Newcastle disease (ND) is considered to be one of the most economically significant avian viral diseases. It has a worldwide distribution and a continuous diversity of genotypes. Despite its limited zoonotic potential, Newcastle disease virus (NDV) outbreaks in Egypt occur frequently and result in serious economic losses in the poultry industry. In this study, we investigated and characterized NDV in wild cattle egrets and house sparrows. Fifty cattle egrets and fifty house sparrows were collected from the vicinity of chicken farms in Kafrelsheikh Governorate, Egypt, which has a history of NDV infection. Lung, spleen, and brain tissue samples were pooled from each bird and screened for NDV by real-time reverse transcriptase polymerase chain reaction (RRT-PCR) and reverse transcriptase polymerase chain reaction (RT-PCR) to amplify the 370 bp NDV F gene fragment. NDV was detected by RRT-PCR in 22 of 50 (44%) cattle egrets and 13 of 50 (26%) house sparrows, while the conventional RT-PCR detected NDV in 18 of 50 (36%) cattle egrets and 10 of 50 (20%) of house sparrows. Phylogenic analysis revealed that the NDV strains identified in the present study are closely related to other Egyptian class II, sub-genotype VII.1.1 NDV strains from GenBank, having 99.7–98.5% identity. The pathogenicity of the wild-bird-origin NDV sub-genotype VII.1.1 NDV strains were assessed by experimental inoculation of identified strains (KFS-Motobas-2, KFS-Elhamoul-1, and KFS-Elhamoul-3) in 28-day-old specific-pathogen-free (SPF) Cobb chickens. The clinical signs and post-mortem changes of velogenic NDV genotype VII (GVII) were observed in inoculated chickens 3 to 7 days post-inoculation, with 67.5–70% mortality rates. NDV was detected in all NDV-inoculated chickens by RRT-PCR and RT-PCR at 3, 7, and 10 days post-inoculation. The histopathological findings of the experimentally infected chickens showed marked pulmonary congestion and pneumonia associated with complete bronchial stenosis. The spleen showed histocytic cell proliferation with marked lymphoid depletion, while the brain had malacia and diffuse gliosis. These findings provide interesting data about the characterization of NDV in wild birds from Egypt and add to our understanding of their possible role in the transmission dynamics of the disease in Egypt. Further research is needed to explore the role of other species of wild birds in the epidemiology of this disease and to compare the strains circulating in wild birds with those found in poultry.

Fish are a source of high-quality protein with low cholesterol, but they are susceptible to parasitic infections, which have a significant impact on aquaculture, in addition to their zoonotic potential. The present study estimated parasitic infections and evaluated the diversity of zoonotic parasites in freshwater Nile tilapia (Oreochromis niloticus) in Assiut Governorate, Upper Egypt. A total of 300 samples were randomly collected from the Assiut Governorate. These fish were examined for both ectoparasites and endoparasites, followed by the experimental infection of mice with encysted metacercariae (EMC) for the retrieval of the adult worms. The overall prevalence of the variable parasites was 82% (246 of 300). Both ecto- and endoparasites were detected in 41% (123 of 300) of the examined fish. The identified ectoparasites were Gyrodactylus, Dactylogrus, Cichlidogyrus, Trichodina and Icthyophthirius multifiliis, in 5%, 4%, 22%, 6% and 4% of the fish, respectively. The endoparasites were trematodes (Orientocreadium batrachoides 3%), nematodes (Contracaecum. 2%), acanthocephala (Acanthosentis tilapiae 25%) and protozoa that included Isospora and Eimeria spp., in 1% and 8% of fish, respectively. Myxobolus was detected in 2% of the examined fish. The overall prevalence of encysted metacercariae (EMC) was 95% (285 of 300), while infection with macroscopic EMC had a prevalence of 37% and microscopic EMC had a prevalence of 58%. The adult worms recovered from the experimental infections were Prohemistomum vivax and Mesostephanus spp., which belong to the family Cyathocotylidae. Collectively, these findings reflect the relatively high occurrence of parasites among the studied fish, confirming the necessity of strict measures to control infection.

The aquaculture industry is a fast-growing sector in Egypt; however, the progress of this industry is impeded by many challenges such as poor water quality and associated bacterial infections. Among others, Motile Aeromonas Septicemia (MAS), caused by aeromonads, is among the most important bacterial diseases affecting aquaculture due to its zoonotic potential. In the present work, motile aeromonads were isolated from water samples (n= 8) and Nile tilapia (n= 240) in four fish farms (farms I, II, III, and IV) in Kafr El-Sheikh province during the period March to August 2017. This step was followed by investigation of the prevalence and phenotypic, molecular, and histopathological characterization of aeromonads. In addition, antimicrobial susceptibility and virulence gene detection were analyzed. Interestingly, physicochemical water analysis revealed different ranges in relation to the fish farms and seasons. More importantly, Aeromonas isolates were phenotypically identified in 33.3% and 12.5% from fish and water samples, respectively. The highest prevalence of motile aeromonads (46.7%) was recorded from farm IV, and only 12.5% of water samples were positive for them. Out of 80 isolates, 65 (81.25%) were molecularly identified at the genus level using gyrase B (gyrB). The prevalence of the virulence genes detected in the isolated motile aeromonads was aerolysin (aer), 52.2%; elastase (ahp), 26.25%; hemolysin (hyl), 35%; and lipase (lip), 3.75%. The antibiogram profile revealed that the highest resistance of aeromonads isolates (80%) was recorded to chloramphenicol, kanamycin, and azithromycin. Meanwhile, lower resistance levels of 40%, 30%, and 20% were found for streptomycin, cefotaxime, and amoxicillin, respectively. The multiple antibiotic resistance (MAR) index values ranged between 0.27 and 0.82 of motile aeromonads isolates. Furthermore, the histopathological examinations of naturally diseased tilapia revealed widespread hepatocellular necrosis with diffuse, numerous rod-shaped bacteria in liver with melanomacrophages and lymphocytic depletion with edema and hemosiderosis in the spleen. Our findings provide an updated epidemiological baseline for future reference and highlight the likely role of the adverse impact of water quality in the outbreaks of motile aeromonads with special reference to virulence genes and antibiotic resistant traits.

