Refinar búsqueda
Resultados 31-40 de 463
A survey of antimicrobial residues in table eggs in Khartoum State, Sudan, 2007–2008
2012
Mohamed M. Sirdar | Jackie Picard | Shahn Bisschop | Alexander R. Jambalang | Bruce Gummow
The risk to consumers of antimicrobial residues in table eggs produced in Khartoum State, Sudan, was studied. All producing layer farms (n = 175) in the state were sampled in April, June and August 2008. A total of 933 eggs from 335 layer houses were screened for antimicrobial residues by using the growth inhibition of Geobacillus stearothermophilus var. calidolactis in-house test. A high proportion of layer farms (72% in April, 61% in June and 66% in August) and layer houses (63% April, 59% in June and 61% in August) were found to have antimicrobial residues, with no significant difference in prevalence (p = 0.57) between study periods. The study showed that the consumer was at constant risk of exposure to antimicrobial residues in table eggs. The paper discusses reasons for the high prevalence of antimicrobial residues in Sudanese eggs and its implications, and makes recommendations to address this important public health problem.
Mostrar más [+] Menos [-]Blocking Babesia bovis vaccine reactions of dairy cattle in milk
2012
Michael P. Combrink | Graham Carr | Ben J. Mans | Frances Marais
The use of 1.16 mg/kg (one third) of the recommended dose of diminazene aceturate, administered indiscriminately to cattle on day seven of the unfrozen <em>Babesia bovis</em> and <em>Babesia bigemina</em> bivalent live blood vaccine reaction, was an infection and block treatment method of immunisation used successfully with no known adverse effect on the parasites or the development of protective immunity. Continuing with this practice after replacement of the unfrozen vaccine with deep-frozen monovalent <em>B. bovis</em> and <em>B. bigemina</em> live blood vaccines resulted in reports of vaccine failure. Laboratory investigation indicated the harmful effect of block treatment in preventing the development of durable immunity against <em>B. bigemina</em> as opposed to the much lesser effect it had on <em>B. bovis</em>. Consequently the practice was no longer recommended. A <em>B. bovis</em> vaccination attempt aimed at controlling the disease of dairy cows in milk (<em>n</em> = 30) resulted in 20% fatalities during the expected vaccine reaction period. The practice of block treating <em>B. bovis</em> was therefore reinvestigated, this time in a field trial using dairy cattle in milk (<em>n</em> = 11). Using 0.88 mg/kg (one quarter) of the recommended dose of diminazene administered on day 12 of the <em>B. bovis</em> vaccine reaction resulted in only two animals (<em>n</em> = 5) testing ≥ 1/80 positive with the indirect fluorescent antibody test (IFAT) although parasites could be demonstrated in three. In the untreated control group, by contrast, five of the vaccinated animals (<em>n</em> = 6) tested ≥ 1/80 positive with IFAT and parasites could be demonstrated in all. The unsatisfactory outcome obtained in this study, combined with that of the earlier investigation, indicated that there are more factors that influence successful vaccination than previously considered. It is therefore concluded that block treatment of the live frozen South African cattle babesiosis vaccines reactions is not recommended.
Mostrar más [+] Menos [-]Morphological Studies on the Postnatal Development of the Gut-associated Lymphoid Tissues of the Rabbit Cecum
2012
Abdelmohaimen M. Saleh
The macroscopic, morphometric, light and scanning electron microscopic structure of gut-associated lymphoid tissue (GALT) of cecum were studied in the rabbits aged from birth to 16 weeks. The GALT were formed of lymph follicles covered by low columnar epithelium containing intraepithelial lymphocytes and leukocytes. They were concentrated at the ileocecal entrance (ileocecal patch) and in the blind end of the cecum vermiform appendix. In the ileocecal patch, GALT were in direct contact with the lumen, while those of the appendix were covered by the interval intestinal villi in young rabbits and mucosal folds in the adult rabbits. The lymphoid follicles of the ileocecal patch were composed of dome region and germinal center and were separated by narrow inter-follicular areas. Whereas, the lymphoid follicles of the appendix were composed dome region and germinal center in the newly born rabbits and up to the 2nd week of age, the follicles became composed of four different sites: dome region, germinal center, coronal area, and a wide interfollicular area between neighboring follicles. Morphometrically; the dimensions of the lymphoid follicles of the cecal GALT increased in size with the advancement of the age. By SEM the lymphoid structures covered with special epithelium consisted of two types of cell absorptive enterocytes and M cells. The M cells in the cecal patch were microvilliated and present on the tips and sides of the dome lymphoid regions while in the appendix were non-microvilliated and present only on the sides of the dome regions.
