Refinar búsqueda
Resultados 1-10 de 29
Meta-analysis of genetic diversity of the VP1 gene among the circulating O, A, and SAT2 serotypes and vaccine strains of FMD virus in Egypt
2020
El Nahas, Abeer F. | Salem, Sayed A.H.
Three strains of the FMD virus (A, O, and SAT 2) were recognised as causes of the FMD circulating in Egypt. The aims of this study were to trace the FMDV isolates from outbreaks in Egypt to understand their epidemiology and evolution and to understand the situation of the vaccine strains compared with the circulating serotypes. A meta-analysis was carried out by using the data available for FMD outbreaks in Egypt from GenBank and the World Reference Laboratory for Foot-and-Mouth Disease (WRLFMD); a comparison was done with both data sets for the three serotypes. MEGA-X was used for the evolution analysis, through constructions of phylogenetic trees for all sequences recorded in GenBank for each serotype in different Egyptian outbreaks in different years and also within the same year. Additionally, nucleotide substitution rate, molecular clock, and mean evolutionary rates were estimated for the three serotypes to understand and compare their evolution. Absence of some records of certain serotype outbreaks from the WRLFMD database was noted as were subsequent missing appropriate vaccine programmes. Genetic variation was recorded among the virus isolates within the same years and also the vaccine strain was associated with up to 26 amino acid substitutions. The evolution rate of the SAT2 strain was the highest of the circulating strains. SAT2 had high amino acid substitution per year at an important immunogenic site (130–170), serotype A had less, and serotype O the least. The need for different strategies for vaccine serotype selection is indicated.
Mostrar más [+] Menos [-]New insight of apparently healthy animals as a potential reservoir for Clostridium perfringens: a public health implication
2018
Hamza, Dalia | Dorgham, Sohad M. | Elhariri, Mahmoud | Elhelw, Rehab | Ismael, Elshaimaa
Introduction: Clostridium perfringens is commonly found in the gastrointestinal tract of animals and humans and continues to cause one of the most prevalent foodborne diseases in man. Material and Methods: A total of 355 samples were examined for the occurrence of C. perfringens: rectal swabs from cattle, sheep, and goats, fresh stool samples from diarrhoea sufferers having been in contact with these animals, irrigation water and soil samples from the husbandry sites, and preharvesting fresh produce from farms irrigated with the sampled water. All samples were collected from Cairo and Giza governorates, Egypt. PCR analysis was carried out with positive isolates using the α-toxin gene. Sequence analysis of the gene of C. perfringens isolates was performed using the neighbour-joining approach. Bootstrap analysis was executed with 1,000 resamplings. Results: 174 C. perfringens strains were isolated with a 49.01% prevalence. The highest prevalence of C. perfringens in apparently healthy animals was found in sheep (65.45%) followed by goats (58%), buffaloes (55%), and cattle (47.1%). Its prevalence in humans being in contact with these animals was 47.5%. The bacterium’s isolation from the soil and irrigation water was achieved in 40% and 31.7% of samples, respectively, posing a risk, particularly when the water and soil contact food in the field, shown by the fresh produce isolation of 40%. A significant relationship between the prevalence of C. perfringens in animal and environmental samples was identified (P < 0.05). A significant relationship was identified neither between animal species and C. perfringens prevalence, nor between the environmental source and C. perfringens prevalence (P > 0.05). All isolates were positive for the α-toxin gene by PCR. The sequence analysis and the phylogenetic relationship of the α-toxin genes from different samples revealed that C. perfringens from faeces of apparently healthy cattle, buffaloes, sheep, and goats is a significant threat in places where it can contaminate the soil and water. In addition, the sequence of C. perfringens from humans suffering from diarrhoea was found in the same cluster with the sequence from cows, goats, and sheep. Conclusion: The role of apparently healthy animals in transmitting C. perfringens to humans, either through being in direct or indirect contact via water or soil in the cultivation of vegetables and fruits, was demonstrated.
Mostrar más [+] Menos [-]Comparative expression analysis of inflammatory and immune-related genes in cattle during acute infection with foot-and-mouth disease virus in Egypt
2021
El Nahas, Abeer F. | Abd El Naby, Walaa S.H. | Khatab, Shymaa A. | Fergany, Al-Zahraa A. | Rashed, Rashed R.
Foot-and-mouth disease is a highly infectious viral disease affecting all cloven-footed domestic animals. The three foot-and-mouth disease virus (FMDV) serotypes A, O and SAT2 are at present the greatest threat to susceptible animals in Egypt. The aim of the present study was, for the host factors associated with different FMDV infections in cattle during the acute phase, to compare these factors’ influence on the expression of the IL-10, TLR-2, TNF-α, CXCL10, CD48, NFATC4 and IFNG inflammatory and immune-related genes. Vesicular fluid and epithelium samples were obtained from at least three infected cattle on the same affected farm during three different FMDV outbreaks and were used for serotyping of the virus and for expression analysis of host genes. A two-step RT-PCR was used for diagnosis of the virus with primers specific for each serotype. In quantitative PCR analysis, the expression patterns of TLR-2 and IFNG were prominent, while NFATC4 expression was absent in all FMDV-infected cattle. The highest expression of CD48 was associated with increased expression of other inflammatory and immune-related genes (IL-10, TLR-2, TNF-α and IFNG), which may be an indication of rapid virus clearance. The use of vesicular fluid and epithelium for investigation of viral and immune-related gene expression levels in acute FMDV infection is possible. Host-dependent variation in the expression of the studied genes was observed in different FMDV serotype outbreaks.
