotype 2.XXI as well as in newly emerged genotype 2.VII isolates. In addition, isolates were indistinguishable by polyclonal chicken sera raised against different genotypes including vaccine viruses. These findings suggest, that factors other than antigenic differences within the HN-protein account for facilitating spread of genotype 2.VII while displacing genotype 2.XXI viruses in Egypt.