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The involvement of the hypothalamopituitary-adrenocortical axis in stress physiology and its significance in the assessment of animal welfare in cattle 全文
2017
Emma J. Brown | Andre Vosloo
The intensification of cattle production has raised concern for animal welfare due to the stress that is associated with farming practices. The welfare of an animal is determined by the animal’s ability to cope with or adapt to its continuously changing environment and the biological cost that is associated with this adaptation and maintenance. Stressors arise from various psychological, physiological and physical aspects of farming practices due to management and human–cattle interactions. Measuring the activity of the hypothalamopituitary-adrenocortical (HPA) axis with plasma cortisol levels is a useful method for determining the effects of stress on animals as it is stimulated at the onset of a perceived stress. The activation of the HPA axis affects various target tissues or systems and can result in suppression of the immune system, increased susceptibility to disease and adverse effects on reproductive success in prenatal and neonatal calves. Although some levels of stress associated with farming practices are unavoidable, improvements in farming methods need to be implemented in order to maintain or increase the efficiency of cattle production in a way that does not compromise the welfare of the animal.
显示更多 [+] 显示较少 [-]B-cell epitopes of African horse sickness virus serotype 4 recognised by immune horse sera 全文
2017
Evans M. Mathebula | Frederika E. Faber | Wouter van Wyngaardt | Antoinette van Schalkwyk | Alri Pretorius | Jeanni Fehrsen
B-cell epitopes of African horse sickness virus serotype 4 recognised by immune horse sera 全文
2017
Evans M. Mathebula | Frederika E. Faber | Wouter van Wyngaardt | Antoinette van Schalkwyk | Alri Pretorius | Jeanni Fehrsen
Identifying antigenic proteins and mapping their epitopes is important for the development of diagnostic reagents and recombinant vaccines. B-cell epitopes of African horse sickness virus (AHSV) have previously been mapped on VP2, VP5, VP7 and NS1, using mouse, rabbit and chicken monoclonal antibodies. A comprehensive study of the humoral immune response of five vaccinated horses to AHSV-4 antigenic peptides was undertaken. A fragmented-genome phage display library expressing a repertoire of AHSV-4 peptides spanning the entire genome was constructed. The library was affinity selected for binders on immobilised polyclonal immunoglobulin G (IgG) isolated from horse sera collected pre- and post-immunisation with an attenuated AHSV-4 monovalent vaccine. The DNA inserts of binding phages were sequenced with Illumina high-throughput sequencing. The data were normalised using preimmune IgG-selected sequences. More sequences mapped to the genes coding for NS3, VP6 and VP5 than to the other genes. However, VP2 and VP5 each had more antigenic regions than each of the other proteins. This study identified a number of epitopes to which the horse’s humoral immune system responds during immunisation with AHSV-4.
显示更多 [+] 显示较少 [-]B-cell epitopes of African horse sickness virus serotype 4 recognised by immune horse sera 全文
2017
Mathebula, Evans M.(Onderstepoort Veterinary Institute Agricultural Research Council ,University of Pretoria Department of Veterinary Tropical Diseases) | Faber, Frederika E.(Onderstepoort Veterinary Institute Agricultural Research Council) | van Wyngaardt, Wouter(Onderstepoort Veterinary Institute Agricultural Research Council) | van Schalkwyk, Antoinette(Onderstepoort Veterinary Institute Agricultural Research Council) | Pretorius, Alri(Onderstepoort Veterinary Institute Agricultural Research Council ,University of Pretoria Department of Veterinary Tropical Diseases) | Fehrsen, Jeanni(Onderstepoort Veterinary Institute Agricultural Research Council ,University of Pretoria Department of Veterinary Tropical Diseases)
Identifying antigenic proteins and mapping their epitopes is important for the development of diagnostic reagents and recombinant vaccines. B-cell epitopes of African horse sickness virus (AHSV) have previously been mapped on VP2, VP5, VP7 and NS1, using mouse, rabbit and chicken monoclonal antibodies. A comprehensive study of the humoral immune response of five vaccinated horses to AHSV-4 antigenic peptides was undertaken. A fragmented-genome phage display library expressing a repertoire of AHSV-4 peptides spanning the entire genome was constructed. The library was affinity selected for binders on immobilised polyclonal immunoglobulin G (IgG) isolated from horse sera collected pre- and post-immunisation with an attenuated AHSV-4 monovalent vaccine. The DNA inserts of binding phages were sequenced with Illumina high-throughput sequencing. The data were normalised using pre-immune IgG-selected sequences. More sequences mapped to the genes coding for NS3, VP6 and VP5 than to the other genes. However, VP2 and VP5 each had more antigenic regions than each of the other proteins. This study identified a number of epitopes to which the horse's humoral immune system responds during immunisation with AHSV-4.
