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The present study is an approach to investigate the chromosomal pattern of Biomphalaria alexandrina snails. This may be useful for breaking the hostparasite relationship, which is very specific and dependable on the genetic (chromosomal) status of these hosts. Freshwater snails are essential for the transmission of schistosomiasis by acting as intermediate hosts for the diseasecausing parasite. The objective of this study clarifies the four meiotic divisions that begin with Interphase, prophase, metaphase, and anaphase by Transmission Electron Microscope (TEM) and measuring the lengths of chromosomes by Scanning Electron Microscope (SEM). Results showed the number of the chromosomes of B. alexandrina snails N=18, 2N=36 including 4 types of chromosomes, 5 metacentric pairs, 4 submetacentric pairs, 3 acrocentric pairs, and 6 telocentric pairs chromosomes, they were arranged in a descending manner according to the total length that between 12-2 µm. Notably, the present work is the first chromosomal study of B. alexandrina snails by using TEM and SEM. So high-resolution SEM has proven to be a useful tool for chromosomal study. [ABSTRACT FROM AUTHOR]

The present study was conducted to study the protective effect of ethanolic extract of propolis given subcutaneously (S/C) either alone or in combination with inactivated formalized Pasteurella multocida (P. multocida) vaccine in rabbits challenged with virulent P. multocida strain. Twenty-eight New-Zealand rabbits, 6 - 8 weeks old and not vaccinated against pasteurellosis, were randomly divided into four equal groups. Group (1) was kept as nonvaccinated control. Group (2) was injected S/C with propolis. Group (3) was vaccinated (S/C) with P. multocida vaccine only. Group (4) was injected with vaccine mixed with propolis as adjuvant. Groups (2,3, and 4) received the same doses of propolis and vaccine after 4 weeks as a booster dose. The experiment continued for six weeks during which clinical signs, body weight, and mortality rate were recorded. Blood samples were collected every 2 weeks of treatment for evaluating the erythrogram and biochemical parameters. At the end of six weeks, all groups were subjected to challenge with a virulent strain of P. multocida. Two weeks later, tissue specimens were collected from different organs for histopathological investigation. Results showed that before challenge all rabbits of different groups were apparently healthy and had good appetite. After challenge, control group (1) showed acute form of the disease, 100% mortality rate, and severe histopathological changes. Rabbits of groups (2 and 3) showed less severe clinical signs, mortality rate, and histopathological changes than control. Rabbits of group (4) were apparently healthy with normal histological picture. In conclusion, an ethanolic extract of propolis injected alone or combined with formalized inactivated P. multocida vaccine improved general health conditions, liver and kidney functions in addition to reduction of the severity of adverse clinical signs, mortality rates, and histopathological changes associated with challenge of rabbits with P. multocida strain. [ABSTRACT FROM AUTHOR]

The present study was conducted to study the protective effect of ethanolic extract of propolis given subcutaneously (S/C) either alone or in combination with inactivated formalized Pasteurella multocida (P. multocida) vaccine in rabbits challenged with virulent P. multocida strain. Twenty-eight New-Zealand rabbits, 6 - 8 weeks old and not vaccinated against pasteurellosis, were randomly divided into four equal groups. Group (1) was kept as nonvaccinated control. Group (2) was injected S/C with propolis. Group (3) was vaccinated (S/C) with P. multocida vaccine only. Group (4) was injected with vaccine mixed with propolis as adjuvant. Groups (2,3, and 4) received the same doses of propolis and vaccine after 4 weeks as a booster dose. The experiment continued for six weeks during which clinical signs, body weight, and mortality rate were recorded. Blood samples were collected every 2 weeks of treatment for evaluating the erythrogram and biochemical parameters. At the end of six weeks, all groups were subjected to challenge with a virulent strain of P. multocida. Two weeks later, tissue specimens were collected from different organs for histopathological investigation. Results showed that before challenge all rabbits of different groups were apparently healthy and had good appetite. After challenge, control group (1) showed acute form of the disease, 100% mortality rate, and severe histopathological changes. Rabbits of groups (2 and 3) showed less severe clinical signs, mortality rate, and histopathological changes than control. Rabbits of group (4) were apparently healthy with normal histological picture. In conclusion, an ethanolic extract of propolis injected alone or combined with formalized inactivated P. multocida vaccine improved general health conditions, liver and kidney functions in addition to reduction of the severity of adverse clinical signs, mortality rates, and histopathological changes associated with challenge of rabbits with P. multocida strain. [ABSTRACT FROM AUTHOR]