Mostrar más [+] Menos [-]Wildlife-associated zoonotic diseases in some southern African countries in relation to game meat safety: A review
2012
Johan L. Bekker | Louw C. Hoffman | Piet J. Jooste
With on-going changes in land use practices from conventional livestock farming to commercial, wildlife-based activities, the interface or interaction between livestock and wildlife is increasing. As part of the wildlife-based activities of ecotourism, breeding and hunting, game farmers are also exploring the utilisation of meat from hunted or harvested game. The expanding interface or increased interaction between livestock and wildlife increases the risk of disease incidence and the emergence of new diseases or the re-emergence of previously diagnosed diseases. The risk is not only related to domestic and wild animal health, but also to the occupational hazards that it poses to animal handlers and the consumers of game meat. This review endeavours to highlight the role that game plays in the spreading of zoonotic diseases to other animals and humans. Examples of zoonotic diseases that have occurred in wild animals in the past, their relevance and risk have been summarised and should function as a quick reference guide for wildlife veterinarians, ecologists, farmers, hunters, slaughter staff, processors and public health professionals.
Mostrar más [+] Menos [-]Ultrasonographic Differential Diagnosis of Superficial Swellings in Farm Animals
2012
Magda M. Ali | Mohamed A.H. Abd El-Hakiem
This report describes the ultrasonographic differential diagnosis of different types of swellings affecting (28) farm animals. The swellings were, abscess (11), cyst (2), hematoma (2), hernia (9) and urethral diverticulum (4). The swellings varied sonographically according to the type, duration, content and location. Cases suffering the same type of swellings may have some degree of difference in echogenicity according to the period of the swelling. Abscesses appeared as hypo/hyperechoic structures with distinct hyperechoic well-developed capsule. Recent hematomas were anechoic with a well demarcated wall, with increased duration, the hematoma gradually became more echoic and textured. The hernial ring was determined as a discontinuation of the abdominal wall echogenicity and the hernial contents were clearly evaluated via ultrasonography. Recent cysts resembled hematoma in compartmentalization but the location and case history helped the differential diagnosis. Urethral dilatation appeared sonographically as an anechoic to hypoechoic homogenous structure with well demarcated wall and acoustic enhancement. Ultrasonography could be considered a successful, noninvasive, rapid technique for differential diagnosis of different types of swellings in farm animals. It could be easily used under field conditions to screen the lesions before the surgical operations and to fellow up the cases after surgery.
Mostrar más [+] Menos [-]Development of a curriculum for training in One Health analytical epidemiology at the University of Zambia
2012
J. Muma | Martin Simuunza | K. Mwachalimba | M. Munyeme | B. Namangala | C. Hankanga | G. Sijumbila | R. Likwa Ndonyo | Yona Sinkala | A. Mwanza | A. Simanyengwe Mweene
Recently, the world has witnessed emergence of novel diseases such as avian influenza, HIV and AIDS, West Nile Virus and Ebola. The evolution of these pathogens has been facilitated mainly by a constantly evolving animal-human interface. Whilst infectious disease control was previously conceptualised as either public health or animal health related issues, the distinction between disciplinary foci have been blurred by multiple causal factors that clearly traverse traditional disciplinary divides. These multiple evolutionary pressures have included changes in land use, ecosystems, human-livestock-wildlife interactions and antibiotic use, representing novel routes for pathogen emergence. With the growing realisation that pathogens do not respect traditional epistemological divides, the ‘One Health’ initiative has emerged to advocate for closer collaboration across the health disciplines and has provided a new agenda for health education. Against this background, the One Health Analytical Epidemiology course was developed under the auspices of the Southern African Centre for Infectious Diseases Surveillance by staff from the University of Zambia with collaborators from the London School of Hygiene and Tropical Medicine and the Royal Veterinary College in London. The course is aimed at equipping scientists with multidisciplinary skill sets to match the contemporary challenges of human, animal and zoonotic disease prevention and control. Epidemiology is an important discipline for both public and animal health. Therefore, this two-year programme has been developed to generate a cadre of epidemiologists with a broad understanding of disease control and prevention and will be able to conceptualise and design holistic programs for informing health and disease control policy decisions.
Mostrar más [+] Menos [-]Monoclonal Antibody Based Latex Agglutination Test for the Diagnosis of Trypanosomosis in Cattle
2012
Shyma K.P. | S.K. Gupta | Ajit Singh | S.S. Chaudhary | Jayprakash Gupta
Trypanosomosis which is an arthropod borne disease had become the menace to the Indian farmers because of its significant impact on the productive status of the animals. Moreover, the zoonotic effect of this disease has also proved now. Research on newer techniques for the diagnosis of this important disease has been carried out for the past hundred years, and still this search is going on for finding a more sensitive and specific test. The parasitological examination which is used for the diagnosis at the field level misses about 80% of positive cases. Keeping in view the shortcomings of the conventional diagnostic methods we carried out the present investigation for the detection of active infection of Trypanosoma evansi by monoclonal antibody based latex agglutination test (MAb-LAT). About 88 blood samples collected from cattle of the karnal district of Haryana were screened initially by Wet Blood Film (WBF) immediately after collection and their corresponding serum samples were subjected to latex agglutination test. WBF could detect the presence of motile trypanosomes only in three samples (3.41%) where as MAb-LAT detected 53 samples (60.23%) positive for the circulating antigens of Trypanosoma evansi. Study found that MAb-LAT is much sensitive than the conventional parasitological examination. Moreover, MAb-LAT is simple to perform, rapid, and cost-effective and can be used in field-level.