显示更多 [+] 显示较少 [-]Comparison of three nucleic acid-based tests for detecting <i>Anaplasma marginale</i> and <i>Anaplasma centrale</i> in cattle 全文
2017
Mamohale E. Chaisi | Janine R. Baxter | Paidashe Hove | Chimvwele N. Choopa | Marinda C. Oosthuizen | Kelly A. Brayton | Zamantungwa T.H. Khumalo | Awelani M. Mutshembele | Moses S. Mtshali | Nicola E. Collins
Several nucleic acid-based assays have been developed for detecting Anaplasma marginale and Anaplasma centrale in vectors and hosts, making the choice of method to use in endemic areas difficult. We evaluated the ability of the reverse line blot (RLB) hybridisation assay, two nested polymerase chain reaction (nPCR) assays and a duplex real-time quantitative polymerase chain reaction (qPCR) assay to detect A. marginale and A. centrale infections in cattle (n = 66) in South Africa. The lowest detection limits for A. marginale plasmid DNA were 2500 copies by the RLB assay, 250 copies by the nPCR and qPCR assays and 2500, 250 and 25 copies of A. centrale plasmid DNA by the RLB, nPCR and qPCR assays respectively. The qPCR assay detected more A. marginale- and A. centrale-positive samples than the other assays, either as single or mixed infections. Although the results of the qPCR and nPCR tests were in agreement for the majority (38) of A. marginale-positive samples, 13 samples tested negative for A. marginale using nPCR but positive using qPCR. To explain this discrepancy, the target sequence region of the nPCR assay was evaluated by cloning and sequencing the msp1β gene from selected field samples. The results indicated sequence variation in the internal forward primer (AM100) area amongst the South African A. marginale msp1β sequences, resulting in false negatives. We propose the use of the duplex qPCR assay in future studies as it is more sensitive and offers the benefits of quantification and multiplex detection of both Anaplasma spp.
显示更多 [+] 显示较少 [-]Coagulase Negative Staphylococci as an emerging cause of bovine mastitis: prevalence, antimicrobial resistance and biofilm formation 全文
2017
Fawzy R. El-Seedy | Ismail A. Radwan | Walid H. Hassan | Amr Shehata
Coagulase negative Staphylococci are the most prevalent cause of bovine subclinical mastitis. The current study were designed to study their occurrence, antibiogram and their ability to form biofilms. A total number of 95 CNS isolates were recovered from 400 lactating. S. xylosus (36.84%), S. chromogenes (12.63%), S. epidermidis (10.53%), S. saprophyticus (8.42%), S. haemolyticus (7.38%) were the most common recovered species. Disk diffusion method against 14 antimicrobials discs was used to detect their antibiogram. 100% were sensitive to Imipenem, 96.84% were sensitive to Enrofloxacin, 85.26% to Chlramphenicol and 84.21% to Vancomycin. But, 95.79% were resistant to Ampicillin, 77.9% resistant to Cefoxitin, 35.8% resistant to Cefuroxime, 32.63% resistant to Amoxycillin and 18.95% resistant to Clindamycin. Cultivation on Congo Red Agar (CRA) was carried out to detect biofilm formation. 47.37% were positive and S. epidermidis was the most biofilm positive species on CRA by the percentage of 70%. Haemolysins were studied by cultivating CNS on sheep blood agar. 25.26% were β-haemolytic, 71.57% (n=68) were γ-haemolytic and 3.15% were α- haemolytic.