Background: The internal defense system of snails consists of both cellular and humoral components. Circulating haemocytes are the principle line of cellular defense. The susceptibility of fresh water snails of genus Biomphalaria to infection by Schistosoma mansoni (S. mansoni) is linked to the haemocytes present in the haemolymph. While the humoral component includes lysosomal enzymes, that helps in recognition of pathogens and parasites. Material and Methods: In the present work, Biomphalaria alexandrina (B. alexandrina), snails were exposed individually to S. mansoni infection; according to their response they were classified into susceptible group (shed cercariae) and resistant group (failed to shed cercariae). Snails not exposed to infection were considered as control group. Flow cytometric analysis was carried out for detecting apoptosis of B. alexandrina haemocytes isolated from pooled haemolymph and tissue. Results: This study is used to discriminate and count the percentage of viable, apoptotic, necrotic, and dead cells in haemolymph of all studied groups. Comparing to control group, we observed that viable cells were the most common cells that significantly decreased in both infected and non-infected groups (P<0.001, P<0.01 respectively), and showed significant decrease in infected in comparison with non-infected group (P<0.01). The haemolymph in infected group showed that dead cells were the most common cells (more than the viable, apoptotic and necrotic cells). At the same time, the apoptotic cells showed decrease in the condensation and de- condensation of DNA. This means failure to restore DNA. Conclusions: There was a significant variation in the number of the cells between susceptible and resistant snails. In susceptible snails the defense process failed, this was confirmed with increase of the dead cells in the infected haemolymph. While in resistant snails the viable spreading cells described as immunological active, are predominantly found in the haemolymph and tissue. [ABSTRACT FROM AUTHOR]

COVID-19 pandemic, which caused by the newly emerged severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), puts the entire world in an unprecedented crisis, leaving behind huge human losses and serious socio-economical damages. The clinical spectrum of COVID-19 varies from asymptomatic to multi-organ manifestations. Diabetes mellitus (DM) is a chronic inflammatory condition, which associated with metabolic and vascular abnormalities, increases the risk for SARSCoV-2 infection, severity and mortality. Due to global prevalence, DM effect on COVID-19 outcomes as well as the potential mechanisms by which DM modulates the host-viral interactions and host-immune responses are discussed in this review. This review also highlights the effects of anti-diabetic drugs on treatment of SARS-CoV-2 infection and vice versa. [ABSTRACT FROM AUTHOR]

Infectious bronchitis virus (IBV) is one of the major respiratory diseases of broiler causing huge economic losses. The inability to control IBV using different vaccination programs owing to the high mutation rate and recombination ability of the RNA genome generates IBV variants. This study was designed to give a specific perspective of carvacrol effect on early immune response, viral shedding titer, oxidative stress, serum biochemical parameters and clinical consequences in broilers experimentally infected by IBV. One hundred and twenty-one-day old commercial broiler chicks were equally divided into 4 groups. First group was considered as control. Second group was given carvacrol, third group was infected with IBV and fourth group was given carvacrol and infected with IBV. Infection with variant IBV induced significant upregulation of chicken interferon-inducible transmembrane protein 3 (chIFITM3) gene in trachea, elevations in serum levels of Alpha-1 acid glycoprotein (α1-AGP) and Interleukin 6 (IL-6), total leucocytic count (TLC), heterophil/lymphocyte (H/L) ratio and oxidative stress in lung and kidney tissues. Beside, histopathological changes in trachea, lung and kidney induced by IBV, elevation of kidney function tests was detected. The pretreatment with carvacrol significantly reduced viral shedding titer, chIFITM3 gene expression, IL-6 and α1-AGP levels, leucocytic response and H/L ratio with minimization of clinical signs intensity. Also, carvacrol relieved oxidative stress, ameliorated the increased uric acid level and histopathological alterations in kidney and lung caused by viral infection. • Carvacrol significantly reduced tracheal shedding titer of IBV. • Carvacrol significantly decreased chIFITM3 gene expression in trachea. • Carvacrol diminished serum levels of IL-6 and α1-AGP. • Carvacrol relieved leucocytic response and histopathological changes induced by IBV. [ABSTRACT FROM AUTHOR]

Abstract: Hepatitis E virus (HEV) is an important cause of hepatitis among young Egyptian adults with high seroprevalence rates seen in both rural areas of the Nile Delta and in suburban Cairo. Because natural antibodies to HEV have been detected in animals and zoonotic transmission is postulated, we surveyed work horses in Cairo for evidence of HEV exposure and viremia. Sera from 200 Cairo work horses were tested by ELISA for the presence of IgG anti-HEV antibody revealed a seropositivity of 13%. Among 100 samples processed for detection of viral genome by means of nested polymerase chain reaction (N-PCR), 4% were positive and indicative of viremia. Viremic animals were less than 1 year old. Relative to PCR-negative horses, PCR-positive animals demonstrated significant elevation of AST (p =0.03). Phylogenetic analysis of a 253-bp fragment, in the ORF-1,2,3 overlap region of the HEV genome from the viremic animals showed that three of these viral strains to be identical, and closely related (97–100% nucleotide identity) to two human isolates from Egypt, and distant (78–96%) from 16 other HEV isolates from human and animals and shared 99.6% NI with the fourth strain. The consensus sequence of the four strains was origin obtained elsewhere. These data indicated that horses acquire HEV infection and suggest that cross-species transmission may occur. Whether horses play a role in the transmission of HEV needs further investigation. [Copyright &y& Elsevier]