Mostrar más [+] Menos [-]Effect of Seminal Plasma Removal on Cell Membrane, Acrosomal Integrity and Mitochondrial Activity of Cooled Stallion Semen
2012
Dhafer M. Aziz | Heinrich Enbergs
Fresh semen samples were collected from 11 warm blood stallions, each ejaculate was distributed into three equal parts. The first part was diluted in a skim milk-glucose diluent (SMG), the second part was diluted in a skim milk-glucose supplemented with Tyrode's medium (SMG-T), the third part was centrifuged to remove the seminal plasma, then the sperm was resuspended in the second diluent (SMG-T-C). The diluted semen were evaluated immediately after dilution (0 hour) and at 24, 48, 72, and 96 hours of storage at 5°C. Flow cytometry was performed to determine sperm viability, mitochondrial activity and acrosomal integrity. Immediately after dilution the tested parameters of sperms that diluted in SMG-T was significantly (P<0.001) higher than those diluted with SMG and SMG-T-C, and with SMG-T-C were higher significantly (P<0.05) than those diluted with SMG. The decreasing rate in tested sperm parameter was greater significantly (P<0.001) in semen samples which were diluted with SMG than those diluted with SMG-T and SMG-T-C. In conclusion, the present study indicated that viability, acrosomal integrity, and mitochondrial activity of stallion sperms were better preserved in SMG-T in comparison with SMG, also centrifugation and removal of the seminal plasma have an adverse effect on these three sperm parameters.
Mostrar más [+] Menos [-]Immuno-affinity Purification of Insect Cell Expressed Rabies Virus Glycoprotein using a Conformational Specific Monoclonal Antibody
2012
Rajendran Ramya | Shanmugam Rajalakshmi | Bhaskaran Mohana Subramanian | Saripalli Umamaheswara Rao | Krothapalli R.S. Sambasiva Rao | Srinivasan Alwar Villupanoor
.Rabies is a disease of nervous system and causes progressive encephalitis with fatal outcome. The conformation-dependent epitopes on the glycoprotein (G) of rabies virus (RV) is responsible for the induction of virus neutralizing antibodies which is ultimately required to get complete protection from viral challenge. Therefore, a suitable chromatography technique is necessary to purify the tag free recombinant rabies virus glycoprotein (rRVG) without altering its immunogenic epitopes. The present study was undertaken to purify the rRVG using a conformational specific anti-rabies virus glycoprotein (RVG) mAb, M5B4, which binds to the natively folded G. The mAb had shown a significant kinetic interaction with RVG. The mAb immobilized onto the NHS-activated Sepharose 4 fast flow™ was used for the purification of rRVG by immuno-affinity chromatography (IAC). The bound rRVG was eluted in IAC using 0.1M glycine with pH 2.5 and the identity of the purified protein was confirmed by MALDI-TOF. The IAC purified rRVG induced neutralizing antibody response and 83% of the immunized mice were protected against intra-cerebral rabies virus challenge. The results indicate that the mAb based IAC method can be an effective purification technique for tag free rRVG with significant level of purity, without compromising the protein’s immunogenic potential.
Mostrar más [+] Menos [-]Phage Therapy an Effective Remedy Against Drug-Resistant Bugs and Hard to Treat Bacterial Infections-A Review
2012
Mudasir Ali Rather | Mir Nadeem Hassan | Maqsood Ahmad Rather
The injudicious use of antibiotics not only in medicine but also to promote the growth of farm animals has led to the development of antibiotic resistance against many bacterial diseases. One of the remedy against such drug resistant bacterial infections is the application of phage (Bacteriophage) therapy. Phage therapy involves using phages or their products as bioagents for the treatment or prophylaxis of bacterial infections. There are two types of phages based on their type of life cycle: the lytic and the lysogenic phages. Only the lytic phages are used in phage therapy, because of the disadvantages of lysogenic pahges (Superinfection immunity, lysogenic conversion, specialized transduction). Apart from live phages the phage byproducts like phage lysins can also be used specifically against certain bacterial infections. The reports indicate that appropriate administration of living phages can be used to treat lethal infectious diseases caused by bacteria, like Pseudomonas aeruginosa, Escherichia coli, Acinetobacter baumannii, Klebsiella pneumoniae, Salmonella spp. and Staphylococcus aureus etc. In the coming time the phage therapy will compensate for unavoidable complications of antimicrobial therapy, particularly the appearance of multidrug resistance bacteria (super bugs).
Mostrar más [+] Menos [-]