显示更多 [+] 显示较少 [-]Preparation of inactivated canine distemper vaccine using different inactivators 全文
2017
Shendy M.B | Soliman A.F. | Amany ELZieny
Development of environmental, safe and protective vaccines against infectious pathogens remains a challenge. In consequence of its high morbidity and mortality rates canine distemper is one of the most important diseases of young dogs. The object of the present study is to develop a selected method for preparation of an inactivated canine distemper vaccine. This method involved exposure of the virus to different concentrations of binary ethyleneimine (BEI), beta propiolactone (ßPL) and hydrogen peroxide (H2O2). Complete virus inactivation was obtained with BEI (0.003M) for 6 hours, ßPL (1/5000) for 4 hours and H2O2 at a concentration of 3% rapidly inactivated a Vero cell adapted canine distemper virus strain within 3 h of exposure without affecting its antigenicity or immunogenicity. The safety, immunogenicity and potency induced in four groups of puppies were evaluated using the three prepared experimental batches of inactivated canine distemper vaccine. These results revealed that no residual infectious virus was detected in H2O2 inactivated CD vaccine that proved to be safe and effective when compared with the same virus harvest that inactivated with the classical inactivating agents as BEI and βPL. Thus, an alternative inactivation method, such as H2O2 is able to maintain the integrity of the virus protein may be essential for improving the potency of inactivated canine distemper virus vaccine produced sufficient of antibodies which measured by serum neutralization test (SNT) and was protected when challenged with virulent CD virus strain. These findings reinforce the idea that H2O2 can replace BEI and βPL as inactivating agents for canine distemper virus to reduce time and cost of inactivation process.
显示更多 [+] 显示较少 [-]Phenotypic and genotypic characterization of methicillin resistant Staphylococcus aureus. 全文
2017
Fawzy R. El Seedy | Hala S. H. Salam | Samy A. A. | Eman A. khairy | Shimaa T. Omar | Aya A. koraney.
Food contaminated with multiple antibiotic-resistant S.aureus can be a major threat to the public health. The purpose of this study was to isolate S.aureus from different food sources, determine their antimicrobial susceptibility as well as detection of mecA gene among some resistant isolates. Out of 125 samples, 19 S.aureus isolates were isolated, and the antimicrobial susceptibility testing showed high resistance against kanamycin, penicillin G, oxacillin, erythromycin and tetracycline were the most resistant antimicrobials agents. All the tested isolates isolates were multiple drug resistant (MDR).Eight out of 19 isolates were phenotypically resistant to oxacillin as well as they were carriers for mecA gene.
显示更多 [+] 显示较少 [-]Efficacy of Ultra-sonographic Examination and Combined Use of PGf2α plus Cephapirin to Identify and Treat Endometritis in Dairy Cows 全文
2017
Hussein, M. M. | Khalil, A.A.Y. | Al Agawany, A. A. | A. A. Zyada
The objectives of the present study were to validate ultra-sonographic examination (US) as a reliable diagnostic tool for endometritis, as well as to determine the effects of intrauterine infusion (IU) of benzathine cephapirin plus systemic PGF2α as a treatment protocol of endometritis in dairy cows. 260 Holstein cows were included in this study. The affected cows were examined rectally and US. The cows were divided according to the diagnostic method and treatment protocol into 3 groups. Group1: rectally diagnosed and received systemic PGF2α. Group2: diagnosed rectally and received IU benzathine cephapirin plus systemic PGF2α. Group3: diagnosed US and received IU benzathine cephapirin plus systemic PGF2α. Good reproductive indices were recorded for cows examined US and treated with combination of IU benzathine cephapirin plus systemic PGF2α. A highly significant positive correlations were observed between days in milking (DIM) and most of tested reproductive indices. Meanwhile, Daily milk yield was negatively correlated with all tested reproductive parameters. In conclusion, transrectal US could be used as a reliable method for early diagnosis of endometritis. In addition, using a combination of IU application of benzathine cephapirin plus systemic PGF2α was superior treatment protocol in endometritis in comparison with PGF2α.