Mostrar más [+] Menos [-]Carbapenem-resistant Pseudomonas aeruginosa originating from farm animals and people in Egypt
2019
Elshafiee, Esraa A. | Nader, Sara M. | Dorgham, Sohad M. | Hamza, Dalia A.
Carbapenem-resistant Pseudomonas aeruginosa (CRPA) has become the leading cause of health care-associated infections. Treatment is difficult due to the lack of an effective antimicrobial therapy, and mortality is high. This study investigated the occurrence of CRPA in farm animals (buffaloes and cattle), livestock drinking water, and humans in Egypt. A total of 180 samples were examined: 50 faecal each from buffaloes and cattle, 30 of livestock drinking water, and 50 stool from humans. The samples were cultured on cetrimide agar and the plates were incubated aerobically at 37°C for 24 h. The isolates were examined for the presence of the blaKPC, blaOXA₋₄₈, and blaNDM carbapenemase-encoding genes using PCR and investigated for the exotoxin A (toxA) gene. The toxA gene from carbapenem- group resistant isolates was phylogenetically analysed. P. aeruginosa was isolated from buffaloes, cattle, drinking water, and humans, with occurrences of 40%, 34%, 10%, and 20%, respectively. Carbapenem resistance genes were found in 60%, 59%, 67%, and 70% in buffalo, cattle, water and human samples, respectively. The toxA gene was detected in 80% of samples. The phylogenetic analysis showed that cattle and water sequences were in one cluster and more related to each other than to human isolates. Occurrence of CRPA among farm animals, drinking water, and humans was high, reflecting the environmental origin of P. aeruginosa and highlighting contaminated water as a potential transmitter of CRPA to livestock and next to humans.
Mostrar más [+] Menos [-]Carbapenem-resistant Pseudomonas aeruginosa originating from farm animals and people in Egypt
2019
Elshafiee Esraa A. | Nader Sara M. | Dorgham Sohad M. | Hamza Dalia A.
Carbapenem-resistant Pseudomonas aeruginosa (CRPA) has become the leading cause of health care-associated infections. Treatment is difficult due to the lack of an effective antimicrobial therapy, and mortality is high. This study investigated the occurrence of CRPA in farm animals (buffaloes and cattle), livestock drinking water, and humans in Egypt.
Mostrar más [+] Menos [-]Determination of the optimal inactivation time of FMD virus Type "A" using BEI inactivator during the outbreak 2006 in Egypt and its effect on the antigenicity of the virus
2018
A. A. Omar | H. M. A. Azab | M. M. Abdel-Aty | S. M. Ali | M. A. Farag
FMD virus type A/1/ Egypt 2006 was inactivated with 0.1 M of BEI (Binary ethylene imine) formed by cyclization of 2- Bromoethyl-amine hydrobromide (BEA) in 0.2 N NaoH at 37oC with PH 8.0 for 24 hours. The virus was complete inactivated after 15 hours post inactivation. No residual virus particles were detected when inoculated in tissue culture. The inactivation rates are linear with a regular loss of titer ranged from 0.5- 1.0 log10 / hour. Control sample of virus at 37oC without BEI showed only a loss of 1.0 log from the original infectivity titer after 24 hours. The sample of virus which kept at -20oC, without BEI, showed loss 0.3 log10 from its original infectivity titer after 24 hours. There is no change in the complement fixing antigen before and after inactivation process with BEI inactivator and in the CFT 7 dilution of antigen was stable (fixed) pre and post inactivation of virus. Also it was found that the inactivation rate of BEI was higher than the inactivation with pure Ethylenimine (EI) and formalin.