In this study, we determined the prevalence and toxin types of antibiotic-resistant Clostridium perfringens in chicken, pigeons, camels, and humans. We investigated the inhibitory effects of AgNPs on biofilm formation ability of the isolates and the genetic relatedness of the isolates from various sources determined using RAPD-PCR. Fifty isolates were identified using PCR, and all the isolates were of type A. The cpe and cpb2 genes were detected in 12% and 56% of the isolates, respectively. The effect of AgNPs on biofilm production of six representative isolates indicated that at the highest concentration of AgNPs (100 µg/mL), the inhibition percentages were 80.8–82.8%. The RAPD-PCR patterns of the 50 C. perfringens isolates from various sources revealed 33 profiles and four clusters, and the discriminatory power of RAPD-PCR was high. Multidrug-resistant C. perfringens isolates are predominant in the study area. The inhibition of biofilm formation by C. perfringens isolates was dose-dependent, and RAPD-PCR is a promising method for studying the genetic relatedness between the isolates from various sources. This is the first report of AgNPs’ anti-biofilm activity against C. perfringens from chickens, pigeons, camels, and humans, to the best of our knowledge.

Mange has been considered one of the most common parasitic infestations among camels. It adversely impacts animal productivity and poses a risk to human health. Given the scarcity of available data about mange in camels, the current study focused on the prevalence of camel mange and its associated risk factors in Aswan Governorate, Egypt. Towards this end, a general visual inspection was conducted on camels (N = 210) in different markets and slaughterhouses in Aswan Governorate. Skin scrapings from suspect infected camels were also examined microscopically. Importantly, these findings were further checked and confirmed by histopathology on samples from suspected cases collected post-slaughter in abattoirs. The possible risk-associated factors, which include the camel’s age, sex and sampling season, were recorded and statistically analyzed. Interestingly, the data showed that a total of 100 camels (47.6%) were found exclusively infested by sarcoptic mange. Furthermore, the predominant histopathological changes included burrowing tunnel of mites in the skin, hyperkeratosis and acanthosisconsis of the epidermis, while the dermis showed hemorrhage, mononuclear inflammatory cell infiltration around the blood vessels and perifolliculitis. These major histopathological findings are consistent with sarcoptic mange. Furthermore, the statistical analysis of the possible associated risk factors, camel’s age (p = 0.006), gender (p = 0.032) and sampling season (p = 0.004), were all found to be significantly affected and related to the disease. In this regard, camels ≥2 years old were found at higher risk of infection (odds ratio (OR) = 2.75; 95% confidence interval (CI), 1.345 to 5.604) versus younger animals (OR = 0.36; 95 CI, 0.1784 to 0.743). Females had higher odds of exposure (OR = 2.02; 95% CI, 1.096 to 3.708) compared to males (OR = 0.50; 95% CI, 0.269 to 0.912). Moreover, the exposure to infection was reported higher in winter (OR = 2.30; 95% CI, 1.297 to 4.098) than in summer (OR = 0.43; 95% CI, 0.244 to 0.771). Collectively, our data provide novel epidemiological and histopathological support for sarcoptic mange being widespread among camels in the studied area. Sarcoptic mange is extremely contagious and zoonotic. Therefore, our baseline investigation indicates an urgent need for additional multicenter-studies to investigate the occurrence of this disease in camels and humans combined with the appropriate control measures of camel importation for combating this disease.

Sarcocystosis is considered one of the major parasitic diseases with a worldwide distribution. It is caused by the obligatory intracellular protozoan parasites of the genus Sarcocystis. Besides its public health issues, sarcocystosis results in significant economic losses due to its impact on productivity and milk yield. A wide range of final and intermediate hosts have been identified, including mammals, birds, and reptiles; however, few studies have investigated the contribution of camels to maintaining the epidemiological foci of the disease in countries such as Egypt. The present study was conducted to grossly and histopathologically identify the prevalence rate of Sarcocystis spp. in camels (N = 100) from the Aswan Governorate, Egypt. Furthermore, the major risk factors related to the development of sarcocystosis in camels were investigated. Samples from the diaphragm, cardiac muscle, esophagus, and testes of the slaughtered camels were collected. Interestingly, Sarcocystis was detected in 75% of the examined camels. Following the studied variable factors, camels aged 5 years or more were found to be at higher risk, with an infection rate of 87.7% (57 of 65) than those younger than 5 years. The infection rate was 81.4% (57 of 70) in males and 60% (18 of 30) in females. The esophagus was the most affected organ (49%), followed by the diaphragm (26%) and cardiac muscle (17%), whereas none of the testes samples were affected. Taken together, the present study demonstrates the high prevalence of Sarcocystis in the examined camels and suggests the importance of these animals in preserving the epidemiological foci of sarcocystosis in Egypt. Future research should map the circulating strains in Egypt and aim to raise public health awareness about the importance of sarcocystosis and other related zoonotic diseases.