显示更多 [+] 显示较少 [-]Lumpy skin disease in cattle: Frequency of occurrence in a dairy farm and a preliminary assessment of its possible impact on Egyptian buffaloes 全文
2017
Mahmoud M. Elhaig | Abdelfattah Selim | Mohamed Mahmoud
Lumpy skin disease (LSD) is an endemic infectious disease of cattle in Egypt. This survey aimed to define the prevalence of clinical and sub-clinical LSD virus (LSDV) infection among cattle and investigate their contact with water buffaloes (Bubalus bubalis) in order to improve the understanding of LSD epidemiology. Cattle and buffalo were examined owing to the appearance of skin lesions. Because clinical signs were consistent with LSDV infection, samples from cattle in a non-grazing dairy farm (n = 450) were submitted for LSDV testing together with those from the in-contact buffaloes (n = 100). Results revealed that the intra-herd percentage of cattle infected with LSDV varied with the detection method. This ranged from 22.4% to 65.4% by virus isolation (VI) and polymerase chain reaction (PCR), respectively, in clinical cattle samples, compared to 0% and 10% by VI and PCR in non-clinical cases. Using the neutralising index (NI), LSDV antibodies were found in 100% (n = 100) of the tested cow’s sera (NI = > 2.0 and ≥ 3.0), whereas buffalo’s sera (n = 34) displayed little increase in antibody level (NI ≥ 1.5). None of the buffalo were positive for LSDV by VI and PCR. In addition, there were no significant differences in LSD prevalence among the cattle with regard to age and sex. In conclusion, the occurrence of LSD in cattle warrants a further epidemiological study of the spread of the disease in the area and adoption of control and prevention strategies. In addition, the PCR assay was confirmed to be useful in the diagnosis of LSDV and for wider epidemiological studies.
显示更多 [+] 显示较少 [-]Epidemiological studies based on multi-locus sequence typing genotype of methicillin susceptible <i>Staphylococcus aureus</i> isolated from camel’s milk 全文
2017
Alsagher O. Ali | Hassan Y.A.H. Mahmoud
One hundred milk samples were collected from camel’s milk for the isolation of Staphylococcus aureus. Thirty-one isolates were S. aureus, 45 were other forms of staphylococci and 24 represented other bacteria. Five isolates from S. aureus were methicillin resistant S. aureus (MRSA) and 26 samples were methicillin susceptible S. aureus (MSSA). The whole genome sequence of S. aureus was annotated and visualised by rapid annotation using subsystem technology (RAST) which is a fully-automated service for annotating complete or nearly complete bacterial genomes. Four isolates from MSSA strains were subjected to multi-locus sequence typing (MLST). Three multilocus sequences types or sequence types (MLST/ST) were found, namely ST15, ST1153 and ST130. The phylogenetic analysis of the concatenated sequences of the seven genes forming the MLST profile of S. aureus classification revealed a high degree of similarity and close relationship between the ST15 and ST1153 while the third ST (ST130) was located in a different cluster.
显示更多 [+] 显示较少 [-]Detection and prevalence of antimicrobial resistance genes in <i>Campylobacter</i> spp. isolated from chickens and humans 全文
2017
Samantha Reddy | Oliver T. Zishiri
Campylobacter spp. are common pathogenic bacteria in both veterinary and human medicine. Infections caused by Campylobacter spp. are usually treated using antibiotics. However, the injudicious use of antibiotics has been proven to spearhead the emergence of antibiotic resistance. The purpose of this study was to detect the prevalence of antibiotic resistance genes in Campylobacter spp. isolated from chickens and human clinical cases in South Africa. One hundred and sixty one isolates of Campylobacter jejuni and Campylobacter coli were collected from chickens and human clinical cases and then screened for the presence of antimicrobial resistance genes. We observed a wide distribution of the tetO gene, which confers resistance to tetracycline. The gyrA genes that are responsible quinolone resistance were also detected. Finally, our study also detected the presence of the blaOXA-61, which is associated with ampicillin resistance. There was a higher (p < 0.05) prevalence of the studied antimicrobial resistance genes in chicken faeces compared with human clinical isolates. The tetO gene was the most prevalent gene detected, which was isolated at 64% and 68% from human and chicken isolates, respectively. The presence of gyrA genes was significantly (p < 0.05) associated with quinolone resistance. In conclusion, this study demonstrated the presence of gyrA (235 bp), gyrA (270 bp), blaOXA-61 and tetO antimicrobial resistance genes in C. jejuni and C. coli isolated from chickens and human clinical cases. This indicates that Campylobacter spp. have the potential of resistance to a number of antibiotic classes.
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