Mostrar más [+] Menos [-]The prevalence of Infectious Bronchitis (IB) in some chicken farms in Egypt: III. Cross protection of vaccinated chickens versus field IB virus
2010
K. M. Kamel | A. A. Bassiouni | M. A. Afify | N. S. Rabie
Four groups of one-day-old SPF chicks were inoculated with the four IBV variants at 1 day old to study the virulence of these isolates. The results at 2 weeks post infection (PI) revealed that all isolates were able to induce serological resposne postinfection, respiratory distress and depression. 20% and 100% mortalities were recorded with isolates 4 and 23; respectively. Assessment of pathogenicity index and pathotyping (at the end of observation period “2wk-PI”), categorized the 4 tested isoaltes (4, 16,18, 23) into three isoaltes of high virulence (4, 18 and 23), and one isolate of intermediate virulence (16). About 50% reduction in body weight was recorded with the four IBV isolates 2 wk PI. Kidney lesions were nephritis-nephrosis with urate deposition in ureters, while microscopic lesions were associated with increase in the amount of rough endoplasmic reticulum (RER). Tracheal lesions recorded as increase the amount of mucin, while microscopic lesions were edema of mucosa and inflammatory cells in the lamina propria. The regime of administering the infectious bronchitis (IB) live commercial H120 vaccine at 1 day old SPF chicks, and the heterologous challenge with four variants (serotypes) at 4 weeks of age, was found to be poorly effective in protecting the respiratory tract of SPF chickens with protection percentages of 8.1%, 55%, 10.5% and 12.6% corresponding to field isolates of IBV 4, 16, 18 and 23; respectively. Protection was measured by assessing ciliary activity of the tracheal epithelium following challenge. It is suggested that the use of the live IB-H120 vaccine will not always broaden the protection against challenge with IB multiple serotypes isolated from Egypt. Therefore it is necessary to develop a new IB vaccines, either locally prepared or imported to overcome any new IB serotype that were emerged, through modifying vaccination strategies to make them appropriate to the field situation.
Mostrar más [+] Menos [-]Seroprevalence of Babesia ovis in small ruminants in Siwa Oasis, Egypt
2007
H. I. Hosein | Samia A. Ahmed | F. A. Ibrahim | T. R. Abou-Elnaga | M. A. Gebely | Mona A. Mahmoud
Seroprevalence of Babesia ovis in sheep and goats was studied in Siwa Oasis between January 2002 and January 2003. A total of 240 blood samples were collected from 108 sheep and 132 goats for preparation of blood smears and for separation of serum samples and tested against B. ovis by using IFAT. B. ovis was detected in 55 (50.92%) and 59 (44.69%) blood smears examined in sheep and goats, respectively. The overall prevalence of B. ovis infection was 71.3% in sheep and 68.2% in goat using IFAT. The seasonal prevalence of B.ovis peaked in both spring and summer as revealed by blood smear examination and IFAT. A total of 143 ticks were collected from 62 sheep and 81 goats during the study. The ticks examined were Rhipicephalus turanicus (75.52%) and Hyalomma anatolicum (24.48%).
Mostrar más [+] Menos [-]Light and electron microscopy of Paranella diplodae N. SP. (Polyopisthocotylea;Microcotylidae; Monogenea ) from some Red Sea Teleost fishes in Egypt
2007
E. M. Bayoumy | O. K. Abd El-Hady | M. A. Hassanain
The present study deals with a monogenean parasite infecting, some marine fish through light and scan electron microscopy. It revealed that the percentage of infection was 48% (14 out of 50 fish), 28% (14 out of 50 fish), 22% (11 out of 50 fish) and 16% (8 out of 50 fish) in Diplodus noct, Gerres oyena, Lethrinus elongates and Siganus revulatus, respectively. The present work recorded Paranaella diplodae (Polyopisthocotylea; Microcotylidae; Monogenea) as a new species collected from the investigated fish gills. They are lanculate flukes, the haptor is not distinguished from the body proper approximately 1/3 of the whole body length. The surface topography of the parasite bears small pits and conspicuous transverse folds and richly supplied with papillae-like unicellate sensory ending. The opisthohaptor is typical of Microcotylidae. The clamp structure and the haptoral tegument are similar to the rest of the body
Mostrar más [+] Menos [-]Characterization of Variant Strain of Newcastle Disease Virus in Egypt
2007
A. S. Abdel-Moneim | Azza A. El-Sawah | M. A. Kandil
During 2005, velogenic Newcastle disease virus (NDV) caused a major outbreak among commercial broiler chicken in Egypt. The outbreak raised concerns regarding the protective immunity of commercially available vaccines for prevention and control of this virus in poultry. The virus was isolated from broiler farm suffered from more than 95% mortalities. The isolate was confirmed not to be avian influenza virus (AIV) by rapid chromatographic strip test, and characterized as NDV using reverse transcription-polymerase chain reaction (RT-PCR) which amplified a portion of the fusion gene of NDV and haemagglutination inhibition (HI) test. This isolate confirmed to be velogenic viscerotropic NDV by mean death time (MDT) test and pathogenicity to 7-week old chickens. We tried to determine whether the existing commercial live NDV La Sota vaccine could provide protection against the isolated virus or not. Birds received a single dose of live La Sota type vaccine at 3 weeks of age and were challenged 2 weeks postvaccination with a lethal dose of NDV. Results indicated that the live vaccine did not protect against morbidity but reduced mortality in comparison to controls. All unvaccinated control chickens challenged with NDV died within 5 days post-challenge (pc). Protection from disease did not correlate with the presence of antibody titers (determined by HI) at day of challenge. These results underscore the need to develop new NDV vaccines and vaccine strategies for use during outbreak situations to protect birds from both disease and infection and to reduce virus shedding.
Mostrar más [+] Menos [-]