Aim:Rickettsioses have an epidemiological importance that includes pathogens, vectors, and hosts. The dog tick Rhipicephalus sanguineus and the camel tick Hyalomma dromedarii play important roles as vectors and reservoirs of Rickettsiae. The aim of this study was to determine the prevalence of Rickettsiae in ixodid ticks species infesting dogs and camels in Egypt, in addition to, the morphological and molecular identification of R. sanguineus and H. dromedarii.Materials and Methods:A total of 601 and 104 of ticks’ specimens were collected from dogs and camels, respectively, in Cairo, Giza and Sinai provinces. Hemolymph staining technique and OmpA and gltA genes amplification were performed to estimate the prevalence rate of Rickettsiae in ticks. For morphological identification of tick species, light microscope (LM) and scanning electron microscope (SEM) were used. In addition to the phylogenetic analyses of 18S rDNA, Second internal transcript spacer, 12S rDNA, cytochrome c oxidase subunit-1, and 16S rDNA were performed for molecular identification of two tick species.Results:The prevalence rate of Rickettsiae in ticks was 11.6% using hemolymph staining technique and 6.17% by OmpA and gltA genes amplification. Morphological identification revealed that 100% of dogs were infested by R. sanguineus while 91.9% of camels had been infested by H. dromedarii. The phylogenetic analyses of five DNA markers confirmed morphological identification by LM and SEM. The two tick species sequences analyses proved 96-100% sequences identities when compared with the reference data in Genbank records.Conclusion:The present studies confirm the suitability of mitochondrial DNA markers for reliable identification of ticks at both intra- and inter-species level over the nuclear ones. In addition to, the detection of Rickettsiae in both ticks’ species and establishment of the phylogenetic status of R. sanguineus and H. dromedarii would be useful in understanding the epidemiology of ticks and tick borne rickettsioses in Egypt.

The main objective of this study is to investigate the antibacterial activity of silver nanoparticles (AgNPs) against multidrug-resistant Salmonella isolates recovered from diarrheic sheep and goats Methods: This study used chemical reduction synthesis of AgNPs to evaluate their antimicrobial effects by estimation of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) for each isolate using the microplate dilution method and tetrazolium salt reduction test to detect the viability percentage. In vivo treatment efficacy was assessed in mice by determining the viable count of Salmonella Enteritidis recovered from feces and by hematologic, biochemical and histopathologic examinations to confirm that use of AgNPs has no toxic or pathologic effects and to evaluate its ability in tissue regeneration following treatment. Results: All recovered strains were identified as MDR with a prevalence of 4% and 3.6% in sheep and goats, respectively. The results of TEM, DLS, Zeta potential, and FTIR revealed typical characteristics of the synthesized AgNPs. Silver nanoparticles showed antibacterial activity against all recovered strains with MIC of ≤0.02-0.313 μg/mL (mean average 0.085 ±0.126 μg/mL) and MBC of 0.078-1.250 μg/mL (average 0.508±0.315 μg/mL). In vivo efficacy of AgNPs was observed by a reduction in the number of viable S. Enteritidis recovered from feces in an S. Enteritidis infected mouse model, with complete shedding stopping between treatment days 4 and 6. Hematologic, serum biochemical, and histopathologic analyses proved the ability of AgNPs to suppress inflammatory reaction caused by S. Enteritidis infection. Conclusion: The study proved the effective ability of AgNPs to fight MDR Salmonella spp. in vitro and in vivo without adverse effects.

Rickettsioses including their pathogens, vectors, and hosts have an epidemiological importance and zoonotic importance. The objective of the present article was to define the prevalence and genotypic properties of Rickettsia in camels and their ticks in Egypt. Sixty one blood samples and 99 adult ticks were taken from camel hosts from Cairo, Giza and Sinai, during a period extending from 2013 to 2014. Based on the morphological identification of both male and female tick specimens, 91.9 % of the collected ticks were Hyalomma dromedarii. The prevalence of Rickettsia in camels using Gimenez staining technique and PCR was 0 and 41 %, respectively. The rickettsiae infection in ticks recorded 10.1 and 1.01 %, by Gimenez stain and PCR, respectively. Further, the phylogenetic analysis was conducted based on the sequences of OmpA and gltAgenes and three intergenic spacers (mppA, dksA and rpmE) of Rickettsia species. The phylogenetic analyses revealed a novel strain of Rickettsia africae in Hyalomma marginatum that was collected from camel in Sinai province. In addition, the phylogenetic analysis based on Clustal omega suggested that Rickettsia sequences which detected in camels were R. africae. Moreover, the highest Rickettsial infection rate was recorded in age groups of 17 to 19 years (80.0 %), Abady camel breeds (56.8 %) and ticks-infested camels (42.8 %). Concerning hematological changes, macrocytic anemia and leucopenia were recorded in camels with rickettsioses. The molecular characterization of Rickettsia detected in camels and their tick vectors will help in a better understanding of the epidemiological approach of rickettsioses in Egypt.

T HE present work was undertaken to study the incidence of β-haemolytic streptococci infection in equine. On clinical examination of a community of 524 Arabian foals and horses in Cairo-Egypt, a total of 164 animals were selected showing respiratory signs (31.30 %) of which 62 (11.83 %) showed respiratory signs and lymph nodes abscessation. Two hundred and twenty six swabs,164 nasal,31submaxillary lymph node pus and 31 retropharyngeal lymph node pus, were collected from 164 foals and horses showing respiratory signs and/ or abscessed lymph nodes for Streptococci isolation and PCR confirmation. A total of 150 isolates of Streptococci were recovered from 226 samples with sample-wise prevalence of (66.37%). Out of these 150 isolates, 124(28.67%) were identified as Streptococcus equisubsp. equi, 26(17.33%) as S. equisubsp.zooepidemicus and no S. dysgalactiae subsp. Equisimilis were identified. The incidence of S. equisubsp.Equi and S. equisubsp.Zooepidemicus infection among the total animal population, in the present study, was 11.83 and 4.96 % respectively. PCR technique showed high sensitivity and specificity for the detection of S. equi species in the examined samples.

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